WO2020071177A1 - Water treatment device, water treatment method, forward osmosis membrane treatment method, forward osmosis membrane treatment system, and water treatment system - Google Patents

Water treatment device, water treatment method, forward osmosis membrane treatment method, forward osmosis membrane treatment system, and water treatment system

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Publication number
WO2020071177A1
WO2020071177A1 PCT/JP2019/037279 JP2019037279W WO2020071177A1 WO 2020071177 A1 WO2020071177 A1 WO 2020071177A1 JP 2019037279 W JP2019037279 W JP 2019037279W WO 2020071177 A1 WO2020071177 A1 WO 2020071177A1
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WO
WIPO (PCT)
Prior art keywords
water
osmosis membrane
forward osmosis
treatment
treated
Prior art date
Application number
PCT/JP2019/037279
Other languages
French (fr)
Japanese (ja)
Inventor
勇規 中村
徹 中野
佳介 瀧口
Original Assignee
オルガノ株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2018190215A external-priority patent/JP7212490B2/en
Priority claimed from JP2018190744A external-priority patent/JP2020058972A/en
Priority claimed from JP2019156729A external-priority patent/JP7228492B2/en
Application filed by オルガノ株式会社 filed Critical オルガノ株式会社
Priority to CN201980064798.7A priority Critical patent/CN112805247B/en
Publication of WO2020071177A1 publication Critical patent/WO2020071177A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/02—Reverse osmosis; Hyperfiltration ; Nanofiltration
    • B01D61/04—Feed pretreatment
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/24—Dialysis ; Membrane extraction
    • B01D61/28—Apparatus therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/58—Multistep processes
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/42—Treatment of water, waste water, or sewage by ion-exchange
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/58—Treatment of water, waste water, or sewage by removing specified dissolved compounds
    • C02F1/60—Silicon compounds
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A20/00—Water conservation; Efficient water supply; Efficient water use
    • Y02A20/124—Water desalination
    • Y02A20/131—Reverse-osmosis

Definitions

  • the present invention relates to a water treatment apparatus and a water treatment method for treating water to be treated containing at least one of soluble silica and a hardness component.
  • the present invention also relates to a forward osmosis membrane treatment method, a forward osmosis membrane treatment system, a forward osmosis membrane treatment method, a water treatment method using the forward osmosis membrane treatment system, and a water treatment system.
  • wastewater In order to reduce the impact of the discharge of wastewater on the environment, wastewater is being purified and reduced in volume before being discharged and disposed of.
  • solid-liquid separation, membrane separation, concentration under reduced pressure, and the like are used for wastewater treatment.
  • Soluble silica and hard components such as calcium contained in wastewater are insolubilized and adhere to pipes and devices used for wastewater treatment, so-called wastewater treatment. It is known that the performance of the system is reduced when scaling occurs. In order to perform efficient wastewater treatment, it is necessary to remove soluble silica and hardness components in wastewater.
  • Patent Literature 1 discloses that a soluble silica-containing wastewater is subjected to solid-liquid separation after insolubilizing soluble silica by adding a magnesium salt under alkaline conditions, and treating the resulting treated water with reverse osmosis membrane treatment or forward osmosis. A method for recovering fresh water from wastewater by membrane treatment is described.
  • water can be transferred to the attractant solution by osmotic pressure without pressurization by providing feed water and the attractant solution through the forward osmosis membrane. Further, by changing the phase of the diluted attracting solution by, for example, heating or the like, the attracting solution can be reused while obtaining fresh water.
  • Patent Literature 3 describes a method in which an alkali agent is added to wastewater containing a hardness component to cause precipitation (so-called lime softening method), and after the coagulation and filtration treatments, the filtered water is treated with a reverse osmosis membrane.
  • lime softening method an alkali agent added to wastewater containing a hardness component to cause precipitation
  • Patent Document 4 discloses a method of adsorbing and removing a hardness component using an ion exchange resin (resin softening method).
  • the lime softening method requires the addition of an alkaline agent, and the resin softening method requires the passage of high-concentration saline (aqueous sodium chloride) to regenerate the ion-exchange resin to which the hardness component has been adsorbed. Cost reduction is required.
  • high-concentration saline aqueous sodium chloride
  • a forward osmosis (FO) membrane treatment system in which concentrated water and a dilute attractant solution are obtained by bringing the water to be treated into contact with an attraction solution having a higher concentration than the to-be-treated water via a forward osmosis membrane, the membrane fouling occurs. Controlling the ring is an important issue.
  • a chlorinated disinfectant such as hypochlorous acid or chloramine
  • an oxidizing agent such as hydrogen peroxide, or 5-chloro-2-methyl-4-isothiazolin-3-one or the like can be used.
  • Organic fungicides are used (for example, see Patent Documents 5 and 6).
  • An object of the present invention is to provide a water treatment apparatus and a water treatment method capable of treating water to be treated containing at least one of soluble silica and a hard component at low cost.
  • Another object of the present invention is to provide a method for treating a forward osmosis membrane, a forward osmosis membrane treatment system, and a forward osmosis membrane, in which a disinfectant is prevented from permeating through the forward osmosis membrane, and the diluted attractant solution can be reused. It is an object of the present invention to provide a treatment method, a water treatment method using a forward osmosis membrane treatment system, and a water treatment system.
  • the present invention relates to a water treatment apparatus for treating water to be treated containing at least one of a soluble silica and a hardness component, wherein the water treatment device is provided with any one of a soluble silica removal unit and a hardness component removal unit.
  • Treatment means a concentration treatment means for concentration treatment of the pretreated water obtained by the pretreatment means, and a forward osmosis membrane treatment means for forward osmosis membrane treatment of the concentrated water obtained by the concentration treatment means,
  • a water treatment apparatus wherein the diluted attracting solution used in the forward osmosis membrane treatment means is used in the pretreatment means.
  • the concentration treatment means is preferably a reverse osmosis membrane treatment means.
  • the present invention relates to a water treatment apparatus for treating water to be treated containing at least one of a soluble silica and a hardness component, wherein the water treatment device is provided with any one of a soluble silica removal unit and a hardness component removal unit.
  • Treatment means for concentrating the pretreated water obtained by the pretreatment means, and forward osmosis membrane treatment means for treating the concentrated water obtained by the first concentration treatment means with a forward osmosis membrane.
  • Second concentration processing means for concentrating a part of the diluted attracting solution used in the forward osmosis membrane processing means, wherein a part of the diluted attracting solution used in the forward osmosis membrane processing means is A water treatment apparatus, wherein the concentrated attraction solution used in the treatment means and concentrated by the second concentration treatment means is reused as the attraction solution in the forward osmosis membrane treatment means.
  • the second concentration treatment means is a concentration means using a semipermeable membrane.
  • the first concentration treatment means is preferably a reverse osmosis membrane treatment means.
  • the attracting solution used in the forward osmosis membrane treatment means is a magnesium salt aqueous solution
  • the magnesium salt dilute aqueous solution used in the forward osmosis membrane treatment means is used in the soluble silica removing means. Is preferred.
  • the water treatment apparatus further includes a preparation means for mixing magnesium hydroxide and an acid and reacting the mixture at a pH of 7 or less to prepare a magnesium salt aqueous solution to be used as an attraction solution used in the forward osmosis membrane treatment means. .
  • the attracting solution used in the forward osmosis membrane processing means may be an aqueous solution of an alkali agent, and the dilute aqueous solution of the alkali agent used in the forward osmosis membrane processing means may be used in the hardness component removing means. preferable.
  • the attracting solution used in the forward osmosis membrane treatment means is an aqueous acid solution or an aqueous sodium chloride solution
  • the acid dilute aqueous solution or the sodium chloride dilute aqueous solution used in the forward osmosis membrane treatment means removes the hardness component.
  • it is used by means.
  • the present invention is a water treatment method for treating water to be treated containing at least one of a soluble silica and a hardness component, wherein one of the soluble silica removal process and the hardness component removal process is performed.
  • a pretreatment step including: a concentration treatment step of concentrating the pretreated water obtained in the pretreatment step; and a forward osmosis membrane treatment step of treating the concentrated water obtained in the concentration treatment step with a forward osmosis membrane.
  • a water treatment method wherein the diluted attracting solution used in the forward osmosis membrane treatment step is used in the pretreatment step.
  • the concentration treatment step is preferably a reverse osmosis membrane treatment step.
  • the present invention is a water treatment method for treating water to be treated containing at least one of a soluble silica and a hardness component, wherein one of the soluble silica removal process and the hardness component removal process is performed.
  • a pre-treatment step including a pre-treatment step, a first concentration treatment step for concentrating the pre-treated water obtained in the pre-treatment step, and a forward osmosis membrane treatment for treating the concentrated water obtained in the first concentration treatment step with a forward osmosis membrane And a second concentration treatment step of concentrating a part of the diluted attracting solution used in the forward osmosis membrane treatment step, and a part of the diluted attractant solution used in the forward osmosis membrane treatment step.
  • This is a water treatment method in which the concentrated attraction solution used in the pretreatment step and concentrated in the second concentration treatment step is reused as the attraction solution in the forward osmosis membrane treatment step.
  • the second concentration treatment step is preferably a concentration step using a semipermeable membrane.
  • the first concentration treatment step is preferably a reverse osmosis membrane treatment step.
  • the attracting solution used in the forward osmosis membrane treatment step is a magnesium salt aqueous solution
  • the magnesium salt dilute aqueous solution used in the forward osmosis membrane treatment step is preferably used in the soluble silica removal step.
  • the water treatment method preferably further includes a preparation step of mixing magnesium hydroxide and an acid and reacting the mixture at a pH of 7 or less to prepare a magnesium salt aqueous solution to be used as an attraction solution used in the forward osmosis membrane treatment step. .
  • the attracting solution used in the forward osmosis membrane treatment step is an aqueous solution of an alkali agent
  • the dilute aqueous solution of the alkali agent used in the forward osmosis membrane treatment step is used in the hardness component removing step.
  • the attracting solution used in the forward osmosis membrane treatment step is an acid aqueous solution or a sodium chloride aqueous solution
  • the acid dilute aqueous solution or sodium chloride dilute aqueous solution used in the forward osmosis membrane treatment step is subjected to the hardness component removal step. It is preferable to use them.
  • the present invention includes a forward osmosis membrane treatment step of obtaining concentrated water and a dilute attractant by contacting the water to be treated and an attraction solution having a higher concentration than the water to be treated through a forward osmosis membrane.
  • a forward osmosis membrane treatment method wherein a disinfectant containing a bromine-based oxidant or a chlorine-based oxidant and a sulfamic acid compound is present in the water to be treated.
  • the present invention includes a forward osmosis membrane treatment step of obtaining concentrated water and a dilute attractant by contacting the water to be treated and an attraction solution having a higher concentration than the water to be treated through a forward osmosis membrane.
  • the present invention includes a forward osmosis membrane treatment step of obtaining concentrated water and a dilute attractant by contacting the water to be treated and an attraction solution having a higher concentration than the water to be treated through a forward osmosis membrane. And a method for treating a forward osmosis membrane, wherein a disinfectant containing bromine and a sulfamic acid compound is present in the water to be treated.
  • the present invention includes the forward osmosis membrane treatment method, and comprises a pretreatment step and a reverse osmosis membrane treatment step before the forward osmosis membrane treatment step, wherein the diluted attracting solution obtained by the forward osmosis membrane treatment step is: This is a water treatment method used in the pretreatment step.
  • the present invention comprises a forward osmosis membrane treatment means for obtaining concentrated water and a dilute attractant by contacting the water to be treated and an attraction solution having a higher concentration than the water to be treated through a forward osmosis membrane.
  • a forward osmosis membrane treatment system wherein a germicide containing a bromine-based oxidant or a chlorine-based oxidant and a sulfamic acid compound is present in the water to be treated.
  • the present invention comprises a forward osmosis membrane treatment means for obtaining concentrated water and a dilute attractant by contacting the water to be treated and an attraction solution having a higher concentration than the water to be treated through a forward osmosis membrane.
  • a forward osmosis membrane treatment system wherein a disinfectant containing a bromine-based oxidizing agent and a sulfamic acid compound is present in the water to be treated.
  • the present invention comprises a forward osmosis membrane treatment means for obtaining concentrated water and a dilute attractant by contacting the water to be treated and an attraction solution having a higher concentration than the water to be treated through a forward osmosis membrane.
  • a forward osmosis membrane treatment system wherein a disinfectant containing bromine and a sulfamic acid compound is present in the water to be treated.
  • the present invention comprises the forward osmosis membrane treatment system, and comprises a pretreatment means and a reverse osmosis membrane treatment means at a preceding stage of the forward osmosis membrane treatment means, wherein the diluted attracting solution obtained by the forward osmosis membrane treatment means is: It is a water treatment system used in the pretreatment means.
  • water to be treated containing at least one of soluble silica and a hardness component can be treated at low cost.
  • a forward osmosis membrane treatment method a forward osmosis membrane treatment system, and a forward osmosis membrane treatment method that suppress the permeation of a germicide through a forward osmosis membrane and enable the reuse of a dilute attractant solution
  • a water treatment method and a water treatment system using a forward osmosis membrane treatment system can be provided.
  • FIG. 1 An outline of an example of a water treatment apparatus according to an embodiment of the present invention is shown in FIG. 1 and its configuration will be described.
  • the water treatment device 1 includes a pretreatment device 10 as a pretreatment device having at least one of a soluble silica removal device and a hardness component removal device, and a concentration device that concentrates pretreatment water obtained by the pretreatment device 10.
  • the apparatus includes a reverse osmosis membrane treatment device 12 as a treatment means and a forward osmosis membrane treatment device 14 as a forward osmosis membrane treatment means for treating the concentrated water obtained by the reverse osmosis membrane treatment device 12 with a forward osmosis membrane.
  • the treated water pipe 16 is connected to the treated water inlet of the pretreatment apparatus 10, and the outlet of the pretreatment apparatus 10 and the entrance of the reverse osmosis membrane treatment apparatus 12 are connected to the pretreated water pipe. 18.
  • a concentrated water outlet of the reverse osmosis membrane treatment device 12 and a concentrated water inlet of the forward osmosis membrane treatment device 14 are connected by a concentrated water piping 20, and a permeated water piping 22 is connected to a permeated water outlet of the reverse osmosis membrane treatment device 12. It is connected.
  • the attracting solution inlet 24 of the forward osmosis membrane processing device 14 is connected to an attracting solution pipe 24, and the diluted attracting solution outlet of the forward osmosis membrane processing device 14 and the diluted attracting solution inlet of the pretreatment device 10 are connected to the diluted attracting solution pipe.
  • a FO concentrated water pipe 28 is connected to an FO concentrated water outlet of the forward osmosis membrane treatment device 14.
  • Water to be treated containing at least one of the soluble silica and the hardness component is sent to the pretreatment device 10 through the treated water pipe 16.
  • the pretreatment device 10 at least one of the soluble silica and the hardness component is removed (pretreatment step).
  • the pretreatment device 10 may, for example, add a magnesium salt to the water to be treated to cause a reaction, and a magnesium reaction means for insolubilizing the soluble silica and a water to be treated after the reaction.
  • a magnesium reaction means for insolubilizing the soluble silica and a water to be treated after the reaction.
  • an aggregating means for adding an aggregating agent to perform aggregation
  • a solid-liquid separating means for separating agglomerates from the treated water subjected to the aggregating treatment.
  • a magnesium salt is added to the water to be treated under alkaline conditions (eg, pH 10 to 12) to insolubilize the soluble silica (magnesium reaction step).
  • an aggregating agent is added, if necessary, to perform an agglomeration treatment (aggregation treatment step), and the aggregates are subjected to solid-liquid separation (solid-liquid separation step).
  • the pretreatment water obtained by the solid-liquid separation is sent to the reverse osmosis membrane treatment device 12 through the pretreatment water pipe 18.
  • the pretreatment device 10 is, for example, an alkali agent that adds an alkali agent to the water to be treated and reacts to insolubilize the hardness component.
  • a reaction means an aggregating treatment means for adding an aggregating agent as needed to the water to be treated after the reaction, and aggregating, and a solid-liquid separating means for separating an aggregate from the treated water subjected to the aggregating treatment, .
  • an alkali agent is added to the water to be treated, and the hardness component is insolubilized (alkali agent reaction step).
  • an aggregating agent is added to perform an agglomeration treatment (aggregation treatment step), and the aggregate is subjected to solid-liquid separation (solid-liquid separation step).
  • the pretreatment water obtained by the solid-liquid separation is sent to the reverse osmosis membrane treatment device 12 through the pretreatment water pipe 18.
  • the pretreatment device 10 includes, for example, an ion exchange treatment unit that performs an ion exchange treatment using an ion exchange resin or the like.
  • the water to be treated is passed through an ion exchange tower filled with an ion exchange resin as an ion exchange treatment means, and the hardness component is adsorbed and removed (ion exchange step).
  • the pretreatment water obtained by the ion exchange treatment is sent to the reverse osmosis membrane treatment device 12 through the pretreatment water pipe 18.
  • the ion exchange resin needs to be regenerated, the ion exchange resin is regenerated by passing the regenerant through the liquid.
  • the pretreated water obtained in the pretreatment step is subjected to concentration treatment in the reverse osmosis membrane treatment device 12 (concentration treatment step).
  • concentration treatment step The concentrated water obtained by the reverse osmosis membrane treatment is sent to the forward osmosis membrane treatment device 14 through the concentrated water piping 20, and the permeated water is discharged through the permeated water piping 22.
  • the concentrated water obtained by the reverse osmosis membrane treatment is subjected to a forward osmosis membrane treatment in the forward osmosis membrane treatment device 14 (forward osmosis membrane treatment step).
  • forward osmosis membrane treatment step the attracting solution is sent to the secondary side of the forward osmosis membrane through the attracting solution pipe 24, and the concentrated water and the attracting solution are made to exist through the forward osmosis membrane, whereby water is osmotically driven. Is transferred to the attraction solution.
  • the dilute attractant used in the forward osmosis membrane treatment step is sent to the pretreatment device 10 through the dilute attractant solution pipe 26, and is used in the pretreatment device 10 in the pretreatment step.
  • the FO concentrated water obtained in the forward osmosis membrane treatment step is discharged through the FO concentrated water piping 28.
  • the FO concentrated water may be collected and reused.
  • the pretreatment device 10 includes a device for removing soluble silica, for example, a magnesium salt aqueous solution is used as the attraction solution in the forward osmosis membrane treatment device 14, and the diluted attraction solution ( The magnesium salt dilute aqueous solution) may be used as a magnesium salt added in the pretreatment device 10.
  • a magnesium salt aqueous solution is used as the attraction solution in the forward osmosis membrane treatment device 14, and the diluted attraction solution ( The magnesium salt dilute aqueous solution) may be used as a magnesium salt added in the pretreatment device 10.
  • an aqueous alkaline solution is used as the attracting solution in the forward osmosis membrane treatment device 14 and used in the forward osmosis membrane treatment device 14.
  • the dilute attracting solution may be used as the alkaline agent added in the pretreatment device 10.
  • the pretreatment device 10 includes a device that removes a hardness component by a resin softening method, for example, an acid aqueous solution or a sodium chloride aqueous solution is used as the attracting solution in the forward osmosis membrane treatment device 14, and the forward osmosis membrane treatment device 14
  • the used dilute attracting solution (acid dilute aqueous solution or sodium chloride dilute aqueous solution) may be used in the pretreatment device 10 as a regenerant for the ion exchange resin.
  • the water to be treated containing at least one of the soluble silica and the hardness component can be treated at low cost.
  • the cost required for reusing the attractant solution originally required is reduced, and it is not necessary to provide a regeneration facility. . Since the diluted attractant solution is only the one that is originally used in the pretreatment step, it has little additional cost.
  • FIG. 3 schematically shows another example of the water treatment apparatus according to the embodiment of the present invention, and its configuration will be described.
  • the water treatment device 5 includes a pretreatment device 10 as a pretreatment device having at least one of a soluble silica removal device and a hardness component removal device, and a second pretreatment device that concentrates pretreatment water obtained by the pretreatment device 10.
  • a reverse osmosis membrane treatment device 12 as a concentration treatment means
  • a forward osmosis membrane treatment device 14 as a forward osmosis membrane treatment means for subjecting the concentrated water obtained by the reverse osmosis membrane treatment device 12 to a forward osmosis membrane treatment
  • a concentration device 34 is provided as second concentration processing means for performing concentration processing on a part of the diluted attracting solution used in the processing device 14.
  • the treated water pipe 16 is connected to the treated water inlet of the pretreatment apparatus 10, and the outlet of the pretreatment apparatus 10 and the entrance of the reverse osmosis membrane treatment apparatus 12 are connected to the pretreated water pipe. 18.
  • a concentrated water outlet of the reverse osmosis membrane treatment device 12 and a concentrated water inlet of the forward osmosis membrane treatment device 14 are connected by a concentrated water piping 20, and a permeated water piping 22 is connected to a permeated water outlet of the reverse osmosis membrane treatment device 12. It is connected.
  • the attracting solution inlet 24 of the forward osmosis membrane processing device 14 is connected to an attracting solution pipe 24, and the diluted attracting solution outlet of the forward osmosis membrane processing device 14 and the diluted attracting solution inlet of the pretreatment device 10 are connected to the diluted attracting solution pipe.
  • a FO concentrated water pipe 28 is connected to an FO concentrated water outlet of the forward osmosis membrane treatment device 14.
  • the diluted attracting solution pipe 36 branched from the diluted attracting solution pipe 26 is connected to the inlet of the concentrating device 34, and the concentrated attracting solution outlet of the concentrating device 34 and the middle of the attracting solution pipe 24 are connected by the concentrated attracting solution pipe 38.
  • a diluent pipe 40 is connected to a diluent outlet of the concentrator 34.
  • Water to be treated containing at least one of the soluble silica and the hardness component is sent to the pretreatment device 10 through the treated water pipe 16.
  • the pretreatment device 10 at least one of the soluble silica and the hardness component is removed (pretreatment step).
  • the pretreatment device 10 may, for example, add a magnesium salt to the water to be treated to cause a reaction, and a magnesium reaction means for insolubilizing the soluble silica and a water to be treated after the reaction.
  • a magnesium reaction means for insolubilizing the soluble silica and a water to be treated after the reaction.
  • an aggregating means for adding an aggregating agent to perform aggregation
  • a solid-liquid separating means for separating agglomerates from the treated water subjected to the aggregating treatment.
  • a magnesium salt is added to the water to be treated under alkaline conditions (eg, pH 10 to 12) to insolubilize the soluble silica (magnesium reaction step).
  • an aggregating agent is added, if necessary, to perform an agglomeration treatment (aggregation treatment step), and the aggregates are subjected to solid-liquid separation (solid-liquid separation step).
  • the pretreatment water obtained by the solid-liquid separation is sent to the reverse osmosis membrane treatment device 12 through the pretreatment water pipe 18.
  • the pretreatment device 10 is, for example, an alkali agent that adds an alkali agent to the water to be treated and reacts to insolubilize the hardness component.
  • a reaction means an aggregating treatment means for adding an aggregating agent as needed to the water to be treated after the reaction, and aggregating, and a solid-liquid separating means for separating an aggregate from the treated water subjected to the aggregating treatment, .
  • an alkali agent is added to the water to be treated, and the hardness component is insolubilized (alkali agent reaction step).
  • an aggregating agent is added to perform an agglomeration treatment (aggregation treatment step), and the aggregate is subjected to solid-liquid separation (solid-liquid separation step).
  • the pretreatment water obtained by the solid-liquid separation is sent to the reverse osmosis membrane treatment device 12 through the pretreatment water pipe 18.
  • the pretreatment device 10 includes, for example, an ion exchange treatment unit that performs an ion exchange treatment using an ion exchange resin or the like.
  • the water to be treated is passed through an ion exchange tower filled with an ion exchange resin as an ion exchange treatment means, and the hardness component is adsorbed and removed (ion exchange step).
  • the pretreatment water obtained by the ion exchange treatment is sent to the reverse osmosis membrane treatment device 12 through the pretreatment water pipe 18.
  • the ion exchange resin needs to be regenerated, the ion exchange resin is regenerated by passing the regenerant through the liquid.
  • the pretreated water obtained in the pretreatment step is concentrated in the reverse osmosis membrane treatment device 12 (first concentration treatment step).
  • the concentrated water (RO concentrated water) obtained by the first concentration treatment is sent to the forward osmosis membrane treatment device 14 through the concentrated water pipe 20, and the permeated water (RO permeated water) is the permeated water. It is discharged through a pipe 22.
  • the concentrated water obtained by the first concentration treatment is subjected to a forward osmosis membrane treatment in the forward osmosis membrane treatment device 14 (forward osmosis membrane treatment step).
  • the attracting solution is sent to the secondary side of the forward osmosis membrane through the attracting solution pipe 24, and the concentrated water and the attracting solution are made to exist through the forward osmosis membrane, whereby water is osmotically driven. Is transferred to the attraction solution.
  • a part of the diluent attracting solution used in the forward osmosis membrane treatment step is sent to the pretreatment device 10 through the dilute attractant solution pipe 26 and is used in the pretreatment device 10 in the pretreatment step.
  • the FO concentrated water obtained in the forward osmosis membrane treatment step is discharged through the FO concentrated water piping 28.
  • the FO concentrated water may be further concentrated and solidified by a concentrating device or a crystallization device, if necessary.
  • Part of the diluent attracting solution used in the forward osmosis membrane treatment step is branched from the dilute attractant solution piping 26, sent to the concentrating device 34 through the dilute attracting solution piping 36, and concentrated in the concentrating device 34 (the 2 concentration treatment step).
  • the concentrated attracting solution obtained by the second concentration treatment is supplied to the middle of the attracting solution piping 24 through the concentrated attracting solution piping 38, and is used again as the attracting solution in the forward osmosis membrane treatment device 14.
  • the diluent obtained by the second concentration process is discharged through the diluent pipe 40.
  • the diluent may be collected and reused after performing an ultrafiltration membrane (UF membrane) treatment, a reverse osmosis membrane (RO membrane) treatment, an ion exchange treatment, and the like, as necessary.
  • UF membrane ultrafiltration membrane
  • RO membrane reverse osmosis membrane
  • the pretreatment device 10 includes a device for removing soluble silica
  • a magnesium salt aqueous solution is used as the attraction solution in the forward osmosis membrane treatment device 14, and the diluted attraction solution ( A part of the magnesium salt diluted aqueous solution may be used as the magnesium salt added in the pretreatment device 10. A part of the diluted attracting solution (dilute aqueous solution of magnesium salt) used in the forward osmosis membrane treatment device 14 may be concentrated in the concentration device 34 and used again as the attracting solution in the forward osmosis membrane treatment device 14. .
  • an aqueous alkaline solution is used as the attracting solution in the forward osmosis membrane treatment device 14 and used in the forward osmosis membrane treatment device 14.
  • a part of the diluted attracting solution (the alkaline agent diluted aqueous solution) may be used as the alkaline agent added in the pretreatment device 10.
  • a part of the diluted attracting solution (dilute aqueous solution of the alkaline agent) used in the forward osmosis membrane treatment device 14 may be concentrated in the concentration device 34 and used again as the attracting solution in the forward osmosis membrane treatment device 14. .
  • the pretreatment device 10 includes a device that removes a hardness component by a resin softening method, for example, an acid aqueous solution or a sodium chloride aqueous solution is used as the attracting solution in the forward osmosis membrane treatment device 14, and the forward osmosis membrane treatment device 14
  • a part of the used diluted attracting solution (acid diluted aqueous solution or sodium chloride diluted aqueous solution) may be used in the pretreatment device 10 as a regenerant for the ion exchange resin.
  • a part of the diluted attracting solution (acid-diluted aqueous solution or sodium chloride-diluted aqueous solution) used in the forward osmosis membrane treatment device 14 is concentrated in the concentration device 34 and reused as the attracting solution in the forward osmosis membrane treatment device 14. It should be done.
  • the water to be treated containing at least one of the soluble silica and the hardness component can be treated at low cost.
  • the cost required for reusing the attracting solution originally needed is reduced, and it is not necessary to provide a regeneration facility. . Since the diluted attractant solution is only the one that is originally used in the pre-treatment step, it has little additional cost.
  • the amount of the diluted attracting solution diluted in the forward osmosis membrane treatment becomes larger than necessary for use in the pretreatment step, a part of the diluted attractant solution used in the forward osmosis membrane treatment is used in the pretreatment step.
  • the loss of the diluted attracting solution can be reduced.
  • the cost is remarkably reduced as compared with the case where the entire amount of the diluted attracting solution is concentrated and reused.
  • the water to be treated which is to be treated by the water treatment method and the water treatment apparatus according to the present embodiment, may be any water containing at least one of soluble silica and a hard component, and is not particularly limited.
  • the concentration of the soluble silica is, for example, in the range of 5 to 400 mg / L.
  • concentration of the calcium hardness component is in the range of 5 to 600 mg / L.
  • the total evaporation residue (TDS: Total Dissolved Solid) in the water to be treated is, for example, in the range of 100 to 50,000 mg / L.
  • the pretreatment means is a means for removing soluble silica (soluble silica).
  • (Hardening component removal step) and a hardness component removing means hardness component removing step).
  • the order of the soluble silica removing means (soluble silica removing step) and the hardness component removing means (hardness component removing step) is as follows: first, soluble silica removing means (soluble silica removing step), and second, hardness component removing means.
  • Hardness component removal step firstly, hardness component removal means (hardness component removal step), and second, soluble silica removal means (soluble silica removal step).
  • a magnesium salt aqueous solution is used as the attracting solution in the forward osmosis membrane processing device 14 (forward osmosis membrane processing step).
  • the diluted attracting solution (at least one of a diluted aqueous solution of a magnesium salt, a diluted aqueous solution of an alkali agent, a diluted aqueous solution of an acid, and a diluted aqueous solution of sodium chloride) is used as a soluble silica removing means (pre-treatment step) in the pretreatment device 10 (pretreatment step). It may be used in a suitable one of the step of removing the silica and the means of removing the hardness component (the step of removing the hardness component).
  • the water treatment method and the water treatment apparatus may further include a turbidity removing unit that removes turbid components and the like in the water to be treated.
  • the turbid removal means include a sand filtration device, a membrane filtration device such as an ultrafiltration (UF) membrane, and a pressure flotation device.
  • UF ultrafiltration
  • a pressure flotation device There is no particular limitation on the installation position of the turbidity removing means, but when the turbidity removing means is a sand filtration device, for example, the turbidity removing means is located at a stage preceding the pretreatment device 10 (pretreatment step), and the turbidity removal means is a membrane filtration device.
  • a pressure flotation device for example, it is between the pretreatment device 10 (pretreatment process) and the reverse osmosis membrane treatment device 12 (concentration treatment process).
  • Pretreatment step Removal of soluble silica
  • a magnesium salt is added to the water to be treated under alkaline conditions to insolubilize the soluble silica (magnesium reaction step).
  • the magnesium salt used may be a magnesium salt such as magnesium chloride (MgCl 2 ) or magnesium sulfate (MgSO 4 ) or a hydrate thereof, and is not particularly limited. From the viewpoint of suppression and the like, magnesium chloride is preferred.
  • the pH in the magnesium reaction step may be an alkaline condition, and is not particularly limited.
  • the pH is in the range of 10 to 12, preferably in the range of 10.5 to 11.5, and more preferably in the range of 11 to 11.5. More preferably, it is within the range. If the pH in the magnesium reaction step is less than 10 or more than 12, the silica removal rate may decrease.
  • an alkali such as sodium hydroxide or calcium hydroxide may be used, and if necessary, an inorganic acid such as hydrochloric acid or sulfuric acid may be used.
  • the temperature in the magnesium reaction step may be a temperature at which the insolubilization reaction of silica proceeds, and is not particularly limited.
  • the temperature is in the range of 1 ° C to less than 50 ° C, and is in the range of 10 ° C to less than 50 ° C. Is more preferred. If the temperature in the magnesium reaction step is lower than 1 ° C., the insolubilization reaction of silica may be insufficient, and if it is higher than 50 ° C., the processing cost may increase.
  • the reaction time in the magnesium reaction step is not particularly limited as long as the insolubilization reaction of the silica can proceed, and is not particularly limited, but is, for example, in the range of 1 minute to 60 minutes, and more preferably in the range of 5 minutes to 30 minutes. preferable. If the reaction time in the magnesium reaction step is less than 1 minute, the silica insolubilization reaction may be insufficient, and if it exceeds 60 minutes, the reaction tank may be excessively large.
  • the amount of the magnesium salt to be added is preferably 0.1 to 10 times, more preferably 0.5 to 5 times as much as the magnesium concentration with respect to the weight concentration of silica in the water to be treated. More preferred. When the addition amount of the magnesium salt is less than 0.1 times the weight concentration of silica in the water to be treated, the insolubilization reaction of silica may be insufficient. May be excessive.
  • aluminum salts such as polyaluminum chloride (PAC) and aluminum sulfate, and iron salts such as ferric chloride and ferric sulfate may be used in addition to the magnesium salt. It is preferable to use a magnesium salt from the viewpoint of the silica removal rate and the like.
  • a coagulation treatment step for example, in a coagulation tank, an inorganic coagulant is added to the water to be treated after the magnesium reaction, and the insolubilized substance is coagulated (coagulation step). Thereafter, a polymer flocculant is added in the floc forming tank to form flocs (flock forming step).
  • Examples of the inorganic coagulant used in the coagulation step include an iron-based inorganic coagulant such as iron chloride, an aluminum-based inorganic coagulant such as polyaluminum chloride (PAC), and the like. Iron-based inorganic flocculants are preferred.
  • the amount of the inorganic coagulant added is preferably in the range of 0.1 to 10 times, more preferably 1 to 5 times the weight of the added magnesium salt. If the amount of the inorganic coagulant is less than 0.1 times the weight of the added magnesium salt, the coagulation may be insufficient. May be excessive.
  • the pH in the aggregation step is, for example, in the range of 3 to 11. If the pH in the aggregation step is less than 3 or more than 11, poor aggregation may occur. Furthermore, if the pH in the aggregating step is less than 9, silica may be dissolved from the floc, so it is desirable to perform the aggregating step in a pH range of 9 to 11.
  • the temperature in the aggregation step is, for example, in the range of 1 ° C to 80 ° C. If the temperature in the aggregation step is less than 1 ° C. or exceeds 80 ° C., poor aggregation may occur.
  • Examples of the polymer flocculant used in the floc formation step include cationic polymer flocculants such as polyacrylamides and polyacrylates, anionic polymer flocculants, and nonionic polymer flocculants. From the viewpoint of properties and the like, an anionic polymer flocculant is preferable.
  • polymer flocculants examples include anionic polymer flocculants such as Olfloc OA-3H (manufactured by Organo Corporation).
  • the amount of the polymer flocculant to be added is preferably in the range of 0.1 to 10 mg / L, more preferably in the range of 1 to 5 mg / L, based on the amount of raw water. If the amount of the polymer flocculant is less than 0.1 mg / L with respect to the amount of the raw water, floc formation may not be improved. If the amount exceeds 10 mg / L, the polymer flocculant dissolved in the treated water may be reduced. It may remain.
  • the pH in the floc forming step is, for example, in the range of 3 to 11. If the pH in the floc formation step is less than 3 or more than 11, poor coagulation may occur. Further, if the pH in the flocking step is less than 9, silica may be dissolved from the floc, so it is desirable to perform the floc forming step in the pH range of 9 to 11.
  • the temperature in the floc forming step is, for example, in the range of 1 ° C to 80 ° C. If the temperature in the floc forming step is lower than 1 ° C. or higher than 80 ° C., poor coagulation may occur.
  • an inorganic coagulant and a polymer coagulant are used as the coagulation step and the floc formation step, but at least one of an inorganic coagulant, a polymer coagulant and the like may be used, and an iron-based inorganic coagulant may be used. It is preferable to use at least one of a flocculant and an anionic polymer flocculant. At the time of aggregating the silica which has been insolubilized by reacting with the magnesium salt, the use of at least one of an iron-based inorganic coagulant and an anionic polymer coagulant improves cohesion and solid-liquid separation.
  • solid-liquid separation step for example, floc-formed aggregates are separated into solid and liquid in a settling tank (solid-liquid separation step).
  • the pretreatment water obtained by the solid-liquid separation is sent to the reverse osmosis membrane treatment device 12.
  • sludge is discharged through sludge piping. Sludge may be collected and reused.
  • Pretreatment step removal of hardness components by lime softening method
  • the hardness component may be removed by a lime softening method.
  • the hardness components are classified into primary hardness and permanent hardness.
  • the primary hardness is removed by adding an alkali agent such as sodium hydroxide (NaOH), and the permanent hardness is removed by adding a carbonate such as sodium carbonate (NaCO 3 ).
  • a carbonate is also described as an alkali agent for convenience. That is, in the pretreatment step, an alkali agent is added to the water to be treated, and the hardness component is insolubilized (alkali agent reaction step).
  • alkaline agent examples include calcium hydroxide (Ca (OH) 2 ), sodium hydroxide (NaOH), potassium hydroxide (KOH), calcium hydrogen carbonate (Ca (HCO 3 ) 2 ), and magnesium hydrogen carbonate ( Mg (HCO 3 ) 2 ), sodium carbonate (Na 2 CO 3 ), potassium carbonate (K 2 CO 3 ), etc., and one or more of these can be used. That is, it is also possible to add sodium hydroxide and sodium carbonate as needed. Sodium carbonate is preferred from the viewpoint of insolubilization efficiency and the like.
  • the pH in the alkaline agent reaction step may be an alkaline condition, and is not particularly limited.
  • the pH is in the range of 9 to 13, preferably 11 to 12. If the pH in the alkaline agent reaction step is less than 9, the hardness component removal rate will be low, and if it exceeds 13, the amount of the alkaline agent added may be large.
  • the temperature in the alkali agent reaction step may be any temperature at which the insolubilization reaction of the hardness component proceeds, and is not particularly limited, but is, for example, in the range of 1 ° C to 80 ° C. If the temperature in the alkali agent reaction step is lower than 1 ° C., the insolubilization reaction of the hardness component may be insufficient, and if it exceeds 80 ° C., the heat resistance temperature of the equipment may become a problem.
  • the reaction time in the alkali agent reaction step is not particularly limited as long as the insolubilization reaction of the hardness component can proceed, and is, for example, in a range of 10 minutes to 30 minutes. If the reaction time in the alkaline agent reaction step is less than 10 minutes, the insolubilization reaction of the hardness component may be insufficient, and if it exceeds 30 minutes, the reaction tank may become large and equipment costs may increase.
  • the amount of the alkali agent to be added is preferably in the range of 1.0 to 2.0 times, and more preferably in the range of 1.0 to 1.2 times the molar concentration of the hardness component in the water to be treated. Is more preferable. If the amount of the alkali agent is less than 1.0 times the molar concentration of the hardness component in the water to be treated, the insolubilization reaction of the hardness component may be insufficient, and if the amount exceeds 2.0 times. In some cases, the cost of chemicals may increase.
  • the subsequent aggregation treatment step and solid-liquid separation step are the same as the above-mentioned pretreatment step (removal of silica with magnesium salt).
  • the pretreatment water obtained by the solid-liquid separation is sent to the reverse osmosis membrane treatment device 12.
  • Pretreatment step removal of hardness components by resin softening method
  • the pretreatment step by the resin softening method in the case where the water to be treated contains a hardness component, for example, the water to be treated is passed through an ion exchange tower filled with an ion exchange resin to adsorb and remove the hardness component (ion exchange). Process).
  • the pretreated water obtained by the ion exchange treatment is sent to the reverse osmosis membrane treatment device 12.
  • the ion exchange resin used in the ion exchange step is a cation exchange resin, and examples thereof include Amberrex 100Na and IRC-76 (manufactured by Organo Corporation).
  • the ion exchange resin When the ion exchange resin needs to be regenerated, the ion exchange resin is regenerated by passing the regenerant through.
  • the regenerating agent examples include an aqueous solution of an acid such as hydrochloric acid, sulfuric acid, and nitric acid, an aqueous solution of sodium chloride, and an aqueous solution of potassium chloride.
  • an aqueous acid solution and an aqueous sodium chloride solution are preferable.
  • the concentration treatment means (first concentration treatment means) is not particularly limited as long as it can concentrate the pretreated water, and is not particularly limited.
  • a membrane using a nanofiltration membrane or the like is used in addition to the reverse osmosis membrane treatment device.
  • a membrane using a nanofiltration membrane or the like is used.
  • One or more of a filtration device, a distillation device, an electrodialysis device and the like can be used. That is, if necessary, the concentrated water obtained by the reverse osmosis membrane treatment apparatus may be further concentrated by electrodialysis treatment, or the concentrated water obtained by the first reverse osmosis treatment may be further concentrated by the second reverse osmosis treatment. It may be further concentrated.
  • a reverse osmosis membrane treatment apparatus is preferable in that the treatment can be performed efficiently when the TDS in the pretreatment water is low.
  • Reverse osmosis membranes used in reverse osmosis membrane treatment equipment include ultra-low pressure reverse osmosis membranes and low pressure reverse osmosis membranes used for pure water production and wastewater recovery, as well as seawater desalination. Examples thereof include a medium pressure reverse osmosis membrane and a high pressure reverse osmosis membrane used.
  • Examples of the ultra-low pressure reverse osmosis membrane and low pressure reverse osmosis membrane include ES15 (manufactured by Nitto Denko), TM720D (manufactured by Toray), BW30HRLE (manufactured by Dow Chemical), and LFC3-LD (manufactured by Hydroranatics).
  • Examples of the high-pressure reverse osmosis membrane include SWC5-LD (manufactured by Hydroranatics), TM820V (manufactured by Toray), and XUS180808 (manufactured by Dow Chemical).
  • concentration treatment step first concentration treatment step
  • chemicals such as a pH adjuster, a scale dispersant for suppressing the scaling of inorganic salts in the system, and a bactericide for suppressing the generation of microorganisms in the system are added. Is also good.
  • the shape of the forward osmosis membrane used in the forward osmosis membrane treatment step is not particularly limited, and for example, a hollow fiber membrane, a spiral membrane, a tubular membrane, a membrane having a plate and frame structure, or the like can be used.
  • the membrane material of the forward osmosis membrane include an aromatic polyamide system and a cellulose acetate system.
  • forward osmosis membrane examples include HP5230 (manufactured by Toyobo), HFFO2 (manufactured by Aquaporin), and OsmoF2O (manufactured by Fluid Technology Solutions). These forward osmosis membranes may be used in a single stage, or may be used by connecting a plurality of stages in series. That is, the FO concentrated water obtained by the first forward osmosis membrane treatment may be further concentrated by the second forward osmosis membrane treatment.
  • the attracting solution used in the forward osmosis membrane treatment step includes a magnesium salt aqueous solution, an alkali agent aqueous solution, an acid aqueous solution, and a sodium chloride aqueous solution.
  • any chemical used in the present water treatment apparatus can be used without limitation. That is, various coagulants used in the coagulation process, scale dispersants and bactericides used in the concentration process can be used as the attracting solution.
  • the above attracting solutions may be used in combination.
  • an aqueous solution of sodium chloride is used as an inducing solution in the first forward osmosis membrane treatment step
  • an aqueous solution of magnesium salt is used as an inducing solution in the second forward osmosis membrane treatment step.
  • the dilute sodium chloride solution obtained in the first forward osmosis membrane treatment step is used as a regenerating solution of the softening resin
  • the dilute magnesium salt solution obtained in the second forward osmosis membrane treatment step is used as a soluble silica. It can be used as a magnesium source in the removal step.
  • the second concentration treatment means is not particularly limited as long as it can concentrate the diluted attracting solution used in the forward osmosis membrane treatment step, and is not particularly limited, but a nanofiltration membrane treatment device, a reverse osmosis membrane treatment device, One or more of a concentrating device using a semipermeable membrane such as a forward osmosis membrane treatment device, a pressure-assisted reverse osmosis membrane treatment device, a membrane filtration device using a nanofiltration membrane, a distillation device, an electrodialysis device and the like can be used. .
  • a concentration apparatus using a semipermeable membrane is preferable, and a pressure-assisted reverse osmosis membrane treatment apparatus that can reduce the influence of osmotic pressure when the TDS concentration of the water to be treated exceeds 5% is more preferable.
  • FIG. 4 shows an example of a concentrator in the water treatment apparatus according to the present embodiment.
  • the concentration device 340 shown in FIG. 4 is an example of a pressure-assisted reverse osmosis membrane treatment device.
  • the concentrating device 340 includes two or more concentrating means for concentrating the water to be treated using the semipermeable membrane, supplies the diluted attracting solution to the primary side of the first-stage semipermeable membrane, and supplies the diluted liquid to the secondary side.
  • a diluent from the other flow path on the secondary side To obtain a concentrated solution from the other flow path on the primary side, a diluent from the other flow path on the secondary side, and supply the diluent to the primary side of the semipermeable membrane of the next stage.
  • This is a device in which the primary side of the semipermeable membrane of each stage is pressurized to allow water contained in the primary side to permeate the secondary side, thereby sequentially obtaining a concentrate and a diluent.
  • the concentrating device 340 includes, for example, a first-stage semipermeable membrane processing device 42, a second-stage semipermeable membrane processing device 44, and a third-stage semipermeable membrane processing device 46.
  • Each semipermeable membrane processing device has a primary side (first space) 48 and a secondary side (second space) 50 partitioned by a semipermeable membrane 52.
  • a pipe 54 is connected to an inlet of the primary side 48 of the first-stage semipermeable membrane processing apparatus 42 via a pump 70, and a pipe 56 is connected to an outlet of the primary side 48.
  • the outlet of the primary side 48 of the second-stage semipermeable membrane processing device 44 and the inlet of the secondary side 50 of the first-stage semipermeable membrane processing device 42 are connected by a pipe 58 and the first-stage semipermeable membrane processing device 42
  • the outlet of the secondary side 50 and the inlet of the primary side 48 of the second-stage semipermeable membrane processing device 44 are connected by a pipe 60 via a pump 72.
  • the outlet of the primary side 48 of the third-stage semipermeable membrane processing device 46 and the inlet of the secondary side 50 of the second-stage semipermeable membrane processing device 44 are connected by a pipe 62, and the second-stage semipermeable membrane processing device 44
  • the outlet of the secondary side 50 and the inlet of the primary side 48 of the third-stage semipermeable membrane processing apparatus 46 are connected by a pipe 64 via a pump 74.
  • a pipe 66 is connected to an inlet of the secondary side 50 of the third-stage semipermeable membrane processing apparatus 46, and a pipe 68 is connected to an outlet of the secondary side 50.
  • the concentration device 340 is a device using a multi-stage semipermeable membrane processing device having a primary side 48 and a secondary side 50 separated by a semipermeable membrane 52.
  • the primary attracting solution eg, MgCl 2 : 8% by mass
  • used in the forward osmosis membrane treatment device 14 as the water to be treated is passed through the pipe 54 to the primary side 48 of the first-stage semipermeable membrane treatment device 42 by the pump 70.
  • the second concentrated liquid for example, MgCl 2 : 10% by mass obtained in the second-stage semipermeable membrane processing device 44 described below is passed through the pipe 58 to the secondary side 50,
  • the side 48 is pressurized and the water contained in its primary side 48 is permeated through the secondary side 50 and the first concentrate (eg, MgCl 2 : 30% by mass) and the first diluent (eg, MgCl 2 : 5). % By mass) (concentration step (first stage)).
  • the first concentrated solution (concentrated attracting solution) is discharged through the pipe 56 and is used again as the attracting solution in the forward osmosis membrane treatment device 14.
  • the first diluent passes through the pipe 60 through a pump 72 to the primary side 48 of the second-stage semipermeable membrane processing apparatus 44, and passes through the secondary side 50 through a pipe 62, through a third-stage semipermeable membrane processing apparatus 46 described later.
  • the obtained third concentrated liquid for example, MgCl 2 : 3% by mass
  • the primary side 48 is pressurized, the water contained in the primary side 48 is transmitted to the secondary side 50
  • the second concentrated A liquid eg, MgCl 2 : 10% by mass
  • a second diluent eg, MgCl 2 : 1% by mass
  • the second concentrate is passed through the pipe 58 to the secondary side 50 of the first-stage semipermeable membrane processing device 42.
  • the second diluent is passed through the pipe 64 to the primary side 48 of the third-stage semipermeable membrane processing apparatus 46 by the pump 74, and the dilute liquid (eg, MgCl 2 : 1% by mass) is passed through the pipe 66 to the secondary side 50.
  • the primary side 48 is pressurized and the water contained in the primary side 48 is permeated to the secondary side 50, and the third concentrated liquid (for example, MgCl 2 : 3% by mass) and the third diluent ( For example, MgCl 2 : ⁇ 1% by mass is obtained (concentration step (third stage)).
  • the third concentrate is passed through the pipe 62 to the secondary side 50 of the second-stage semipermeable membrane processing device 44.
  • the third diluent is discharged through a pipe 68.
  • a part of the second concentrate and the third concentrate may be used again as the attraction solution in the forward osmosis membrane treatment device 14.
  • the third diluent may be collected and reused after performing an ultrafiltration membrane (UF membrane) treatment, a reverse osmosis membrane (RO membrane) treatment, an ion exchange treatment, or the like, as necessary.
  • UF membrane ultrafiltration membrane
  • RO membrane reverse osmosis membrane
  • ion exchange treatment or the like
  • This pressure-assisted reverse osmosis membrane treatment device can reduce the osmotic pressure difference between the primary side 48 and the secondary side 50, operate with less energy than a normal reverse osmosis membrane treatment device, and can be operated at lower cost. Driving can be performed.
  • the concentrated attracting solution obtained from the diluted attracting solution is reused as the attracting solution in the forward osmosis membrane treatment device 14.
  • the liquid passing through the secondary side 50 of the first-stage semipermeable membrane processing device 42 and the second-stage and subsequent semipermeable membrane treatment devices is supplied to the first-stage semipermeable membrane processing device. It may be a liquid of a different component from the dilute attracting solution that passes through the primary side 48 of the device 42.
  • FIG. 5 shows an example of such a concentrator.
  • the concentration device 342 shown in FIG. 5 is a device having the same configuration as the concentration device 340 shown in FIG.
  • the primary attracting solution eg, MgCl 2 : 8% by mass
  • the primary attracting solution used in the forward osmosis membrane treatment device 14 as the water to be treated is passed through the pipe 54 to the primary side 48 of the first-stage semipermeable membrane treatment device 42 by the pump 70.
  • the second concentrated liquid for example, glucose: 20% by mass
  • the second concentrated liquid obtained in the second-stage semipermeable membrane processing device 44 described below
  • the first concentrated liquid eg, MgCl 2 : 30% by mass
  • the first diluent eg, glucose: 10% by mass
  • the first concentrated solution is discharged through the pipe 56 and is used again as the attracting solution in the forward osmosis membrane treatment device 14.
  • the first diluent passes through the pipe 60 through a pump 72 to the primary side 48 of the second-stage semipermeable membrane processing apparatus 44, and passes through the secondary side 50 through a pipe 62, through a third-stage semipermeable membrane processing apparatus 46 described later.
  • the obtained third concentrated liquid for example, NaCl: 3% by mass
  • the primary side 48 is pressurized, and the water contained in the primary side 48 is transmitted to the secondary side 50
  • the second concentrated liquid Eg, glucose: 20% by mass
  • a second diluent eg, NaCl: 1% by mass
  • the second concentrate is passed through the pipe 58 to the secondary side 50 of the first-stage semipermeable membrane processing device 42.
  • the second diluent passes through the primary side 48 of the third-stage semipermeable membrane treatment device 46 by the pump 74 through the pipe 64 and the dilute liquid (for example, NaCl: 1% by mass) passes through the pipe 66 to the secondary side 50.
  • the primary side 48 is pressurized and the water contained in the primary side 48 is transmitted to the secondary side 50, and the third concentrated liquid (for example, NaCl: 3% by mass) and the third diluted liquid (for example, NaCl: ⁇ 1% by mass) (concentration step (third stage)).
  • the third concentrate is passed through the pipe 62 to the secondary side 50 of the second-stage semipermeable membrane processing device 44.
  • the third diluent is discharged through a pipe 68.
  • the third diluent may be collected and reused after performing an ultrafiltration membrane (UF membrane) treatment, a reverse osmosis membrane (RO membrane) treatment, an ion exchange treatment, or the like, as necessary.
  • UF membrane ultrafiltration membrane
  • the liquid passing through the secondary side 50 of the first-stage semipermeable membrane processing device 42 and the semipermeable membrane processing devices of the second and subsequent stages may be any liquid having an osmotic pressure, and is not particularly limited. .
  • examples thereof include an aqueous solution containing an inorganic salt such as sodium chloride, an aqueous solution containing an organic substance such as glucose, an aqueous solution containing a polymer, and an ionic liquid. From the viewpoint of reducing the influence of component diffusion from the primary side to the secondary side, use of a liquid having the same components as the dilute attracting solution passing through the primary side 48 of the first-stage semipermeable membrane processing device 42 Is preferred.
  • FIG. 6 shows another example of the concentration device 34 in the water treatment device 5 according to the present embodiment.
  • the concentration device 344 shown in FIG. 6 is an example of a pressure-assisted reverse osmosis membrane treatment device.
  • the concentrating device 344 includes one or more concentrating means for concentrating the water to be treated using a semi-permeable membrane and further concentrating the concentrated liquid using a semi-permeable membrane, and is provided on the primary side of the first-stage semi-permeable membrane.
  • the diluted attracting solution is supplied, and the concentrated liquid is sequentially supplied to the primary side of the semipermeable membrane of each stage, and a part of the diluted attracting solution or any one of the stages is arranged on the secondary side of the semipermeable membrane of each stage.
  • This is a device that supplies a part of the concentrated liquid, pressurizes the primary side of the semipermeable membrane of each stage, and permeates water contained in the primary side to the secondary side.
  • the concentrating device 344 includes, for example, a first-stage semipermeable membrane processing device 78, a second-stage semipermeable membrane processing device 80, and a third-stage semipermeable membrane processing device 82.
  • Each semipermeable membrane processing device has a primary side (first space) 84 and a secondary side (second space) 86 partitioned by a semipermeable membrane 88.
  • a pipe 90 is connected via a pump 106 to an inlet of the primary side 84 of the first-stage semipermeable membrane processing device 78.
  • the outlet of the primary side 84 of the first-stage semipermeable membrane processing apparatus 78 and the inlet of the primary side 84 of the second-stage semipermeable membrane processing apparatus 80 are connected by a pipe 92.
  • the outlet of the primary side 84 of the second-stage semipermeable membrane processing apparatus 80 and the inlet of the primary side 84 of the third-stage semipermeable membrane processing apparatus 82 are connected by a pipe 94.
  • a pipe 96 is connected to an outlet of the primary side 84 of the third-stage semipermeable membrane processing device 82.
  • a pipe 98 branched from the pipe 96 is connected to an inlet on the secondary side 86 of the third-stage semipermeable membrane processing device 82.
  • the outlet of the secondary side 86 of the third-stage semipermeable membrane processing apparatus 82 and the inlet of the secondary side 86 of the second-stage semipermeable membrane processing apparatus 80 are connected by a pipe 100.
  • the outlet of the secondary side 86 of the second-stage semipermeable membrane processing apparatus 80 and the inlet of the secondary side 86 of the first-stage semipermeable membrane processing apparatus 78 are connected by a pipe 102.
  • a pipe 104 is connected to an outlet on the secondary side 86 of the first-stage semipermeable membrane processing device 78. If necessary, the pipes 92, 94, 96, 98, 100, 102 are supplied with a pressure adjusting mechanism such as a valve for adjusting pressure applied to the semi-permeable membrane, a pump for pressurization and liquid sending, and treated water. A tank or the like for temporarily storing may be provided.
  • the liquid is sent to the primary side 84 of the film processing apparatus 78.
  • the diluent (secondary-side treated water) returned from the third-stage semipermeable membrane processing device 82 in the final stage described below via the secondary side 86 of the second-stage semipermeable membrane processing device 80 (for example, (MgCl 2 : 6% by mass) is sent to the secondary side 86 of the first-stage semipermeable membrane processing apparatus 78 through the pipe 102.
  • the primary side 84 of the semipermeable membrane is pressurized, and water contained in the primary side 84 is transmitted to the secondary side 86 (concentration step (first stage)).
  • the concentrated liquid (primary treatment water) (eg, MgCl 2 : 18% by mass) of the first-stage semipermeable membrane processing apparatus 78 is sent to the primary side 84 of the second-stage semipermeable membrane processing apparatus 80 through a pipe 92. Is done.
  • the diluent (secondary treated water) (eg, MgCl 2 : 15% by mass) returned from the third-stage semipermeable membrane processing device 82 in the final stage described later passes through the pipe 100 and passes through the second-stage semipermeable membrane.
  • the liquid is sent to the secondary side 86 of the processing device 80.
  • the primary side 84 of the semipermeable membrane is pressurized, and the water contained in the primary side 84 is permeated to the secondary side 86 (concentration). Step (second stage)).
  • the concentrated liquid (primary treatment water) (for example, MgCl 2 : 23% by mass) of the second-stage semipermeable membrane processing apparatus 80 is sent to the primary side 84 of the third-stage semipermeable membrane processing apparatus 82 through a pipe 94. Is done.
  • the concentrated liquid (for example, MgCl 2 : 30% by mass) returned from the third-stage semipermeable membrane processing device 82 of the final stage described below passes through the pipe 98 to the secondary of the third-stage semipermeable membrane processing device 82.
  • the liquid is sent to the side 86.
  • the primary side 84 of the semipermeable membrane is pressurized, and the water contained in the primary side 84 is transmitted to the secondary side 86. (Concentration step (third stage)).
  • a part of the concentrated liquid (primary-side treated water) (for example, MgCl 2 : 30% by mass) in the third-stage semipermeable membrane processing device 82 in the final stage is discharged through a pipe 96 and attracted in the forward osmosis membrane processing device 14. Used again as a solution.
  • the remaining part of the concentrated liquid in the third-stage semipermeable membrane processing device 82 is sent to the secondary side 86 of the third-stage semipermeable membrane processing device 82 through pipes 96 and 98.
  • the primary side 84 of the semipermeable membrane is pressurized, and the water contained in the primary side 84 is transmitted to the secondary side 86 (the concentration step (the third step)). Eye)).
  • the diluent (secondary treated water) (for example, MgCl 2 : 15% by mass) in the third-stage semipermeable membrane processing device 82 passes through the pipe 100 to the secondary side 86 of the second-stage semipermeable membrane processing device 80. It is sent. As described above, in the second-stage semipermeable membrane processing apparatus 80, the primary side 84 of the semipermeable membrane is pressurized, and the water contained in the primary side 84 is transmitted to the secondary side 86 (concentration step (second step)). Eye)).
  • secondary treated water for example, MgCl 2 : 15% by mass
  • the diluent (secondary-side treated water) (for example, MgCl 2 : 6% by mass) of the second-stage semipermeable membrane processing apparatus 80 passes through the pipe 102 to the secondary side 86 of the first-stage semipermeable membrane processing apparatus 78. It is sent. As described above, in the first-stage semipermeable membrane processing apparatus 78, the primary side 84 of the semipermeable membrane is pressurized, and the water contained in the primary side 84 is transmitted to the secondary side 86 (concentration step (first stage). Eye)).
  • the diluent (secondary treatment water) (for example, MgCl 2 : ⁇ 1% by mass) of the first-stage semipermeable membrane treatment device 78 is discharged through the pipe 104.
  • the diluent may be collected and reused after performing an ultrafiltration membrane (UF membrane) treatment, a reverse osmosis membrane (RO membrane) treatment, an ion exchange treatment, and the like, as necessary.
  • UF membrane ultra
  • a pressure-assisted reverse osmosis membrane treatment device such as the concentrator 344 uses a part of the water to be treated as a diluent for osmotic pressure assistance, it is not necessary to prepare a separate diluent, and the device configuration is also reduced. It can be simpler than a pressure-assisted reverse osmosis membrane treatment device such as the concentration device 340.
  • the concentrated attracting solution obtained from the diluted attracting solution is reused as the attracting solution in the forward osmosis membrane treatment device 14.
  • a part of the diluted attracting solution used in the forward osmosis membrane treatment device 14 or the concentrate of any one of the stages is provided on the secondary side of the semipermeable membrane of each stage. May be supplied, and there is no particular limitation on the method.
  • the diluted attracting solution used in the forward osmosis membrane treatment device 14 as the water to be treated is distributed, and the primary side 84 of the first-stage semipermeable membrane treatment device 78,
  • the concentrated liquid and the permeated liquid are supplied to the secondary side 86, respectively, and the concentrated liquid and the permeated liquid are sequentially supplied to the primary side 84 and the secondary side 86 of the semipermeable membrane of each stage, respectively, and the primary side of the semipermeable membrane of each stage is pressurized. Water contained in the primary side may be transmitted to the secondary side.
  • the diluted attracting solution used in the forward osmosis membrane treatment device 14 as the water to be treated is supplied to the primary side 84 of the first-stage semipermeable membrane treatment device 78, and the concentrated solution Is supplied to the primary side of the semipermeable membrane of each stage in order, and a part of the concentrated solution of the third stage semipermeable membrane processing device 82 at the final stage is supplied to the secondary side 86 of the first stage semipermeable membrane processing device 78 Then, the permeated liquid is sequentially supplied to the secondary side of the semipermeable membrane of each stage, and the water contained in the primary side is permeated to the secondary side by pressurizing the primary side of the semipermeable membrane of each stage. Good.
  • the diluted attracting solution used in the forward osmosis membrane treatment device 14 which is water to be treated, is supplied to the primary side 84 of the first-stage semipermeable membrane treatment device 78, and the concentrated solution Is supplied to the primary side of the semipermeable membrane of each stage in order, and a part of the concentrated liquid of the semipermeable membrane processing device of each stage is supplied to the secondary side 86 of the semipermeable membrane processing device itself.
  • the primary side of the permeable membrane may be pressurized to allow water contained in the primary side to permeate the secondary side.
  • the number of stages of the semipermeable membrane treatment device may be determined according to the concentration of the target treated water. For example, in the concentrators 344, 346, 348, and 350, when it is desired to obtain treated water having a higher concentration (concentrated attracting solution) from a dilute attracting solution having a lower concentration, the number of stages of the semipermeable membrane treatment device may be increased. .
  • a membrane module unit including two or more membrane modules connected in parallel may be used as the semipermeable membrane processing device in each stage.
  • the number of membrane modules in each membrane module unit may be determined according to the flow rate of the diluted attracting solution to be treated.
  • Examples of the semipermeable membrane provided in the semipermeable membrane processing apparatus include semipermeable membranes such as a reverse osmosis membrane (RO membrane), a forward osmosis membrane (FO membrane), and a nanofiltration membrane (NF membrane).
  • the semipermeable membrane is preferably a reverse osmosis membrane, a forward osmosis membrane, or a nanofiltration membrane.
  • the pressure of the target solution on the primary side is preferably 0.5 to 10.0 MPa.
  • a material constituting the semipermeable membrane is not particularly limited, and examples thereof include a cellulose resin such as a cellulose acetate resin, a polysulfone resin such as a polyethersulfone resin, and a polyamide resin.
  • the material constituting the semipermeable membrane is preferably a cellulose acetate resin.
  • the shape of the semipermeable membrane is not particularly limited as long as it has a structure capable of supplying a solution to each of the primary side and the secondary side of the membrane, and examples thereof include a spiral type, a hollow fiber membrane, and a plate and frame type.
  • FIG. 2 shows a schematic configuration of another example of the water treatment apparatus according to the embodiment of the present invention.
  • the water treatment apparatus 3 shown in FIG. 2 further includes an attraction solution preparation tank 30 as a preparation means for mixing magnesium hydroxide and an acid and reacting them at a pH of 7 or less to prepare an aqueous magnesium salt solution to be used as an attraction solution. .
  • the outlet of the attraction solution preparation tank 30 and the attraction solution inlet of the forward osmosis membrane treatment device 14 are connected by the attraction solution piping 32.
  • a pretreatment step including one of a soluble silica removal step and a hardness component removal step, and a concentration treatment for concentrating pretreatment water obtained in the pretreatment step. And a processing step.
  • magnesium hydroxide and an acid are mixed and reacted at pH 7 or less to prepare a magnesium salt aqueous solution to be used as the attraction solution (preparation step).
  • the concentrated water obtained by the reverse osmosis membrane treatment is subjected to a forward osmosis membrane treatment in the forward osmosis membrane treatment device 14 (forward osmosis membrane treatment step).
  • the attractant solution prepared in the attractant solution preparation tank 30 is sent to the secondary side of the forward osmosis membrane through the attractant solution pipe 32, and the concentrated water and the attractant solution are passed through the forward osmosis membrane.
  • the presence causes osmotic pressure to transfer water to the attracting solution.
  • the dilute attractant used in the forward osmosis membrane treatment step is sent to the pretreatment device 10 through the dilute attractant solution pipe 26, and is used in the pretreatment device 10 in the pretreatment step.
  • An inducing solution preparation tank may be further provided.
  • magnesium hydroxide and an acid are mixed and reacted at a pH of 7 or less to prepare an aqueous solution of a magnesium salt (preparation step). May be sent to the secondary side of the above to be used as an attraction solution.
  • Examples of the acid used in the preparation step include hydrochloric acid, sulfuric acid, nitric acid and the like, and hydrochloric acid or nitric acid is preferable from the viewpoint of suppressing the formation of hardly soluble substances.
  • the pH in the preparation step is not particularly limited as long as it is 7 or less, and is, for example, in the range of 1 to 7 and preferably in the range of 2 to 5. If the pH in the preparation step exceeds 7, the dissolution of the magnesium salt may be insufficient, and if it is less than 1, the amount of the acid added may be excessive.
  • the temperature in the preparation step is not particularly limited as long as the dissolution reaction of the magnesium salt proceeds, and is, for example, in the range of 1 ° C to 80 ° C. If the temperature in the preparation step is less than 1 ° C., the dissolution reaction of the magnesium salt may be insufficient, and if it exceeds 80 ° C., the heat resistance of the equipment may become a problem.
  • the reaction time in the preparation step is not particularly limited as long as the dissolution reaction of the magnesium salt can proceed, and is, for example, in the range of 5 minutes to 120 minutes. If the reaction time in the preparation step is less than 5 minutes, the dissolution reaction of the magnesium salt may be insufficient, and if it exceeds 120 minutes, equipment may be a problem.
  • FIG. 11 shows an outline of an example of a forward osmosis membrane processing system according to an embodiment of the present invention, and its configuration will be described.
  • the forward osmosis membrane processing system 8 through the forward osmosis membrane 110, the water to be treated (FO treated water) and the attracting solution having a higher concentration than the treated water (FO treated water).
  • a forward osmosis membrane treatment device 14 is provided as forward osmosis membrane treatment means for obtaining a concentrated water (FO concentrated water) and a dilute attractant solution by bringing them into contact with each other.
  • the FO to-be-treated water pipe 16 is connected to the FO to-be-treated water inlet of the forward osmosis membrane treatment apparatus 14, and the FO concentrated water pipe 28 is connected to the FO concentrated water outlet.
  • the attracting solution inlet 24 of the forward osmosis membrane treatment apparatus 14 is connected to an attracting solution pipe 24, and the diluted attracting solution outlet is connected to a diluted attracting solution pipe 26.
  • a germicide addition pipe 112 is connected to the FO treated water pipe 16 as a germicide addition means.
  • FO to-be-treated water is sent to the primary side of the forward osmosis membrane treatment device 14 through the FO to-be-treated water pipe 16 and subjected to forward osmosis membrane treatment in the forward osmosis membrane treatment device 14 (forward osmosis membrane treatment step).
  • the attracting solution is sent to the secondary side of the forward osmosis membrane through the attracting solution pipe 24, and the water to be treated with FO and the attracting solution are caused to exist through the forward osmosis membrane 110, whereby the osmosis is performed.
  • Water is transferred to the attracting solution by pressure.
  • the diluted attracting solution used in the forward osmosis membrane treatment step is discharged through the diluted attracting solution pipe 26.
  • the FO concentrated water obtained in the forward osmosis membrane treatment step is discharged through the FO concentrated water piping 28. At least one of the dilute attractant solution and the FO retentate may be recovered and reused.
  • a bactericide containing a bromine-based oxidizing agent or a chlorine-based oxidizing agent and a sulfamic acid compound (hereinafter, may be referred to as “forward osmosis membrane bactericide”) is present in the FO treated water.
  • the forward osmosis membrane disinfectant is added to the FO untreated water in the FO untreated water piping 16 through the disinfectant addition piping 112.
  • a FO treatment water tank for storing the FO treatment water may be separately provided at the previous stage of the forward osmosis membrane treatment device 14, and a forward osmosis membrane sterilant may be added to the FO treatment water tank.
  • the forward osmosis membrane treatment method and the forward osmosis membrane treatment system 8 when the to-be-treated water is subjected to the forward osmosis membrane treatment, bromine is added to the to-be-treated water of the forward osmosis membrane treatment (FO treated water).
  • a bactericide for a forward osmosis membrane containing a oxidizing agent or a chlorinated oxidizing agent and a sulfamic acid compound is present.
  • the present inventors have found that a bactericide for a forward osmosis membrane containing a bromine-based oxidant or a chlorine-based oxidant and a sulfamic acid compound hardly permeates a forward osmosis membrane.
  • This fungicide for forward osmosis membranes exhibits a more sufficient bactericidal effect on forward osmosis membranes than conventional chlorine-based germicides, oxidants, and organic germicides. Further, since there is almost no leak of the germicide into the attracting solution, the dilute attracting solution can be reused.
  • the sterilizing agent for the forward osmosis membrane is concentrated toward the outlet of the forward osmosis membrane treatment apparatus 14 (FO concentrated water outlet). Therefore, the germicidal active ingredient of the germicide can sufficiently reach the outlet (FO concentrated water outlet) side of the forward osmosis membrane treatment device 14 and can be sufficiently sterilized to the outlet side of the forward osmosis membrane.
  • a disinfectant containing a brominated oxidant and a sulfamic acid compound is a disinfectant containing a stabilized hypobromite composition containing a mixture of a "brominated oxidant” and a “sulfamic acid compound”.
  • a bactericide containing a stabilized hypobromite composition containing “a reaction product of a brominated oxidizing agent and a sulfamic acid compound” may be used.
  • a disinfectant containing a chlorine-based oxidant and a sulfamic acid compound is a disinfectant containing a stabilized hypochlorous acid composition containing a mixture of a "chlorine-based oxidant” and a “sulfamic acid compound”, It may be a bactericide containing a stabilized hypochlorous acid composition containing “a reaction product of a chlorine-based oxidizing agent and a sulfamic acid compound”.
  • the forward osmosis membrane treatment method provides a method of treating a mixture of a “bromine-based oxidizing agent” and a “sulfamic acid compound” or a “chlorine-based oxidizing agent” in water to be treated (FO treated water). "And a mixture of" sulfamic acid compound ". Thereby, it is considered that a stabilized hypobromous acid composition or a stabilized hypochlorous acid composition is formed in the water to be treated.
  • the forward osmosis membrane treatment method according to the embodiment of the present invention is characterized in that, in the water to be treated (FO water to be treated), stabilized hypobromite which is a “reaction product of a bromine-based oxidizing agent and a sulfamic acid compound” is used.
  • This is a method in which an acid composition or a stabilized hypochlorous acid composition which is a "reaction product of a chlorine-based oxidizing agent and a sulfamic acid compound" is present.
  • the forward osmosis membrane treatment method comprises the steps of: adding "bromine”, “bromine chloride”, “hypobromous acid” or “sodium bromide to hypochlorous acid” in the water to be treated; This is a method in which a mixture of “reactant” and “sulfamic acid compound” is present. Alternatively, this is a method in which a mixture of “hypochlorous acid” and “sulfamic acid compound” is present in the water to be treated.
  • the forward osmosis membrane treatment method in the water to be treated, for example, "reaction product of bromine and sulfamic acid compound", “reaction product of bromine chloride and sulfamic acid compound”, Stabilized hypobromite, which is a “reaction product of hypobromite and a sulfamic acid compound” or a “reaction product of a reaction product of sodium bromide and hypochlorous acid with a sulfamic acid compound” It is a method of making the composition present. Alternatively, this is a method in which a stabilized hypochlorous acid composition which is a “reaction product of hypochlorous acid and a sulfamic acid compound” is present in the water to be treated.
  • the stabilized hypobromous acid composition or stabilized hypochlorous acid composition is equal to or more than a conventional disinfectant such as a chlorine-based oxidizing agent such as hypochlorous acid. Despite having a bactericidal effect, it has a lower degradation effect on the forward osmosis membrane than conventional bactericides such as chlorine-based oxidizing agents. Can be suppressed from oxidative deterioration. For this reason, the stabilized hypobromous acid composition or the stabilized hypochlorous acid composition used in the forward osmosis membrane treatment method according to the present embodiment is a disinfectant used in the method of treating the water to be treated with the forward osmosis membrane. Is preferable.
  • a "bromine oxidant” or a "chlorine oxidant” and a “sulfamic acid compound” may be injected into the water to be treated by a chemical injection pump or the like.
  • the "bromine oxidant” or the “chlorine oxidant” and the “sulfamic acid compound” may be separately added to the water to be treated, or may be mixed with the stock solutions and then added to the water to be treated. Good.
  • a "reaction product of a brominated oxidant and a sulfamic acid compound” or a “reaction product of a chlorine-based oxidizing agent and a sulfamic acid compound” may be injected by a chemical injection pump or the like. Good.
  • the ratio of the equivalent of the “sulfamic acid compound” to the equivalent of the “bromine oxidant” or the “chlorine oxidant” is preferably 1 or more, and more preferably 1 or more. More preferably, it is in the following range. If the ratio of the equivalent of “sulfamic acid compound” to the equivalent of “bromine oxidant” or “chlorine oxidant” is less than 1, the film may be deteriorated, and if it exceeds 2, the production cost increases. May be.
  • the total chlorine concentration in contact with the forward osmosis membrane is preferably 0.01 to 100 mg / L in terms of effective chlorine concentration. If the amount is less than 0.01 mg / L, a sufficient sterilizing effect may not be obtained. If the amount is more than 100 mg / L, deterioration of the forward osmosis membrane and corrosion of pipes and the like may be caused.
  • bromine-based oxidizing agent examples include bromine (liquid bromine), bromine chloride, bromic acid, bromate, hypobromite, and the like.
  • the hypobromite may be formed by reacting a bromide such as sodium bromide with a chlorine-based oxidizing agent such as hypochlorous acid.
  • bromine and sulfamic acid compound (mixture of bromine and sulfamic acid compound)" or “reaction product of bromine and sulfamic acid compound” using bromine is described as “hypochlorous acid and bromine compound and Compared to the preparation of “sulfamic acid” and the preparation of “bromine chloride and sulfamic acid” and the like, since there is less by-product of bromate and the forward osmosis membrane is not further deteriorated, it is more preferable as a bactericide for the forward osmosis membrane.
  • bromine and a sulfamic acid compound be present in the water to be treated (a mixture of bromine and a sulfamic acid compound is present). Further, it is preferable that a reaction product of bromine and a sulfamic acid compound is present in the water to be treated.
  • bromine compound examples include sodium bromide, potassium bromide, lithium bromide, ammonium bromide, and hydrobromic acid. Of these, sodium bromide is preferred from the viewpoint of formulation cost and the like.
  • Examples of the chlorine-based oxidizing agent include chlorine gas, chlorine dioxide, hypochlorous acid or a salt thereof, chlorite or a salt thereof, chloric acid or a salt thereof, perchloric acid or a salt thereof, chlorinated isocyanuric acid or a salt thereof.
  • examples of the salt include alkali metal hypochlorites such as sodium hypochlorite and potassium hypochlorite, and alkaline earth hypochlorite such as calcium hypochlorite and barium hypochlorite.
  • alkali metal chlorites such as sodium chlorite and potassium chlorite
  • alkaline earth metal chlorites such as barium chlorite
  • other metal chlorites such as nickel chlorite
  • alkali metal chlorates such as ammonium chlorate, sodium chlorate and potassium chlorate
  • alkaline earth metal chlorates such as calcium chlorate and barium chlorate.
  • chlorine-based oxidizing agents may be used alone, or two or more thereof may be used in combination.
  • sodium hypochlorite is preferably used from the viewpoint of handleability and the like.
  • the sulfamic acid compound is a compound represented by the following general formula (1).
  • R 2 NSO 3 H (1) (In the formula, R is independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms.)
  • sulfamic acid compound examples include, in addition to sulfamic acid (amidosulfate) in which both R groups are both hydrogen atoms, N-methylsulfamic acid, N-ethylsulfamic acid, N-propylsulfamic acid, N- One of two R groups such as isopropylsulfamic acid and N-butylsulfamic acid is a hydrogen atom, and the other is an alkyl group having 1 to 8 carbon atoms; a sulfamic acid compound; N, N-dimethylsulfamic acid; Two R groups such as N-diethylsulfamic acid, N, N-dipropylsulfamic acid, N, N-dibutylsulfamic acid, N-methyl-N-ethylsulfamic acid and N-methyl-N-propylsulfamic acid; One of two R groups such as a sulf
  • sulfamic acid salts examples include, for example, alkali metal salts such as sodium salt and potassium salt, alkaline earth metal salts such as calcium salt, strontium salt and barium salt, manganese salt, copper salt, zinc salt, iron salt, cobalt salt, and the like. Other metal salts such as nickel salts, ammonium salts, guanidine salts and the like.
  • the sulfamic acid compounds and salts thereof may be used alone or in combination of two or more.
  • the sulfamic acid compound it is preferable to use sulfamic acid (amidosulfuric acid) from the viewpoint of environmental load and the like.
  • an alkali may be further present.
  • the alkali include alkali hydroxides such as sodium hydroxide and potassium hydroxide.
  • Sodium hydroxide and potassium hydroxide may be used in combination from the viewpoint of low-temperature product stability and the like.
  • the alkali may be used as an aqueous solution instead of a solid.
  • the shape of the forward osmosis membrane used in the forward osmosis membrane treatment step is not particularly limited, but for example, a hollow fiber membrane, a spiral membrane, a tubular membrane, a membrane having a plate and frame structure, or the like can be used.
  • the membrane material of the forward osmosis membrane include aromatic polyamides, cellulose acetates, and polyketones.
  • the forward osmosis membrane treatment method according to the present embodiment is an aromatic polyamide-based as a forward osmosis membrane, a membrane provided with separation performance or water permeability by incorporating a functional protein or an inorganic material into an amide-based substrate. It can be suitably applied. It is known that these films are particularly susceptible to deterioration by conventionally used chlorine-based oxidizing agents.
  • forward osmosis membrane examples include HP5230 (manufactured by Toyobo), HFFO2 (manufactured by Aquaporin), and OsmoF2O (manufactured by Fluid Technology Solutions). These forward osmosis membranes may be used in a single stage, or may be used by connecting a plurality of stages in series. That is, the concentrated water obtained by the first forward osmosis membrane treatment may be further concentrated by the second forward osmosis membrane treatment.
  • the forward osmosis membrane and the reverse osmosis membrane have different structures and properties depending on the operation method. Since a reverse osmosis membrane applies a high pressure to the primary side of the membrane, it is necessary to increase the film thickness in order to maintain mechanical strength that can withstand the pressure. On the other hand, the forward osmosis membrane does not need to have the mechanical strength of the reverse osmosis membrane because the pressure applied to the membrane is lower than that of the reverse osmosis membrane, and furthermore, it is necessary to suppress the concentration polarization inside the membrane, It is required to reduce the film thickness.
  • the reverse osmosis membrane and the forward osmosis membrane have the same membrane material, but have different membrane structures, and have different permeation performance and blocking performance. Therefore, if the reverse osmosis membrane used in the reverse osmosis membrane treatment is used for forward osmosis, sufficient performance cannot be obtained.
  • Examples of the attracting solution used in the forward osmosis membrane treatment step include an aqueous solution of an inorganic salt such as an aqueous solution of ammonium carbonate, an aqueous solution of a magnesium salt, and an aqueous solution of a sodium salt; an aqueous solution of an organic substance such as sucrose, glucose, and an organic polymer; and an ionic liquid.
  • the diluted attracting solution used in the forward osmosis membrane treatment step may be used as it is in a separate step, or water may be separated from the diluted attracting solution by performing operations such as heating and membrane separation on the diluted attracting solution. The water and concentrated attracting solution may be reused.
  • the above attracting solutions may be used in combination.
  • the water to be treated is not particularly limited.
  • seawater desalination treatment in which industrial water, surface water, tap water, groundwater, seawater, seawater is desalinated by a reverse osmosis method, an evaporation method, or the like.
  • Water and various kinds of wastewater for example, wastewater discharged in a semiconductor manufacturing process and the like can be given.
  • the pH of the water to be treated is, for example, in the range of 2 to 12, preferably in the range of 4 to 11.
  • the forward osmosis membrane may be deteriorated.
  • a dispersant when scale is generated at pH 5.5 or higher of the water to be treated, a dispersant may be used in combination with the bactericide to suppress the scale.
  • the dispersant include polyacrylic acid, polymaleic acid, and phosphonic acid.
  • the amount of the dispersant added to the water to be treated is, for example, in the range of 0.1 to 1,000 mg / L as the concentration in the FO concentrated water.
  • ⁇ Applications of the forward osmosis membrane treatment system include, for example, desalination of seawater, volume reduction of wastewater, concentration of valuable resources, and concentration of foods and beverages.
  • the water treatment method according to the embodiment of the present invention includes the forward osmosis membrane treatment method, and includes a pretreatment step and a reverse osmosis membrane treatment step before the forward osmosis membrane treatment step, and is obtained by the forward osmosis membrane treatment step.
  • This is a water treatment method in which the diluted attracting solution is used in a pretreatment step.
  • the water treatment system according to the embodiment of the present invention includes the forward osmosis membrane treatment system, and includes a pretreatment unit and a reverse osmosis membrane treatment unit at a stage preceding the forward osmosis membrane treatment unit.
  • a water treatment system in which the obtained dilute attractant solution is used in pretreatment means.
  • FIG. 1 An outline of an example of a water treatment system according to the embodiment of the present invention is shown in FIG.
  • the water treatment system 9 performs a reverse osmosis membrane treatment of a pretreatment device 114 as a pretreatment device for performing a pretreatment of the treatment water and a pretreatment water obtained by the pretreatment.
  • Osmosis membrane treatment device 118 as a reverse osmosis membrane treatment means for obtaining the water and RO permeated water
  • a forward osmosis membrane as a forward osmosis membrane treatment means for performing the RO treatment of the RO concentrated water obtained by the reverse osmosis membrane treatment
  • the water treatment system 9 may include a turbidity removing device 116 as turbidity removing means for performing turbidity removing treatment of pretreated water obtained by the pretreatment.
  • the treated water pipe 120 is connected to the treated water inlet of the pretreatment device 114, and the outlet of the pretreatment device 114 and the entrance of the turbidity removal device 116 are connected by the piping 122.
  • the outlet of the turbidity removing device 116 and the inlet of the reverse osmosis membrane treatment device 118 are connected by a pipe 124.
  • the RO concentrated water outlet of the reverse osmosis membrane treatment device 118 and the FO treated water inlet of the forward osmosis membrane treatment device 14 are connected by the FO treated water piping 16.
  • RO permeated water pipe 126 is connected.
  • the attracting solution inlet 24 of the forward osmosis membrane processing device 14 is connected to an attracting solution pipe 24, and the diluted attracting solution outlet of the forward osmosis membrane processing device 14 and the diluted attracting solution inlet of the pretreatment device 114 are connected to the diluted attracting solution pipe.
  • a FO concentrated water pipe 28 is connected to an FO concentrated water outlet of the forward osmosis membrane treatment device 14.
  • a backwash drainage pipe 128 may be connected to the backwash drainage outlet of the turbidity removal device 116.
  • the water to be treated is sent to the pretreatment device 114 through the water pipe 120 to be treated.
  • a process of removing soluble silica, hardness components, and the like contained in the water to be treated is performed (pretreatment step).
  • the pretreatment device 114 may, for example, add a magnesium salt to the water to be treated and cause the water to react to insolubilize the soluble silica.
  • a magnesium salt for example, is added to the water to be treated under alkaline conditions (eg, pH 10 to 12) to insolubilize the soluble silica (magnesium reaction step).
  • an aggregating agent is added, if necessary, to perform an agglomeration treatment (aggregation treatment step), and the aggregates are subjected to solid-liquid separation (solid-liquid separation step).
  • the solid-liquid separation treated water obtained by the solid-liquid separation is sent as pretreatment water to the turbidity removing device 116 through the pipe 122, and the turbidity removing treatment is performed by a UF membrane or the like to remove the turbidity components and the like.
  • the solution is sent to the reverse osmosis membrane treatment device 118.
  • the pretreatment device 114 is, for example, an alkali agent that adds an alkali agent to the water to be treated and reacts to insolubilize the hardness component.
  • a reaction means an aggregating treatment means for adding an aggregating agent as needed to the water to be treated after the reaction, and aggregating, and a solid-liquid separating means for separating an aggregate from the treated water subjected to the aggregating treatment, .
  • an alkali agent is added to the water to be treated, and the hardness component is insolubilized (alkali agent reaction step).
  • an aggregating agent is added, if necessary, to perform an agglomeration treatment (aggregation treatment step), and the aggregates are subjected to solid-liquid separation (solid-liquid separation step).
  • the solid-liquid separation treated water obtained by the solid-liquid separation is sent as pretreatment water to the turbidity removing device 116 through the pipe 122, and the turbidity removing treatment is performed by a UF membrane or the like to remove the turbidity components and the like.
  • the solution is sent to the reverse osmosis membrane treatment device 118.
  • the pretreatment device 114 has, for example, an ion exchange treatment unit that performs an ion exchange treatment using an ion exchange resin or the like.
  • the water to be treated is passed through an ion exchange tower filled with an ion exchange resin as an ion exchange treatment means, and the hardness component is adsorbed and removed (ion exchange step).
  • the pre-treated water obtained by the ion exchange treatment is sent to the turbidity removing device 116 through the pipe 122, and the turbidity removing treatment is performed by a UF membrane or the like. Removal step), the liquid is sent to the reverse osmosis membrane treatment device 118.
  • the ion exchange resin needs to be regenerated, the ion exchange resin is regenerated by passing the regenerant through the liquid.
  • the pretreated water subjected to the turbidity removal treatment is subjected to reverse osmosis membrane treatment in the reverse osmosis membrane treatment device 118 to obtain RO concentrated water and RO permeated water (reverse osmosis membrane treatment step).
  • the RO concentrated water obtained by the reverse osmosis membrane treatment is sent to the primary side of the forward osmosis membrane treatment device 14 through the FO treatment water piping 16 as the FO treatment water. Is discharged through.
  • the membrane may be backwashed at predetermined time intervals. For example, RO permeated water or the like is supplied to the turbidity removing device 116 as backwash water, and backwash wastewater is discharged through a backwash wastewater pipe 128.
  • the RO concentrated water obtained by the reverse osmosis membrane treatment is subjected to a forward osmosis membrane treatment in the forward osmosis membrane treatment device 14 (forward osmosis membrane treatment step).
  • the attracting solution is sent to the secondary side of the forward osmosis membrane through the attracting solution pipe 24, and through the forward osmosis membrane, the RO concentrated water and the attracting solution are caused to exist. Water is transferred to the attracting solution.
  • a disinfectant for a forward osmosis membrane containing a bromine-based oxidizing agent or a chlorine-based oxidizing agent and a sulfamic acid compound is present in the RO concentrated water (water to be treated with FO).
  • the forward osmosis membrane disinfectant is added to the RO concentrated water (FO untreated water) in the FO untreated water pipe 16 through the disinfectant addition pipe 112.
  • a FO treatment water tank for storing RO concentrated water (FO treatment water) is separately provided at a stage preceding the forward osmosis membrane treatment device 14, for example, between the reverse osmosis membrane treatment device 118 and the forward osmosis membrane treatment device 14.
  • a bactericide for a forward osmosis membrane may be added in the treatment water tank.
  • This fungicide for forward osmosis membranes exhibits a more sufficient bactericidal effect on forward osmosis membranes than conventional chlorine-based germicides, oxidants, and organic germicides.
  • a dilute attracting solution diluted by the forward osmosis membrane treatment is used in the pretreatment. And the reuse of the dilute attractant solution becomes possible.
  • the bactericidal active ingredient is contained in the backwash wastewater of the turbidity removing device 116 and the RO permeated water of the reverse osmosis membrane treatment device 118.
  • a chlorine-based disinfectant or an oxidant is contained in the diluted attraction solution, when the chlorine-based disinfectant or the oxidant flows into the turbidity removing device 116 or the reverse osmosis membrane treatment device 118, the membrane is deteriorated.
  • the above-mentioned fungicide for forward osmosis membrane is used, such a risk is suppressed because the sterilizing active ingredient hardly permeates through the forward osmosis membrane.
  • the dilute attractant used in the forward osmosis membrane treatment step is sent to the pretreatment device 114 through the dilute attractant solution pipe 26, and is used in the pretreatment device 114 in the pretreatment step.
  • the FO concentrated water obtained in the forward osmosis membrane treatment step is discharged through the FO concentrated water piping 28.
  • the FO concentrated water may be collected and reused.
  • the pretreatment device 114 includes a device for removing soluble silica, for example, a magnesium salt aqueous solution is used as the attraction solution in the forward osmosis membrane treatment device 14, and the diluted attraction solution ( The magnesium salt diluted aqueous solution) may be used as a magnesium salt added in the pretreatment device 114.
  • a magnesium salt aqueous solution is used as the attraction solution in the forward osmosis membrane treatment device 14
  • the magnesium salt diluted aqueous solution may be used as a magnesium salt added in the pretreatment device 114.
  • an aqueous alkaline solution is used as the attraction solution in the forward osmosis membrane treatment device 14 and used in the forward osmosis membrane treatment device 14.
  • the dilute attracting solution may be used as the alkaline agent added in the pretreatment device 114.
  • the pretreatment device 114 includes a device that removes a hardness component by a resin softening method, for example, an acid aqueous solution or a sodium chloride aqueous solution is used as the attracting solution in the forward osmosis membrane treatment device 14, and the forward osmosis membrane treatment device 14
  • the used dilute attracting solution (acid dilute aqueous solution or sodium chloride dilute aqueous solution) may be used as a regenerant for the ion exchange resin in the pretreatment device 114.
  • the water to be treated containing at least one of the soluble silica and the hardness component can be treated at low cost.
  • the cost required for reusing the attractant solution originally required is reduced, and it is not necessary to provide a regeneration facility. . Since the diluted attractant solution is only the one that is originally used in the pretreatment step, it has little additional cost.
  • the target water to be treated by the water treatment method and the water treatment apparatus according to the present embodiment is not particularly limited, and is, for example, water containing at least one of soluble silica and a hardness component.
  • the concentration of the soluble silica is, for example, in the range of 5 to 400 mg / L.
  • concentration of the calcium hardness component is in the range of 5 to 600 mg / L.
  • the total evaporation residue (TDS: Total Dissolved Solid) in the water to be treated is, for example, in the range of 100 to 50,000 mg / L.
  • the pretreatment means is a means for removing soluble silica (soluble silica).
  • (Hardening component removal step) and a hardness component removing means hardness component removing step).
  • the order of the soluble silica removing means (soluble silica removing step) and the hardness component removing means (hardness component removing step) is as follows: first, soluble silica removing means (soluble silica removing step), and second, hardness component removing means.
  • Hardness component removal step firstly, hardness component removal means (hardness component removal step), and second, soluble silica removal means (soluble silica removal step).
  • At least one of an aqueous solution of a magnesium salt, an aqueous solution of an alkali agent, an aqueous solution of an acid, and an aqueous solution of sodium chloride is used as the attracting solution in the forward osmosis membrane processing apparatus 14 (forward osmosis membrane processing step).
  • the diluted attracting solution (at least one of a dilute aqueous solution of a magnesium salt, a dilute aqueous solution of an alkali agent, a dilute aqueous solution of an acid, and a dilute aqueous solution of sodium chloride) is used as the soluble silica removing means (pre-treatment step) of the pretreatment device 114 (pretreatment step). It may be used in a suitable one of the step of removing the silica and the means of removing the hardness component (the step of removing the hardness component).
  • the turbidity removing means includes, for example, a sand filtration device, a membrane filtration device such as an ultrafiltration (UF) membrane, and a pressure flotation device.
  • a pre-treatment device 114 pre-treatment process
  • a pre-treatment device 114 pre-treatment process
  • a reverse osmosis membrane treatment device 118 reverse osmosis membrane treatment
  • the pretreated water obtained by the solid-liquid separation is sent to the reverse osmosis membrane treatment device 118 or to the reverse osmosis membrane treatment device 118 through the turbidity removal device 116. It should be done.
  • the pretreated water obtained by the ion exchange treatment may be sent to the reverse osmosis membrane treatment device 118 or to the reverse osmosis membrane treatment device 118 through the turbidity removal device 116.
  • a sterilizing agent containing a bromine-based oxidizing agent or a chlorine-based oxidizing agent and a sulfamic acid compound in the concentrated water that is the FO treated water in the water treatment apparatuses 1, 3, and 5 shown in FIGS. )) May be present.
  • the forward osmosis membrane disinfectant is added to the FO treated water (concentrated water) in the concentrated water pipe 20 through the disinfectant addition pipe.
  • a concentrated water tank for storing FO to-be-treated water (concentrated water) is provided separately before the forward osmosis membrane treatment apparatus 14, for example, between the reverse osmosis membrane treatment apparatus 12 and the forward osmosis membrane treatment apparatus 14.
  • a bactericide for the membrane may be added.
  • Reverse osmosis membrane treatment step As a reverse osmosis membrane used in the reverse osmosis membrane treatment step, it can be suitably applied to a polyamide-based polymer membrane which is currently mainstream.
  • the polyamide-based polymer membrane has relatively low resistance to an oxidizing agent, and when free chlorine or the like is continuously brought into contact with the polyamide-based polymer membrane, the membrane performance is significantly reduced.
  • the sterilizing active ingredient hardly permeates the forward osmosis membrane by using the above-mentioned forward osmosis membrane bactericide, such a remarkable membrane performance is obtained even in the polyamide-based polymer membrane. Hardly occurs.
  • reverse osmosis membrane treatment a plurality of reverse osmosis membrane treatments may be used in series or in parallel.
  • the concentrated water obtained by the first reverse osmosis membrane treatment may be further concentrated by the second and third reverse osmosis membrane treatments, and the permeated water obtained by the first reverse osmosis membrane treatment is subjected to another reverse osmosis treatment.
  • the membrane treatment By performing the membrane treatment, the water quality can be further improved.
  • Reverse osmosis membranes used in the reverse osmosis membrane treatment process include ultra-low pressure reverse osmosis membranes and low pressure reverse osmosis membranes used for pure water production and wastewater recovery, as well as seawater desalination. Examples thereof include a medium pressure reverse osmosis membrane and a high pressure reverse osmosis membrane used. Examples of the ultra-low pressure reverse osmosis membrane and low pressure reverse osmosis membrane include ES15 (manufactured by Nitto Denko), TM720D (manufactured by Toray), BW30HRLE (manufactured by Dow Chemical), and LFC3-LD (manufactured by Hydroranatics).
  • high-pressure reverse osmosis membrane examples include SWC5-LD (manufactured by Hydroranatics), TM820V (manufactured by Toray), and XUS180808 (manufactured by Dow Chemical).
  • SWC5-LD manufactured by Hydroranatics
  • TM820V manufactured by Toray
  • XUS180808 manufactured by Dow Chemical
  • different types of membranes can be selected according to conditions such as TDS, pH, and water temperature of the water to be treated in each stage.
  • chemicals such as a pH adjuster, a scale dispersant for suppressing the scaling of inorganic salts in the system, and a bactericide for suppressing the generation of microorganisms in the system may be added.
  • the fungicide for forward osmosis membrane is a stabilized hypobromite composition or stabilized hypochlorous acid containing a mixture of "brominated oxidizing agent or chlorine oxidizing agent" and "sulfamic acid compound". It contains a composition and may further contain an alkali.
  • the fungicide for forward osmosis membrane is a stabilized hypobromite composition containing "a reaction product of a brominated oxidizing agent and a sulfamic acid compound", or a "chlorinated oxidizing agent and a sulfamic acid. It contains a stabilized hypochlorous acid composition containing a "reaction product with a compound”, and may further contain an alkali.
  • the bromine-based oxidant, bromine compound, chlorine-based oxidant, and sulfamic acid compound are as described above.
  • a commercially available stabilized hypochlorous acid composition containing a chlorine-based oxidizing agent and a sulfamic acid compound is, for example, “Krivator IK-110” manufactured by Kurita Water Industries Ltd.
  • fungicide for forward osmosis membrane in order not to further deteriorate the forward osmosis membrane, those containing bromine and a sulfamic acid compound (containing a mixture of bromine and a sulfamic acid compound), for example, A mixture of bromine and a sulfamic acid compound and an alkali and water, or a mixture containing a reaction product of a bromine and a sulfamic acid compound, for example, a reaction product of a bromine and a sulfamic acid compound, an alkali, and water Mixtures are preferred.
  • a bactericide containing a stabilized hypobromite composition containing a brominated oxidizing agent and a sulfamic acid compound, and in particular, stabilization containing bromine and a sulfamic acid compound.
  • the disinfectant containing the hypobromite composition has a higher oxidizing power and a remarkable slime suppressing power and a slime peeling power compared to a disinfectant containing a chlorine-based oxidizing agent and a sulfamic acid compound (such as chlorosulfamic acid).
  • a disinfectant containing a chlorine-based oxidizing agent and a sulfamic acid compound such as chlorosulfamic acid
  • the disinfectant for forward osmosis membrane according to the present embodiment hardly permeates through the forward osmosis membrane, and thus has little effect on the diluted attractant solution.
  • the concentration can be measured on site similarly to hypochlorous acid or the like, more accurate concentration control is possible.
  • the pH of the fungicide for forward osmosis membrane is, for example, more than 13.0, and more preferably more than 13.2.
  • the pH of the fungicide for forward osmosis membrane is 13.0 or less, the effective halogen in the fungicide for forward osmosis membrane may become unstable.
  • the bromic acid concentration in the forward osmosis membrane fungicide is preferably less than 5 mg / kg.
  • concentration of bromate in the fungicide for forward osmosis membrane is 5 mg / kg or more, the concentration of bromate ion in the dilute attracting solution may increase.
  • the germicide for a forward osmosis membrane according to this embodiment is obtained by mixing a bromine-based oxidant or a chlorine-based oxidant with a sulfamic acid compound, and may further contain an alkali.
  • bromine is added to a mixed solution containing water, alkali and a sulfamic acid compound in an inert gas atmosphere. It is preferable to include a step of adding and reacting under an inert gas atmosphere or a step of adding bromine to a mixed solution containing water, an alkali and a sulfamic acid compound under an inert gas atmosphere.
  • the bromate ion concentration in the fungicide for the forward osmosis membrane is reduced, and the bromate ion concentration in the dilute attractant solution is reduced. Becomes lower.
  • the inert gas used is not limited, but is preferably at least one of nitrogen and argon from the viewpoint of production and the like, and particularly preferably nitrogen from the viewpoint of production cost and the like.
  • the oxygen concentration in the reactor when adding bromine is preferably 6% or less, more preferably 4% or less, further preferably 2% or less, and particularly preferably 1% or less. If the oxygen concentration in the reactor during the reaction of bromine exceeds 6%, the amount of bromic acid generated in the reaction system may increase.
  • the bromine addition rate is preferably 25% by weight or less, more preferably 1% by weight or more and 20% by weight or less based on the total amount of the fungicide for forward osmosis membranes. If the bromine addition rate exceeds 25% by weight based on the total amount of the fungicide for the forward osmosis membrane, the amount of bromic acid generated in the reaction system may increase. If it is less than 1% by weight, the bactericidal activity may be poor.
  • the reaction temperature at the time of adding bromine is preferably controlled in the range of 0 ° C. or more and 25 ° C. or less, but is more preferably controlled in the range of 0 ° C. or more and 15 ° C. or less from the viewpoint of production cost and the like. If the reaction temperature at the time of adding bromine exceeds 25 ° C., the amount of bromic acid generated in the reaction system may increase, and if it is lower than 0 ° C., it may freeze.
  • Example 1 An industrial water containing 100 ppm of TDS and 15 ppm of soluble silica was subjected to a concentration treatment using the water treatment apparatus shown in FIG.
  • the TDS was concentrated to 8% by a reverse osmosis membrane treatment device.
  • This concentrated water was supplied to a forward osmosis membrane treatment device (forward osmosis membrane: HP5230 (manufactured by Toyobo)), and a 30% by weight magnesium chloride solution was further supplied as an attraction solution to obtain a FO concentrated water having a TDS of 20%.
  • the diluted magnesium chloride solution diluted by the forward osmosis membrane treatment was directly added to a soluble silica removing device.
  • the energy cost used for the forward osmosis membrane treatment was calculated. Table 1 shows the results.
  • Example 1 In the water treatment apparatus used in Example 1, a concentration operation using an evaporator was performed in place of the forward osmosis membrane treatment apparatus, and a concentrated water having a TDS of 20% was also obtained. The energy cost used for the evaporator was calculated and compared with Example 1. Table 1 shows the results.
  • Example 2 In the water treatment apparatus used in Example 1, a 30% by weight ammonium carbonate solution was used as an attraction solution for the forward osmosis membrane treatment apparatus, and a TDS 20% concentrated water was also obtained. The diluted ammonium carbonate solution diluted by the forward osmosis membrane treatment was sent to a regenerating device, and regenerated by heat (regeneration step). The energy cost used for the forward osmosis membrane treatment was calculated (including the energy used for the regeneration step). Table 1 shows the results.
  • the treatment method of Example 1 can be concentrated at a lower energy cost than the treatment methods of Comparative Examples 1 and 2, and the water to be treated containing at least one of the soluble silica and the hardness component. Can be processed at low cost.
  • Example 2 Concentration treatment was performed on industrial water containing 100 ppm of TDS and 15 ppm of soluble silica using the water treatment apparatus shown in FIG.
  • the TDS was concentrated to 8% by a reverse osmosis membrane treatment device.
  • This concentrated water was supplied to a forward osmosis membrane treatment device (forward osmosis membrane: HP5230 (manufactured by Toyobo)), and a 30% by weight magnesium chloride solution was further supplied as an attraction solution to obtain a FO concentrated water having a TDS of 20%.
  • a part of the diluted magnesium chloride solution diluted by the forward osmosis membrane treatment is directly added to a soluble silica removing device, and the rest is concentrated to 30% of magnesium chloride using a concentrating device having the configuration shown in FIG. It was reused as an attracting solution for the membrane treatment device.
  • the energy cost used for the forward osmosis membrane treatment was calculated. Table 2 shows the results.
  • Example 3 In the water treatment apparatus used in Example 2, a concentration operation using an evaporator was performed in place of the forward osmosis membrane treatment apparatus, and a concentrated water having a TDS of 20% was also obtained. The energy cost used for the evaporator was calculated and compared with Example 2. Table 2 shows the results.
  • Example 4 In the water treatment apparatus used in Example 2, a 30% by weight ammonium carbonate solution was used as an attraction solution for the forward osmosis membrane treatment apparatus, and a TDS 20% concentrated water was also obtained. The diluted ammonium carbonate solution diluted by the forward osmosis membrane treatment was sent to a regenerating device, and regenerated by heat (regeneration step). The energy cost used for the forward osmosis membrane treatment was calculated (including the energy used for the regeneration step). Table 2 shows the results.
  • the treatment method of Example 2 can be concentrated at a lower energy cost than the treatment methods of Comparative Examples 3 and 4, and the water to be treated containing at least one of the soluble silica and the hardness component. Can be processed at low cost.
  • composition 1 Preparation of stabilized hypobromite composition (composition 1)] Under a nitrogen atmosphere, liquid bromine: 16.9% by weight (wt%), sulfamic acid: 10.7% by weight, sodium hydroxide: 12.9% by weight, potassium hydroxide: 3.94% by weight, water: residual The stabilized components were mixed to prepare a stabilized hypobromite composition (composition 1). The pH of the stabilized hypobromite composition was 14, and the total chlorine concentration was 7.5% by weight. The total chlorine concentration is a value (mg / LasCl 2 ) measured by a total chlorine measurement method (DPD (diethyl-p-phenylenediamine) method) using a multi-item water quality analyzer DR / 4000 manufactured by HACH.
  • DPD diethyl-p-phenylenediamine
  • the pH of the resulting solution was 14, as measured by the glass electrode method.
  • the bromine content of the resulting solution was measured by a method of converting bromine to iodine with potassium iodide and then performing redox titration with sodium thiosulfate, and found to be 16.9%. The theoretical content was 16.9% ) Was 100.0%.
  • the oxygen concentration in the reaction vessel during the bromine reaction was measured using “Oxygen Monitor JKO-02 @ LJDII” manufactured by Jiko Corporation. The bromate concentration was less than 5 mg / kg.
  • Electrode type Glass electrode type pH meter: Toa DKK, IOL-30 type
  • Calibration of electrode Neutral phosphate pH (6.86) standard solution (2nd class), Kanto Chemical Co., boric acid Performed by two-point calibration of salt pH (9.18) standard solution (second type)
  • Measured value The electrode was immersed in the test solution, and the value after stabilization was taken as the measured value, the average of three measurements
  • composition 2 A 12% aqueous sodium hypochlorite solution: 50% by weight, sulfamic acid: 12% by weight, sodium hydroxide: 8% by weight, water: the residue is mixed, and the stabilized hypochlorous acid composition (Composition 2) was prepared. Composition 2 had a pH of 13.7 and a total chlorine concentration of 6.2% by weight.
  • Example 3 Industrial effluent concentrated to a total evaporation residue (TDS) of 8% by weight was used as the FO water to be treated, and the attracting solution was a 30% by weight aqueous MgCl 2 solution, and a forward osmosis membrane treatment was performed. The flow rate of the attracting solution was adjusted so that the flow rate at the outlet of the FO concentrated water was 50% of the inlet of the FO treated water (concentration ratio was 2 times).
  • the forward osmosis membrane an FO membrane made of cellulose acetate (HPC3205, manufactured by Toyobo) was used.
  • composition 1 a stabilized hypobromite composition
  • composition 2 chlorosulfamic acid
  • a forward osmosis membrane treatment was performed in the same manner as in Example 3 except that the total chlorine concentration was 1 ppmCl at the inlet of the water to be treated. Table 3 shows the results.
  • composition 1 As a fungicide for a forward osmosis membrane, 5-chloro-2-methyl-4-isothiazoline-3- as an organic fungicide is used in the FO treated water.
  • a forward osmosis membrane treatment was carried out in the same manner as in Example 3, except that ON was added at the inlet of the FO treated water at a TOC of 10 ppm. Table 3 shows the results.
  • Example 3 it was possible to suppress an increase in the differential pressure of water passing through the forward osmosis membrane. Fungicides were also blocked by more than 99%.
  • Example 4 has the same tendency, but the pressure difference in water flow slightly increased.
  • the water pressure difference was> 0.2 MPa, which exceeded the allowable water pressure difference (0.2 MPa) of the membrane.
  • the fungicide rejection was also 85% or less, and leakage of the fungicidal active ingredient into the diluted attractant solution was confirmed.
  • a stabilized hypobromous acid composition or a stabilized hypochlorous acid composition as a disinfectant, the disinfectant is prevented from passing through the forward osmosis membrane, and the diluted attractant solution is reused. was found to be possible.

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Abstract

Provided are a water treatment device and a water treatment method, whereby it is possible to treat water of interest which contains at least one of soluble silica and a hard component at low cost. A water treatment device 1 for treating water of interest which contains at least one of soluble silica and a hard component, the water treatment device 1 being provided with a pretreatment device 10 which is equipped with one of a soluble silica removal means and a hard component removal means, a reverse osmosis membrane treatment device 12 which serves as a condensation treatment means for performing the condensation treatment of pretreated water obtained in the pretreatment device 10, and a forward osmosis membrane treatment device 14 for performing the forward osmosis membrane treatment of condensed water obtained in the reverse osmosis membrane treatment device 12, wherein a dilution draw solution that is used in the forward osmosis membrane treatment device 14 is also used in the pretreatment device 10.

Description

水処理装置、水処理方法、正浸透膜処理方法、正浸透膜処理システムおよび水処理システムWater treatment device, water treatment method, forward osmosis membrane treatment method, forward osmosis membrane treatment system, and water treatment system
　本発明は、溶解性シリカおよび硬度成分のうち少なくとも１つを含む被処理水の処理を行う水処理装置および水処理方法に関する。また、本発明は、正浸透膜処理方法、正浸透膜処理システム、および、その正浸透膜処理方法、正浸透膜処理システムを用いる水処理方法、水処理システムに関する。 The present invention relates to a water treatment apparatus and a water treatment method for treating water to be treated containing at least one of soluble silica and a hardness component. The present invention also relates to a forward osmosis membrane treatment method, a forward osmosis membrane treatment system, a forward osmosis membrane treatment method, a water treatment method using the forward osmosis membrane treatment system, and a water treatment system.
　排水の放流が環境に与える影響を低減するため、排水の浄化や減容化等の処理を行ってから、放流、廃棄する動きが進んでいる。排水処理には固液分離、膜分離、減圧濃縮等が用いられるが、排水に含まれる溶解性シリカや、カルシウム等の硬度成分が不溶化して、排水処理に用いる配管や装置に付着する、いわゆるスケーリングが起こることで、システムの性能が低下することが知られている。効率的な排水処理を行うため、排水中の溶解性シリカや硬度成分を除去する必要がある。 In order to reduce the impact of the discharge of wastewater on the environment, wastewater is being purified and reduced in volume before being discharged and disposed of. For wastewater treatment, solid-liquid separation, membrane separation, concentration under reduced pressure, and the like are used. Soluble silica and hard components such as calcium contained in wastewater are insolubilized and adhere to pipes and devices used for wastewater treatment, so-called wastewater treatment. It is known that the performance of the system is reduced when scaling occurs. In order to perform efficient wastewater treatment, it is necessary to remove soluble silica and hardness components in wastewater.
　例えば特許文献１には、溶解性シリカ含有排水について、アルカリ条件下でマグネシウム塩を添加して溶解性シリカを不溶化したのちに固液分離し、得られた処理水を逆浸透膜処理または正浸透膜処理して、排水から淡水を回収する方法が記載されている。 For example, Patent Literature 1 discloses that a soluble silica-containing wastewater is subjected to solid-liquid separation after insolubilizing soluble silica by adding a magnesium salt under alkaline conditions, and treating the resulting treated water with reverse osmosis membrane treatment or forward osmosis. A method for recovering fresh water from wastewater by membrane treatment is described.
　正浸透膜処理では、正浸透膜を介して、供給水と誘引溶液を存在させることにより、加圧せずとも浸透圧で水を誘引溶液に移動させることができる。さらに希釈された誘引溶液を、例えば加温等の手段により相変化させることで、淡水と得つつ、誘引溶液を再利用することができる。 In forward osmosis membrane treatment, water can be transferred to the attractant solution by osmotic pressure without pressurization by providing feed water and the attractant solution through the forward osmosis membrane. Further, by changing the phase of the diluted attracting solution by, for example, heating or the like, the attracting solution can be reused while obtaining fresh water.
　正浸透膜処理の誘引溶液として、炭酸アンモニウム水溶液や、無機塩と温度感応性薬剤の混合物が用いられる（特許文献２参照）。 (4) An aqueous solution of ammonium carbonate or a mixture of an inorganic salt and a temperature-sensitive drug is used as an inducing solution for forward osmosis membrane treatment (see Patent Document 2).
　誘引溶液を再利用するためには加温等の外的エネルギーを加える必要があり、誘引溶液の再利用のための装置を追加で備える必要があるため（図１０参照）、トータルとしてシステムのコスト増大につながる。 In order to reuse the attracting solution, it is necessary to add external energy such as heating, and it is necessary to additionally provide a device for reusing the attracting solution (see FIG. 10). Leads to an increase.
　硬度成分の除去方法として、特許文献３には、硬度成分含有排水にアルカリ剤を添加して析出させ（いわゆる石灰軟化法）、凝集、ろ過処理の後にろ過水を逆浸透膜処理する方法が記載されている。また、特許文献４には、イオン交換樹脂を用いて硬度成分を吸着除去する方法（樹脂軟化法）が記載されている。 As a method for removing the hardness component, Patent Literature 3 describes a method in which an alkali agent is added to wastewater containing a hardness component to cause precipitation (so-called lime softening method), and after the coagulation and filtration treatments, the filtered water is treated with a reverse osmosis membrane. Have been. Patent Document 4 discloses a method of adsorbing and removing a hardness component using an ion exchange resin (resin softening method).
　しかし、石灰軟化法ではアルカリ剤の添加が必要であり、樹脂軟化法では、硬度成分が吸着したイオン交換樹脂を再生するため、高濃度塩水（塩化ナトリウム水溶液）を通水する必要があり、薬品コストの低減が求められている。 However, the lime softening method requires the addition of an alkaline agent, and the resin softening method requires the passage of high-concentration saline (aqueous sodium chloride) to regenerate the ion-exchange resin to which the hardness component has been adsorbed. Cost reduction is required.
　一方、被処理水と被処理水よりも高濃度の誘引溶液とを正浸透膜を介して接触させることによって濃縮水と希薄誘引溶液とを得る正浸透（ＦＯ）膜処理システムにおいて、膜のファウリングの制御が重要な課題である。正浸透膜処理システムの殺菌方法として、次亜塩素酸やクロラミン等の塩素系殺菌剤や、過酸化水素等の酸化剤、または５－クロロ－２－メチル－４－イソチアゾリン－３－オン等の有機系殺菌剤が用いられている（例えば、特許文献５，６参照）。 On the other hand, in a forward osmosis (FO) membrane treatment system in which concentrated water and a dilute attractant solution are obtained by bringing the water to be treated into contact with an attraction solution having a higher concentration than the to-be-treated water via a forward osmosis membrane, the membrane fouling occurs. Controlling the ring is an important issue. As a method for disinfecting a forward osmosis membrane treatment system, a chlorinated disinfectant such as hypochlorous acid or chloramine, an oxidizing agent such as hydrogen peroxide, or 5-chloro-2-methyl-4-isothiazolin-3-one or the like can be used. Organic fungicides are used (for example, see Patent Documents 5 and 6).
　しかし、これらの殺菌剤（塩素系殺菌剤、酸化剤、有機系殺菌剤）は正浸透膜を透過してしまうため、殺菌剤の殺菌有効成分が正浸透膜処理装置の出口側まで十分に行きわたらず、正浸透膜を十分に殺菌することができないという問題が生じる。また、特に有機系殺菌剤は生体、環境等に対して影響を与える場合がある。特に加熱等の処理によって希薄誘引溶液中から生産水を分離して利用する場合、生産水中に有機系殺菌剤が含まれていると、工業用途、食品用途、飲的用途等への用途適応が著しく制限される。また、正浸透膜を透過した殺菌剤を含む希薄誘引溶液の一部または全部を系外に排出するためには、それらを除去する必要がある。さらに、塩素系殺菌剤や酸化剤は、逆浸透膜、特にポリアミド系逆浸透膜の性能を低下させることがあるため、希薄誘引溶液の一部または全部を逆浸透膜で再処理する場合、これら殺菌剤が逆浸透膜の性能を低下させる懸念がある。 However, since these disinfectants (chlorine disinfectants, oxidizing agents, and organic disinfectants) permeate the forward osmosis membrane, the disinfectant active components of the disinfectant sufficiently pass to the exit side of the forward osmosis membrane treatment device. This causes a problem that the forward osmosis membrane cannot be sufficiently sterilized. In particular, organic germicides may have an effect on living bodies, the environment, and the like. In particular, when the production water is separated and used from the diluted attracting solution by a treatment such as heating, if the production water contains an organic bactericide, the application adaptation to industrial use, food use, drinking use, etc. Limited significantly. In addition, in order to discharge a part or all of the diluted attracting solution containing the bactericide that has passed through the forward osmosis membrane, it is necessary to remove them. Furthermore, chlorine-based disinfectants and oxidizing agents may reduce the performance of reverse osmosis membranes, especially polyamide-based reverse osmosis membranes. There is a concern that disinfectants may reduce the performance of reverse osmosis membranes.
国際特許出願公開第２０１３／１５３５８７号パンフレットInternational Patent Application Publication No. 2013/153587 pamphlet 特開２０１７－０５６４２４号公報JP 2017-056424 A 特開２０１７－１７０２７５号公報JP-A-2017-170275 特開２０１４－２３１０３９号公報JP 2014-231039 A 特開２０１５－１８８７８７号公報JP-A-2015-188787 特開２０１８－０１５６８４号公報JP, 2018-015684, A
　本発明の目的は、溶解性シリカおよび硬度成分のうち少なくとも１つを含む被処理水を低コストで処理することができる水処理装置および水処理方法を提供することにある。 目的 An object of the present invention is to provide a water treatment apparatus and a water treatment method capable of treating water to be treated containing at least one of soluble silica and a hard component at low cost.
　また、本発明の目的は、殺菌剤が正浸透膜を透過するのを抑制し、希薄誘引溶液の再利用が可能となる正浸透膜処理方法、正浸透膜処理システム、および、その正浸透膜処理方法、正浸透膜処理システムを用いる水処理方法、水処理システムを提供することにある。 Another object of the present invention is to provide a method for treating a forward osmosis membrane, a forward osmosis membrane treatment system, and a forward osmosis membrane, in which a disinfectant is prevented from permeating through the forward osmosis membrane, and the diluted attractant solution can be reused. It is an object of the present invention to provide a treatment method, a water treatment method using a forward osmosis membrane treatment system, and a water treatment system.
　本発明は、溶解性シリカおよび硬度成分のうち少なくとも１つを含む被処理水の処理を行う水処理装置であって、溶解性シリカ除去手段および硬度成分除去手段のうちいずれか１つを備える前処理手段と、前記前処理手段で得られた前処理水を濃縮処理する濃縮処理手段と、前記濃縮処理手段で得られた濃縮水を正浸透膜処理する正浸透膜処理手段と、を備え、前記正浸透膜処理手段で使用された希薄誘引溶液が前記前処理手段で使用される、水処理装置である。 The present invention relates to a water treatment apparatus for treating water to be treated containing at least one of a soluble silica and a hardness component, wherein the water treatment device is provided with any one of a soluble silica removal unit and a hardness component removal unit. Treatment means, a concentration treatment means for concentration treatment of the pretreated water obtained by the pretreatment means, and a forward osmosis membrane treatment means for forward osmosis membrane treatment of the concentrated water obtained by the concentration treatment means, A water treatment apparatus, wherein the diluted attracting solution used in the forward osmosis membrane treatment means is used in the pretreatment means.
　前記水処理装置において、前記濃縮処理手段は、逆浸透膜処理手段であることが好ましい。 に お い て In the water treatment apparatus, the concentration treatment means is preferably a reverse osmosis membrane treatment means.
　本発明は、溶解性シリカおよび硬度成分のうち少なくとも１つを含む被処理水の処理を行う水処理装置であって、溶解性シリカ除去手段および硬度成分除去手段のうちいずれか１つを備える前処理手段と、前記前処理手段で得られた前処理水を濃縮処理する第１濃縮処理手段と、前記第１濃縮処理手段で得られた濃縮水を正浸透膜処理する正浸透膜処理手段と、前記正浸透膜処理手段で使用された希薄誘引溶液の一部を濃縮処理する第２濃縮処理手段と、を備え、前記正浸透膜処理手段で使用された希薄誘引溶液の一部が前記前処理手段で使用され、前記第２濃縮処理手段で濃縮された濃縮誘引溶液が前記正浸透膜処理手段における誘引溶液として再度使用される、水処理装置である。 The present invention relates to a water treatment apparatus for treating water to be treated containing at least one of a soluble silica and a hardness component, wherein the water treatment device is provided with any one of a soluble silica removal unit and a hardness component removal unit. Treatment means, first concentration treatment means for concentrating the pretreated water obtained by the pretreatment means, and forward osmosis membrane treatment means for treating the concentrated water obtained by the first concentration treatment means with a forward osmosis membrane. Second concentration processing means for concentrating a part of the diluted attracting solution used in the forward osmosis membrane processing means, wherein a part of the diluted attracting solution used in the forward osmosis membrane processing means is A water treatment apparatus, wherein the concentrated attraction solution used in the treatment means and concentrated by the second concentration treatment means is reused as the attraction solution in the forward osmosis membrane treatment means.
　前記水処理装置において、前記第２濃縮処理手段は、半透膜を用いる濃縮手段であることが好ましい。 に お い て In the water treatment apparatus, it is preferable that the second concentration treatment means is a concentration means using a semipermeable membrane.
　前記水処理装置において、前記第１濃縮処理手段は、逆浸透膜処理手段であることが好ましい。 に お い て In the water treatment apparatus, the first concentration treatment means is preferably a reverse osmosis membrane treatment means.
　前記水処理装置において、前記正浸透膜処理手段で用いる誘引溶液がマグネシウム塩水溶液であり、前記正浸透膜処理手段で使用されたマグネシウム塩希薄水溶液が、前記溶解性シリカ除去手段で使用されることが好ましい。 In the water treatment apparatus, the attracting solution used in the forward osmosis membrane treatment means is a magnesium salt aqueous solution, and the magnesium salt dilute aqueous solution used in the forward osmosis membrane treatment means is used in the soluble silica removing means. Is preferred.
　前記水処理装置において、水酸化マグネシウムと酸とを混合し、ｐＨ７以下で反応させて、前記正浸透膜処理手段で用いる誘引溶液として使用するマグネシウム塩水溶液を調製する調製手段をさらに備えることが好ましい。 In the water treatment apparatus, it is preferable that the water treatment apparatus further includes a preparation means for mixing magnesium hydroxide and an acid and reacting the mixture at a pH of 7 or less to prepare a magnesium salt aqueous solution to be used as an attraction solution used in the forward osmosis membrane treatment means. .
　前記水処理装置において、前記正浸透膜処理手段で用いる誘引溶液がアルカリ剤水溶液であり、前記正浸透膜処理手段で使用されたアルカリ剤希薄水溶液が、前記硬度成分除去手段で使用されることが好ましい。 In the water treatment apparatus, the attracting solution used in the forward osmosis membrane processing means may be an aqueous solution of an alkali agent, and the dilute aqueous solution of the alkali agent used in the forward osmosis membrane processing means may be used in the hardness component removing means. preferable.
　前記水処理装置において、前記正浸透膜処理手段で用いる誘引溶液が酸水溶液または塩化ナトリウム水溶液であり、前記正浸透膜処理手段で使用された酸希薄水溶液または塩化ナトリウム希薄水溶液が、前記硬度成分除去手段で使用されることが好ましい。 In the water treatment apparatus, the attracting solution used in the forward osmosis membrane treatment means is an aqueous acid solution or an aqueous sodium chloride solution, and the acid dilute aqueous solution or the sodium chloride dilute aqueous solution used in the forward osmosis membrane treatment means removes the hardness component. Preferably it is used by means.
　また、本発明は、溶解性シリカおよび硬度成分のうち少なくとも１つを含む被処理水の処理を行う水処理方法であって、溶解性シリカ除去工程および硬度成分除去工程のうちいずれか１つを含む前処理工程と、前記前処理工程で得られた前処理水を濃縮処理する濃縮処理工程と、前記濃縮処理工程で得られた濃縮水を正浸透膜処理する正浸透膜処理工程と、を含み、前記正浸透膜処理工程で使用した希薄誘引溶液を前記前処理工程で使用する、水処理方法である。 Further, the present invention is a water treatment method for treating water to be treated containing at least one of a soluble silica and a hardness component, wherein one of the soluble silica removal process and the hardness component removal process is performed. A pretreatment step including: a concentration treatment step of concentrating the pretreated water obtained in the pretreatment step; and a forward osmosis membrane treatment step of treating the concentrated water obtained in the concentration treatment step with a forward osmosis membrane. A water treatment method, wherein the diluted attracting solution used in the forward osmosis membrane treatment step is used in the pretreatment step.
　前記水処理方法において、前記濃縮処理工程は、逆浸透膜処理工程であることが好ましい。 に お い て In the water treatment method, the concentration treatment step is preferably a reverse osmosis membrane treatment step.
　また、本発明は、溶解性シリカおよび硬度成分のうち少なくとも１つを含む被処理水の処理を行う水処理方法であって、溶解性シリカ除去工程および硬度成分除去工程のうちいずれか１つを含む前処理工程と、前記前処理工程で得られた前処理水を濃縮処理する第１濃縮処理工程と、前記第１濃縮処理工程で得られた濃縮水を正浸透膜処理する正浸透膜処理工程と、前記正浸透膜処理工程で使用された希薄誘引溶液の一部を濃縮処理する第２濃縮処理工程と、を含み、前記正浸透膜処理工程で使用した希薄誘引溶液の一部を前記前処理工程で使用し、前記第２濃縮処理工程で濃縮した濃縮誘引溶液を前記正浸透膜処理工程における誘引溶液として再度使用する、水処理方法である。 Further, the present invention is a water treatment method for treating water to be treated containing at least one of a soluble silica and a hardness component, wherein one of the soluble silica removal process and the hardness component removal process is performed. A pre-treatment step including a pre-treatment step, a first concentration treatment step for concentrating the pre-treated water obtained in the pre-treatment step, and a forward osmosis membrane treatment for treating the concentrated water obtained in the first concentration treatment step with a forward osmosis membrane And a second concentration treatment step of concentrating a part of the diluted attracting solution used in the forward osmosis membrane treatment step, and a part of the diluted attractant solution used in the forward osmosis membrane treatment step This is a water treatment method in which the concentrated attraction solution used in the pretreatment step and concentrated in the second concentration treatment step is reused as the attraction solution in the forward osmosis membrane treatment step.
　前記水処理方法において、前記第２濃縮処理工程は、半透膜を用いる濃縮工程であることが好ましい。 に お い て In the water treatment method, the second concentration treatment step is preferably a concentration step using a semipermeable membrane.
　前記水処理方法において、前記第１濃縮処理工程は、逆浸透膜処理工程であることが好ましい。 に お い て In the water treatment method, the first concentration treatment step is preferably a reverse osmosis membrane treatment step.
　前記水処理方法において、前記正浸透膜処理工程で用いる誘引溶液がマグネシウム塩水溶液であり、前記正浸透膜処理工程で使用したマグネシウム塩希薄水溶液を、前記溶解性シリカ除去工程で使用することが好ましい。 In the water treatment method, the attracting solution used in the forward osmosis membrane treatment step is a magnesium salt aqueous solution, and the magnesium salt dilute aqueous solution used in the forward osmosis membrane treatment step is preferably used in the soluble silica removal step. .
　前記水処理方法において、水酸化マグネシウムと酸とを混合し、ｐＨ７以下で反応させて、前記正浸透膜処理工程で用いる誘引溶液として使用するマグネシウム塩水溶液を調製する調製工程をさらに含むことが好ましい。 The water treatment method preferably further includes a preparation step of mixing magnesium hydroxide and an acid and reacting the mixture at a pH of 7 or less to prepare a magnesium salt aqueous solution to be used as an attraction solution used in the forward osmosis membrane treatment step. .
　前記水処理方法において、前記正浸透膜処理工程で用いる誘引溶液がアルカリ剤水溶液であり、前記正浸透膜処理工程で使用したアルカリ剤希薄水溶液を、前記硬度成分除去工程で使用することが好ましい。 In the water treatment method, it is preferable that the attracting solution used in the forward osmosis membrane treatment step is an aqueous solution of an alkali agent, and the dilute aqueous solution of the alkali agent used in the forward osmosis membrane treatment step is used in the hardness component removing step.
　前記水処理方法において、前記正浸透膜処理工程で用いる誘引溶液が酸水溶液または塩化ナトリウム水溶液であり、前記正浸透膜処理工程で使用した酸希薄水溶液または塩化ナトリウム希薄水溶液を、前記硬度成分除去工程で使用することが好ましい。 In the water treatment method, the attracting solution used in the forward osmosis membrane treatment step is an acid aqueous solution or a sodium chloride aqueous solution, and the acid dilute aqueous solution or sodium chloride dilute aqueous solution used in the forward osmosis membrane treatment step is subjected to the hardness component removal step. It is preferable to use them.
　本発明は、被処理水と、前記被処理水よりも高濃度の誘引溶液とを、正浸透膜を介して接触させることによって、濃縮水と希薄誘引溶液とを得る正浸透膜処理工程を含み、前記被処理水中に、臭素系酸化剤または塩素系酸化剤とスルファミン酸化合物とを含む殺菌剤を存在させる、正浸透膜処理方法である。 The present invention includes a forward osmosis membrane treatment step of obtaining concentrated water and a dilute attractant by contacting the water to be treated and an attraction solution having a higher concentration than the water to be treated through a forward osmosis membrane. A forward osmosis membrane treatment method, wherein a disinfectant containing a bromine-based oxidant or a chlorine-based oxidant and a sulfamic acid compound is present in the water to be treated.
　本発明は、被処理水と、前記被処理水よりも高濃度の誘引溶液とを、正浸透膜を介して接触させることによって、濃縮水と希薄誘引溶液とを得る正浸透膜処理工程を含み、前記被処理水中に、臭素系酸化剤とスルファミン酸化合物とを含む殺菌剤を存在させる、正浸透膜処理方法である。 The present invention includes a forward osmosis membrane treatment step of obtaining concentrated water and a dilute attractant by contacting the water to be treated and an attraction solution having a higher concentration than the water to be treated through a forward osmosis membrane. A method of treating a forward osmosis membrane, wherein a disinfectant containing a bromine-based oxidizing agent and a sulfamic acid compound is present in the water to be treated.
　本発明は、被処理水と、前記被処理水よりも高濃度の誘引溶液とを、正浸透膜を介して接触させることによって、濃縮水と希薄誘引溶液とを得る正浸透膜処理工程を含み、前記被処理水中に、臭素とスルファミン酸化合物とを含む殺菌剤を存在させる、正浸透膜処理方法である。 The present invention includes a forward osmosis membrane treatment step of obtaining concentrated water and a dilute attractant by contacting the water to be treated and an attraction solution having a higher concentration than the water to be treated through a forward osmosis membrane. And a method for treating a forward osmosis membrane, wherein a disinfectant containing bromine and a sulfamic acid compound is present in the water to be treated.
　本発明は、前記正浸透膜処理方法を含み、前記正浸透膜処理工程の前段に、前処理工程および逆浸透膜処理工程を含み、前記正浸透膜処理工程により得られた希薄誘引溶液を、前記前処理工程で使用する、水処理方法である。 The present invention includes the forward osmosis membrane treatment method, and comprises a pretreatment step and a reverse osmosis membrane treatment step before the forward osmosis membrane treatment step, wherein the diluted attracting solution obtained by the forward osmosis membrane treatment step is: This is a water treatment method used in the pretreatment step.
　本発明は、被処理水と、前記被処理水よりも高濃度の誘引溶液とを、正浸透膜を介して接触させることによって、濃縮水と希薄誘引溶液とを得る正浸透膜処理手段を備え、前記被処理水中に、臭素系酸化剤または塩素系酸化剤とスルファミン酸化合物とを含む殺菌剤を存在させる、正浸透膜処理システムである。 The present invention comprises a forward osmosis membrane treatment means for obtaining concentrated water and a dilute attractant by contacting the water to be treated and an attraction solution having a higher concentration than the water to be treated through a forward osmosis membrane. A forward osmosis membrane treatment system, wherein a germicide containing a bromine-based oxidant or a chlorine-based oxidant and a sulfamic acid compound is present in the water to be treated.
　本発明は、被処理水と、前記被処理水よりも高濃度の誘引溶液とを、正浸透膜を介して接触させることによって、濃縮水と希薄誘引溶液とを得る正浸透膜処理手段を備え、前記被処理水中に、臭素系酸化剤とスルファミン酸化合物とを含む殺菌剤を存在させる、正浸透膜処理システムである。 The present invention comprises a forward osmosis membrane treatment means for obtaining concentrated water and a dilute attractant by contacting the water to be treated and an attraction solution having a higher concentration than the water to be treated through a forward osmosis membrane. A forward osmosis membrane treatment system, wherein a disinfectant containing a bromine-based oxidizing agent and a sulfamic acid compound is present in the water to be treated.
　本発明は、被処理水と、前記被処理水よりも高濃度の誘引溶液とを、正浸透膜を介して接触させることによって、濃縮水と希薄誘引溶液とを得る正浸透膜処理手段を備え、前記被処理水中に、臭素とスルファミン酸化合物とを含む殺菌剤を存在させる、正浸透膜処理システムである。 The present invention comprises a forward osmosis membrane treatment means for obtaining concentrated water and a dilute attractant by contacting the water to be treated and an attraction solution having a higher concentration than the water to be treated through a forward osmosis membrane. A forward osmosis membrane treatment system, wherein a disinfectant containing bromine and a sulfamic acid compound is present in the water to be treated.
　本発明は、前記正浸透膜処理システムを備え、前記正浸透膜処理手段の前段に、前処理手段および逆浸透膜処理手段を備え、前記正浸透膜処理手段により得られた希薄誘引溶液が、前記前処理手段で使用される、水処理システムである。 The present invention comprises the forward osmosis membrane treatment system, and comprises a pretreatment means and a reverse osmosis membrane treatment means at a preceding stage of the forward osmosis membrane treatment means, wherein the diluted attracting solution obtained by the forward osmosis membrane treatment means is: It is a water treatment system used in the pretreatment means.
　本発明により、溶解性シリカおよび硬度成分のうち少なくとも１つを含む被処理水を低コストで処理することができる。 According to the present invention, water to be treated containing at least one of soluble silica and a hardness component can be treated at low cost.
　また、本発明により、殺菌剤が正浸透膜を透過するのを抑制し、希薄誘引溶液の再利用が可能となる正浸透膜処理方法、正浸透膜処理システム、および、その正浸透膜処理方法、正浸透膜処理システムを用いる水処理方法、水処理システムを提供することができる。 Further, according to the present invention, a forward osmosis membrane treatment method, a forward osmosis membrane treatment system, and a forward osmosis membrane treatment method that suppress the permeation of a germicide through a forward osmosis membrane and enable the reuse of a dilute attractant solution A water treatment method and a water treatment system using a forward osmosis membrane treatment system can be provided.
本発明の実施形態に係る水処理装置の一例を示す概略構成図である。It is a schematic structure figure showing an example of a water treatment device concerning an embodiment of the present invention. 本発明の実施形態に係る水処理装置の他の例を示す概略構成図である。It is a schematic structure figure showing other examples of a water treatment device concerning an embodiment of the present invention. 本発明の実施形態に係る水処理装置の他の例を示す概略構成図である。It is a schematic structure figure showing other examples of a water treatment device concerning an embodiment of the present invention. 本発明の実施形態に係る水処理装置における濃縮装置の一例を示す概略構成図である。It is a schematic structure figure showing an example of the concentration device in the water treatment equipment concerning the embodiment of the present invention. 本発明の実施形態に係る水処理装置における濃縮装置の他の例を示す概略構成図である。It is a schematic structure figure showing other examples of a concentration device in a water treatment device concerning an embodiment of the present invention. 本発明の実施形態に係る水処理装置における濃縮装置の他の例を示す概略構成図である。It is a schematic structure figure showing other examples of a concentration device in a water treatment device concerning an embodiment of the present invention. 本発明の実施形態に係る水処理装置における濃縮装置の他の例を示す概略構成図である。It is a schematic structure figure showing other examples of a concentration device in a water treatment device concerning an embodiment of the present invention. 本発明の実施形態に係る水処理装置における濃縮装置の他の例を示す概略構成図である。It is a schematic structure figure showing other examples of a concentration device in a water treatment device concerning an embodiment of the present invention. 本発明の実施形態に係る水処理装置における濃縮装置の他の例を示す概略構成図である。It is a schematic structure figure showing other examples of a concentration device in a water treatment device concerning an embodiment of the present invention. 従来の水処理装置を示す概略構成図である。It is a schematic structure figure showing the conventional water treatment equipment. 本発明の実施形態に係る正浸透膜処理システムの一例を示す概略構成図である。It is a schematic structure figure showing an example of a forward osmosis membrane processing system concerning an embodiment of the present invention. 本発明の実施形態に係る水処理システムの一例を示す概略構成図である。It is a schematic structure figure showing an example of the water treatment system concerning the embodiment of the present invention.
　本発明の実施の形態について以下説明する。本実施形態は本発明を実施する一例であって、本発明は本実施形態に限定されるものではない。 (4) An embodiment of the present invention will be described below. The present embodiment is an example for implementing the present invention, and the present invention is not limited to the present embodiment.
　本発明の実施形態に係る水処理装置の一例の概略を図１に示し、その構成について説明する。 概略 An outline of an example of a water treatment apparatus according to an embodiment of the present invention is shown in FIG. 1 and its configuration will be described.
　水処理装置１は、溶解性シリカ除去手段および硬度成分除去手段のうち少なくとも１つを備える前処理手段としての前処理装置１０と、前処理装置１０で得られた前処理水を濃縮処理する濃縮処理手段としての逆浸透膜処理装置１２と、逆浸透膜処理装置１２で得られた濃縮水を正浸透膜処理する正浸透膜処理手段としての正浸透膜処理装置１４とを備える。 The water treatment device 1 includes a pretreatment device 10 as a pretreatment device having at least one of a soluble silica removal device and a hardness component removal device, and a concentration device that concentrates pretreatment water obtained by the pretreatment device 10. The apparatus includes a reverse osmosis membrane treatment device 12 as a treatment means and a forward osmosis membrane treatment device 14 as a forward osmosis membrane treatment means for treating the concentrated water obtained by the reverse osmosis membrane treatment device 12 with a forward osmosis membrane.
　図１の水処理装置１において、被処理水配管１６が前処理装置１０の被処理水入口に接続され、前処理装置１０の出口と逆浸透膜処理装置１２の入口とは、前処理水配管１８により接続されている。逆浸透膜処理装置１２の濃縮水出口と正浸透膜処理装置１４の濃縮水入口とは、濃縮水配管２０により接続され、逆浸透膜処理装置１２の透過水出口には、透過水配管２２が接続されている。正浸透膜処理装置１４の誘引溶液入口には、誘引溶液配管２４が接続され、正浸透膜処理装置１４の希薄誘引溶液出口と、前処理装置１０の希薄誘引溶液入口とは、希薄誘引溶液配管２６により接続され、正浸透膜処理装置１４のＦＯ濃縮水出口には、ＦＯ濃縮水配管２８が接続されている。 In the water treatment apparatus 1 of FIG. 1, the treated water pipe 16 is connected to the treated water inlet of the pretreatment apparatus 10, and the outlet of the pretreatment apparatus 10 and the entrance of the reverse osmosis membrane treatment apparatus 12 are connected to the pretreated water pipe. 18. A concentrated water outlet of the reverse osmosis membrane treatment device 12 and a concentrated water inlet of the forward osmosis membrane treatment device 14 are connected by a concentrated water piping 20, and a permeated water piping 22 is connected to a permeated water outlet of the reverse osmosis membrane treatment device 12. It is connected. The attracting solution inlet 24 of the forward osmosis membrane processing device 14 is connected to an attracting solution pipe 24, and the diluted attracting solution outlet of the forward osmosis membrane processing device 14 and the diluted attracting solution inlet of the pretreatment device 10 are connected to the diluted attracting solution pipe. 26, a FO concentrated water pipe 28 is connected to an FO concentrated water outlet of the forward osmosis membrane treatment device 14.
　本実施形態に係る水処理方法および水処理装置１の動作について説明する。 動作 The operation of the water treatment method and the water treatment device 1 according to the present embodiment will be described.
　溶解性シリカおよび硬度成分のうち少なくとも１つを含む被処理水は、被処理水配管１６を通して前処理装置１０へ送液される。前処理装置１０において、溶解性シリカおよび硬度成分のうち少なくとも１つの除去処理が行われる（前処理工程）。 被 Water to be treated containing at least one of the soluble silica and the hardness component is sent to the pretreatment device 10 through the treated water pipe 16. In the pretreatment device 10, at least one of the soluble silica and the hardness component is removed (pretreatment step).
　被処理水が溶解性シリカを含む場合、前処理装置１０は、例えば、被処理水にマグネシウム塩を添加して反応させ、溶解性シリカを不溶化させるマグネシウム反応手段と、反応後の被処理水に凝集剤を添加して、凝集させる凝集処理手段と、凝集処理させた被処理水から凝集物を分離する固液分離手段と、を有する。前処理装置１０において、例えばアルカリ条件（例えば、ｐＨ１０～１２）下で被処理水にマグネシウム塩が添加され、溶解性シリカが不溶化される（マグネシウム反応工程）。その後、必要に応じて凝集剤が添加されて、凝集処理され（凝集処理工程）、凝集物が固液分離される（固液分離工程）。固液分離で得られた前処理水は、前処理水配管１８を通して、逆浸透膜処理装置１２へ送液される。 In the case where the water to be treated contains soluble silica, the pretreatment device 10 may, for example, add a magnesium salt to the water to be treated to cause a reaction, and a magnesium reaction means for insolubilizing the soluble silica and a water to be treated after the reaction. There is provided an aggregating means for adding an aggregating agent to perform aggregation, and a solid-liquid separating means for separating agglomerates from the treated water subjected to the aggregating treatment. In the pretreatment device 10, for example, a magnesium salt is added to the water to be treated under alkaline conditions (eg, pH 10 to 12) to insolubilize the soluble silica (magnesium reaction step). Thereafter, an aggregating agent is added, if necessary, to perform an agglomeration treatment (aggregation treatment step), and the aggregates are subjected to solid-liquid separation (solid-liquid separation step). The pretreatment water obtained by the solid-liquid separation is sent to the reverse osmosis membrane treatment device 12 through the pretreatment water pipe 18.
　被処理水が硬度成分を含み、石灰軟化法により硬度成分の除去が行われる場合、前処理装置１０は、例えば、被処理水にアルカリ剤を添加して反応させ、硬度成分を不溶化させるアルカリ剤反応手段と、反応後の被処理水に必要に応じて凝集剤を添加して、凝集させる凝集処理手段と、凝集処理させた被処理水から凝集物を分離する固液分離手段と、を有する。前処理装置１０において、例えば被処理水にアルカリ剤が添加され、硬度成分が不溶化される（アルカリ剤反応工程）。その後、凝集剤が添加されて、凝集処理され（凝集処理工程）、凝集物が固液分離される（固液分離工程）。固液分離で得られた前処理水は、前処理水配管１８を通して、逆浸透膜処理装置１２へ送液される。 When the water to be treated contains a hardness component and the removal of the hardness component is performed by the lime softening method, the pretreatment device 10 is, for example, an alkali agent that adds an alkali agent to the water to be treated and reacts to insolubilize the hardness component. A reaction means, an aggregating treatment means for adding an aggregating agent as needed to the water to be treated after the reaction, and aggregating, and a solid-liquid separating means for separating an aggregate from the treated water subjected to the aggregating treatment, . In the pretreatment device 10, for example, an alkali agent is added to the water to be treated, and the hardness component is insolubilized (alkali agent reaction step). Thereafter, an aggregating agent is added to perform an agglomeration treatment (aggregation treatment step), and the aggregate is subjected to solid-liquid separation (solid-liquid separation step). The pretreatment water obtained by the solid-liquid separation is sent to the reverse osmosis membrane treatment device 12 through the pretreatment water pipe 18.
　被処理水が硬度成分を含み、樹脂軟化法により硬度成分の除去が行われる場合、前処理装置１０は、例えば、イオン交換樹脂等を用いてイオン交換処理を行うイオン交換処理手段を有する。前処理装置１０において、例えばイオン交換処理手段としてイオン交換樹脂が充填されたイオン交換塔に被処理水が通液され、硬度成分が吸着除去される（イオン交換工程）。イオン交換処理で得られた前処理水は、前処理水配管１８を通して逆浸透膜処理装置１２へ送液される。イオン交換樹脂の再生が必要になった場合は、再生剤が通液されることによりイオン交換樹脂が再生される。 (4) When the water to be treated contains a hardness component and the hardness component is removed by a resin softening method, the pretreatment device 10 includes, for example, an ion exchange treatment unit that performs an ion exchange treatment using an ion exchange resin or the like. In the pretreatment device 10, for example, the water to be treated is passed through an ion exchange tower filled with an ion exchange resin as an ion exchange treatment means, and the hardness component is adsorbed and removed (ion exchange step). The pretreatment water obtained by the ion exchange treatment is sent to the reverse osmosis membrane treatment device 12 through the pretreatment water pipe 18. When the ion exchange resin needs to be regenerated, the ion exchange resin is regenerated by passing the regenerant through the liquid.
　次に、前処理工程で得られた前処理水は、逆浸透膜処理装置１２において濃縮処理される（濃縮処理工程）。逆浸透膜処理により得られた濃縮水は、濃縮水配管２０を通して正浸透膜処理装置１４へ送液され、透過水は、透過水配管２２を通して排出される。 Next, the pretreated water obtained in the pretreatment step is subjected to concentration treatment in the reverse osmosis membrane treatment device 12 (concentration treatment step). The concentrated water obtained by the reverse osmosis membrane treatment is sent to the forward osmosis membrane treatment device 14 through the concentrated water piping 20, and the permeated water is discharged through the permeated water piping 22.
　逆浸透膜処理により得られた濃縮水は、正浸透膜処理装置１４において正浸透膜処理される（正浸透膜処理工程）。正浸透膜処理装置１４において、誘引溶液が誘引溶液配管２４を通して正浸透膜の２次側に送液され、正浸透膜を介して、濃縮水と誘引溶液を存在させることにより、浸透圧で水が誘引溶液に移動される。 The concentrated water obtained by the reverse osmosis membrane treatment is subjected to a forward osmosis membrane treatment in the forward osmosis membrane treatment device 14 (forward osmosis membrane treatment step). In the forward osmosis membrane treatment device 14, the attracting solution is sent to the secondary side of the forward osmosis membrane through the attracting solution pipe 24, and the concentrated water and the attracting solution are made to exist through the forward osmosis membrane, whereby water is osmotically driven. Is transferred to the attraction solution.
　正浸透膜処理工程で使用された希薄誘引溶液は、希薄誘引溶液配管２６を通して前処理装置１０へ送液され、前処理装置１０において前処理工程で使用される。正浸透膜処理工程で得られたＦＯ濃縮水は、ＦＯ濃縮水配管２８を通して排出される。ＦＯ濃縮水は、回収、再利用されてもよい。 希 The dilute attractant used in the forward osmosis membrane treatment step is sent to the pretreatment device 10 through the dilute attractant solution pipe 26, and is used in the pretreatment device 10 in the pretreatment step. The FO concentrated water obtained in the forward osmosis membrane treatment step is discharged through the FO concentrated water piping 28. The FO concentrated water may be collected and reused.
　前処理装置１０が溶解性シリカ除去を行う装置を含む場合、例えば、正浸透膜処理装置１４における誘引溶液として、マグネシウム塩水溶液が用いられ、正浸透膜処理装置１４で使用された希薄誘引溶液（マグネシウム塩希薄水溶液）は、前処理装置１０において添加されるマグネシウム塩として使用されればよい。 When the pretreatment device 10 includes a device for removing soluble silica, for example, a magnesium salt aqueous solution is used as the attraction solution in the forward osmosis membrane treatment device 14, and the diluted attraction solution ( The magnesium salt dilute aqueous solution) may be used as a magnesium salt added in the pretreatment device 10.
　前処理装置１０が石灰軟化法により硬度成分の除去を行う装置を含む場合、例えば、正浸透膜処理装置１４における誘引溶液として、アルカリ剤水溶液が用いられ、正浸透膜処理装置１４で使用された希薄誘引溶液（アルカリ剤希薄水溶液）は、前処理装置１０において添加されるアルカリ剤として使用されればよい。 When the pretreatment device 10 includes a device that removes a hardness component by a lime softening method, for example, an aqueous alkaline solution is used as the attracting solution in the forward osmosis membrane treatment device 14 and used in the forward osmosis membrane treatment device 14. The dilute attracting solution (dilute aqueous solution of the alkaline agent) may be used as the alkaline agent added in the pretreatment device 10.
　前処理装置１０が樹脂軟化法により硬度成分の除去を行う装置を含む場合、例えば、正浸透膜処理装置１４における誘引溶液として、酸水溶液または塩化ナトリウム水溶液が用いられ、正浸透膜処理装置１４で使用された希薄誘引溶液（酸希薄水溶液または塩化ナトリウム希薄水溶液）は、前処理装置１０においてイオン交換樹脂の再生剤として使用されればよい。 When the pretreatment device 10 includes a device that removes a hardness component by a resin softening method, for example, an acid aqueous solution or a sodium chloride aqueous solution is used as the attracting solution in the forward osmosis membrane treatment device 14, and the forward osmosis membrane treatment device 14 The used dilute attracting solution (acid dilute aqueous solution or sodium chloride dilute aqueous solution) may be used in the pretreatment device 10 as a regenerant for the ion exchange resin.
　本実施形態に係る水処理方法および水処理装置により、溶解性シリカおよび硬度成分のうち少なくとも１つを含む被処理水を低コストで処理することができる。 に よ り By the water treatment method and the water treatment apparatus according to the present embodiment, the water to be treated containing at least one of the soluble silica and the hardness component can be treated at low cost.
　正浸透膜処理で希釈された希薄誘引溶液が前処理工程で使用されることで、本来必要であった誘引溶液の再利用に必要なコストが削減され、また、再生設備を備えなくてもよい。希薄誘引溶液は前処理工程で本来使用するものが希釈されているだけなので、追加のコストがほとんど発生しない。 By using the diluted attractant solution diluted by the forward osmosis membrane treatment in the pretreatment step, the cost required for reusing the attractant solution originally required is reduced, and it is not necessary to provide a regeneration facility. . Since the diluted attractant solution is only the one that is originally used in the pretreatment step, it has little additional cost.
　本発明の実施形態に係る水処理装置の他の例の概略を図３に示し、その構成について説明する。 概略 FIG. 3 schematically shows another example of the water treatment apparatus according to the embodiment of the present invention, and its configuration will be described.
　水処理装置５は、溶解性シリカ除去手段および硬度成分除去手段のうち少なくとも１つを備える前処理手段としての前処理装置１０と、前処理装置１０で得られた前処理水を濃縮処理する第１濃縮処理手段としての逆浸透膜処理装置１２と、逆浸透膜処理装置１２で得られた濃縮水を正浸透膜処理する正浸透膜処理手段としての正浸透膜処理装置１４と、正浸透膜処理装置１４で使用された希薄誘引溶液の一部を濃縮処理する第２濃縮処理手段として濃縮装置３４と、を備える。 The water treatment device 5 includes a pretreatment device 10 as a pretreatment device having at least one of a soluble silica removal device and a hardness component removal device, and a second pretreatment device that concentrates pretreatment water obtained by the pretreatment device 10. (1) a reverse osmosis membrane treatment device 12 as a concentration treatment means, a forward osmosis membrane treatment device 14 as a forward osmosis membrane treatment means for subjecting the concentrated water obtained by the reverse osmosis membrane treatment device 12 to a forward osmosis membrane treatment, A concentration device 34 is provided as second concentration processing means for performing concentration processing on a part of the diluted attracting solution used in the processing device 14.
　図３の水処理装置１において、被処理水配管１６が前処理装置１０の被処理水入口に接続され、前処理装置１０の出口と逆浸透膜処理装置１２の入口とは、前処理水配管１８により接続されている。逆浸透膜処理装置１２の濃縮水出口と正浸透膜処理装置１４の濃縮水入口とは、濃縮水配管２０により接続され、逆浸透膜処理装置１２の透過水出口には、透過水配管２２が接続されている。正浸透膜処理装置１４の誘引溶液入口には、誘引溶液配管２４が接続され、正浸透膜処理装置１４の希薄誘引溶液出口と、前処理装置１０の希薄誘引溶液入口とは、希薄誘引溶液配管２６により接続され、正浸透膜処理装置１４のＦＯ濃縮水出口には、ＦＯ濃縮水配管２８が接続されている。希薄誘引溶液配管２６から分岐した希薄誘引溶液配管３６は、濃縮装置３４の入口に接続され、濃縮装置３４の濃縮誘引溶液出口と誘引溶液配管２４の途中とは、濃縮誘引溶液配管３８により接続されている。濃縮装置３４の希釈液出口には、希釈液配管４０が接続されている。 In the water treatment apparatus 1 of FIG. 3, the treated water pipe 16 is connected to the treated water inlet of the pretreatment apparatus 10, and the outlet of the pretreatment apparatus 10 and the entrance of the reverse osmosis membrane treatment apparatus 12 are connected to the pretreated water pipe. 18. A concentrated water outlet of the reverse osmosis membrane treatment device 12 and a concentrated water inlet of the forward osmosis membrane treatment device 14 are connected by a concentrated water piping 20, and a permeated water piping 22 is connected to a permeated water outlet of the reverse osmosis membrane treatment device 12. It is connected. The attracting solution inlet 24 of the forward osmosis membrane processing device 14 is connected to an attracting solution pipe 24, and the diluted attracting solution outlet of the forward osmosis membrane processing device 14 and the diluted attracting solution inlet of the pretreatment device 10 are connected to the diluted attracting solution pipe. 26, a FO concentrated water pipe 28 is connected to an FO concentrated water outlet of the forward osmosis membrane treatment device 14. The diluted attracting solution pipe 36 branched from the diluted attracting solution pipe 26 is connected to the inlet of the concentrating device 34, and the concentrated attracting solution outlet of the concentrating device 34 and the middle of the attracting solution pipe 24 are connected by the concentrated attracting solution pipe 38. ing. A diluent pipe 40 is connected to a diluent outlet of the concentrator 34.
　本実施形態に係る水処理方法および水処理装置５の動作について説明する。 動作 The operation of the water treatment method and the water treatment device 5 according to the present embodiment will be described.
　溶解性シリカおよび硬度成分のうち少なくとも１つを含む被処理水は、被処理水配管１６を通して前処理装置１０へ送液される。前処理装置１０において、溶解性シリカおよび硬度成分のうち少なくとも１つの除去処理が行われる（前処理工程）。 被 Water to be treated containing at least one of the soluble silica and the hardness component is sent to the pretreatment device 10 through the treated water pipe 16. In the pretreatment device 10, at least one of the soluble silica and the hardness component is removed (pretreatment step).
　被処理水が溶解性シリカを含む場合、前処理装置１０は、例えば、被処理水にマグネシウム塩を添加して反応させ、溶解性シリカを不溶化させるマグネシウム反応手段と、反応後の被処理水に凝集剤を添加して、凝集させる凝集処理手段と、凝集処理させた被処理水から凝集物を分離する固液分離手段と、を有する。前処理装置１０において、例えばアルカリ条件（例えば、ｐＨ１０～１２）下で被処理水にマグネシウム塩が添加され、溶解性シリカが不溶化される（マグネシウム反応工程）。その後、必要に応じて凝集剤が添加されて、凝集処理され（凝集処理工程）、凝集物が固液分離される（固液分離工程）。固液分離で得られた前処理水は、前処理水配管１８を通して、逆浸透膜処理装置１２へ送液される。 In the case where the water to be treated contains soluble silica, the pretreatment device 10 may, for example, add a magnesium salt to the water to be treated to cause a reaction, and a magnesium reaction means for insolubilizing the soluble silica and a water to be treated after the reaction. There is provided an aggregating means for adding an aggregating agent to perform aggregation, and a solid-liquid separating means for separating agglomerates from the treated water subjected to the aggregating treatment. In the pretreatment device 10, for example, a magnesium salt is added to the water to be treated under alkaline conditions (eg, pH 10 to 12) to insolubilize the soluble silica (magnesium reaction step). Thereafter, an aggregating agent is added, if necessary, to perform an agglomeration treatment (aggregation treatment step), and the aggregates are subjected to solid-liquid separation (solid-liquid separation step). The pretreatment water obtained by the solid-liquid separation is sent to the reverse osmosis membrane treatment device 12 through the pretreatment water pipe 18.
　被処理水が硬度成分を含み、石灰軟化法により硬度成分の除去が行われる場合、前処理装置１０は、例えば、被処理水にアルカリ剤を添加して反応させ、硬度成分を不溶化させるアルカリ剤反応手段と、反応後の被処理水に必要に応じて凝集剤を添加して、凝集させる凝集処理手段と、凝集処理させた被処理水から凝集物を分離する固液分離手段と、を有する。前処理装置１０において、例えば被処理水にアルカリ剤が添加され、硬度成分が不溶化される（アルカリ剤反応工程）。その後、凝集剤が添加されて、凝集処理され（凝集処理工程）、凝集物が固液分離される（固液分離工程）。固液分離で得られた前処理水は、前処理水配管１８を通して、逆浸透膜処理装置１２へ送液される。 When the water to be treated contains a hardness component and the removal of the hardness component is performed by the lime softening method, the pretreatment device 10 is, for example, an alkali agent that adds an alkali agent to the water to be treated and reacts to insolubilize the hardness component. A reaction means, an aggregating treatment means for adding an aggregating agent as needed to the water to be treated after the reaction, and aggregating, and a solid-liquid separating means for separating an aggregate from the treated water subjected to the aggregating treatment, . In the pretreatment device 10, for example, an alkali agent is added to the water to be treated, and the hardness component is insolubilized (alkali agent reaction step). Thereafter, an aggregating agent is added to perform an agglomeration treatment (aggregation treatment step), and the aggregate is subjected to solid-liquid separation (solid-liquid separation step). The pretreatment water obtained by the solid-liquid separation is sent to the reverse osmosis membrane treatment device 12 through the pretreatment water pipe 18.
　被処理水が硬度成分を含み、樹脂軟化法により硬度成分の除去が行われる場合、前処理装置１０は、例えば、イオン交換樹脂等を用いてイオン交換処理を行うイオン交換処理手段を有する。前処理装置１０において、例えばイオン交換処理手段としてイオン交換樹脂が充填されたイオン交換塔に被処理水が通液され、硬度成分が吸着除去される（イオン交換工程）。イオン交換処理で得られた前処理水は、前処理水配管１８を通して逆浸透膜処理装置１２へ送液される。イオン交換樹脂の再生が必要になった場合は、再生剤が通液されることによりイオン交換樹脂が再生される。 (4) When the water to be treated contains a hardness component and the hardness component is removed by a resin softening method, the pretreatment device 10 includes, for example, an ion exchange treatment unit that performs an ion exchange treatment using an ion exchange resin or the like. In the pretreatment device 10, for example, the water to be treated is passed through an ion exchange tower filled with an ion exchange resin as an ion exchange treatment means, and the hardness component is adsorbed and removed (ion exchange step). The pretreatment water obtained by the ion exchange treatment is sent to the reverse osmosis membrane treatment device 12 through the pretreatment water pipe 18. When the ion exchange resin needs to be regenerated, the ion exchange resin is regenerated by passing the regenerant through the liquid.
　次に、前処理工程で得られた前処理水は、逆浸透膜処理装置１２において濃縮処理される（第１濃縮処理工程）。第１濃縮処理（逆浸透膜処理）により得られた濃縮水（ＲＯ濃縮水）は、濃縮水配管２０を通して正浸透膜処理装置１４へ送液され、透過水（ＲＯ透過水）は、透過水配管２２を通して排出される。 Next, the pretreated water obtained in the pretreatment step is concentrated in the reverse osmosis membrane treatment device 12 (first concentration treatment step). The concentrated water (RO concentrated water) obtained by the first concentration treatment (reverse osmosis membrane treatment) is sent to the forward osmosis membrane treatment device 14 through the concentrated water pipe 20, and the permeated water (RO permeated water) is the permeated water. It is discharged through a pipe 22.
　第１濃縮処理（逆浸透膜処理）により得られた濃縮水は、正浸透膜処理装置１４において正浸透膜処理される（正浸透膜処理工程）。正浸透膜処理装置１４において、誘引溶液が誘引溶液配管２４を通して正浸透膜の２次側に送液され、正浸透膜を介して、濃縮水と誘引溶液を存在させることにより、浸透圧で水が誘引溶液に移動される。 The concentrated water obtained by the first concentration treatment (reverse osmosis membrane treatment) is subjected to a forward osmosis membrane treatment in the forward osmosis membrane treatment device 14 (forward osmosis membrane treatment step). In the forward osmosis membrane treatment device 14, the attracting solution is sent to the secondary side of the forward osmosis membrane through the attracting solution pipe 24, and the concentrated water and the attracting solution are made to exist through the forward osmosis membrane, whereby water is osmotically driven. Is transferred to the attraction solution.
　正浸透膜処理工程で使用された希薄誘引溶液の一部は、希薄誘引溶液配管２６を通して前処理装置１０へ送液され、前処理装置１０において前処理工程で使用される。正浸透膜処理工程で得られたＦＯ濃縮水は、ＦＯ濃縮水配管２８を通して排出される。ＦＯ濃縮水は、必要に応じて濃縮装置や結晶化装置等によりさらに濃縮、固形化処理してもよい。 一部 A part of the diluent attracting solution used in the forward osmosis membrane treatment step is sent to the pretreatment device 10 through the dilute attractant solution pipe 26 and is used in the pretreatment device 10 in the pretreatment step. The FO concentrated water obtained in the forward osmosis membrane treatment step is discharged through the FO concentrated water piping 28. The FO concentrated water may be further concentrated and solidified by a concentrating device or a crystallization device, if necessary.
　正浸透膜処理工程で使用された希薄誘引溶液の一部は、希薄誘引溶液配管２６から分岐されて希薄誘引溶液配管３６を通して濃縮装置３４へ送液され、濃縮装置３４において濃縮処理される（第２濃縮処理工程）。第２濃縮処理により得られた濃縮誘引溶液は、濃縮誘引溶液配管３８を通して誘引溶液配管２４の途中へ供給され、正浸透膜処理装置１４における誘引溶液として再度使用される。第２濃縮処理により得られた希釈液は、希釈液配管４０を通して排出される。希釈液は、必要に応じて限外ろ過膜（ＵＦ膜）処理、逆浸透膜（ＲＯ膜）処理、イオン交換処理等を実施したのち、回収、再利用されてもよい。 Part of the diluent attracting solution used in the forward osmosis membrane treatment step is branched from the dilute attractant solution piping 26, sent to the concentrating device 34 through the dilute attracting solution piping 36, and concentrated in the concentrating device 34 (the 2 concentration treatment step). The concentrated attracting solution obtained by the second concentration treatment is supplied to the middle of the attracting solution piping 24 through the concentrated attracting solution piping 38, and is used again as the attracting solution in the forward osmosis membrane treatment device 14. The diluent obtained by the second concentration process is discharged through the diluent pipe 40. The diluent may be collected and reused after performing an ultrafiltration membrane (UF membrane) treatment, a reverse osmosis membrane (RO membrane) treatment, an ion exchange treatment, and the like, as necessary.
　前処理装置１０が溶解性シリカ除去を行う装置を含む場合、例えば、正浸透膜処理装置１４における誘引溶液として、マグネシウム塩水溶液が用いられ、正浸透膜処理装置１４で使用された希薄誘引溶液（マグネシウム塩希薄水溶液）の一部は、前処理装置１０において添加されるマグネシウム塩として使用されればよい。また、正浸透膜処理装置１４で使用された希薄誘引溶液（マグネシウム塩希薄水溶液）の一部は、濃縮装置３４において濃縮処理され、正浸透膜処理装置１４における誘引溶液として再度使用されればよい。 When the pretreatment device 10 includes a device for removing soluble silica, for example, a magnesium salt aqueous solution is used as the attraction solution in the forward osmosis membrane treatment device 14, and the diluted attraction solution ( A part of the magnesium salt diluted aqueous solution may be used as the magnesium salt added in the pretreatment device 10. A part of the diluted attracting solution (dilute aqueous solution of magnesium salt) used in the forward osmosis membrane treatment device 14 may be concentrated in the concentration device 34 and used again as the attracting solution in the forward osmosis membrane treatment device 14. .
　前処理装置１０が石灰軟化法により硬度成分の除去を行う装置を含む場合、例えば、正浸透膜処理装置１４における誘引溶液として、アルカリ剤水溶液が用いられ、正浸透膜処理装置１４で使用された希薄誘引溶液（アルカリ剤希薄水溶液）の一部は、前処理装置１０において添加されるアルカリ剤として使用されればよい。また、正浸透膜処理装置１４で使用された希薄誘引溶液（アルカリ剤希薄水溶液）の一部は、濃縮装置３４において濃縮処理され、正浸透膜処理装置１４における誘引溶液として再度使用されればよい。 When the pretreatment device 10 includes a device that removes a hardness component by a lime softening method, for example, an aqueous alkaline solution is used as the attracting solution in the forward osmosis membrane treatment device 14 and used in the forward osmosis membrane treatment device 14. A part of the diluted attracting solution (the alkaline agent diluted aqueous solution) may be used as the alkaline agent added in the pretreatment device 10. In addition, a part of the diluted attracting solution (dilute aqueous solution of the alkaline agent) used in the forward osmosis membrane treatment device 14 may be concentrated in the concentration device 34 and used again as the attracting solution in the forward osmosis membrane treatment device 14. .
　前処理装置１０が樹脂軟化法により硬度成分の除去を行う装置を含む場合、例えば、正浸透膜処理装置１４における誘引溶液として、酸水溶液または塩化ナトリウム水溶液が用いられ、正浸透膜処理装置１４で使用された希薄誘引溶液（酸希薄水溶液または塩化ナトリウム希薄水溶液）の一部は、前処理装置１０においてイオン交換樹脂の再生剤として使用されればよい。また、正浸透膜処理装置１４で使用された希薄誘引溶液（酸希薄水溶液または塩化ナトリウム希薄水溶液）の一部は、濃縮装置３４において濃縮処理され、正浸透膜処理装置１４における誘引溶液として再度使用されればよい。 When the pretreatment device 10 includes a device that removes a hardness component by a resin softening method, for example, an acid aqueous solution or a sodium chloride aqueous solution is used as the attracting solution in the forward osmosis membrane treatment device 14, and the forward osmosis membrane treatment device 14 A part of the used diluted attracting solution (acid diluted aqueous solution or sodium chloride diluted aqueous solution) may be used in the pretreatment device 10 as a regenerant for the ion exchange resin. A part of the diluted attracting solution (acid-diluted aqueous solution or sodium chloride-diluted aqueous solution) used in the forward osmosis membrane treatment device 14 is concentrated in the concentration device 34 and reused as the attracting solution in the forward osmosis membrane treatment device 14. It should be done.
　本実施形態に係る水処理方法および水処理装置により、溶解性シリカおよび硬度成分のうち少なくとも１つを含む被処理水を低コストで処理することができる。 に よ り By the water treatment method and the water treatment apparatus according to the present embodiment, the water to be treated containing at least one of the soluble silica and the hardness component can be treated at low cost.
　正浸透膜処理で希釈された希薄誘引溶液が前処理工程で使用されることで、本来必要であった誘引溶液の再利用に必要なコストが削減され、また、再生設備を備えなくてもよい。希薄誘引溶液は前処理工程で本来使用するものが希釈されているだけなので、追加のコストがほとんど発生しない。 By using the diluted attracting solution diluted by the forward osmosis membrane treatment in the pretreatment step, the cost required for reusing the attracting solution originally needed is reduced, and it is not necessary to provide a regeneration facility. . Since the diluted attractant solution is only the one that is originally used in the pre-treatment step, it has little additional cost.
　正浸透膜処理で希釈された希薄誘引溶液が前処理工程で使用するのに必要な量よりも多くなった場合、正浸透膜処理で使用した希薄誘引溶液の一部を前処理工程で使用し、前処理工程で使用しなかった希薄誘引溶液の一部を濃縮し、誘引溶液として正浸透膜処理工程で再度使用することにより、希薄誘引溶液のロスを少なくすることができる。このとき濃縮する希薄誘引溶液は一部であるため、希薄誘引溶液の全量を濃縮して再利用するよりも、コストが著しく低下する。 When the amount of the diluted attracting solution diluted in the forward osmosis membrane treatment becomes larger than necessary for use in the pretreatment step, a part of the diluted attractant solution used in the forward osmosis membrane treatment is used in the pretreatment step. By concentrating a part of the diluted attracting solution not used in the pretreatment step and reusing it in the forward osmosis membrane treatment step as the attracting solution, the loss of the diluted attracting solution can be reduced. At this time, since the diluted attracting solution to be concentrated is a part, the cost is remarkably reduced as compared with the case where the entire amount of the diluted attracting solution is concentrated and reused.
　本実施形態に係る水処理方法および水処理装置の処理対象となる被処理水は、溶解性シリカおよび硬度成分のうち少なくとも１つを含む水であればよく、特に制限はないが、例えば、工業用水、表層水、水道水、地下水、海水、海水を逆浸透法もしくは蒸発法によって脱塩した海水淡水化処理水、各種排水、例えば半導体製造工程で排出される排水等が挙げられる。 The water to be treated, which is to be treated by the water treatment method and the water treatment apparatus according to the present embodiment, may be any water containing at least one of soluble silica and a hard component, and is not particularly limited. Water, surface water, tap water, groundwater, seawater, seawater desalinated water obtained by desalinating seawater by a reverse osmosis method or an evaporation method, and various kinds of wastewater, for example, wastewater discharged in a semiconductor manufacturing process.
　被処理水中に溶解性シリカが含まれる場合、溶解性シリカの濃度は、例えば、５～４００ｍｇ／Ｌの範囲である。被処理水中に硬度成分が含まれる場合、カルシウム硬度成分の濃度は、５～６００ｍｇ／Ｌの範囲である。被処理水中の全蒸発残留物（ＴＤＳ：Ｔｏｔａｌ　Ｄｉｓｓｏｌｖｅｄ　Ｓｏｌｉｄ）は、例えば、１００～５００００ｍｇ／Ｌの範囲である。 場合 When the water to be treated contains soluble silica, the concentration of the soluble silica is, for example, in the range of 5 to 400 mg / L. When the water to be treated contains a hardness component, the concentration of the calcium hardness component is in the range of 5 to 600 mg / L. The total evaporation residue (TDS: Total Dissolved Solid) in the water to be treated is, for example, in the range of 100 to 50,000 mg / L.
　本実施形態に係る水処理方法および水処理装置において、被処理水が溶解性シリカおよび硬度成分の両者を含む場合は、前処理手段（前処理工程）は、溶解性シリカ除去手段（溶解性シリカ除去工程）および硬度成分除去手段（硬度成分除去工程）の両者を備えてもよい。溶解性シリカ除去手段（溶解性シリカ除去工程）および硬度成分除去手段（硬度成分除去工程）の順序は、第１に溶解性シリカ除去手段（溶解性シリカ除去工程）、第２に硬度成分除去手段（硬度成分除去工程）であっても、第１に硬度成分除去手段（硬度成分除去工程）、第２に溶解性シリカ除去手段（溶解性シリカ除去工程）であってもよい。 In the water treatment method and the water treatment apparatus according to the present embodiment, when the water to be treated contains both soluble silica and a hardness component, the pretreatment means (pretreatment step) is a means for removing soluble silica (soluble silica). (Hardening component removal step) and a hardness component removing means (hardness component removing step). The order of the soluble silica removing means (soluble silica removing step) and the hardness component removing means (hardness component removing step) is as follows: first, soluble silica removing means (soluble silica removing step), and second, hardness component removing means. (Hardness component removal step), firstly, hardness component removal means (hardness component removal step), and second, soluble silica removal means (soluble silica removal step).
　この場合、正浸透膜処理装置１４（正浸透膜処理工程）における誘引溶液として、マグネシウム塩水溶液、アルカリ剤水溶液、酸水溶液および塩化ナトリウム水溶液のうち少なくとも１つが用いられ、正浸透膜処理装置１４で使用された希薄誘引溶液（マグネシウム塩希薄水溶液、アルカリ剤希薄水溶液、酸希薄水溶液および塩化ナトリウム希薄水溶液のうち少なくとも１つ）が、前処理装置１０（前処理工程）の溶解性シリカ除去手段（溶解性シリカ除去工程）および硬度成分除去手段（硬度成分除去工程）のうち適した方において使用されればよい。 In this case, at least one of a magnesium salt aqueous solution, an alkali agent aqueous solution, an acid aqueous solution, and a sodium chloride aqueous solution is used as the attracting solution in the forward osmosis membrane processing device 14 (forward osmosis membrane processing step). The diluted attracting solution (at least one of a diluted aqueous solution of a magnesium salt, a diluted aqueous solution of an alkali agent, a diluted aqueous solution of an acid, and a diluted aqueous solution of sodium chloride) is used as a soluble silica removing means (pre-treatment step) in the pretreatment device 10 (pretreatment step). It may be used in a suitable one of the step of removing the silica and the means of removing the hardness component (the step of removing the hardness component).
　本実施形態に係る水処理方法および水処理装置において、被処理水中の濁質成分等を除去する濁質除去手段をさらに備えてもよい。濁質除去手段としては、例えば、砂ろ過装置、限外ろ過（ＵＦ）膜等の膜ろ過装置、加圧浮上装置等が挙げられる。濁質除去手段の設置位置は、特に制限はないが、濁質除去手段が砂ろ過装置の場合、例えば、前処理装置１０（前処理工程）の前段であり、濁質除去手段が膜ろ過装置や加圧浮上装置の場合、例えば、前処理装置１０（前処理工程）と逆浸透膜処理装置１２（濃縮処理工程）との間である。 水 The water treatment method and the water treatment apparatus according to the present embodiment may further include a turbidity removing unit that removes turbid components and the like in the water to be treated. Examples of the turbid removal means include a sand filtration device, a membrane filtration device such as an ultrafiltration (UF) membrane, and a pressure flotation device. There is no particular limitation on the installation position of the turbidity removing means, but when the turbidity removing means is a sand filtration device, for example, the turbidity removing means is located at a stage preceding the pretreatment device 10 (pretreatment step), and the turbidity removal means is a membrane filtration device. In the case of a pressure flotation device, for example, it is between the pretreatment device 10 (pretreatment process) and the reverse osmosis membrane treatment device 12 (concentration treatment process).
［前処理工程：溶解性シリカ除去］
　被処理水が溶解性シリカを含む場合の前処理工程において、例えば、アルカリ条件下で被処理水にマグネシウム塩が添加され、溶解性シリカが不溶化される（マグネシウム反応工程）。 [Pretreatment step: Removal of soluble silica]
In the pretreatment step when the water to be treated contains soluble silica, for example, a magnesium salt is added to the water to be treated under alkaline conditions to insolubilize the soluble silica (magnesium reaction step).
　用いられるマグネシウム塩としては、塩化マグネシウム（ＭｇＣｌ２）、硫酸マグネシウム（ＭｇＳＯ４）等のマグネシウム塩またはその水和物であればよく、特に制限はないが、硫酸塩添加による難溶解性物質生成を抑制する等の観点から、塩化マグネシウムが好ましい。 The magnesium salt used may be a magnesium salt such as magnesium chloride (MgCl 2 ) or magnesium sulfate (MgSO 4 ) or a hydrate thereof, and is not particularly limited. From the viewpoint of suppression and the like, magnesium chloride is preferred.
　マグネシウム反応工程におけるｐＨはアルカリ条件であればよく、特に制限はないが、例えば、ｐＨ１０～１２の範囲であり、１０．５～１１．５の範囲であることが好ましく、１１～１１．５の範囲であることがより好ましい。マグネシウム反応工程におけるｐＨが１０未満、または１２を超えると、シリカ除去率が低くなる場合がある。 The pH in the magnesium reaction step may be an alkaline condition, and is not particularly limited. For example, the pH is in the range of 10 to 12, preferably in the range of 10.5 to 11.5, and more preferably in the range of 11 to 11.5. More preferably, it is within the range. If the pH in the magnesium reaction step is less than 10 or more than 12, the silica removal rate may decrease.
　ｐＨ調整剤としては、水酸化ナトリウム、水酸化カルシウム等のアルカリを用いればよく、必要に応じて塩酸、硫酸等の無機酸を用いてもよい。 (4) As the pH adjuster, an alkali such as sodium hydroxide or calcium hydroxide may be used, and if necessary, an inorganic acid such as hydrochloric acid or sulfuric acid may be used.
　マグネシウム反応工程における温度は、シリカの不溶化反応が進行する温度であればよく、特に制限はないが、例えば、１℃～５０℃未満の範囲であり、１０℃～５０℃未満の範囲であることがより好ましい。マグネシウム反応工程における温度が１℃未満であると、シリカの不溶化反応が不十分となる場合があり、５０℃以上であると、処理コストが高くなる場合がある。 The temperature in the magnesium reaction step may be a temperature at which the insolubilization reaction of silica proceeds, and is not particularly limited. For example, the temperature is in the range of 1 ° C to less than 50 ° C, and is in the range of 10 ° C to less than 50 ° C. Is more preferred. If the temperature in the magnesium reaction step is lower than 1 ° C., the insolubilization reaction of silica may be insufficient, and if it is higher than 50 ° C., the processing cost may increase.
　マグネシウム反応工程における反応時間は、シリカの不溶化反応が進行することができればよく、特に制限はないが、例えば、１分～６０分の範囲であり、５分～３０分の範囲であることがより好ましい。マグネシウム反応工程における反応時間が１分未満であると、シリカの不溶化反応が不十分となる場合があり、６０分を超えると、反応槽が過大になる場合がある。 The reaction time in the magnesium reaction step is not particularly limited as long as the insolubilization reaction of the silica can proceed, and is not particularly limited, but is, for example, in the range of 1 minute to 60 minutes, and more preferably in the range of 5 minutes to 30 minutes. preferable. If the reaction time in the magnesium reaction step is less than 1 minute, the silica insolubilization reaction may be insufficient, and if it exceeds 60 minutes, the reaction tank may be excessively large.
　マグネシウム塩の添加量は、被処理水中のシリカの重量濃度に対して、マグネシウム濃度として０．１～１０倍量の範囲であることが好ましく、０．５～５倍量の範囲であることがより好ましい。マグネシウム塩の添加量が被処理水中のシリカの重量濃度に対して０．１倍量未満であると、シリカの不溶化反応が不十分となる場合があり、１０倍量を超えると、汚泥発生量が過剰になってしまう場合がある。 The amount of the magnesium salt to be added is preferably 0.1 to 10 times, more preferably 0.5 to 5 times as much as the magnesium concentration with respect to the weight concentration of silica in the water to be treated. More preferred. When the addition amount of the magnesium salt is less than 0.1 times the weight concentration of silica in the water to be treated, the insolubilization reaction of silica may be insufficient. May be excessive.
　溶解性シリカを不溶化させるために、マグネシウム塩の他に、ポリ塩化アルミニウム（ＰＡＣ）、硫酸アルミニウム等のアルミニウム塩、塩化第二鉄、硫酸第二鉄等の鉄塩等が用いられてもよい。シリカ除去率等の点から、マグネシウム塩を用いることが好ましい。 、 In order to insolubilize the soluble silica, aluminum salts such as polyaluminum chloride (PAC) and aluminum sulfate, and iron salts such as ferric chloride and ferric sulfate may be used in addition to the magnesium salt. It is preferable to use a magnesium salt from the viewpoint of the silica removal rate and the like.
　凝集処理工程では、例えば、凝集槽において、無機凝集剤が、マグネシウム反応後の被処理水に添加され、不溶化物が凝集される（凝集工程）。その後、フロック形成槽において、高分子凝集剤が、添加され、フロックが形成される（フロック形成工程）。 In the coagulation treatment step, for example, in a coagulation tank, an inorganic coagulant is added to the water to be treated after the magnesium reaction, and the insolubilized substance is coagulated (coagulation step). Thereafter, a polymer flocculant is added in the floc forming tank to form flocs (flock forming step).
　凝集工程で用いられる無機凝集剤としては、塩化鉄等の鉄系無機凝集剤、ポリ塩化アルミニウム（ＰＡＣ）等のアルミニウム系無機凝集剤等が挙げられ、薬品コストおよび凝集ｐＨ範囲等の点から、鉄系無機凝集剤が好ましい。 Examples of the inorganic coagulant used in the coagulation step include an iron-based inorganic coagulant such as iron chloride, an aluminum-based inorganic coagulant such as polyaluminum chloride (PAC), and the like. Iron-based inorganic flocculants are preferred.
　無機凝集剤の添加量は、添加したマグネシウム塩の量に対して重量比で０．１～１０倍量の範囲であることが好ましく、１～５倍量の範囲であることがより好ましい。無機凝集剤の添加量が添加したマグネシウム塩の量に対して重量比で０．１倍量未満であると、凝集が不十分となる場合があり、１０倍量を超えると、汚泥発生量が過剰になる場合がある。 添加 The amount of the inorganic coagulant added is preferably in the range of 0.1 to 10 times, more preferably 1 to 5 times the weight of the added magnesium salt. If the amount of the inorganic coagulant is less than 0.1 times the weight of the added magnesium salt, the coagulation may be insufficient. May be excessive.
　凝集工程におけるｐＨは、例えば、３～１１の範囲である。凝集工程におけるｐＨが３未満、または１１を超えると、凝集不良を生じる場合がある。さらに、凝集工程におけるｐＨが９未満となると、フロックからシリカが溶け出してしまうことがあることから、ｐＨ９～１１の範囲で凝集工程を行うことが望ましい。 ＰＨ The pH in the aggregation step is, for example, in the range of 3 to 11. If the pH in the aggregation step is less than 3 or more than 11, poor aggregation may occur. Furthermore, if the pH in the aggregating step is less than 9, silica may be dissolved from the floc, so it is desirable to perform the aggregating step in a pH range of 9 to 11.
　凝集工程における温度は、例えば、１℃～８０℃の範囲である。凝集工程における温度が１℃未満、または８０℃を超えると、凝集不良を生じる場合がある。 温度 The temperature in the aggregation step is, for example, in the range of 1 ° C to 80 ° C. If the temperature in the aggregation step is less than 1 ° C. or exceeds 80 ° C., poor aggregation may occur.
　フロック形成工程で用いられる高分子凝集剤としては、ポリアクリルアミド系、ポリアクリル酸エステル系等のカチオン系高分子凝集剤、アニオン系高分子凝集剤、ノニオン系高分子凝集剤等が挙げられ、凝集性等の点から、アニオン系高分子凝集剤が好ましい。 Examples of the polymer flocculant used in the floc formation step include cationic polymer flocculants such as polyacrylamides and polyacrylates, anionic polymer flocculants, and nonionic polymer flocculants. From the viewpoint of properties and the like, an anionic polymer flocculant is preferable.
　市販の高分子凝集剤としては、オルフロックＯＡ－３Ｈ（オルガノ株式会社製）等のアニオン系高分子凝集剤が挙げられる。 Examples of commercially available polymer flocculants include anionic polymer flocculants such as Olfloc OA-3H (manufactured by Organo Corporation).
　高分子凝集剤の添加量は、原水の水量に対して０．１～１０ｍｇ／Ｌの範囲であることが好ましく、１～５ｍｇ／Ｌの範囲であることがより好ましい。高分子凝集剤の添加量が原水の水量に対して０．１ｍｇ／Ｌ未満であると、フロック形成が向上しない場合があり、１０ｍｇ／Ｌを超えると、処理水中に溶存の高分子凝集剤が残留してしまう場合がある。 添加 The amount of the polymer flocculant to be added is preferably in the range of 0.1 to 10 mg / L, more preferably in the range of 1 to 5 mg / L, based on the amount of raw water. If the amount of the polymer flocculant is less than 0.1 mg / L with respect to the amount of the raw water, floc formation may not be improved. If the amount exceeds 10 mg / L, the polymer flocculant dissolved in the treated water may be reduced. It may remain.
　フロック形成工程におけるｐＨは、例えば、３～１１の範囲である。フロック形成工程におけるｐＨが３未満、または１１を超えると、凝集不良を生じる場合がある。さらに、フロック工程におけるｐＨが９未満となると、フロックからシリカが溶け出してしまうことがあることから、ｐＨ９～１１の範囲でフロック形成工程を行うことが望ましい。 ＰＨ The pH in the floc forming step is, for example, in the range of 3 to 11. If the pH in the floc formation step is less than 3 or more than 11, poor coagulation may occur. Further, if the pH in the flocking step is less than 9, silica may be dissolved from the floc, so it is desirable to perform the floc forming step in the pH range of 9 to 11.
　フロック形成工程における温度は、例えば、１℃～８０℃の範囲である。フロック形成工程における温度が１℃未満、または８０℃を超えると、凝集不良を生じる場合がある。 温度 The temperature in the floc forming step is, for example, in the range of 1 ° C to 80 ° C. If the temperature in the floc forming step is lower than 1 ° C. or higher than 80 ° C., poor coagulation may occur.
　上記凝集処理では、凝集工程およびフロック形成工程として、無機凝集剤および高分子凝集剤を用いているが、無機凝集剤、高分子凝集剤等のうちの少なくとも１つを用いればよく、鉄系無機凝集剤およびアニオン系高分子凝集剤のうちの少なくとも１つを用いることが好ましい。マグネシウム塩と反応し不溶化されたシリカを凝集させる際、鉄系無機凝集剤およびアニオン系高分子凝集剤のうちの少なくとも１つを用いることで、凝集性および固液分離性が向上する。 In the above-mentioned coagulation treatment, an inorganic coagulant and a polymer coagulant are used as the coagulation step and the floc formation step, but at least one of an inorganic coagulant, a polymer coagulant and the like may be used, and an iron-based inorganic coagulant may be used. It is preferable to use at least one of a flocculant and an anionic polymer flocculant. At the time of aggregating the silica which has been insolubilized by reacting with the magnesium salt, the use of at least one of an iron-based inorganic coagulant and an anionic polymer coagulant improves cohesion and solid-liquid separation.
　固液分離工程では、例えば、沈殿槽において、フロック形成された凝集物が固液分離される（固液分離工程）。固液分離で得られた前処理水は、逆浸透膜処理装置１２へ送液される。一方、汚泥は、汚泥配管を通して排出される。汚泥は、回収、再利用されてもよい。 で は In the solid-liquid separation step, for example, floc-formed aggregates are separated into solid and liquid in a settling tank (solid-liquid separation step). The pretreatment water obtained by the solid-liquid separation is sent to the reverse osmosis membrane treatment device 12. On the other hand, sludge is discharged through sludge piping. Sludge may be collected and reused.
　固液分離工程における固液分離としては、自然沈降による沈降分離の他に、加圧浮上処理、膜ろ過処理等が挙げられ、分離性等の点から、沈降分離が好ましい。 固 As the solid-liquid separation in the solid-liquid separation step, in addition to the sedimentation separation by natural sedimentation, a pressure flotation treatment, a membrane filtration treatment and the like can be mentioned.
［前処理工程：石灰軟化法による硬度成分除去］
　被処理水が硬度成分を含む場合、石灰軟化法により硬度成分を除去すればよい。硬度成分は一次硬度と永久硬度とに分類され、一次硬度は水酸化ナトリウム（ＮａＯＨ）等のアルカリ剤によって、永久硬度は炭酸ナトリウム（ＮａＣＯ３）等の炭酸塩の添加によって除去される。本明細書では便宜上、炭酸塩もアルカリ剤として記載する。すなわち、前処理工程において、被処理水にアルカリ剤が添加され、硬度成分が不溶化される（アルカリ剤反応工程）。 [Pretreatment step: removal of hardness components by lime softening method]
When the water to be treated contains a hardness component, the hardness component may be removed by a lime softening method. The hardness components are classified into primary hardness and permanent hardness. The primary hardness is removed by adding an alkali agent such as sodium hydroxide (NaOH), and the permanent hardness is removed by adding a carbonate such as sodium carbonate (NaCO 3 ). In this specification, a carbonate is also described as an alkali agent for convenience. That is, in the pretreatment step, an alkali agent is added to the water to be treated, and the hardness component is insolubilized (alkali agent reaction step).
　用いられるアルカリ剤としては、例えば、水酸化カルシウム（Ｃａ（ＯＨ）２）、水酸化ナトリウム（ＮａＯＨ）、水酸化カリウム（ＫＯＨ）、炭酸水素カルシウム（Ｃａ（ＨＣＯ３）２）、炭酸水素マグネシウム（Ｍｇ（ＨＣＯ３）２）、炭酸ナトリウム（Ｎａ２ＣＯ３）、炭酸カリウム（Ｋ２ＣＯ３）等が挙げられ、これらのうち一つ以上を用いることができる。すなわち、必要に応じて水酸化ナトリウムと炭酸ナトリウムをそれぞれ添加することも可能である。不溶化効率等の観点から炭酸ナトリウムが好ましい。 Examples of the alkaline agent used include calcium hydroxide (Ca (OH) 2 ), sodium hydroxide (NaOH), potassium hydroxide (KOH), calcium hydrogen carbonate (Ca (HCO 3 ) 2 ), and magnesium hydrogen carbonate ( Mg (HCO 3 ) 2 ), sodium carbonate (Na 2 CO 3 ), potassium carbonate (K 2 CO 3 ), etc., and one or more of these can be used. That is, it is also possible to add sodium hydroxide and sodium carbonate as needed. Sodium carbonate is preferred from the viewpoint of insolubilization efficiency and the like.
　アルカリ剤反応工程におけるｐＨはアルカリ条件であればよく、特に制限はないが、例えば、ｐＨ９～１３の範囲であり、１１～１２の範囲であることが好ましい。アルカリ剤反応工程におけるｐＨが９未満であると、硬度成分除去率が低くなり、１３を超えると、アルカリ剤の添加量が多くなる場合がある。 ＰＨ The pH in the alkaline agent reaction step may be an alkaline condition, and is not particularly limited. For example, the pH is in the range of 9 to 13, preferably 11 to 12. If the pH in the alkaline agent reaction step is less than 9, the hardness component removal rate will be low, and if it exceeds 13, the amount of the alkaline agent added may be large.
　アルカリ剤反応工程における温度は、硬度成分の不溶化反応が進行する温度であればよく、特に制限はないが、例えば、１℃～８０℃の範囲である。アルカリ剤反応工程における温度が１℃未満であると、硬度成分の不溶化反応が不十分となる場合があり、８０℃を超えると、設備の耐熱温度が問題となる場合がある。 温度 The temperature in the alkali agent reaction step may be any temperature at which the insolubilization reaction of the hardness component proceeds, and is not particularly limited, but is, for example, in the range of 1 ° C to 80 ° C. If the temperature in the alkali agent reaction step is lower than 1 ° C., the insolubilization reaction of the hardness component may be insufficient, and if it exceeds 80 ° C., the heat resistance temperature of the equipment may become a problem.
　アルカリ剤反応工程における反応時間は、硬度成分の不溶化反応が進行することができればよく、特に制限はないが、例えば、１０分～３０分の範囲である。アルカリ剤反応工程における反応時間が１０分未満であると、硬度成分の不溶化反応が不十分となる場合があり、３０分を超えると、反応槽が大きくなって設備コストが高くなる場合がある。 反 応 The reaction time in the alkali agent reaction step is not particularly limited as long as the insolubilization reaction of the hardness component can proceed, and is, for example, in a range of 10 minutes to 30 minutes. If the reaction time in the alkaline agent reaction step is less than 10 minutes, the insolubilization reaction of the hardness component may be insufficient, and if it exceeds 30 minutes, the reaction tank may become large and equipment costs may increase.
　アルカリ剤の添加量は、被処理水中の硬度成分のモル濃度に対して、１．０～２．０倍量の範囲であることが好ましく、１．０～１．２倍量の範囲であることがより好ましい。アルカリ剤の添加量が被処理水中の硬度成分のモル濃度に対して１．０倍量未満であると、硬度成分の不溶化反応が不十分となる場合があり、２．０倍量を超えると、薬品コストが高くなる場合がある。 The amount of the alkali agent to be added is preferably in the range of 1.0 to 2.0 times, and more preferably in the range of 1.0 to 1.2 times the molar concentration of the hardness component in the water to be treated. Is more preferable. If the amount of the alkali agent is less than 1.0 times the molar concentration of the hardness component in the water to be treated, the insolubilization reaction of the hardness component may be insufficient, and if the amount exceeds 2.0 times. In some cases, the cost of chemicals may increase.
　以降の凝集処理工程および固液分離工程は、上記前処理工程（マグネシウム塩によるシリカ除去）と同様である。固液分離で得られた前処理水は、逆浸透膜処理装置１２へ送液される。 The subsequent aggregation treatment step and solid-liquid separation step are the same as the above-mentioned pretreatment step (removal of silica with magnesium salt). The pretreatment water obtained by the solid-liquid separation is sent to the reverse osmosis membrane treatment device 12.
［前処理工程：樹脂軟化法による硬度成分除去］
　被処理水が硬度成分を含む場合の樹脂軟化法による前処理工程において、例えば、イオン交換樹脂が充填されたイオン交換塔に被処理水が通液され、硬度成分が吸着除去される（イオン交換工程）。イオン交換処理で得られた前処理水は、逆浸透膜処理装置１２へ送液される。 [Pretreatment step: removal of hardness components by resin softening method]
In the pretreatment step by the resin softening method in the case where the water to be treated contains a hardness component, for example, the water to be treated is passed through an ion exchange tower filled with an ion exchange resin to adsorb and remove the hardness component (ion exchange). Process). The pretreated water obtained by the ion exchange treatment is sent to the reverse osmosis membrane treatment device 12.
　イオン交換工程で用いられるイオン交換樹脂は、陽イオン交換樹脂であり、例えば、Ａｍｂｅｒｒｅｘ１００Ｎａ、ＩＲＣ－７６（オルガノ株式会社製）等が挙げられる。 イ オ ン The ion exchange resin used in the ion exchange step is a cation exchange resin, and examples thereof include Amberrex 100Na and IRC-76 (manufactured by Organo Corporation).
　イオン交換樹脂の再生が必要になった場合は、再生剤が通液されることによりイオン交換樹脂が再生される。 再生 When the ion exchange resin needs to be regenerated, the ion exchange resin is regenerated by passing the regenerant through.
　用いられる再生剤としては、塩酸、硫酸、硝酸等の酸水溶液、塩化ナトリウム水溶液、塩化カリウム水溶液等が挙げられ、これらのうち一つ以上を用いることができる。すなわち、必要に応じて酸水溶液で再生をしたのちに、塩化ナトリウム水溶液で追加再生をすることも可能である。誘引溶液の再利用等の観点から、酸水溶液、塩化ナトリウム水溶液が好ましい。酸水溶液で再生されれば、イオン交換樹脂はＨ形となり、塩化ナトリウム水溶液で再生されれば、イオン交換樹脂はＮａ形となる。 再生 Examples of the regenerating agent include an aqueous solution of an acid such as hydrochloric acid, sulfuric acid, and nitric acid, an aqueous solution of sodium chloride, and an aqueous solution of potassium chloride. One or more of these can be used. That is, after regeneration with an acid aqueous solution as necessary, additional regeneration with an aqueous sodium chloride solution is also possible. From the viewpoint of reusing the attraction solution, an aqueous acid solution and an aqueous sodium chloride solution are preferable. When regenerated with an aqueous acid solution, the ion exchange resin is in the H form, and when regenerated with an aqueous sodium chloride solution, the ion exchange resin is in the Na form.
［濃縮処理工程（第１濃縮処理工程）］
　濃縮処理手段（第１濃縮処理手段）としては、前処理水を濃縮することができるものであればよく、特に制限はないが、逆浸透膜処理装置の他に、ナノろ過膜等を用いる膜ろ過装置、蒸留装置、電気透析装置等のうち一つ以上を用いることができる。すなわち、必要に応じて逆浸透膜処理装置によって得られた濃縮水を電気透析処理によってさらに濃縮してもよいし、第１の逆浸透処理によって得られた濃縮水を第２の逆浸透処理によってさらに濃縮してもよい。前処理水中のＴＤＳが低い場合に効率的に処理することができる等の点から、逆浸透膜処理装置が好ましい。 [Concentration treatment step (first concentration treatment step)]
The concentration treatment means (first concentration treatment means) is not particularly limited as long as it can concentrate the pretreated water, and is not particularly limited. In addition to the reverse osmosis membrane treatment device, a membrane using a nanofiltration membrane or the like is used. One or more of a filtration device, a distillation device, an electrodialysis device and the like can be used. That is, if necessary, the concentrated water obtained by the reverse osmosis membrane treatment apparatus may be further concentrated by electrodialysis treatment, or the concentrated water obtained by the first reverse osmosis treatment may be further concentrated by the second reverse osmosis treatment. It may be further concentrated. A reverse osmosis membrane treatment apparatus is preferable in that the treatment can be performed efficiently when the TDS in the pretreatment water is low.
　逆浸透膜処理装置で使用される逆浸透膜としては、純水製造用途や排水回収等の用途に使用される超低圧逆浸透膜、低圧逆浸透膜の他に、海水淡水化等の用途に使用される中圧逆浸透膜や高圧逆浸透膜等が挙げられる。超低圧逆浸透膜、低圧逆浸透膜としては、例えば、ＥＳ１５（日東電工製）、ＴＭ７２０Ｄ（東レ製）、ＢＷ３０ＨＲＬＥ（ダウケミカル製）、ＬＦＣ３－ＬＤ（Ｈｙｄｒａｎａｕｔｉｃｓ製）が挙げられる。高圧逆浸透膜としては、例えば、ＳＷＣ５－ＬＤ（Ｈｙｄｒａｎａｕｔｉｃｓ製）、ＴＭ８２０Ｖ（東レ製）、ＸＵＳ１８０８０８（ダウケミカル製）が挙げられる。 Reverse osmosis membranes used in reverse osmosis membrane treatment equipment include ultra-low pressure reverse osmosis membranes and low pressure reverse osmosis membranes used for pure water production and wastewater recovery, as well as seawater desalination. Examples thereof include a medium pressure reverse osmosis membrane and a high pressure reverse osmosis membrane used. Examples of the ultra-low pressure reverse osmosis membrane and low pressure reverse osmosis membrane include ES15 (manufactured by Nitto Denko), TM720D (manufactured by Toray), BW30HRLE (manufactured by Dow Chemical), and LFC3-LD (manufactured by Hydroranatics). Examples of the high-pressure reverse osmosis membrane include SWC5-LD (manufactured by Hydroranatics), TM820V (manufactured by Toray), and XUS180808 (manufactured by Dow Chemical).
　濃縮処理工程（第１濃縮処理工程）において、ｐＨ調整剤や、系内での無機塩のスケーリングを抑制するスケール分散剤、系内での微生物発生を抑制する殺菌剤等の薬品を添加してもよい。 In the concentration treatment step (first concentration treatment step), chemicals such as a pH adjuster, a scale dispersant for suppressing the scaling of inorganic salts in the system, and a bactericide for suppressing the generation of microorganisms in the system are added. Is also good.
［正浸透膜処理工程］
　正浸透膜処理工程で用いられる正浸透膜の形状としては、特に制限はないが、例えば、中空糸膜、スパイラル膜、チューブラ膜、プレートアンドフレーム構造の膜等を使用することができる。正浸透膜の膜材質としては、芳香族ポリアミド系、酢酸セルロース系等が挙げられる。また、分離膜の基材に、機能性たんぱく質や無機材料等を組み込んで分離性能や透水性等を付与した膜を用いることも可能である。正浸透膜としては、例えば、ＨＰ５２３０（東洋紡製）、ＨＦＦＯ２（アクアポリン製）、ＯｓｍｏＦ２Ｏ（Ｆｒｕｉｄ　Ｔｅｃｈｎｏｌｏｇｙ　Ｓｏｌｕｔｉｏｎｓ製）が挙げられる。これら正浸透膜は、単段で使用してもよいし、複数段を直列に接続して使用してもよい。すなわち、第１の正浸透膜処理によって得られたＦＯ濃縮水を第２の正浸透膜処理によってさらに濃縮してもよい。 [Forward osmosis membrane treatment process]
The shape of the forward osmosis membrane used in the forward osmosis membrane treatment step is not particularly limited, and for example, a hollow fiber membrane, a spiral membrane, a tubular membrane, a membrane having a plate and frame structure, or the like can be used. Examples of the membrane material of the forward osmosis membrane include an aromatic polyamide system and a cellulose acetate system. Further, it is also possible to use a membrane in which a functional protein, an inorganic material, or the like is incorporated into the base material of the separation membrane to impart separation performance, water permeability, and the like. Examples of the forward osmosis membrane include HP5230 (manufactured by Toyobo), HFFO2 (manufactured by Aquaporin), and OsmoF2O (manufactured by Fluid Technology Solutions). These forward osmosis membranes may be used in a single stage, or may be used by connecting a plurality of stages in series. That is, the FO concentrated water obtained by the first forward osmosis membrane treatment may be further concentrated by the second forward osmosis membrane treatment.
　正浸透膜処理工程で用いられる誘引溶液としては、上記の通り、マグネシウム塩水溶液、アルカリ剤水溶液、酸水溶液、塩化ナトリウム水溶液等が挙げられる。また、上記以外にも、本水処理装置で使用する薬品であれば制限なく使用することができる。すなわち、凝集処理工程で使用される各種凝集剤や、濃縮処理工程で使用されるスケール分散剤や殺菌剤等を、誘引溶液として用いることも可能である。 誘 As described above, the attracting solution used in the forward osmosis membrane treatment step includes a magnesium salt aqueous solution, an alkali agent aqueous solution, an acid aqueous solution, and a sodium chloride aqueous solution. In addition to the above, any chemical used in the present water treatment apparatus can be used without limitation. That is, various coagulants used in the coagulation process, scale dispersants and bactericides used in the concentration process can be used as the attracting solution.
　正浸透膜処理工程において複数段の正浸透膜処理を行う場合、上記誘引溶液を組み合わせて用いてもよい。例えば、第１の正浸透膜処理工程の誘引溶液として塩化ナトリウム水溶液を用い、第２の正浸透膜処理工程の誘引溶液としてマグネシウム塩水溶液を用いる。また、例えば、第１の正浸透膜処理工程によって得られた希薄塩化ナトリウム溶液は、軟化樹脂の再生液として、第２の正浸透膜処理工程によって得られた希薄マグネシウム塩溶液は、溶解性シリカ除去工程のマグネシウム源として使用することができる。 場合 When performing a plurality of stages of forward osmosis membrane treatment in the forward osmosis membrane treatment step, the above attracting solutions may be used in combination. For example, an aqueous solution of sodium chloride is used as an inducing solution in the first forward osmosis membrane treatment step, and an aqueous solution of magnesium salt is used as an inducing solution in the second forward osmosis membrane treatment step. Further, for example, the dilute sodium chloride solution obtained in the first forward osmosis membrane treatment step is used as a regenerating solution of the softening resin, and the dilute magnesium salt solution obtained in the second forward osmosis membrane treatment step is used as a soluble silica. It can be used as a magnesium source in the removal step.
［第２濃縮処理工程］
　第２濃縮処理手段としては、正浸透膜処理工程で使用された希薄誘引溶液を濃縮することができるものであればよく、特に制限はないが、ナノろ過膜処理装置、逆浸透膜処理装置、正浸透膜処理装置、圧力補助逆浸透膜処理装置等の半透膜を用いる濃縮装置、ナノろ過膜等を用いる膜ろ過装置、蒸留装置、電気透析装置等のうち一つ以上を用いることができる。濃縮コスト低減等の観点から、半透膜を用いる濃縮装置が好ましく、特に被処理水のＴＤＳ濃度が５％を超える場合に浸透圧の影響を低減できる圧力補助逆浸透膜処理装置がより好ましい。 [Second concentration treatment step]
The second concentration treatment means is not particularly limited as long as it can concentrate the diluted attracting solution used in the forward osmosis membrane treatment step, and is not particularly limited, but a nanofiltration membrane treatment device, a reverse osmosis membrane treatment device, One or more of a concentrating device using a semipermeable membrane such as a forward osmosis membrane treatment device, a pressure-assisted reverse osmosis membrane treatment device, a membrane filtration device using a nanofiltration membrane, a distillation device, an electrodialysis device and the like can be used. . From the viewpoint of reducing the cost of concentration and the like, a concentration apparatus using a semipermeable membrane is preferable, and a pressure-assisted reverse osmosis membrane treatment apparatus that can reduce the influence of osmotic pressure when the TDS concentration of the water to be treated exceeds 5% is more preferable.
　図４に、本実施形態に係る水処理装置における濃縮装置の一例を示す。 FIG. 4 shows an example of a concentrator in the water treatment apparatus according to the present embodiment.
　図４に示す濃縮装置３４０は、圧力補助逆浸透膜処理装置の一例である。濃縮装置３４０は、半透膜を用いて処理対象水を濃縮する濃縮手段を２つ以上備え、第１段の半透膜の一次側に上記希薄誘引溶液を供給し、二次側に希薄液を供給し、一次側のもう一方の流路より濃縮液を、二次側のもう一方の流路から希釈液を得て、その希釈液を次段の半透膜の一次側に供給していき、各段の半透膜の一次側を加圧してその一次側に含まれる水を二次側に透過させ、順次濃縮液と希釈液を得る装置である。 濃縮 The concentration device 340 shown in FIG. 4 is an example of a pressure-assisted reverse osmosis membrane treatment device. The concentrating device 340 includes two or more concentrating means for concentrating the water to be treated using the semipermeable membrane, supplies the diluted attracting solution to the primary side of the first-stage semipermeable membrane, and supplies the diluted liquid to the secondary side. To obtain a concentrated solution from the other flow path on the primary side, a diluent from the other flow path on the secondary side, and supply the diluent to the primary side of the semipermeable membrane of the next stage. This is a device in which the primary side of the semipermeable membrane of each stage is pressurized to allow water contained in the primary side to permeate the secondary side, thereby sequentially obtaining a concentrate and a diluent.
　濃縮装置３４０は、例えば、１段目半透膜処理装置４２、２段目半透膜処理装置４４、３段目半透膜処理装置４６を備える。それぞれの半透膜処理装置は、半透膜５２で仕切られた一次側（第一空間）４８および二次側（第二空間）５０を有する。 The concentrating device 340 includes, for example, a first-stage semipermeable membrane processing device 42, a second-stage semipermeable membrane processing device 44, and a third-stage semipermeable membrane processing device 46. Each semipermeable membrane processing device has a primary side (first space) 48 and a secondary side (second space) 50 partitioned by a semipermeable membrane 52.
　図４に示す濃縮装置３４０において、１段目半透膜処理装置４２の一次側４８の入口には配管５４がポンプ７０を介して接続され、一次側４８の出口には配管５６が接続されている。２段目半透膜処理装置４４の一次側４８の出口と１段目半透膜処理装置４２の二次側５０の入口とは配管５８により接続され、１段目半透膜処理装置４２の二次側５０の出口と２段目半透膜処理装置４４の一次側４８の入口とはポンプ７２を介して配管６０により接続されている。３段目半透膜処理装置４６の一次側４８の出口と２段目半透膜処理装置４４の二次側５０の入口とは配管６２により接続され、２段目半透膜処理装置４４の二次側５０の出口と３段目半透膜処理装置４６の一次側４８の入口とはポンプ７４を介して配管６４により接続されている。３段目半透膜処理装置４６の二次側５０の入口には配管６６が接続され、二次側５０の出口には配管６８が接続されている。 In the concentration device 340 shown in FIG. 4, a pipe 54 is connected to an inlet of the primary side 48 of the first-stage semipermeable membrane processing apparatus 42 via a pump 70, and a pipe 56 is connected to an outlet of the primary side 48. I have. The outlet of the primary side 48 of the second-stage semipermeable membrane processing device 44 and the inlet of the secondary side 50 of the first-stage semipermeable membrane processing device 42 are connected by a pipe 58 and the first-stage semipermeable membrane processing device 42 The outlet of the secondary side 50 and the inlet of the primary side 48 of the second-stage semipermeable membrane processing device 44 are connected by a pipe 60 via a pump 72. The outlet of the primary side 48 of the third-stage semipermeable membrane processing device 46 and the inlet of the secondary side 50 of the second-stage semipermeable membrane processing device 44 are connected by a pipe 62, and the second-stage semipermeable membrane processing device 44 The outlet of the secondary side 50 and the inlet of the primary side 48 of the third-stage semipermeable membrane processing apparatus 46 are connected by a pipe 64 via a pump 74. A pipe 66 is connected to an inlet of the secondary side 50 of the third-stage semipermeable membrane processing apparatus 46, and a pipe 68 is connected to an outlet of the secondary side 50.
　濃縮装置３４０は、半透膜５２で仕切られた一次側４８および二次側５０を有する多段式の半透膜処理装置を用いる装置である。１段目半透膜処理装置４２の一次側４８にポンプ７０により配管５４を通して、被処理水である正浸透膜処理装置１４で使用された希薄誘引溶液（例えば、ＭｇＣｌ２：８質量％）の一部を通水し、二次側５０に配管５８を通して後述する２段目半透膜処理装置４４で得られた第２濃縮液（例えば、ＭｇＣｌ２：１０質量％）を通水し、一次側４８が加圧されてその一次側４８に含まれる水が二次側５０に透過され、第１濃縮液（例えば、ＭｇＣｌ２：３０質量％）および第１希釈液（例えば、ＭｇＣｌ２：５質量％）を得る（濃縮工程（１段目））。第１濃縮液（濃縮誘引溶液）は、配管５６を通して排出され、正浸透膜処理装置１４における誘引溶液として再度使用される。 The concentration device 340 is a device using a multi-stage semipermeable membrane processing device having a primary side 48 and a secondary side 50 separated by a semipermeable membrane 52. The primary attracting solution (eg, MgCl 2 : 8% by mass) used in the forward osmosis membrane treatment device 14 as the water to be treated is passed through the pipe 54 to the primary side 48 of the first-stage semipermeable membrane treatment device 42 by the pump 70. Part of the water is passed, and the second concentrated liquid (for example, MgCl 2 : 10% by mass) obtained in the second-stage semipermeable membrane processing device 44 described below is passed through the pipe 58 to the secondary side 50, The side 48 is pressurized and the water contained in its primary side 48 is permeated through the secondary side 50 and the first concentrate (eg, MgCl 2 : 30% by mass) and the first diluent (eg, MgCl 2 : 5). % By mass) (concentration step (first stage)). The first concentrated solution (concentrated attracting solution) is discharged through the pipe 56 and is used again as the attracting solution in the forward osmosis membrane treatment device 14.
　第１希釈液は、配管６０を通してポンプ７２により２段目半透膜処理装置４４の一次側４８に通水し、二次側５０に配管６２を通して後述する３段目半透膜処理装置４６で得られた第３濃縮液（例えば、ＭｇＣｌ２：３質量％）を通水し、一次側４８が加圧されてその一次側４８に含まれる水が二次側５０に透過され、第２濃縮液（例えば、ＭｇＣｌ２：１０質量％）および第２希釈液（例えば、ＭｇＣｌ２：１質量％）を得る（濃縮工程（２段目））。第２濃縮液は、配管５８を通して１段目半透膜処理装置４２の二次側５０に通水される。 The first diluent passes through the pipe 60 through a pump 72 to the primary side 48 of the second-stage semipermeable membrane processing apparatus 44, and passes through the secondary side 50 through a pipe 62, through a third-stage semipermeable membrane processing apparatus 46 described later. The obtained third concentrated liquid (for example, MgCl 2 : 3% by mass) is passed through, the primary side 48 is pressurized, the water contained in the primary side 48 is transmitted to the secondary side 50, and the second concentrated A liquid (eg, MgCl 2 : 10% by mass) and a second diluent (eg, MgCl 2 : 1% by mass) are obtained (concentration step (second stage)). The second concentrate is passed through the pipe 58 to the secondary side 50 of the first-stage semipermeable membrane processing device 42.
　第２希釈液は、配管６４を通してポンプ７４により３段目半透膜処理装置４６の一次側４８に通水し、二次側５０に配管６６を通して希薄液（例えば、ＭｇＣｌ２：１質量％）を通水し、一次側４８が加圧されてその一次側４８に含まれる水が二次側５０に透過され、第３濃縮液（例えば、ＭｇＣｌ２：３質量％）および第３希釈液（例えば、ＭｇＣｌ２：＜１質量％）を得る（濃縮工程（３段目））。第３濃縮液は、配管６２を通して２段目半透膜処理装置４４の二次側５０に通水される。第３希釈液は、配管６８を通して排出される。第２濃縮液、第３濃縮液の一部が正浸透膜処理装置１４における誘引溶液として再度使用されてもよい。第３希釈液は、必要に応じて限外ろ過膜（ＵＦ膜）処理、逆浸透膜（ＲＯ膜）処理、イオン交換処理等を実施したのち、回収、再利用されてもよい。 The second diluent is passed through the pipe 64 to the primary side 48 of the third-stage semipermeable membrane processing apparatus 46 by the pump 74, and the dilute liquid (eg, MgCl 2 : 1% by mass) is passed through the pipe 66 to the secondary side 50. The primary side 48 is pressurized and the water contained in the primary side 48 is permeated to the secondary side 50, and the third concentrated liquid (for example, MgCl 2 : 3% by mass) and the third diluent ( For example, MgCl 2 : <1% by mass is obtained (concentration step (third stage)). The third concentrate is passed through the pipe 62 to the secondary side 50 of the second-stage semipermeable membrane processing device 44. The third diluent is discharged through a pipe 68. A part of the second concentrate and the third concentrate may be used again as the attraction solution in the forward osmosis membrane treatment device 14. The third diluent may be collected and reused after performing an ultrafiltration membrane (UF membrane) treatment, a reverse osmosis membrane (RO membrane) treatment, an ion exchange treatment, or the like, as necessary.
　この圧力補助逆浸透膜処理装置は、一次側４８と二次側５０との浸透圧差を小さくして、通常の逆浸透膜処理装置よりも少ないエネルギーで運転を行うことができ、より低コストで運転を行うことができる。 This pressure-assisted reverse osmosis membrane treatment device can reduce the osmotic pressure difference between the primary side 48 and the secondary side 50, operate with less energy than a normal reverse osmosis membrane treatment device, and can be operated at lower cost. Driving can be performed.
　以上のようにして、上記希薄誘引溶液から得られた濃縮誘引溶液は、正浸透膜処理装置１４における誘引溶液として再度使用される。 濃縮 As described above, the concentrated attracting solution obtained from the diluted attracting solution is reused as the attracting solution in the forward osmosis membrane treatment device 14.
　図４に示す濃縮装置３４０において、１段目の半透膜処理装置４２の二次側５０および２段目以降の半透膜処理装置に通水する液は、１段目の半透膜処理装置４２の一次側４８に通水する希薄誘引溶液とは別成分の液であってもよい。図５に、このような濃縮装置の例を示す。 In the concentration device 340 shown in FIG. 4, the liquid passing through the secondary side 50 of the first-stage semipermeable membrane processing device 42 and the second-stage and subsequent semipermeable membrane treatment devices is supplied to the first-stage semipermeable membrane processing device. It may be a liquid of a different component from the dilute attracting solution that passes through the primary side 48 of the device 42. FIG. 5 shows an example of such a concentrator.
　図５に示す濃縮装置３４２は、図４に示す濃縮装置３４０と同様の構成を有する装置である。１段目半透膜処理装置４２の一次側４８にポンプ７０により配管５４を通して、被処理水である正浸透膜処理装置１４で使用された希薄誘引溶液（例えば、ＭｇＣｌ２：８質量％）の一部を通水し、二次側５０に配管５８を通して後述する２段目半透膜処理装置４４で得られた第２濃縮液（例えば、グルコース：２０質量％）を通水し、一次側４８が加圧されてその一次側４８に含まれる水が二次側５０に透過され、第１濃縮液（例えば、ＭｇＣｌ２：３０質量％）および第１希釈液（例えば、グルコース：１０質量％）を得る（濃縮工程（１段目））。第１濃縮液（濃縮誘引溶液）は、配管５６を通して排出され、正浸透膜処理装置１４における誘引溶液として再度使用される。 The concentration device 342 shown in FIG. 5 is a device having the same configuration as the concentration device 340 shown in FIG. The primary attracting solution (eg, MgCl 2 : 8% by mass) used in the forward osmosis membrane treatment device 14 as the water to be treated is passed through the pipe 54 to the primary side 48 of the first-stage semipermeable membrane treatment device 42 by the pump 70. Part of the water is passed through, and the second concentrated liquid (for example, glucose: 20% by mass) obtained in the second-stage semipermeable membrane processing device 44 described below is passed through the pipe 58 to the secondary side 50, 48 is pressurized and the water contained in its primary side 48 is permeated to the secondary side 50, and the first concentrated liquid (eg, MgCl 2 : 30% by mass) and the first diluent (eg, glucose: 10% by mass) ) Is obtained (concentration step (first stage)). The first concentrated solution (concentrated attracting solution) is discharged through the pipe 56 and is used again as the attracting solution in the forward osmosis membrane treatment device 14.
　第１希釈液は、配管６０を通してポンプ７２により２段目半透膜処理装置４４の一次側４８に通水し、二次側５０に配管６２を通して後述する３段目半透膜処理装置４６で得られた第３濃縮液（例えば、ＮａＣｌ：３質量％）を通水し、一次側４８が加圧されてその一次側４８に含まれる水が二次側５０に透過され、第２濃縮液（例えば、グルコース：２０質量％）および第２希釈液（例えば、ＮａＣｌ：１質量％）を得る（濃縮工程（２段目））。第２濃縮液は、配管５８を通して１段目半透膜処理装置４２の二次側５０に通水される。 The first diluent passes through the pipe 60 through a pump 72 to the primary side 48 of the second-stage semipermeable membrane processing apparatus 44, and passes through the secondary side 50 through a pipe 62, through a third-stage semipermeable membrane processing apparatus 46 described later. The obtained third concentrated liquid (for example, NaCl: 3% by mass) is passed through, the primary side 48 is pressurized, and the water contained in the primary side 48 is transmitted to the secondary side 50, and the second concentrated liquid (Eg, glucose: 20% by mass) and a second diluent (eg, NaCl: 1% by mass) are obtained (concentration step (second stage)). The second concentrate is passed through the pipe 58 to the secondary side 50 of the first-stage semipermeable membrane processing device 42.
　第２希釈液は、配管６４を通してポンプ７４により３段目半透膜処理装置４６の一次側４８に通水し、二次側５０に配管６６を通して希薄液（例えば、ＮａＣｌ：１質量％）を通水し、一次側４８が加圧されてその一次側４８に含まれる水が二次側５０に透過され、第３濃縮液（例えば、ＮａＣｌ：３質量％）および第３希釈液（例えば、ＮａＣｌ：＜１質量％）を得る（濃縮工程（３段目））。第３濃縮液は、配管６２を通して２段目半透膜処理装置４４の二次側５０に通水される。第３希釈液は、配管６８を通して排出される。第３希釈液は、必要に応じて限外ろ過膜（ＵＦ膜）処理、逆浸透膜（ＲＯ膜）処理、イオン交換処理等を実施したのち、回収、再利用されてもよい。 The second diluent passes through the primary side 48 of the third-stage semipermeable membrane treatment device 46 by the pump 74 through the pipe 64 and the dilute liquid (for example, NaCl: 1% by mass) passes through the pipe 66 to the secondary side 50. When the water is passed, the primary side 48 is pressurized and the water contained in the primary side 48 is transmitted to the secondary side 50, and the third concentrated liquid (for example, NaCl: 3% by mass) and the third diluted liquid (for example, NaCl: <1% by mass) (concentration step (third stage)). The third concentrate is passed through the pipe 62 to the secondary side 50 of the second-stage semipermeable membrane processing device 44. The third diluent is discharged through a pipe 68. The third diluent may be collected and reused after performing an ultrafiltration membrane (UF membrane) treatment, a reverse osmosis membrane (RO membrane) treatment, an ion exchange treatment, or the like, as necessary.
　１段目の半透膜処理装置４２の二次側５０および２段目以降の半透膜処理装置に通水する液は、浸透圧を有している液であればよく、特に制限はない。例えば、塩化ナトリウム等の無機塩類を含む水溶液、グルコース等の有機物を含む水溶液、ポリマーを含む水溶液や、イオン液体等が挙げられる。１次側から２次側への成分拡散の影響を低減する等の観点から、１段目の半透膜処理装置４２の一次側４８に通水する希薄誘引溶液と同じ成分の液を用いることが好ましい。 The liquid passing through the secondary side 50 of the first-stage semipermeable membrane processing device 42 and the semipermeable membrane processing devices of the second and subsequent stages may be any liquid having an osmotic pressure, and is not particularly limited. . Examples thereof include an aqueous solution containing an inorganic salt such as sodium chloride, an aqueous solution containing an organic substance such as glucose, an aqueous solution containing a polymer, and an ionic liquid. From the viewpoint of reducing the influence of component diffusion from the primary side to the secondary side, use of a liquid having the same components as the dilute attracting solution passing through the primary side 48 of the first-stage semipermeable membrane processing device 42 Is preferred.
　図６に、本実施形態に係る水処理装置５における濃縮装置３４の他の例を示す。 FIG. 6 shows another example of the concentration device 34 in the water treatment device 5 according to the present embodiment.
　図６に示す濃縮装置３４４は、圧力補助逆浸透膜処理装置の一例である。濃縮装置３４４は、半透膜を用いて処理対象水を濃縮し、その濃縮液をさらに半透膜を用いて濃縮する濃縮手段を１つ以上備え、第１段の半透膜の一次側に前記希薄誘引溶液を供給し、その濃縮液を各段の半透膜の一次側に順に供給し、各段の半透膜の二次側に前記希薄誘引溶液の一部またはいずれかの段の濃縮液の一部を供給し、各段の半透膜の一次側を加圧してその一次側に含まれる水を二次側に透過させる装置である。 濃縮 The concentration device 344 shown in FIG. 6 is an example of a pressure-assisted reverse osmosis membrane treatment device. The concentrating device 344 includes one or more concentrating means for concentrating the water to be treated using a semi-permeable membrane and further concentrating the concentrated liquid using a semi-permeable membrane, and is provided on the primary side of the first-stage semi-permeable membrane. The diluted attracting solution is supplied, and the concentrated liquid is sequentially supplied to the primary side of the semipermeable membrane of each stage, and a part of the diluted attracting solution or any one of the stages is arranged on the secondary side of the semipermeable membrane of each stage. This is a device that supplies a part of the concentrated liquid, pressurizes the primary side of the semipermeable membrane of each stage, and permeates water contained in the primary side to the secondary side.
　濃縮装置３４４は、例えば、１段目半透膜処理装置７８、２段目半透膜処理装置８０、３段目半透膜処理装置８２を備える。それぞれの半透膜処理装置は、半透膜８８で仕切られた一次側（第一空間）８４および二次側（第二空間）８６を有する。 The concentrating device 344 includes, for example, a first-stage semipermeable membrane processing device 78, a second-stage semipermeable membrane processing device 80, and a third-stage semipermeable membrane processing device 82. Each semipermeable membrane processing device has a primary side (first space) 84 and a secondary side (second space) 86 partitioned by a semipermeable membrane 88.
　図６に示す濃縮装置３４４において、１段目半透膜処理装置７８の一次側８４の入口には配管９０がポンプ１０６を介して接続されている。１段目半透膜処理装置７８の一次側８４の出口と２段目半透膜処理装置８０の一次側８４の入口とは配管９２により接続されている。２段目半透膜処理装置８０の一次側８４の出口と３段目半透膜処理装置８２の一次側８４の入口とは配管９４により接続されている。３段目半透膜処理装置８２の一次側８４の出口には配管９６が接続されている。配管９６から分岐した配管９８が、３段目半透膜処理装置８２の二次側８６の入口に接続されている。３段目半透膜処理装置８２の二次側８６の出口と２段目半透膜処理装置８０の二次側８６の入口とは配管１００により接続されている。２段目半透膜処理装置８０の二次側８６の出口と１段目半透膜処理装置７８の二次側８６の入口とは配管１０２により接続されている。１段目半透膜処理装置７８の二次側８６の出口には配管１０４が接続されている。必要に応じて、配管９２，９４，９６，９８，１００，１０２に、加圧、送液用のポンプ、半透膜にかかる圧力を調整するための、バルブ等の圧力調整機構、処理水を一時的に貯留するためのタンク等を備えてもよい。 に お い て In the concentration device 344 shown in FIG. 6, a pipe 90 is connected via a pump 106 to an inlet of the primary side 84 of the first-stage semipermeable membrane processing device 78. The outlet of the primary side 84 of the first-stage semipermeable membrane processing apparatus 78 and the inlet of the primary side 84 of the second-stage semipermeable membrane processing apparatus 80 are connected by a pipe 92. The outlet of the primary side 84 of the second-stage semipermeable membrane processing apparatus 80 and the inlet of the primary side 84 of the third-stage semipermeable membrane processing apparatus 82 are connected by a pipe 94. A pipe 96 is connected to an outlet of the primary side 84 of the third-stage semipermeable membrane processing device 82. A pipe 98 branched from the pipe 96 is connected to an inlet on the secondary side 86 of the third-stage semipermeable membrane processing device 82. The outlet of the secondary side 86 of the third-stage semipermeable membrane processing apparatus 82 and the inlet of the secondary side 86 of the second-stage semipermeable membrane processing apparatus 80 are connected by a pipe 100. The outlet of the secondary side 86 of the second-stage semipermeable membrane processing apparatus 80 and the inlet of the secondary side 86 of the first-stage semipermeable membrane processing apparatus 78 are connected by a pipe 102. A pipe 104 is connected to an outlet on the secondary side 86 of the first-stage semipermeable membrane processing device 78. If necessary, the pipes 92, 94, 96, 98, 100, 102 are supplied with a pressure adjusting mechanism such as a valve for adjusting pressure applied to the semi-permeable membrane, a pump for pressurization and liquid sending, and treated water. A tank or the like for temporarily storing may be provided.
　濃縮装置３４４において、被処理水である正浸透膜処理装置１４で使用された希薄誘引溶液（例えば、ＭｇＣｌ２：１０質量％）の一部は、ポンプ１０６により配管９０を通して、１段目半透膜処理装置７８の一次側８４へ送液される。一方、後述する最終段の３段目半透膜処理装置８２から２段目半透膜処理装置８０の二次側８６を経由して返送された希釈液（二次側処理水）（例えば、ＭｇＣｌ２：６質量％）が配管１０２を通して、１段目半透膜処理装置７８の二次側８６へ送液される。１段目半透膜処理装置７８において、半透膜の一次側８４が加圧されてその一次側８４に含まれる水が二次側８６に透過される（濃縮工程（１段目））。 In the concentration device 344, a part of the diluted attracting solution (for example, MgCl 2 : 10% by mass) used in the forward osmosis membrane treatment device 14, which is the water to be treated, is passed through the pipe 90 by the pump 106, and is subjected to the first-stage semipermeable treatment. The liquid is sent to the primary side 84 of the film processing apparatus 78. On the other hand, the diluent (secondary-side treated water) returned from the third-stage semipermeable membrane processing device 82 in the final stage described below via the secondary side 86 of the second-stage semipermeable membrane processing device 80 (for example, (MgCl 2 : 6% by mass) is sent to the secondary side 86 of the first-stage semipermeable membrane processing apparatus 78 through the pipe 102. In the first-stage semipermeable membrane processing apparatus 78, the primary side 84 of the semipermeable membrane is pressurized, and water contained in the primary side 84 is transmitted to the secondary side 86 (concentration step (first stage)).
　１段目半透膜処理装置７８の濃縮液（一次側処理水）（例えば、ＭｇＣｌ２：１８質量％）は、配管９２を通して、２段目半透膜処理装置８０の一次側８４へ送液される。一方、後述する最終段の３段目半透膜処理装置８２から返送された希釈液（二次側処理水）（例えば、ＭｇＣｌ２：１５質量％）が配管１００を通して、２段目半透膜処理装置８０の二次側８６へ送液される。１段目と同様にして、２段目半透膜処理装置８０において、半透膜の一次側８４が加圧されてその一次側８４に含まれる水が二次側８６に透過される（濃縮工程（２段目））。 The concentrated liquid (primary treatment water) (eg, MgCl 2 : 18% by mass) of the first-stage semipermeable membrane processing apparatus 78 is sent to the primary side 84 of the second-stage semipermeable membrane processing apparatus 80 through a pipe 92. Is done. On the other hand, the diluent (secondary treated water) (eg, MgCl 2 : 15% by mass) returned from the third-stage semipermeable membrane processing device 82 in the final stage described later passes through the pipe 100 and passes through the second-stage semipermeable membrane. The liquid is sent to the secondary side 86 of the processing device 80. Similarly to the first stage, in the second-stage semipermeable membrane processing device 80, the primary side 84 of the semipermeable membrane is pressurized, and the water contained in the primary side 84 is permeated to the secondary side 86 (concentration). Step (second stage)).
　２段目半透膜処理装置８０の濃縮液（一次側処理水）（例えば、ＭｇＣｌ２：２３質量％）は、配管９４を通して、３段目半透膜処理装置８２の一次側８４へ送液される。一方、後述する最終段の３段目半透膜処理装置８２から返送された濃縮液（例えば、ＭｇＣｌ２：３０質量％）は、配管９８を通して、３段目半透膜処理装置８２の二次側８６へ送液される。１，２段目と同様にして、３段目半透膜処理装置８２において、半透膜の一次側８４が加圧されてその一次側８４に含まれる水が二次側８６に透過される（濃縮工程（３段目））。 The concentrated liquid (primary treatment water) (for example, MgCl 2 : 23% by mass) of the second-stage semipermeable membrane processing apparatus 80 is sent to the primary side 84 of the third-stage semipermeable membrane processing apparatus 82 through a pipe 94. Is done. On the other hand, the concentrated liquid (for example, MgCl 2 : 30% by mass) returned from the third-stage semipermeable membrane processing device 82 of the final stage described below passes through the pipe 98 to the secondary of the third-stage semipermeable membrane processing device 82. The liquid is sent to the side 86. In the same manner as in the first and second stages, in the third-stage semipermeable membrane processing device 82, the primary side 84 of the semipermeable membrane is pressurized, and the water contained in the primary side 84 is transmitted to the secondary side 86. (Concentration step (third stage)).
　最終段の３段目半透膜処理装置８２の濃縮液（一次側処理水）（例えば、ＭｇＣｌ２：３０質量％）の一部は、配管９６を通して排出され、正浸透膜処理装置１４における誘引溶液として再度使用される。３段目半透膜処理装置８２の濃縮液の残りの一部は、配管９６，９８を通して、３段目半透膜処理装置８２の二次側８６へ送液される。上記の通り、３段目半透膜処理装置８２において、半透膜の一次側８４が加圧されてその一次側８４に含まれる水が二次側８６に透過される（濃縮工程（３段目））。 A part of the concentrated liquid (primary-side treated water) (for example, MgCl 2 : 30% by mass) in the third-stage semipermeable membrane processing device 82 in the final stage is discharged through a pipe 96 and attracted in the forward osmosis membrane processing device 14. Used again as a solution. The remaining part of the concentrated liquid in the third-stage semipermeable membrane processing device 82 is sent to the secondary side 86 of the third-stage semipermeable membrane processing device 82 through pipes 96 and 98. As described above, in the third-stage semipermeable membrane processing device 82, the primary side 84 of the semipermeable membrane is pressurized, and the water contained in the primary side 84 is transmitted to the secondary side 86 (the concentration step (the third step)). Eye)).
　３段目半透膜処理装置８２の希釈液（二次側処理水）（例えば、ＭｇＣｌ２：１５質量％）は、配管１００を通して、２段目半透膜処理装置８０の二次側８６へ送液される。上記の通り、２段目半透膜処理装置８０において、半透膜の一次側８４が加圧されてその一次側８４に含まれる水が二次側８６に透過される（濃縮工程（２段目））。 The diluent (secondary treated water) (for example, MgCl 2 : 15% by mass) in the third-stage semipermeable membrane processing device 82 passes through the pipe 100 to the secondary side 86 of the second-stage semipermeable membrane processing device 80. It is sent. As described above, in the second-stage semipermeable membrane processing apparatus 80, the primary side 84 of the semipermeable membrane is pressurized, and the water contained in the primary side 84 is transmitted to the secondary side 86 (concentration step (second step)). Eye)).
　２段目半透膜処理装置８０の希釈液（二次側処理水）（例えば、ＭｇＣｌ２：６質量％）は、配管１０２を通して、１段目半透膜処理装置７８の二次側８６へ送液される。上記の通り、１段目半透膜処理装置７８において、半透膜の一次側８４が加圧されてその一次側８４に含まれる水が二次側８６に透過される（濃縮工程（１段目））。１段目半透膜処理装置７８の希釈液（二次側処理水）（例えば、ＭｇＣｌ２：＜１質量％）は、配管１０４を通して排出される。希釈液は、必要に応じて限外ろ過膜（ＵＦ膜）処理、逆浸透膜（ＲＯ膜）処理、イオン交換処理等を実施したのち、回収、再利用されてもよい。 The diluent (secondary-side treated water) (for example, MgCl 2 : 6% by mass) of the second-stage semipermeable membrane processing apparatus 80 passes through the pipe 102 to the secondary side 86 of the first-stage semipermeable membrane processing apparatus 78. It is sent. As described above, in the first-stage semipermeable membrane processing apparatus 78, the primary side 84 of the semipermeable membrane is pressurized, and the water contained in the primary side 84 is transmitted to the secondary side 86 (concentration step (first stage). Eye)). The diluent (secondary treatment water) (for example, MgCl 2 : <1% by mass) of the first-stage semipermeable membrane treatment device 78 is discharged through the pipe 104. The diluent may be collected and reused after performing an ultrafiltration membrane (UF membrane) treatment, a reverse osmosis membrane (RO membrane) treatment, an ion exchange treatment, and the like, as necessary.
　この濃縮装置３４４のような圧力補助逆浸透膜処理装置は、被処理水の一部を浸透圧補助用の希釈用液として使用するため、別途希釈液を用意しなくてもよく、装置構成も濃縮装置３４０のような圧力補助逆浸透膜処理装置より簡略化することができる。 Since a pressure-assisted reverse osmosis membrane treatment device such as the concentrator 344 uses a part of the water to be treated as a diluent for osmotic pressure assistance, it is not necessary to prepare a separate diluent, and the device configuration is also reduced. It can be simpler than a pressure-assisted reverse osmosis membrane treatment device such as the concentration device 340.
　以上のようにして、上記希薄誘引溶液から得られた濃縮誘引溶液は、正浸透膜処理装置１４における誘引溶液として再度使用される。 濃縮 As described above, the concentrated attracting solution obtained from the diluted attracting solution is reused as the attracting solution in the forward osmosis membrane treatment device 14.
　濃縮装置３４４のような圧力補助逆浸透膜処理装置において、各段の半透膜の二次側に正浸透膜処理装置１４で使用された希薄誘引溶液の一部またはいずれかの段の濃縮液の一部を供給すればよく、その方法に特に制限はない。 In a pressure-assisted reverse osmosis membrane treatment device such as the concentration device 344, a part of the diluted attracting solution used in the forward osmosis membrane treatment device 14 or the concentrate of any one of the stages is provided on the secondary side of the semipermeable membrane of each stage. May be supplied, and there is no particular limitation on the method.
　例えば、図７の濃縮装置３４６として示すように、被処理水である正浸透膜処理装置１４で使用された希薄誘引溶液を分配して、１段目半透膜処理装置７８の一次側８４、二次側８６にそれぞれ供給し、その濃縮液および透過液を各段の半透膜の一次側８４および二次側８６にそれぞれ順に供給し、各段の半透膜の一次側を加圧してその一次側に含まれる水を二次側に透過させでもよい。 For example, as shown as a concentration device 346 in FIG. 7, the diluted attracting solution used in the forward osmosis membrane treatment device 14 as the water to be treated is distributed, and the primary side 84 of the first-stage semipermeable membrane treatment device 78, The concentrated liquid and the permeated liquid are supplied to the secondary side 86, respectively, and the concentrated liquid and the permeated liquid are sequentially supplied to the primary side 84 and the secondary side 86 of the semipermeable membrane of each stage, respectively, and the primary side of the semipermeable membrane of each stage is pressurized. Water contained in the primary side may be transmitted to the secondary side.
　図８の濃縮装置３４８として示すように、被処理水である正浸透膜処理装置１４で使用された希薄誘引溶液を１段目半透膜処理装置７８の一次側８４に供給し、その濃縮液を各段の半透膜の一次側に順に供給し、最終段の３段目半透膜処理装置８２の濃縮液の一部を１段目半透膜処理装置７８の二次側８６に供給し、その透過液を各段の半透膜の二次側に順に供給し、各段の半透膜の一次側を加圧してその一次側に含まれる水を二次側に透過させてもよい。 As shown as a concentration device 348 in FIG. 8, the diluted attracting solution used in the forward osmosis membrane treatment device 14 as the water to be treated is supplied to the primary side 84 of the first-stage semipermeable membrane treatment device 78, and the concentrated solution Is supplied to the primary side of the semipermeable membrane of each stage in order, and a part of the concentrated solution of the third stage semipermeable membrane processing device 82 at the final stage is supplied to the secondary side 86 of the first stage semipermeable membrane processing device 78 Then, the permeated liquid is sequentially supplied to the secondary side of the semipermeable membrane of each stage, and the water contained in the primary side is permeated to the secondary side by pressurizing the primary side of the semipermeable membrane of each stage. Good.
　図９の濃縮装置３５０として示すように、被処理水である正浸透膜処理装置１４で使用された希薄誘引溶液を１段目半透膜処理装置７８の一次側８４に供給し、その濃縮液を各段の半透膜の一次側に順に供給し、各段の半透膜処理装置の濃縮液の一部をその半透膜処理装置自身の二次側８６に供給し、各段の半透膜の一次側を加圧してその一次側に含まれる水を二次側に透過させてもよい。 As shown as a concentration device 350 in FIG. 9, the diluted attracting solution used in the forward osmosis membrane treatment device 14, which is water to be treated, is supplied to the primary side 84 of the first-stage semipermeable membrane treatment device 78, and the concentrated solution Is supplied to the primary side of the semipermeable membrane of each stage in order, and a part of the concentrated liquid of the semipermeable membrane processing device of each stage is supplied to the secondary side 86 of the semipermeable membrane processing device itself. The primary side of the permeable membrane may be pressurized to allow water contained in the primary side to permeate the secondary side.
　上記濃縮装置３４０，３４２，３４４，３４６，３４８，３５０において、半透膜処理装置の段数は、目的の処理水の濃度等によって決めればよい。例えば、濃縮装置３４４，３４６，３４８，３５０において、より薄い濃度の希薄誘引溶液からより濃い濃度の処理水（濃縮誘引溶液）を得たい場合には、半透膜処理装置の段数を増やせばよい。 に お い て In the concentration devices 340, 342, 344, 346, 348, and 350, the number of stages of the semipermeable membrane treatment device may be determined according to the concentration of the target treated water. For example, in the concentrators 344, 346, 348, and 350, when it is desired to obtain treated water having a higher concentration (concentrated attracting solution) from a dilute attracting solution having a lower concentration, the number of stages of the semipermeable membrane treatment device may be increased. .
　上記濃縮装置３４０，３４２，３４４，３４６，３４８，３５０において、各段の半透膜処理装置として、並列的に接続された２つ以上の膜モジュールを備える膜モジュールユニットを用いてもよい。各膜モジュールユニットにおける膜モジュールの本数は、処理対象の希薄誘引溶液の流量等によって決めればよい。 In the concentrators 340, 342, 344, 346, 348, and 350, a membrane module unit including two or more membrane modules connected in parallel may be used as the semipermeable membrane processing device in each stage. The number of membrane modules in each membrane module unit may be determined according to the flow rate of the diluted attracting solution to be treated.
　半透膜処理装置が備える半透膜としては、例えば、逆浸透膜（ＲＯ膜）、正浸透膜（ＦＯ膜）、ナノろ過膜（ＮＦ膜）等の半透膜が挙げられる。半透膜は、逆浸透膜、正浸透膜、ナノろ過膜が好ましい。なお、半透膜として逆浸透膜または正浸透膜、ナノろ過膜を用いる場合、一次側の対象溶液の圧力は、好ましくは０．５～１０．０ＭＰａである。 (5) Examples of the semipermeable membrane provided in the semipermeable membrane processing apparatus include semipermeable membranes such as a reverse osmosis membrane (RO membrane), a forward osmosis membrane (FO membrane), and a nanofiltration membrane (NF membrane). The semipermeable membrane is preferably a reverse osmosis membrane, a forward osmosis membrane, or a nanofiltration membrane. When a reverse osmosis membrane, a forward osmosis membrane, or a nanofiltration membrane is used as the semipermeable membrane, the pressure of the target solution on the primary side is preferably 0.5 to 10.0 MPa.
　半透膜を構成する材料としては、特に限定されないが、例えば、酢酸セルロース系樹脂等のセルロース系樹脂、ポリエーテルスルホン系樹脂等のポリスルホン系樹脂、ポリアミド系樹脂等が挙げられる。半透膜を構成する材料は、酢酸セルロース系樹脂であることが好ましい。 材料 A material constituting the semipermeable membrane is not particularly limited, and examples thereof include a cellulose resin such as a cellulose acetate resin, a polysulfone resin such as a polyethersulfone resin, and a polyamide resin. The material constituting the semipermeable membrane is preferably a cellulose acetate resin.
　半透膜の形状としては、膜の一次側と二次側にそれぞれ溶液が供給できる構造をとっていれば特に限定されず、スパイラル型、中空糸膜、プレートアンドフレーム型等が挙げられる。 形状 The shape of the semipermeable membrane is not particularly limited as long as it has a structure capable of supplying a solution to each of the primary side and the secondary side of the membrane, and examples thereof include a spiral type, a hollow fiber membrane, and a plate and frame type.
［水処理装置の他の例］
　本発明の実施形態に係る水処理装置の他の例の概略構成を図２に示す。図２に示す水処理装置３は、水酸化マグネシウムと酸とを混合し、ｐＨ７以下で反応させて、誘引溶液として使用するマグネシウム塩水溶液を調製する調製手段として、誘引溶液調製槽３０をさらに備える。 [Other examples of water treatment equipment]
FIG. 2 shows a schematic configuration of another example of the water treatment apparatus according to the embodiment of the present invention. The water treatment apparatus 3 shown in FIG. 2 further includes an attraction solution preparation tank 30 as a preparation means for mixing magnesium hydroxide and an acid and reacting them at a pH of 7 or less to prepare an aqueous magnesium salt solution to be used as an attraction solution. .
　図２の水処理装置３において、誘引溶液調製槽３０の出口と正浸透膜処理装置１４の誘引溶液入口とは、誘引溶液配管３２により接続されている。 に お い て In the water treatment device 3 of FIG. 2, the outlet of the attraction solution preparation tank 30 and the attraction solution inlet of the forward osmosis membrane treatment device 14 are connected by the attraction solution piping 32.
　図１の水処理装置１と同様にして、溶解性シリカ除去工程および硬度成分除去工程のうちいずれか１つを含む前処理工程と、前処理工程で得られた前処理水を濃縮処理する濃縮処理工程と、が行われる。 In the same manner as in the water treatment apparatus 1 of FIG. 1, a pretreatment step including one of a soluble silica removal step and a hardness component removal step, and a concentration treatment for concentrating pretreatment water obtained in the pretreatment step. And a processing step.
　一方、誘引溶液調製槽３０において、水酸化マグネシウムと酸とが混合され、ｐＨ７以下で反応されて、誘引溶液として使用するマグネシウム塩水溶液が調製される（調製工程）。 On the other hand, in the attraction solution preparation tank 30, magnesium hydroxide and an acid are mixed and reacted at pH 7 or less to prepare a magnesium salt aqueous solution to be used as the attraction solution (preparation step).
　逆浸透膜処理により得られた濃縮水は、正浸透膜処理装置１４において正浸透膜処理される（正浸透膜処理工程）。正浸透膜処理装置１４において、誘引溶液調製槽３０で調製された誘引溶液が誘引溶液配管３２を通して正浸透膜の２次側に送液され、正浸透膜を介して、濃縮水と誘引溶液を存在させることにより、浸透圧で水が誘引溶液に移動される。 The concentrated water obtained by the reverse osmosis membrane treatment is subjected to a forward osmosis membrane treatment in the forward osmosis membrane treatment device 14 (forward osmosis membrane treatment step). In the forward osmosis membrane treatment device 14, the attractant solution prepared in the attractant solution preparation tank 30 is sent to the secondary side of the forward osmosis membrane through the attractant solution pipe 32, and the concentrated water and the attractant solution are passed through the forward osmosis membrane. The presence causes osmotic pressure to transfer water to the attracting solution.
　正浸透膜処理工程で使用された希薄誘引溶液は、希薄誘引溶液配管２６を通して前処理装置１０へ送液され、前処理装置１０において前処理工程で使用される。 希 The dilute attractant used in the forward osmosis membrane treatment step is sent to the pretreatment device 10 through the dilute attractant solution pipe 26, and is used in the pretreatment device 10 in the pretreatment step.
　図３の水処理装置５において、図２の水処理装置３と同様に、水酸化マグネシウムと酸とを混合し、ｐＨ７以下で反応させて、誘引溶液として使用するマグネシウム塩水溶液を調製する調製手段として誘引溶液調製槽をさらに備えてもよい。誘引溶液調製槽において、水酸化マグネシウムと酸とを混合し、ｐＨ７以下で反応させて、マグネシウム塩水溶液を調製し（調製工程）、調製したマグネシウム塩水溶液を正浸透膜処理装置１４の正浸透膜の２次側に送液し、誘引溶液として使用すればよい。 In the water treatment apparatus 5 of FIG. 3, as in the case of the water treatment apparatus 3 of FIG. 2, a preparation means for mixing magnesium hydroxide and an acid and reacting the mixture at a pH of 7 or less to prepare a magnesium salt aqueous solution to be used as an attraction solution. , An inducing solution preparation tank may be further provided. In the attracting solution preparation tank, magnesium hydroxide and an acid are mixed and reacted at a pH of 7 or less to prepare an aqueous solution of a magnesium salt (preparation step). May be sent to the secondary side of the above to be used as an attraction solution.
　調製工程で用いられる酸としては、塩酸、硫酸、硝酸等が挙げられ、難溶解性物質生成抑制等の観点から、塩酸または硝酸が好ましい。 (4) Examples of the acid used in the preparation step include hydrochloric acid, sulfuric acid, nitric acid and the like, and hydrochloric acid or nitric acid is preferable from the viewpoint of suppressing the formation of hardly soluble substances.
　調製工程におけるｐＨは７以下であればよく、特に制限はないが、例えば、ｐＨ１～７の範囲であり、２～５の範囲であることが好ましい。調製工程におけるｐＨが７を超えると、マグネシウム塩の溶解が不十分となる場合があり、１未満であると、酸の添加量が過剰となる場合がある。 ＰＨ The pH in the preparation step is not particularly limited as long as it is 7 or less, and is, for example, in the range of 1 to 7 and preferably in the range of 2 to 5. If the pH in the preparation step exceeds 7, the dissolution of the magnesium salt may be insufficient, and if it is less than 1, the amount of the acid added may be excessive.
　調製工程における温度は、マグネシウム塩の溶解反応が進行する温度であればよく、特に制限はないが、例えば、１℃～８０℃の範囲である。調製工程における温度が１℃未満であると、マグネシウム塩の溶解反応が不十分となる場合があり、８０℃を超えると、設備の耐熱性等が問題となる場合がある。 温度 The temperature in the preparation step is not particularly limited as long as the dissolution reaction of the magnesium salt proceeds, and is, for example, in the range of 1 ° C to 80 ° C. If the temperature in the preparation step is less than 1 ° C., the dissolution reaction of the magnesium salt may be insufficient, and if it exceeds 80 ° C., the heat resistance of the equipment may become a problem.
　調製工程における反応時間は、マグネシウム塩の溶解反応が進行することができればよく、特に制限はないが、例えば、５分～１２０分の範囲である。調製工程における反応時間が５分未満であると、マグネシウム塩の溶解反応が不十分となる場合があり、１２０分を超えると、設備が課題となる場合がある。 The reaction time in the preparation step is not particularly limited as long as the dissolution reaction of the magnesium salt can proceed, and is, for example, in the range of 5 minutes to 120 minutes. If the reaction time in the preparation step is less than 5 minutes, the dissolution reaction of the magnesium salt may be insufficient, and if it exceeds 120 minutes, equipment may be a problem.
＜正浸透膜処理方法および正浸透膜処理システム＞
　本発明の実施形態に係る正浸透膜処理システムの一例の概略を図１１に示し、その構成について説明する。 <Forward osmosis membrane treatment method and forward osmosis membrane treatment system>
FIG. 11 shows an outline of an example of a forward osmosis membrane processing system according to an embodiment of the present invention, and its configuration will be described.
　本実施形態に係る正浸透膜処理システム８は、被処理水（ＦＯ被処理水）と、被処理水（ＦＯ被処理水）よりも高濃度の誘引溶液とを、正浸透膜１１０を介して接触させることによって、濃縮水（ＦＯ濃縮水）と希薄誘引溶液とを得る正浸透膜処理手段としての正浸透膜処理装置１４を備える。 The forward osmosis membrane processing system 8 according to the present embodiment, through the forward osmosis membrane 110, the water to be treated (FO treated water) and the attracting solution having a higher concentration than the treated water (FO treated water). A forward osmosis membrane treatment device 14 is provided as forward osmosis membrane treatment means for obtaining a concentrated water (FO concentrated water) and a dilute attractant solution by bringing them into contact with each other.
　図１１の正浸透膜処理システム８において、正浸透膜処理装置１４のＦＯ被処理水入口には、ＦＯ被処理水配管１６が接続され、ＦＯ濃縮水出口には、ＦＯ濃縮水配管２８が接続されている。正浸透膜処理装置１４の誘引溶液入口には、誘引溶液配管２４が接続され、希薄誘引溶液出口には、希薄誘引溶液配管２６が接続されている。ＦＯ被処理水配管１６には、殺菌剤添加手段として、殺菌剤添加配管１１２が接続されている。 In the forward osmosis membrane treatment system 8 of FIG. 11, the FO to-be-treated water pipe 16 is connected to the FO to-be-treated water inlet of the forward osmosis membrane treatment apparatus 14, and the FO concentrated water pipe 28 is connected to the FO concentrated water outlet. Have been. The attracting solution inlet 24 of the forward osmosis membrane treatment apparatus 14 is connected to an attracting solution pipe 24, and the diluted attracting solution outlet is connected to a diluted attracting solution pipe 26. A germicide addition pipe 112 is connected to the FO treated water pipe 16 as a germicide addition means.
　本実施形態に係る正浸透膜処理方法および正浸透膜処理システム８の動作について説明する。 The operation of the forward osmosis membrane processing method and the forward osmosis membrane processing system 8 according to the present embodiment will be described.
　ＦＯ被処理水は、ＦＯ被処理水配管１６を通して正浸透膜処理装置１４の１次側へ送液され、正浸透膜処理装置１４において正浸透膜処理される（正浸透膜処理工程）。正浸透膜処理装置１４において、誘引溶液が誘引溶液配管２４を通して正浸透膜の２次側に送液され、正浸透膜１１０を介して、ＦＯ被処理水と誘引溶液を存在させることにより、浸透圧で水が誘引溶液に移動される。正浸透膜処理工程で使用された希薄誘引溶液は、希薄誘引溶液配管２６を通して排出される。正浸透膜処理工程で得られたＦＯ濃縮水は、ＦＯ濃縮水配管２８を通して排出される。希薄誘引溶液およびＦＯ濃縮水のうちの少なくとも１つは、回収、再利用されてもよい。 FO to-be-treated water is sent to the primary side of the forward osmosis membrane treatment device 14 through the FO to-be-treated water pipe 16 and subjected to forward osmosis membrane treatment in the forward osmosis membrane treatment device 14 (forward osmosis membrane treatment step). In the forward osmosis membrane treatment device 14, the attracting solution is sent to the secondary side of the forward osmosis membrane through the attracting solution pipe 24, and the water to be treated with FO and the attracting solution are caused to exist through the forward osmosis membrane 110, whereby the osmosis is performed. Water is transferred to the attracting solution by pressure. The diluted attracting solution used in the forward osmosis membrane treatment step is discharged through the diluted attracting solution pipe 26. The FO concentrated water obtained in the forward osmosis membrane treatment step is discharged through the FO concentrated water piping 28. At least one of the dilute attractant solution and the FO retentate may be recovered and reused.
　ここで、ＦＯ被処理水中に、臭素系酸化剤または塩素系酸化剤とスルファミン酸化合物とを含む殺菌剤（以下、「正浸透膜用殺菌剤」と呼ぶ場合がある）を存在させる。例えば、正浸透膜用殺菌剤は、殺菌剤添加配管１１２を通してＦＯ被処理水配管１６においてＦＯ被処理水に添加される。正浸透膜処理装置１４の前段にＦＯ被処理水を貯留するＦＯ被処理水槽を別途設け、ＦＯ被処理水槽において正浸透膜用殺菌剤が添加されてもよい。 Here, a bactericide containing a bromine-based oxidizing agent or a chlorine-based oxidizing agent and a sulfamic acid compound (hereinafter, may be referred to as “forward osmosis membrane bactericide”) is present in the FO treated water. For example, the forward osmosis membrane disinfectant is added to the FO untreated water in the FO untreated water piping 16 through the disinfectant addition piping 112. A FO treatment water tank for storing the FO treatment water may be separately provided at the previous stage of the forward osmosis membrane treatment device 14, and a forward osmosis membrane sterilant may be added to the FO treatment water tank.
　このように、本実施形態に係る正浸透膜処理方法および正浸透膜処理システム８では、被処理水を正浸透膜処理する際、正浸透膜処理の被処理水（ＦＯ被処理水）に臭素系酸化剤または塩素系酸化剤とスルファミン酸化合物とを含む正浸透膜用殺菌剤を存在させる。本発明者らは、臭素系酸化剤または塩素系酸化剤とスルファミン酸化合物とを含む正浸透膜用殺菌剤は、正浸透膜をほとんど透過しないことを見出した。この正浸透膜用殺菌剤は、従来の塩素系殺菌剤、酸化剤、有機系殺菌剤よりも、正浸透膜に対して十分な殺菌効果を発揮する。また、誘引溶液中への殺菌剤のリークがほとんどないため、希薄誘引溶液の再利用が可能になる。 As described above, in the forward osmosis membrane treatment method and the forward osmosis membrane treatment system 8 according to the present embodiment, when the to-be-treated water is subjected to the forward osmosis membrane treatment, bromine is added to the to-be-treated water of the forward osmosis membrane treatment (FO treated water). A bactericide for a forward osmosis membrane containing a oxidizing agent or a chlorinated oxidizing agent and a sulfamic acid compound is present. The present inventors have found that a bactericide for a forward osmosis membrane containing a bromine-based oxidant or a chlorine-based oxidant and a sulfamic acid compound hardly permeates a forward osmosis membrane. This fungicide for forward osmosis membranes exhibits a more sufficient bactericidal effect on forward osmosis membranes than conventional chlorine-based germicides, oxidants, and organic germicides. Further, since there is almost no leak of the germicide into the attracting solution, the dilute attracting solution can be reused.
　この正浸透膜用殺菌剤は、殺菌有効成分が正浸透膜をほとんど透過しないため、正浸透膜処理装置１４の出口（ＦＯ濃縮水出口）に行くに従い、濃縮される。そのため、殺菌剤の殺菌有効成分が正浸透膜処理装置１４の出口（ＦＯ濃縮水出口）側まで十分に行きわたり、正浸透膜の出口側まで十分に殺菌することができる。 正 Since the fungicide for the forward osmosis membrane hardly permeates the forward osmosis membrane, the sterilizing agent for the forward osmosis membrane is concentrated toward the outlet of the forward osmosis membrane treatment apparatus 14 (FO concentrated water outlet). Therefore, the germicidal active ingredient of the germicide can sufficiently reach the outlet (FO concentrated water outlet) side of the forward osmosis membrane treatment device 14 and can be sufficiently sterilized to the outlet side of the forward osmosis membrane.
　従来の方法では、ＦＯ被処理水中に次亜塩素酸、クロラミン、過酸化水素、有機系殺菌剤等の殺菌剤を添加すると、誘引溶液との浸透圧差によってＦＯ被処理水の一部が誘引溶液側に移動するとともに、殺菌剤の一部が誘引溶液側に移動する。これに対して、本実施形態に係る正浸透膜処理方法および正浸透膜処理システム１では、上記正浸透膜用殺菌剤を用いることにより、殺菌剤が正浸透膜を透過するのを抑制し、希薄誘引溶液の再利用が可能となる。 In the conventional method, when a bactericide such as hypochlorous acid, chloramine, hydrogen peroxide, or an organic bactericide is added to the FO untreated water, a part of the FO untreated water is caused by an osmotic pressure difference from the attracting solution. Side and a part of the germicide moves to the attracting solution side. On the other hand, in the forward osmosis membrane treatment method and the forward osmosis membrane treatment system 1 according to the present embodiment, the use of the forward osmosis membrane germicide suppresses the germicide from passing through the forward osmosis membrane, Reuse of the diluted attractant solution becomes possible.
　「臭素系酸化剤とスルファミン酸化合物とを含む殺菌剤」は、「臭素系酸化剤」と「スルファミン酸化合物」との混合物を含む安定化次亜臭素酸組成物を含有する殺菌剤であってもよいし、「臭素系酸化剤とスルファミン酸化合物との反応生成物」を含む安定化次亜臭素酸組成物を含有する殺菌剤であってもよい。「塩素系酸化剤とスルファミン酸化合物とを含む殺菌剤」は、「塩素系酸化剤」と「スルファミン酸化合物」との混合物を含む安定化次亜塩素酸組成物を含有する殺菌剤であってもよいし、「塩素系酸化剤とスルファミン酸化合物との反応生成物」を含む安定化次亜塩素酸組成物を含有する殺菌剤であってもよい。 "A disinfectant containing a brominated oxidant and a sulfamic acid compound" is a disinfectant containing a stabilized hypobromite composition containing a mixture of a "brominated oxidant" and a "sulfamic acid compound". Alternatively, a bactericide containing a stabilized hypobromite composition containing “a reaction product of a brominated oxidizing agent and a sulfamic acid compound” may be used. "A disinfectant containing a chlorine-based oxidant and a sulfamic acid compound" is a disinfectant containing a stabilized hypochlorous acid composition containing a mixture of a "chlorine-based oxidant" and a "sulfamic acid compound", It may be a bactericide containing a stabilized hypochlorous acid composition containing “a reaction product of a chlorine-based oxidizing agent and a sulfamic acid compound”.
　すなわち、本発明の実施形態に係る正浸透膜処理方法は、被処理水（ＦＯ被処理水）中に、「臭素系酸化剤」と「スルファミン酸化合物」との混合物、または「塩素系酸化剤」と「スルファミン酸化合物」との混合物を存在させる方法である。これにより、被処理水中で、安定化次亜臭素酸組成物または安定化次亜塩素酸組成物が生成すると考えられる。 That is, the forward osmosis membrane treatment method according to the embodiment of the present invention provides a method of treating a mixture of a “bromine-based oxidizing agent” and a “sulfamic acid compound” or a “chlorine-based oxidizing agent” in water to be treated (FO treated water). "And a mixture of" sulfamic acid compound ". Thereby, it is considered that a stabilized hypobromous acid composition or a stabilized hypochlorous acid composition is formed in the water to be treated.
　また、本発明の実施形態に係る正浸透膜処理方法は、被処理水（ＦＯ被処理水）中に、「臭素系酸化剤とスルファミン酸化合物との反応生成物」である安定化次亜臭素酸組成物、または「塩素系酸化剤とスルファミン酸化合物との反応生成物」である安定化次亜塩素酸組成物を存在させる方法である。 Further, the forward osmosis membrane treatment method according to the embodiment of the present invention is characterized in that, in the water to be treated (FO water to be treated), stabilized hypobromite which is a “reaction product of a bromine-based oxidizing agent and a sulfamic acid compound” is used. This is a method in which an acid composition or a stabilized hypochlorous acid composition which is a "reaction product of a chlorine-based oxidizing agent and a sulfamic acid compound" is present.
　具体的には本発明の実施形態に係る正浸透膜処理方法は、被処理水中に、「臭素」、「塩化臭素」、「次亜臭素酸」または「臭化ナトリウムと次亜塩素酸との反応物」と、「スルファミン酸化合物」との混合物を存在させる方法である。または、被処理水中に、「次亜塩素酸」と、「スルファミン酸化合物」との混合物を存在させる方法である。 Specifically, the forward osmosis membrane treatment method according to the embodiment of the present invention comprises the steps of: adding "bromine", "bromine chloride", "hypobromous acid" or "sodium bromide to hypochlorous acid" in the water to be treated; This is a method in which a mixture of "reactant" and "sulfamic acid compound" is present. Alternatively, this is a method in which a mixture of “hypochlorous acid” and “sulfamic acid compound” is present in the water to be treated.
　また、本発明の実施形態に係る正浸透膜処理方法は、被処理水中に、例えば、「臭素とスルファミン酸化合物との反応生成物」、「塩化臭素とスルファミン酸化合物との反応生成物」、「次亜臭素酸とスルファミン酸化合物との反応生成物」、または「臭化ナトリウムと次亜塩素酸との反応物と、スルファミン酸化合物と、の反応生成物」である安定化次亜臭素酸組成物を存在させる方法である。または、被処理水中に、「次亜塩素酸とスルファミン酸化合物との反応生成物」である安定化次亜塩素酸組成物を存在させる方法である。 Further, the forward osmosis membrane treatment method according to the embodiment of the present invention, in the water to be treated, for example, "reaction product of bromine and sulfamic acid compound", "reaction product of bromine chloride and sulfamic acid compound", Stabilized hypobromite, which is a "reaction product of hypobromite and a sulfamic acid compound" or a "reaction product of a reaction product of sodium bromide and hypochlorous acid with a sulfamic acid compound" It is a method of making the composition present. Alternatively, this is a method in which a stabilized hypochlorous acid composition which is a “reaction product of hypochlorous acid and a sulfamic acid compound” is present in the water to be treated.
　本実施形態に係る正浸透膜処理方法において、安定化次亜臭素酸組成物または安定化次亜塩素酸組成物は次亜塩素酸等の塩素系酸化剤等の従来の殺菌剤と同等以上の殺菌効果を発揮するにも関わらず、塩素系酸化剤等の従来の殺菌剤と比較すると、正浸透膜への劣化影響が低いため、正浸透膜でのファウリングを抑制しながら、正浸透膜の酸化劣化を抑制できる。このため、本実施形態に係る正浸透膜処理方法で用いられる安定化次亜臭素酸組成物または安定化次亜塩素酸組成物は、被処理水を正浸透膜で処理する方法で用いる殺菌剤としては好適である。 In the forward osmosis membrane treatment method according to the present embodiment, the stabilized hypobromous acid composition or stabilized hypochlorous acid composition is equal to or more than a conventional disinfectant such as a chlorine-based oxidizing agent such as hypochlorous acid. Despite having a bactericidal effect, it has a lower degradation effect on the forward osmosis membrane than conventional bactericides such as chlorine-based oxidizing agents. Can be suppressed from oxidative deterioration. For this reason, the stabilized hypobromous acid composition or the stabilized hypochlorous acid composition used in the forward osmosis membrane treatment method according to the present embodiment is a disinfectant used in the method of treating the water to be treated with the forward osmosis membrane. Is preferable.
　本実施形態に係る正浸透膜処理方法のうち、「臭素系酸化剤とスルファミン酸化合物とを含む殺菌剤」の場合、塩素系酸化剤が存在しないため、正浸透膜への劣化影響がより低い。塩素系酸化剤を含む場合は、塩素酸の生成が懸念される。 Among the forward osmosis membrane treatment methods according to the present embodiment, in the case of "a bactericide containing a bromine-based oxidizing agent and a sulfamic acid compound", since there is no chlorine-based oxidizing agent, the deterioration effect on the forward osmosis membrane is lower. . When a chlorine-based oxidizing agent is contained, chloric acid may be generated.
　本実施形態に係る正浸透膜処理方法のうち、「臭素系酸化剤」が、臭素である場合、塩素系酸化剤が存在しないため、正浸透膜への劣化影響が著しく低い。 の う ち In the forward osmosis membrane treatment method according to the present embodiment, when the “bromine-based oxidizing agent” is bromine, there is no chlorine-based oxidizing agent, so that the deterioration effect on the forward osmosis membrane is extremely low.
　本実施形態に係る正浸透膜処理方法では、例えば、被処理水中に、「臭素系酸化剤」または「塩素系酸化剤」と「スルファミン酸化合物」とを薬注ポンプ等により注入してもよい。「臭素系酸化剤」または「塩素系酸化剤」と「スルファミン酸化合物」とは別々に被処理水に添加してもよく、または、原液同士で混合させてから被処理水に添加してもよい。 In the forward osmosis membrane treatment method according to the present embodiment, for example, a "bromine oxidant" or a "chlorine oxidant" and a "sulfamic acid compound" may be injected into the water to be treated by a chemical injection pump or the like. . The "bromine oxidant" or the "chlorine oxidant" and the "sulfamic acid compound" may be separately added to the water to be treated, or may be mixed with the stock solutions and then added to the water to be treated. Good.
　また、例えば、被処理水中に、「臭素系酸化剤とスルファミン酸化合物との反応生成物」または「塩素系酸化剤とスルファミン酸化合物との反応生成物」を薬注ポンプ等により注入してもよい。 Also, for example, into the water to be treated, a "reaction product of a brominated oxidant and a sulfamic acid compound" or a "reaction product of a chlorine-based oxidizing agent and a sulfamic acid compound" may be injected by a chemical injection pump or the like. Good.
　本実施形態に係る正浸透膜処理方法において、「臭素系酸化剤」または「塩素系酸化剤」の当量に対する「スルファミン酸化合物」の当量の比は、１以上であることが好ましく、１以上２以下の範囲であることがより好ましい。「臭素系酸化剤」または「塩素系酸化剤」の当量に対する「スルファミン酸化合物」の当量の比が１未満であると、膜を劣化させる可能性があり、２を超えると、製造コストが増加する場合がある。 In the forward osmosis membrane treatment method according to this embodiment, the ratio of the equivalent of the “sulfamic acid compound” to the equivalent of the “bromine oxidant” or the “chlorine oxidant” is preferably 1 or more, and more preferably 1 or more. More preferably, it is in the following range. If the ratio of the equivalent of “sulfamic acid compound” to the equivalent of “bromine oxidant” or “chlorine oxidant” is less than 1, the film may be deteriorated, and if it exceeds 2, the production cost increases. May be.
　正浸透膜に接触する全塩素濃度は有効塩素濃度換算で、０．０１～１００ｍｇ／Ｌであることが好ましい。０．０１ｍｇ／Ｌ未満であると、十分な殺菌効果を得ることができない場合があり、１００ｍｇ／Ｌより多いと、正浸透膜の劣化、配管等の腐食を引き起こす可能性がある。 全 The total chlorine concentration in contact with the forward osmosis membrane is preferably 0.01 to 100 mg / L in terms of effective chlorine concentration. If the amount is less than 0.01 mg / L, a sufficient sterilizing effect may not be obtained. If the amount is more than 100 mg / L, deterioration of the forward osmosis membrane and corrosion of pipes and the like may be caused.
　臭素系酸化剤としては、臭素（液体臭素）、塩化臭素、臭素酸、臭素酸塩、次亜臭素酸等が挙げられる。次亜臭素酸は、臭化ナトリウム等の臭化物と次亜塩素酸等の塩素系酸化剤とを反応させて生成させたものであってもよい。 Examples of the bromine-based oxidizing agent include bromine (liquid bromine), bromine chloride, bromic acid, bromate, hypobromite, and the like. The hypobromite may be formed by reacting a bromide such as sodium bromide with a chlorine-based oxidizing agent such as hypochlorous acid.
　これらのうち、臭素を用いた「臭素とスルファミン酸化合物（臭素とスルファミン酸化合物の混合物）」または「臭素とスルファミン酸化合物との反応生成物」の製剤は、「次亜塩素酸と臭素化合物とスルファミン酸」の製剤および「塩化臭素とスルファミン酸」の製剤等に比べて、臭素酸の副生が少なく、正浸透膜をより劣化させないため、正浸透膜用の殺菌剤としてはより好ましい。 Of these, the formulation of "bromine and sulfamic acid compound (mixture of bromine and sulfamic acid compound)" or "reaction product of bromine and sulfamic acid compound" using bromine is described as "hypochlorous acid and bromine compound and Compared to the preparation of “sulfamic acid” and the preparation of “bromine chloride and sulfamic acid” and the like, since there is less by-product of bromate and the forward osmosis membrane is not further deteriorated, it is more preferable as a bactericide for the forward osmosis membrane.
　すなわち、本発明の実施形態に係る正浸透膜処理方法は、被処理水中に、臭素と、スルファミン酸化合物とを存在させる（臭素とスルファミン酸化合物の混合物を存在させる）ことが好ましい。また、被処理水中に、臭素とスルファミン酸化合物との反応生成物を存在させることが好ましい。 That is, in the forward osmosis membrane treatment method according to the embodiment of the present invention, it is preferable that bromine and a sulfamic acid compound be present in the water to be treated (a mixture of bromine and a sulfamic acid compound is present). Further, it is preferable that a reaction product of bromine and a sulfamic acid compound is present in the water to be treated.
　臭素化合物としては、臭化ナトリウム、臭化カリウム、臭化リチウム、臭化アンモニウムおよび臭化水素酸等が挙げられる。これらのうち、製剤コスト等の点から、臭化ナトリウムが好ましい。 Examples of the bromine compound include sodium bromide, potassium bromide, lithium bromide, ammonium bromide, and hydrobromic acid. Of these, sodium bromide is preferred from the viewpoint of formulation cost and the like.
　塩素系酸化剤としては、例えば、塩素ガス、二酸化塩素、次亜塩素酸またはその塩、亜塩素酸またはその塩、塩素酸またはその塩、過塩素酸またはその塩、塩素化イソシアヌル酸またはその塩等が挙げられる。これらのうち、塩としては、例えば、次亜塩素酸ナトリウム、次亜塩素酸カリウム等の次亜塩素酸アルカリ金属塩、次亜塩素酸カルシウム、次亜塩素酸バリウム等の次亜塩素酸アルカリ土類金属塩、亜塩素酸ナトリウム、亜塩素酸カリウム等の亜塩素酸アルカリ金属塩、亜塩素酸バリウム等の亜塩素酸アルカリ土類金属塩、亜塩素酸ニッケル等の他の亜塩素酸金属塩、塩素酸アンモニウム、塩素酸ナトリウム、塩素酸カリウム等の塩素酸アルカリ金属塩、塩素酸カルシウム、塩素酸バリウム等の塩素酸アルカリ土類金属塩等が挙げられる。これらの塩素系酸化剤は、１種を単独で用いても、２種以上を組み合わせて用いてもよい。塩素系酸化剤としては、取り扱い性等の点から、次亜塩素酸ナトリウムを用いるのが好ましい。 Examples of the chlorine-based oxidizing agent include chlorine gas, chlorine dioxide, hypochlorous acid or a salt thereof, chlorite or a salt thereof, chloric acid or a salt thereof, perchloric acid or a salt thereof, chlorinated isocyanuric acid or a salt thereof. And the like. Among these, examples of the salt include alkali metal hypochlorites such as sodium hypochlorite and potassium hypochlorite, and alkaline earth hypochlorite such as calcium hypochlorite and barium hypochlorite. Metal salts, alkali metal chlorites such as sodium chlorite and potassium chlorite, alkaline earth metal chlorites such as barium chlorite, and other metal chlorites such as nickel chlorite And alkali metal chlorates such as ammonium chlorate, sodium chlorate and potassium chlorate, and alkaline earth metal chlorates such as calcium chlorate and barium chlorate. One of these chlorine-based oxidizing agents may be used alone, or two or more thereof may be used in combination. As the chlorine-based oxidizing agent, sodium hypochlorite is preferably used from the viewpoint of handleability and the like.
　スルファミン酸化合物は、以下の一般式（１）で示される化合物である。
　　Ｒ２ＮＳＯ３Ｈ　　　（１）
（式中、Ｒは独立して水素原子または炭素数１～８のアルキル基である。） The sulfamic acid compound is a compound represented by the following general formula (1).
R 2 NSO 3 H (1)
(In the formula, R is independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms.)
　スルファミン酸化合物としては、例えば、２個のＲ基の両方が水素原子であるスルファミン酸（アミド硫酸）の他に、Ｎ－メチルスルファミン酸、Ｎ－エチルスルファミン酸、Ｎ－プロピルスルファミン酸、Ｎ－イソプロピルスルファミン酸、Ｎ－ブチルスルファミン酸等の２個のＲ基の一方が水素原子であり、他方が炭素数１～８のアルキル基であるスルファミン酸化合物、Ｎ，Ｎ－ジメチルスルファミン酸、Ｎ，Ｎ－ジエチルスルファミン酸、Ｎ，Ｎ－ジプロピルスルファミン酸、Ｎ，Ｎ－ジブチルスルファミン酸、Ｎ－メチル－Ｎ－エチルスルファミン酸、Ｎ－メチル－Ｎ－プロピルスルファミン酸等の２個のＲ基の両方が炭素数１～８のアルキル基であるスルファミン酸化合物、Ｎ－フェニルスルファミン酸等の２個のＲ基の一方が水素原子であり、他方が炭素数６～１０のアリール基であるスルファミン酸化合物、またはこれらの塩等が挙げられる。スルファミン酸塩としては、例えば、ナトリウム塩、カリウム塩等のアルカリ金属塩、カルシウム塩、ストロンチウム塩、バリウム塩等のアルカリ土類金属塩、マンガン塩、銅塩、亜鉛塩、鉄塩、コバルト塩、ニッケル塩等の他の金属塩、アンモニウム塩およびグアニジン塩等が挙げられる。スルファミン酸化合物およびこれらの塩は、１種を単独で用いても、２種以上を組み合わせて用いてもよい。スルファミン酸化合物としては、環境負荷等の点から、スルファミン酸（アミド硫酸）を用いるのが好ましい。 Examples of the sulfamic acid compound include, in addition to sulfamic acid (amidosulfate) in which both R groups are both hydrogen atoms, N-methylsulfamic acid, N-ethylsulfamic acid, N-propylsulfamic acid, N- One of two R groups such as isopropylsulfamic acid and N-butylsulfamic acid is a hydrogen atom, and the other is an alkyl group having 1 to 8 carbon atoms; a sulfamic acid compound; N, N-dimethylsulfamic acid; Two R groups such as N-diethylsulfamic acid, N, N-dipropylsulfamic acid, N, N-dibutylsulfamic acid, N-methyl-N-ethylsulfamic acid and N-methyl-N-propylsulfamic acid; One of two R groups such as a sulfamic acid compound and an N-phenylsulfamic acid, each of which is an alkyl group having 1 to 8 carbon atoms; Is a hydrogen atom and the other sulfamic acid compound or a salt thereof, such as an aryl group having 6 to 10 carbon atoms. Examples of the sulfamic acid salts include, for example, alkali metal salts such as sodium salt and potassium salt, alkaline earth metal salts such as calcium salt, strontium salt and barium salt, manganese salt, copper salt, zinc salt, iron salt, cobalt salt, and the like. Other metal salts such as nickel salts, ammonium salts, guanidine salts and the like. The sulfamic acid compounds and salts thereof may be used alone or in combination of two or more. As the sulfamic acid compound, it is preferable to use sulfamic acid (amidosulfuric acid) from the viewpoint of environmental load and the like.
　本実施形態に係る正浸透膜処理方法において、さらにアルカリを存在させてもよい。アルカリとしては、水酸化ナトリウム、水酸化カリウム等の水酸化アルカリ等が挙げられる。低温の製品安定性等の点から、水酸化ナトリウムと水酸化カリウムとを併用してもよい。また、アルカリは、固形でなく、水溶液として用いてもよい。 に お い て In the forward osmosis membrane treatment method according to the present embodiment, an alkali may be further present. Examples of the alkali include alkali hydroxides such as sodium hydroxide and potassium hydroxide. Sodium hydroxide and potassium hydroxide may be used in combination from the viewpoint of low-temperature product stability and the like. The alkali may be used as an aqueous solution instead of a solid.
　正浸透膜処理工程で用いられる正浸透膜の形状としては、特に制限はないが、例えば、中空糸膜、スパイラル膜、チューブラ膜、プレートアンドフレーム構造の膜等を使用することができる。正浸透膜の膜材質としては、芳香族ポリアミド系、酢酸セルロース系、ポリケトン系等が挙げられる。また、分離膜の基材に、機能性たんぱく質や無機材料等を組み込んで分離性能や透水性等を付与した膜を用いることも可能である。本実施形態に係る正浸透膜処理方法は、正浸透膜として芳香族ポリアミド系、アミド系の基材に機能性たんぱく質や無機材料等を組み込んで分離性能や透水性等を付与した膜に対して好適に適用することができる。これらの膜は、従来用いられる塩素系酸化剤による劣化の影響を特に受けやすいことが知られている。 形状 The shape of the forward osmosis membrane used in the forward osmosis membrane treatment step is not particularly limited, but for example, a hollow fiber membrane, a spiral membrane, a tubular membrane, a membrane having a plate and frame structure, or the like can be used. Examples of the membrane material of the forward osmosis membrane include aromatic polyamides, cellulose acetates, and polyketones. Further, it is also possible to use a membrane in which a functional protein, an inorganic material, or the like is incorporated into the base material of the separation membrane to impart separation performance, water permeability, and the like. The forward osmosis membrane treatment method according to the present embodiment is an aromatic polyamide-based as a forward osmosis membrane, a membrane provided with separation performance or water permeability by incorporating a functional protein or an inorganic material into an amide-based substrate. It can be suitably applied. It is known that these films are particularly susceptible to deterioration by conventionally used chlorine-based oxidizing agents.
　正浸透膜としては、例えば、ＨＰ５２３０（東洋紡製）、ＨＦＦＯ２（アクアポリン製）、ＯｓｍｏＦ２Ｏ（Ｆｒｕｉｄ　Ｔｅｃｈｎｏｌｏｇｙ　Ｓｏｌｕｔｉｏｎｓ製）が挙げられる。これら正浸透膜は、単段で使用してもよいし、複数段を直列に接続して使用してもよい。すなわち、第１の正浸透膜処理によって得られた濃縮水を第２の正浸透膜処理によってさらに濃縮してもよい。 Examples of the forward osmosis membrane include HP5230 (manufactured by Toyobo), HFFO2 (manufactured by Aquaporin), and OsmoF2O (manufactured by Fluid Technology Solutions). These forward osmosis membranes may be used in a single stage, or may be used by connecting a plurality of stages in series. That is, the concentrated water obtained by the first forward osmosis membrane treatment may be further concentrated by the second forward osmosis membrane treatment.
　ところで、正浸透膜と逆浸透膜は、その運転方法の違いにより膜の構造、性質が異なるものである。逆浸透膜は、膜の一次側に高い圧力をかけるため、圧力に耐えうる機械的強度を保持するために膜厚を厚くする必要がある。一方、正浸透膜は、膜にかける圧力は逆浸透膜よりも低いため、逆浸透膜ほどの機械的強度を有さなくてもよく、さらに膜内部の濃度分極を抑制する必要があるため、膜厚を薄くすることが求められる。求められる運転条件に膜を最適化した結果、逆浸透膜と正浸透膜は、膜材質こそ同じものの、異なった膜構造を取っており、透過性能、阻止性能は異なったものである。そのため、逆浸透膜処理で使用されている逆浸透膜を正浸透用途に用いると、十分な性能が得られないことになる。 By the way, the forward osmosis membrane and the reverse osmosis membrane have different structures and properties depending on the operation method. Since a reverse osmosis membrane applies a high pressure to the primary side of the membrane, it is necessary to increase the film thickness in order to maintain mechanical strength that can withstand the pressure. On the other hand, the forward osmosis membrane does not need to have the mechanical strength of the reverse osmosis membrane because the pressure applied to the membrane is lower than that of the reverse osmosis membrane, and furthermore, it is necessary to suppress the concentration polarization inside the membrane, It is required to reduce the film thickness. As a result of optimizing the membrane to the required operating conditions, the reverse osmosis membrane and the forward osmosis membrane have the same membrane material, but have different membrane structures, and have different permeation performance and blocking performance. Therefore, if the reverse osmosis membrane used in the reverse osmosis membrane treatment is used for forward osmosis, sufficient performance cannot be obtained.
　正浸透膜処理工程で用いられる誘引溶液としては、炭酸アンモニウム水溶液、マグネシウム塩水溶液、ナトリウム塩水溶液等の無機塩水溶液、ショ糖、グルコース、有機性ポリマ等の有機物水溶液、イオン液体等が挙げられる。正浸透膜処理工程で使用された希薄誘引溶液はそのまま別工程で使用してもよいし、希薄誘引溶液に加熱、膜分離等の操作を加えることによって希薄誘引溶液から水を分離し、得られた水および濃縮誘引溶液を再利用してもよい。正浸透膜処理工程において複数段の正浸透膜処理を行う場合、上記誘引溶液を組み合わせて用いてもよい。 誘 Examples of the attracting solution used in the forward osmosis membrane treatment step include an aqueous solution of an inorganic salt such as an aqueous solution of ammonium carbonate, an aqueous solution of a magnesium salt, and an aqueous solution of a sodium salt; an aqueous solution of an organic substance such as sucrose, glucose, and an organic polymer; and an ionic liquid. The diluted attracting solution used in the forward osmosis membrane treatment step may be used as it is in a separate step, or water may be separated from the diluted attracting solution by performing operations such as heating and membrane separation on the diluted attracting solution. The water and concentrated attracting solution may be reused. When performing a plurality of stages of forward osmosis membrane treatment in the forward osmosis membrane treatment step, the above attracting solutions may be used in combination.
　被処理水（ＦＯ被処理水）としては、特に制限はないが、例えば、工業用水、表層水、水道水、地下水、海水、海水を逆浸透法または蒸発法等によって脱塩した海水淡水化処理水、各種排水、例えば半導体製造工程等で排出される排水等が挙げられる。 The water to be treated (FO treated water) is not particularly limited. For example, seawater desalination treatment in which industrial water, surface water, tap water, groundwater, seawater, seawater is desalinated by a reverse osmosis method, an evaporation method, or the like. Water and various kinds of wastewater, for example, wastewater discharged in a semiconductor manufacturing process and the like can be given.
　被処理水のｐＨは、例えば、２～１２の範囲であり、４～１１の範囲であることが好ましい。被処理水のｐＨが２未満、または１２を超えると、正浸透膜が劣化する場合がある。 ＰＨ The pH of the water to be treated is, for example, in the range of 2 to 12, preferably in the range of 4 to 11. When the pH of the water to be treated is less than 2 or more than 12, the forward osmosis membrane may be deteriorated.
　正浸透膜処理装置において、被処理水のｐＨ５．５以上でスケールが発生する場合には、スケール抑制のために分散剤を上記殺菌剤と併用してもよい。分散剤としては、例えば、ポリアクリル酸、ポリマレイン酸、ホスホン酸等が挙げられる。分散剤の被処理水への添加量は、例えば、ＦＯ濃縮水中の濃度として０．１～１，０００ｍｇ／Ｌの範囲である。 に お い て In the forward osmosis membrane treatment apparatus, when scale is generated at pH 5.5 or higher of the water to be treated, a dispersant may be used in combination with the bactericide to suppress the scale. Examples of the dispersant include polyacrylic acid, polymaleic acid, and phosphonic acid. The amount of the dispersant added to the water to be treated is, for example, in the range of 0.1 to 1,000 mg / L as the concentration in the FO concentrated water.
　また、分散剤を使用せずにスケールの発生を抑制するためには、例えば、ＦＯ濃縮水中のシリカ濃度を溶解度以下に、カルシウムスケールの指標であるランゲリア指数を０以下になるように、正浸透膜処理装置の回収率、水温、ｐＨ等の運転条件を調整することが挙げられる。 Further, in order to suppress the generation of scale without using a dispersant, for example, forward osmosis is performed so that the silica concentration in the FO concentrated water is equal to or less than the solubility, and the Langelia index which is an index of the calcium scale is equal to or less than 0. Adjustment of operating conditions such as the recovery rate, water temperature, and pH of the membrane processing apparatus may be mentioned.
　正浸透膜処理システムの用途としては、例えば、海水淡水化、排水の減容化、有価物の濃縮、食品および飲料の濃縮等が挙げられる。 用途 Applications of the forward osmosis membrane treatment system include, for example, desalination of seawater, volume reduction of wastewater, concentration of valuable resources, and concentration of foods and beverages.
＜水処理方法、水処理システム＞
　次に、上記正浸透膜処理方法、正浸透膜処理システムを用いる水処理方法、水処理システムについて説明する。 <Water treatment method, water treatment system>
Next, a water treatment method and a water treatment system using the forward osmosis membrane treatment method and the forward osmosis membrane treatment system will be described.
　本発明の実施形態に係る水処理方法は、上記正浸透膜処理方法を含み、正浸透膜処理工程の前段に、前処理工程および逆浸透膜処理工程を含み、正浸透膜処理工程により得られた希薄誘引溶液を、前処理工程で使用する、水処理方法である。また、本発明の実施形態に係る水処理システムは、上記正浸透膜処理システムを備え、正浸透膜処理手段の前段に、前処理手段および逆浸透膜処理手段を備え、正浸透膜処理手段により得られた希薄誘引溶液が、前処理手段で使用される、水処理システムである。 The water treatment method according to the embodiment of the present invention includes the forward osmosis membrane treatment method, and includes a pretreatment step and a reverse osmosis membrane treatment step before the forward osmosis membrane treatment step, and is obtained by the forward osmosis membrane treatment step. This is a water treatment method in which the diluted attracting solution is used in a pretreatment step. Further, the water treatment system according to the embodiment of the present invention includes the forward osmosis membrane treatment system, and includes a pretreatment unit and a reverse osmosis membrane treatment unit at a stage preceding the forward osmosis membrane treatment unit. A water treatment system in which the obtained dilute attractant solution is used in pretreatment means.
　本発明の実施形態に係る水処理システムの一例の概略を図１２に示し、その構成について説明する。 概略 An outline of an example of a water treatment system according to the embodiment of the present invention is shown in FIG.
　本実施形態に係る水処理システム９は、被処理水の前処理を行う前処理手段としての前処理装置１１４と、前処理により得られた前処理水の逆浸透膜処理を行い、ＲＯ濃縮水とＲＯ透過水とを得る逆浸透膜処理手段としての逆浸透膜処理装置１１８と、逆浸透膜処理により得られたＲＯ濃縮水の正浸透膜処理を行う正浸透膜処理手段としての正浸透膜処理装置１４とを備える。水処理システム９は、前処理により得られた前処理水の濁質除去処理を行う濁質除去手段として、濁質除去装置１１６を備えてもよい。 The water treatment system 9 according to the present embodiment performs a reverse osmosis membrane treatment of a pretreatment device 114 as a pretreatment device for performing a pretreatment of the treatment water and a pretreatment water obtained by the pretreatment. Osmosis membrane treatment device 118 as a reverse osmosis membrane treatment means for obtaining the water and RO permeated water, and a forward osmosis membrane as a forward osmosis membrane treatment means for performing the RO treatment of the RO concentrated water obtained by the reverse osmosis membrane treatment And a processing device 14. The water treatment system 9 may include a turbidity removing device 116 as turbidity removing means for performing turbidity removing treatment of pretreated water obtained by the pretreatment.
　図１２の水処理システム９において、被処理水配管１２０が前処理装置１１４の被処理水入口に接続され、前処理装置１１４の出口と濁質除去装置１１６の入口とは、配管１２２により接続され、濁質除去装置１１６の出口と逆浸透膜処理装置１１８の入口とは、配管１２４により接続されている。逆浸透膜処理装置１１８のＲＯ濃縮水出口と正浸透膜処理装置１４のＦＯ被処理水入口とは、ＦＯ被処理水配管１６により接続され、逆浸透膜処理装置１１８のＲＯ透過水出口には、ＲＯ透過水配管１２６が接続されている。正浸透膜処理装置１４の誘引溶液入口には、誘引溶液配管２４が接続され、正浸透膜処理装置１４の希薄誘引溶液出口と、前処理装置１１４の希薄誘引溶液入口とは、希薄誘引溶液配管２６により接続され、正浸透膜処理装置１４のＦＯ濃縮水出口には、ＦＯ濃縮水配管２８が接続されている。濁質除去装置１１６の逆洗排水出口には、逆洗排水配管１２８が接続されていてもよい。 In the water treatment system 9 of FIG. 12, the treated water pipe 120 is connected to the treated water inlet of the pretreatment device 114, and the outlet of the pretreatment device 114 and the entrance of the turbidity removal device 116 are connected by the piping 122. The outlet of the turbidity removing device 116 and the inlet of the reverse osmosis membrane treatment device 118 are connected by a pipe 124. The RO concentrated water outlet of the reverse osmosis membrane treatment device 118 and the FO treated water inlet of the forward osmosis membrane treatment device 14 are connected by the FO treated water piping 16. , RO permeated water pipe 126 is connected. The attracting solution inlet 24 of the forward osmosis membrane processing device 14 is connected to an attracting solution pipe 24, and the diluted attracting solution outlet of the forward osmosis membrane processing device 14 and the diluted attracting solution inlet of the pretreatment device 114 are connected to the diluted attracting solution pipe. 26, a FO concentrated water pipe 28 is connected to an FO concentrated water outlet of the forward osmosis membrane treatment device 14. A backwash drainage pipe 128 may be connected to the backwash drainage outlet of the turbidity removal device 116.
　本実施形態に係る水処理方法および水処理システム９の動作について説明する。 動作 The operation of the water treatment method and the water treatment system 9 according to the present embodiment will be described.
　被処理水は、被処理水配管１２０を通して前処理装置１１４へ送液される。前処理装置１１４において、例えば、被処理水に含まれる溶解性シリカ、硬度成分等の除去処理が行われる（前処理工程）。 The water to be treated is sent to the pretreatment device 114 through the water pipe 120 to be treated. In the pretreatment device 114, for example, a process of removing soluble silica, hardness components, and the like contained in the water to be treated is performed (pretreatment step).
　被処理水が溶解性シリカを含む場合、前処理装置１１４は、例えば、被処理水にマグネシウム塩を添加して反応させ、溶解性シリカを不溶化させるマグネシウム反応手段と、反応後の被処理水に凝集剤を添加して、凝集させる凝集処理手段と、凝集処理させた被処理水から凝集物を分離する固液分離手段と、を有する。前処理装置１１４において、例えばアルカリ条件（例えば、ｐＨ１０～１２）下で被処理水にマグネシウム塩が添加され、溶解性シリカが不溶化される（マグネシウム反応工程）。その後、必要に応じて凝集剤が添加されて、凝集処理され（凝集処理工程）、凝集物が固液分離される（固液分離工程）。固液分離で得られた固液分離処理水は、前処理水として配管１２２を通して、濁質除去装置１１６へ送液され、ＵＦ膜等による濁質除去処理が行われ、濁質成分等が除去された後（濁質除去工程）、逆浸透膜処理装置１１８へ送液される。 When the water to be treated contains soluble silica, the pretreatment device 114 may, for example, add a magnesium salt to the water to be treated and cause the water to react to insolubilize the soluble silica. There is provided an aggregating means for adding an aggregating agent to perform aggregation, and a solid-liquid separating means for separating agglomerates from the treated water subjected to the aggregating treatment. In the pretreatment device 114, for example, a magnesium salt is added to the water to be treated under alkaline conditions (eg, pH 10 to 12) to insolubilize the soluble silica (magnesium reaction step). Thereafter, an aggregating agent is added, if necessary, to perform an agglomeration treatment (aggregation treatment step), and the aggregates are subjected to solid-liquid separation (solid-liquid separation step). The solid-liquid separation treated water obtained by the solid-liquid separation is sent as pretreatment water to the turbidity removing device 116 through the pipe 122, and the turbidity removing treatment is performed by a UF membrane or the like to remove the turbidity components and the like. After the cleaning (turbidity removing step), the solution is sent to the reverse osmosis membrane treatment device 118.
　被処理水が硬度成分を含み、石灰軟化法により硬度成分の除去が行われる場合、前処理装置１１４は、例えば、被処理水にアルカリ剤を添加して反応させ、硬度成分を不溶化させるアルカリ剤反応手段と、反応後の被処理水に必要に応じて凝集剤を添加して、凝集させる凝集処理手段と、凝集処理させた被処理水から凝集物を分離する固液分離手段と、を有する。前処理装置１１４において、例えば被処理水にアルカリ剤が添加され、硬度成分が不溶化される（アルカリ剤反応工程）。その後、必要に応じて凝集剤が添加されて、凝集処理され（凝集処理工程）、凝集物が固液分離される（固液分離工程）。固液分離で得られた固液分離処理水は、前処理水として配管１２２を通して、濁質除去装置１１６へ送液され、ＵＦ膜等による濁質除去処理が行われ、濁質成分等が除去された後（濁質除去工程）、逆浸透膜処理装置１１８へ送液される。 When the water to be treated contains a hardness component and the removal of the hardness component is performed by the lime softening method, the pretreatment device 114 is, for example, an alkali agent that adds an alkali agent to the water to be treated and reacts to insolubilize the hardness component. A reaction means, an aggregating treatment means for adding an aggregating agent as needed to the water to be treated after the reaction, and aggregating, and a solid-liquid separating means for separating an aggregate from the treated water subjected to the aggregating treatment, . In the pretreatment device 114, for example, an alkali agent is added to the water to be treated, and the hardness component is insolubilized (alkali agent reaction step). Thereafter, an aggregating agent is added, if necessary, to perform an agglomeration treatment (aggregation treatment step), and the aggregates are subjected to solid-liquid separation (solid-liquid separation step). The solid-liquid separation treated water obtained by the solid-liquid separation is sent as pretreatment water to the turbidity removing device 116 through the pipe 122, and the turbidity removing treatment is performed by a UF membrane or the like to remove the turbidity components and the like. After the cleaning (turbidity removing step), the solution is sent to the reverse osmosis membrane treatment device 118.
　被処理水が硬度成分を含み、樹脂軟化法により硬度成分の除去が行われる場合、前処理装置１１４は、例えば、イオン交換樹脂等を用いてイオン交換処理を行うイオン交換処理手段を有する。前処理装置１１４において、例えばイオン交換処理手段としてイオン交換樹脂が充填されたイオン交換塔に被処理水が通液され、硬度成分が吸着除去される（イオン交換工程）。イオン交換処理で得られた前処理水は、配管１２２を通して、濁質除去装置１１６へ送液され、ＵＦ膜等による濁質除去処理が行われ、濁質成分等が除去された後（濁質除去工程）、逆浸透膜処理装置１１８へ送液される。イオン交換樹脂の再生が必要になった場合は、再生剤が通液されることによりイオン交換樹脂が再生される。 (4) When the water to be treated contains a hardness component and the hardness component is removed by a resin softening method, the pretreatment device 114 has, for example, an ion exchange treatment unit that performs an ion exchange treatment using an ion exchange resin or the like. In the pretreatment device 114, for example, the water to be treated is passed through an ion exchange tower filled with an ion exchange resin as an ion exchange treatment means, and the hardness component is adsorbed and removed (ion exchange step). The pre-treated water obtained by the ion exchange treatment is sent to the turbidity removing device 116 through the pipe 122, and the turbidity removing treatment is performed by a UF membrane or the like. Removal step), the liquid is sent to the reverse osmosis membrane treatment device 118. When the ion exchange resin needs to be regenerated, the ion exchange resin is regenerated by passing the regenerant through the liquid.
　次に、濁質除去処理された前処理水は、逆浸透膜処理装置１１８において逆浸透膜処理されて、ＲＯ濃縮水とＲＯ透過水とが得られる（逆浸透膜処理工程）。逆浸透膜処理により得られたＲＯ濃縮水は、ＦＯ被処理水としてＦＯ被処理水配管１６を通して正浸透膜処理装置１４の１次側へ送液され、ＲＯ透過水は、ＲＯ透過水配管１２６を通して排出される。なお、濁質除去装置１１６では、所定に時間毎に膜の逆洗を行ってもよい。例えば、ＲＯ透過水等が逆洗水として濁質除去装置１１６へ供給され、逆洗排水は、逆洗排水配管１２８を通して排出される。 Next, the pretreated water subjected to the turbidity removal treatment is subjected to reverse osmosis membrane treatment in the reverse osmosis membrane treatment device 118 to obtain RO concentrated water and RO permeated water (reverse osmosis membrane treatment step). The RO concentrated water obtained by the reverse osmosis membrane treatment is sent to the primary side of the forward osmosis membrane treatment device 14 through the FO treatment water piping 16 as the FO treatment water. Is discharged through. In the turbidity removing device 116, the membrane may be backwashed at predetermined time intervals. For example, RO permeated water or the like is supplied to the turbidity removing device 116 as backwash water, and backwash wastewater is discharged through a backwash wastewater pipe 128.
　逆浸透膜処理により得られたＲＯ濃縮水は、正浸透膜処理装置１４において正浸透膜処理される（正浸透膜処理工程）。正浸透膜処理装置１４において、誘引溶液が誘引溶液配管２４を通して正浸透膜の２次側に送液され、正浸透膜を介して、ＲＯ濃縮水と誘引溶液を存在させることにより、浸透圧で水が誘引溶液に移動される。 濃縮 The RO concentrated water obtained by the reverse osmosis membrane treatment is subjected to a forward osmosis membrane treatment in the forward osmosis membrane treatment device 14 (forward osmosis membrane treatment step). In the forward osmosis membrane treatment device 14, the attracting solution is sent to the secondary side of the forward osmosis membrane through the attracting solution pipe 24, and through the forward osmosis membrane, the RO concentrated water and the attracting solution are caused to exist. Water is transferred to the attracting solution.
　ここで、ＲＯ濃縮水（ＦＯ被処理水）中に、臭素系酸化剤または塩素系酸化剤とスルファミン酸化合物とを含む正浸透膜用殺菌剤を存在させる。例えば、正浸透膜用殺菌剤は、殺菌剤添加配管１１２を通してＦＯ被処理水配管１６においてＲＯ濃縮水（ＦＯ被処理水）に添加される。正浸透膜処理装置１４の前段、例えば、逆浸透膜処理装置１１８と正浸透膜処理装置１４との間にＲＯ濃縮水（ＦＯ被処理水）を貯留するＦＯ被処理水槽を別途設け、ＦＯ被処理水槽において正浸透膜用殺菌剤が添加されてもよい。 殺菌 Here, a disinfectant for a forward osmosis membrane containing a bromine-based oxidizing agent or a chlorine-based oxidizing agent and a sulfamic acid compound is present in the RO concentrated water (water to be treated with FO). For example, the forward osmosis membrane disinfectant is added to the RO concentrated water (FO untreated water) in the FO untreated water pipe 16 through the disinfectant addition pipe 112. A FO treatment water tank for storing RO concentrated water (FO treatment water) is separately provided at a stage preceding the forward osmosis membrane treatment device 14, for example, between the reverse osmosis membrane treatment device 118 and the forward osmosis membrane treatment device 14. A bactericide for a forward osmosis membrane may be added in the treatment water tank.
　この正浸透膜用殺菌剤は、従来の塩素系殺菌剤、酸化剤、有機系殺菌剤よりも、正浸透膜に対して十分な殺菌効果を発揮する。本実施形態に係る水処理方法では上記正浸透膜用殺菌剤を用いることにより、殺菌有効成分が正浸透膜をほとんど透過しないので、正浸透膜処理により希釈された希薄誘引溶液を前処理で用いることができ、希薄誘引溶液の再利用が可能になる。希薄誘引溶液に有機系殺菌剤が含まれる場合、殺菌有効成分は濁質除去装置１１６の逆洗排水や、逆浸透膜処理装置１１８のＲＯ透過水に含まれることになる。希薄誘引溶液に塩素系殺菌剤や酸化剤が含まれる場合、塩素系殺菌剤や酸化剤が濁質除去装置１１６や逆浸透膜処理装置１１８に流入すると、膜を劣化させてしまう。上記正浸透膜用殺菌剤を用いると、殺菌有効成分が正浸透膜をほとんど透過しないため、このようなリスクが抑制される。 殺菌 This fungicide for forward osmosis membranes exhibits a more sufficient bactericidal effect on forward osmosis membranes than conventional chlorine-based germicides, oxidants, and organic germicides. In the water treatment method according to the present embodiment, by using the fungicide for the forward osmosis membrane, since the sterilizing active ingredient hardly permeates through the forward osmosis membrane, a dilute attracting solution diluted by the forward osmosis membrane treatment is used in the pretreatment. And the reuse of the dilute attractant solution becomes possible. When the diluted attractant solution contains an organic bactericide, the bactericidal active ingredient is contained in the backwash wastewater of the turbidity removing device 116 and the RO permeated water of the reverse osmosis membrane treatment device 118. When a chlorine-based disinfectant or an oxidant is contained in the diluted attraction solution, when the chlorine-based disinfectant or the oxidant flows into the turbidity removing device 116 or the reverse osmosis membrane treatment device 118, the membrane is deteriorated. When the above-mentioned fungicide for forward osmosis membrane is used, such a risk is suppressed because the sterilizing active ingredient hardly permeates through the forward osmosis membrane.
　正浸透膜処理工程で使用された希薄誘引溶液は、希薄誘引溶液配管２６を通して前処理装置１１４へ送液され、前処理装置１１４において前処理工程で使用される。正浸透膜処理工程で得られたＦＯ濃縮水は、ＦＯ濃縮水配管２８を通して排出される。ＦＯ濃縮水は、回収、再利用されてもよい。 希 The dilute attractant used in the forward osmosis membrane treatment step is sent to the pretreatment device 114 through the dilute attractant solution pipe 26, and is used in the pretreatment device 114 in the pretreatment step. The FO concentrated water obtained in the forward osmosis membrane treatment step is discharged through the FO concentrated water piping 28. The FO concentrated water may be collected and reused.
　前処理装置１１４が溶解性シリカ除去を行う装置を含む場合、例えば、正浸透膜処理装置１４における誘引溶液として、マグネシウム塩水溶液が用いられ、正浸透膜処理装置１４で使用された希薄誘引溶液（マグネシウム塩希薄水溶液）は、前処理装置１１４において添加されるマグネシウム塩として使用されればよい。 When the pretreatment device 114 includes a device for removing soluble silica, for example, a magnesium salt aqueous solution is used as the attraction solution in the forward osmosis membrane treatment device 14, and the diluted attraction solution ( The magnesium salt diluted aqueous solution) may be used as a magnesium salt added in the pretreatment device 114.
　前処理装置１１４が石灰軟化法により硬度成分の除去を行う装置を含む場合、例えば、正浸透膜処理装置１４における誘引溶液として、アルカリ剤水溶液が用いられ、正浸透膜処理装置１４で使用された希薄誘引溶液（アルカリ剤希薄水溶液）は、前処理装置１１４において添加されるアルカリ剤として使用されればよい。 In the case where the pretreatment device 114 includes a device that removes a hardness component by a lime softening method, for example, an aqueous alkaline solution is used as the attraction solution in the forward osmosis membrane treatment device 14 and used in the forward osmosis membrane treatment device 14. The dilute attracting solution (dilute aqueous solution of the alkaline agent) may be used as the alkaline agent added in the pretreatment device 114.
　前処理装置１１４が樹脂軟化法により硬度成分の除去を行う装置を含む場合、例えば、正浸透膜処理装置１４における誘引溶液として、酸水溶液または塩化ナトリウム水溶液が用いられ、正浸透膜処理装置１４で使用された希薄誘引溶液（酸希薄水溶液または塩化ナトリウム希薄水溶液）は、前処理装置１１４においてイオン交換樹脂の再生剤として使用されればよい。 When the pretreatment device 114 includes a device that removes a hardness component by a resin softening method, for example, an acid aqueous solution or a sodium chloride aqueous solution is used as the attracting solution in the forward osmosis membrane treatment device 14, and the forward osmosis membrane treatment device 14 The used dilute attracting solution (acid dilute aqueous solution or sodium chloride dilute aqueous solution) may be used as a regenerant for the ion exchange resin in the pretreatment device 114.
　本実施形態に係る水処理方法および水処理装置により、例えば溶解性シリカおよび硬度成分のうち少なくとも１つを含む被処理水を低コストで処理することができる。 に よ り By the water treatment method and the water treatment apparatus according to the present embodiment, for example, the water to be treated containing at least one of the soluble silica and the hardness component can be treated at low cost.
　正浸透膜処理で希釈された希薄誘引溶液が前処理工程で使用されることで、本来必要であった誘引溶液の再利用に必要なコストが削減され、また、再生設備を備えなくてもよい。希薄誘引溶液は前処理工程で本来使用するものが希釈されているだけなので、追加のコストがほとんど発生しない。 By using the diluted attractant solution diluted by the forward osmosis membrane treatment in the pretreatment step, the cost required for reusing the attractant solution originally required is reduced, and it is not necessary to provide a regeneration facility. . Since the diluted attractant solution is only the one that is originally used in the pretreatment step, it has little additional cost.
　本実施形態に係る水処理方法および水処理装置の処理対象となる被処理水は、特に制限はないが、例えば溶解性シリカおよび硬度成分のうち少なくとも１つを含む水であり、例えば、工業用水、表層水、水道水、地下水、海水、海水を逆浸透法もしくは蒸発法によって脱塩した海水淡水化処理水、各種排水、例えば半導体製造工程で排出される排水等が挙げられる。 The target water to be treated by the water treatment method and the water treatment apparatus according to the present embodiment is not particularly limited, and is, for example, water containing at least one of soluble silica and a hardness component. Surface water, tap water, groundwater, seawater, seawater desalinated water obtained by desalinating seawater by a reverse osmosis method or an evaporation method, and various kinds of wastewater, for example, wastewater discharged in a semiconductor manufacturing process.
　被処理水中に溶解性シリカが含まれる場合、溶解性シリカの濃度は、例えば、５～４００ｍｇ／Ｌの範囲である。被処理水中に硬度成分が含まれる場合、カルシウム硬度成分の濃度は、５～６００ｍｇ／Ｌの範囲である。被処理水中の全蒸発残留物（ＴＤＳ：Ｔｏｔａｌ　Ｄｉｓｓｏｌｖｅｄ　Ｓｏｌｉｄ）は、例えば、１００～５００００ｍｇ／Ｌの範囲である。 場合 When the water to be treated contains soluble silica, the concentration of the soluble silica is, for example, in the range of 5 to 400 mg / L. When the water to be treated contains a hardness component, the concentration of the calcium hardness component is in the range of 5 to 600 mg / L. The total evaporation residue (TDS: Total Dissolved Solid) in the water to be treated is, for example, in the range of 100 to 50,000 mg / L.
　本実施形態に係る水処理方法および水処理装置において、被処理水が溶解性シリカおよび硬度成分の両者を含む場合は、前処理手段（前処理工程）は、溶解性シリカ除去手段（溶解性シリカ除去工程）および硬度成分除去手段（硬度成分除去工程）の両者を備えてもよい。溶解性シリカ除去手段（溶解性シリカ除去工程）および硬度成分除去手段（硬度成分除去工程）の順序は、第１に溶解性シリカ除去手段（溶解性シリカ除去工程）、第２に硬度成分除去手段（硬度成分除去工程）であっても、第１に硬度成分除去手段（硬度成分除去工程）、第２に溶解性シリカ除去手段（溶解性シリカ除去工程）であってもよい。 In the water treatment method and the water treatment apparatus according to the present embodiment, when the water to be treated contains both soluble silica and a hardness component, the pretreatment means (pretreatment step) is a means for removing soluble silica (soluble silica). (Hardening component removal step) and a hardness component removing means (hardness component removing step). The order of the soluble silica removing means (soluble silica removing step) and the hardness component removing means (hardness component removing step) is as follows: first, soluble silica removing means (soluble silica removing step), and second, hardness component removing means. (Hardness component removal step), firstly, hardness component removal means (hardness component removal step), and second, soluble silica removal means (soluble silica removal step).
　この場合、正浸透膜処理装置１４（正浸透膜処理工程）における誘引溶液として、マグネシウム塩水溶液、アルカリ剤水溶液、酸水溶液および塩化ナトリウム水溶液のうち少なくとも１つが用いられ、正浸透膜処理装置１４で使用された希薄誘引溶液（マグネシウム塩希薄水溶液、アルカリ剤希薄水溶液、酸希薄水溶液および塩化ナトリウム希薄水溶液のうち少なくとも１つ）が、前処理装置１１４（前処理工程）の溶解性シリカ除去手段（溶解性シリカ除去工程）および硬度成分除去手段（硬度成分除去工程）のうち適した方において使用されればよい。 In this case, at least one of an aqueous solution of a magnesium salt, an aqueous solution of an alkali agent, an aqueous solution of an acid, and an aqueous solution of sodium chloride is used as the attracting solution in the forward osmosis membrane processing apparatus 14 (forward osmosis membrane processing step). The diluted attracting solution (at least one of a dilute aqueous solution of a magnesium salt, a dilute aqueous solution of an alkali agent, a dilute aqueous solution of an acid, and a dilute aqueous solution of sodium chloride) is used as the soluble silica removing means (pre-treatment step) of the pretreatment device 114 (pretreatment step). It may be used in a suitable one of the step of removing the silica and the means of removing the hardness component (the step of removing the hardness component).
　濁質除去手段としては、例えば、砂ろ過装置、限外ろ過（ＵＦ）膜等の膜ろ過装置、加圧浮上装置等が挙げられる。濁質除去手段の設置位置は、特に制限はなく、例えば、前処理装置１１４（前処理工程）の前段、または前処理装置１１４（前処理工程）と逆浸透膜処理装置１１８（逆浸透膜処理工程）との間である。 The turbidity removing means includes, for example, a sand filtration device, a membrane filtration device such as an ultrafiltration (UF) membrane, and a pressure flotation device. There is no particular limitation on the installation position of the turbidity removing means. For example, a pre-treatment device 114 (pre-treatment process) or a pre-treatment device 114 (pre-treatment process) and a reverse osmosis membrane treatment device 118 (reverse osmosis membrane treatment) Step).
　前処理工程の詳細は、前述したとおりである。溶解性シリカ除去および石灰軟化法による硬度成分除去において、固液分離で得られた前処理水は、逆浸透膜処理装置１１８へ、または濁質除去装置１１６を通して逆浸透膜処理装置１１８へ送液されればよい。樹脂軟化法による硬度成分除去において、イオン交換処理で得られた前処理水は、逆浸透膜処理装置１１８へ、または濁質除去装置１１６を通して逆浸透膜処理装置１１８へ送液されればよい。 詳細 The details of the pretreatment step are as described above. In the removal of the soluble silica and the removal of the hardness component by the lime softening method, the pretreated water obtained by the solid-liquid separation is sent to the reverse osmosis membrane treatment device 118 or to the reverse osmosis membrane treatment device 118 through the turbidity removal device 116. It should be done. In the removal of the hardness component by the resin softening method, the pretreated water obtained by the ion exchange treatment may be sent to the reverse osmosis membrane treatment device 118 or to the reverse osmosis membrane treatment device 118 through the turbidity removal device 116.
　図１～３の水処理装置１，３，５におけるＦＯ被処理水である濃縮水中に、臭素系酸化剤または塩素系酸化剤とスルファミン酸化合物とを含む殺菌剤（「正浸透膜用殺菌剤」）を存在させてもよい。例えば、正浸透膜用殺菌剤は、殺菌剤添加配管を通して濃縮水配管２０においてＦＯ被処理水（濃縮水）に添加される。正浸透膜処理装置１４の前段、例えば、逆浸透膜処理装置１２と正浸透膜処理装置１４との間にＦＯ被処理水（濃縮水）を貯留する濃縮水槽を別途設け、濃縮水槽において正浸透膜用殺菌剤が添加されてもよい。 A sterilizing agent containing a bromine-based oxidizing agent or a chlorine-based oxidizing agent and a sulfamic acid compound in the concentrated water that is the FO treated water in the water treatment apparatuses 1, 3, and 5 shown in FIGS. )) May be present. For example, the forward osmosis membrane disinfectant is added to the FO treated water (concentrated water) in the concentrated water pipe 20 through the disinfectant addition pipe. A concentrated water tank for storing FO to-be-treated water (concentrated water) is provided separately before the forward osmosis membrane treatment apparatus 14, for example, between the reverse osmosis membrane treatment apparatus 12 and the forward osmosis membrane treatment apparatus 14. A bactericide for the membrane may be added.
［逆浸透膜処理工程］
　逆浸透膜処理工程で用いられる逆浸透膜として昨今主流であるポリアミド系高分子膜に好適に適用することができる。ポリアミド系高分子膜は、酸化剤に対する耐性が比較的低く、遊離塩素等をポリアミド系高分子膜に連続的に接触させると、膜性能の著しい低下が起こる。しかしながら、本実施形態に係る水処理方法では上記正浸透膜用殺菌剤を用いることにより、殺菌有効成分が正浸透膜をほとんど透過しないので、ポリアミド系高分子膜においても、このような著しい膜性能の低下はほとんど起こらない。 [Reverse osmosis membrane treatment step]
As a reverse osmosis membrane used in the reverse osmosis membrane treatment step, it can be suitably applied to a polyamide-based polymer membrane which is currently mainstream. The polyamide-based polymer membrane has relatively low resistance to an oxidizing agent, and when free chlorine or the like is continuously brought into contact with the polyamide-based polymer membrane, the membrane performance is significantly reduced. However, in the water treatment method according to the present embodiment, since the sterilizing active ingredient hardly permeates the forward osmosis membrane by using the above-mentioned forward osmosis membrane bactericide, such a remarkable membrane performance is obtained even in the polyamide-based polymer membrane. Hardly occurs.
　逆浸透膜処理は、複数の逆浸透膜処理を直列または並列にして使用してもよい。第１の逆浸透膜処理によって得られた濃縮水を第２、第３の逆浸透膜処理によってさらに濃縮してもよく、第１の逆浸透膜処理によって得られた透過水について別の逆浸透膜処理を実施することで、水質をより高めることができる。 In reverse osmosis membrane treatment, a plurality of reverse osmosis membrane treatments may be used in series or in parallel. The concentrated water obtained by the first reverse osmosis membrane treatment may be further concentrated by the second and third reverse osmosis membrane treatments, and the permeated water obtained by the first reverse osmosis membrane treatment is subjected to another reverse osmosis treatment. By performing the membrane treatment, the water quality can be further improved.
　逆浸透膜処理工程で使用される逆浸透膜としては、純水製造用途や排水回収等の用途に使用される超低圧逆浸透膜、低圧逆浸透膜の他に、海水淡水化等の用途に使用される中圧逆浸透膜や高圧逆浸透膜等が挙げられる。超低圧逆浸透膜、低圧逆浸透膜としては、例えば、ＥＳ１５（日東電工製）、ＴＭ７２０Ｄ（東レ製）、ＢＷ３０ＨＲＬＥ（ダウケミカル製）、ＬＦＣ３－ＬＤ（Ｈｙｄｒａｎａｕｔｉｃｓ製）が挙げられる。高圧逆浸透膜としては、例えば、ＳＷＣ５－ＬＤ（Ｈｙｄｒａｎａｕｔｉｃｓ製）、ＴＭ８２０Ｖ（東レ製）、ＸＵＳ１８０８０８（ダウケミカル製）が挙げられる。逆浸透膜工程が複数段用いられる場合は、各段の被処理水のＴＤＳ、ｐＨ、水温等の条件に応じて、異種の膜を選択することができる。 Reverse osmosis membranes used in the reverse osmosis membrane treatment process include ultra-low pressure reverse osmosis membranes and low pressure reverse osmosis membranes used for pure water production and wastewater recovery, as well as seawater desalination. Examples thereof include a medium pressure reverse osmosis membrane and a high pressure reverse osmosis membrane used. Examples of the ultra-low pressure reverse osmosis membrane and low pressure reverse osmosis membrane include ES15 (manufactured by Nitto Denko), TM720D (manufactured by Toray), BW30HRLE (manufactured by Dow Chemical), and LFC3-LD (manufactured by Hydroranatics). Examples of the high-pressure reverse osmosis membrane include SWC5-LD (manufactured by Hydroranatics), TM820V (manufactured by Toray), and XUS180808 (manufactured by Dow Chemical). When a plurality of stages of reverse osmosis membranes are used, different types of membranes can be selected according to conditions such as TDS, pH, and water temperature of the water to be treated in each stage.
　濃縮処理工程において、ｐＨ調整剤や、系内での無機塩のスケーリングを抑制するスケール分散剤、系内での微生物発生を抑制する殺菌剤等の薬品を添加してもよい。 (4) In the concentration treatment step, chemicals such as a pH adjuster, a scale dispersant for suppressing the scaling of inorganic salts in the system, and a bactericide for suppressing the generation of microorganisms in the system may be added.
＜正浸透膜用殺菌剤＞
　本実施形態に係る正浸透膜用殺菌剤は、「臭素系酸化剤または塩素系酸化剤」と「スルファミン酸化合物」との混合物を含む安定化次亜臭素酸組成物または安定化次亜塩素酸組成物を含有するものであり、さらにアルカリを含有してもよい。 <Disinfectant for forward osmosis membrane>
The fungicide for forward osmosis membrane according to the present embodiment is a stabilized hypobromite composition or stabilized hypochlorous acid containing a mixture of "brominated oxidizing agent or chlorine oxidizing agent" and "sulfamic acid compound". It contains a composition and may further contain an alkali.
　また、本実施形態に係る正浸透膜用殺菌剤は、「臭素系酸化剤とスルファミン酸化合物との反応生成物」を含む安定化次亜臭素酸組成物、または「塩素系酸化剤とスルファミン酸化合物との反応生成物」を含む安定化次亜塩素酸組成物を含有するものであり、さらにアルカリを含有してもよい。 Further, the fungicide for forward osmosis membrane according to the present embodiment is a stabilized hypobromite composition containing "a reaction product of a brominated oxidizing agent and a sulfamic acid compound", or a "chlorinated oxidizing agent and a sulfamic acid. It contains a stabilized hypochlorous acid composition containing a "reaction product with a compound", and may further contain an alkali.
　臭素系酸化剤、臭素化合物、塩素系酸化剤およびスルファミン酸化合物については、上述した通りである。 The bromine-based oxidant, bromine compound, chlorine-based oxidant, and sulfamic acid compound are as described above.
　塩素系酸化剤とスルファミン酸化合物とを含む安定化次亜塩素酸組成物の市販品としては、例えば、栗田工業株式会社製の「クリバーターＩＫ－１１０」が挙げられる。 市 販 A commercially available stabilized hypochlorous acid composition containing a chlorine-based oxidizing agent and a sulfamic acid compound is, for example, “Krivator IK-110” manufactured by Kurita Water Industries Ltd.
　本実施形態に係る正浸透膜用殺菌剤としては、正浸透膜をより劣化させないため、臭素と、スルファミン酸化合物とを含有するもの（臭素とスルファミン酸化合物の混合物を含有するもの）、例えば、臭素とスルファミン酸化合物とアルカリと水との混合物、または、臭素とスルファミン酸化合物との反応生成物を含有するもの、例えば、臭素とスルファミン酸化合物との反応生成物と、アルカリと、水との混合物が好ましい。 As the fungicide for forward osmosis membrane according to the present embodiment, in order not to further deteriorate the forward osmosis membrane, those containing bromine and a sulfamic acid compound (containing a mixture of bromine and a sulfamic acid compound), for example, A mixture of bromine and a sulfamic acid compound and an alkali and water, or a mixture containing a reaction product of a bromine and a sulfamic acid compound, for example, a reaction product of a bromine and a sulfamic acid compound, an alkali, and water Mixtures are preferred.
　本実施形態に係る正浸透膜用殺菌剤のうち、臭素系酸化剤とスルファミン酸化合物とを含む安定化次亜臭素酸組成物を含有する殺菌剤、特に臭素とスルファミン酸化合物とを含む安定化次亜臭素酸組成物を含有する殺菌剤は、塩素系酸化剤とスルファミン酸化合物とを含む殺菌剤（クロロスルファミン酸等）と比較すると、酸化力が高く、スライム抑制力、スライム剥離力が著しく高いにもかかわらず、同じく酸化力の高い次亜塩素酸のような著しい膜劣化をほとんど引き起こすことがない。通常の使用濃度では、膜劣化への影響は実質的に無視することができる。このため、殺菌剤としては最適である。 Among the bactericides for the forward osmosis membrane according to the present embodiment, a bactericide containing a stabilized hypobromite composition containing a brominated oxidizing agent and a sulfamic acid compound, and in particular, stabilization containing bromine and a sulfamic acid compound. The disinfectant containing the hypobromite composition has a higher oxidizing power and a remarkable slime suppressing power and a slime peeling power compared to a disinfectant containing a chlorine-based oxidizing agent and a sulfamic acid compound (such as chlorosulfamic acid). Despite being high, it hardly causes remarkable film deterioration like hypochlorous acid having high oxidizing power. At normal use concentrations, the effect on film degradation can be substantially ignored. Therefore, it is most suitable as a disinfectant.
　本実施形態に係る正浸透膜用殺菌剤は、次亜塩素酸等の殺菌剤とは異なり、正浸透膜をほとんど透過しないため、希薄誘引溶液への影響がほとんどない。また、次亜塩素酸等と同様に現場で濃度を測定することができるため、より正確な濃度管理が可能である。 殺菌 Unlike the disinfectant such as hypochlorous acid, the disinfectant for forward osmosis membrane according to the present embodiment hardly permeates through the forward osmosis membrane, and thus has little effect on the diluted attractant solution. In addition, since the concentration can be measured on site similarly to hypochlorous acid or the like, more accurate concentration control is possible.
　正浸透膜用殺菌剤のｐＨは、例えば、１３．０超であり、１３．２超であることがより好ましい。正浸透膜用殺菌剤のｐＨが１３．０以下であると正浸透膜用殺菌剤中の有効ハロゲンが不安定になる場合がある。 ＰＨ The pH of the fungicide for forward osmosis membrane is, for example, more than 13.0, and more preferably more than 13.2. When the pH of the fungicide for forward osmosis membrane is 13.0 or less, the effective halogen in the fungicide for forward osmosis membrane may become unstable.
　正浸透膜用殺菌剤中の臭素酸濃度は、５ｍｇ／ｋｇ未満であることが好ましい。正浸透膜用殺菌剤中の臭素酸濃度が５ｍｇ／ｋｇ以上であると、希薄誘引溶液の臭素酸イオンの濃度が高くなる場合がある。 臭 The bromic acid concentration in the forward osmosis membrane fungicide is preferably less than 5 mg / kg. When the concentration of bromate in the fungicide for forward osmosis membrane is 5 mg / kg or more, the concentration of bromate ion in the dilute attracting solution may increase.
＜正浸透膜用殺菌剤の製造方法＞
　本実施形態に係る正浸透膜用殺菌剤は、臭素系酸化剤または塩素系酸化剤とスルファミン酸化合物とを混合することにより得られ、さらにアルカリを混合してもよい。 <Production method of fungicide for forward osmosis membrane>
The germicide for a forward osmosis membrane according to this embodiment is obtained by mixing a bromine-based oxidant or a chlorine-based oxidant with a sulfamic acid compound, and may further contain an alkali.
　臭素と、スルファミン酸化合物とを含む安定化次亜臭素酸組成物を含有する正浸透膜用殺菌剤の製造方法としては、水、アルカリおよびスルファミン酸化合物を含む混合液に臭素を不活性ガス雰囲気下で添加して反応させる工程、または、水、アルカリおよびスルファミン酸化合物を含む混合液に臭素を不活性ガス雰囲気下で添加する工程を含むことが好ましい。不活性ガス雰囲気下で添加して反応させる、または、不活性ガス雰囲気下で添加することにより、正浸透膜用殺菌剤中の臭素酸イオン濃度が低くなり、希薄誘引溶液中の臭素酸イオン濃度が低くなる。 As a method for producing a fungicide for a forward osmosis membrane containing a stabilized hypobromite composition containing bromine and a sulfamic acid compound, bromine is added to a mixed solution containing water, alkali and a sulfamic acid compound in an inert gas atmosphere. It is preferable to include a step of adding and reacting under an inert gas atmosphere or a step of adding bromine to a mixed solution containing water, an alkali and a sulfamic acid compound under an inert gas atmosphere. By adding and reacting under an inert gas atmosphere, or by adding under an inert gas atmosphere, the bromate ion concentration in the fungicide for the forward osmosis membrane is reduced, and the bromate ion concentration in the dilute attractant solution is reduced. Becomes lower.
　用いる不活性ガスとしては限定されないが、製造等の面から窒素およびアルゴンのうち少なくとも１つが好ましく、特に製造コスト等の面から窒素が好ましい。 The inert gas used is not limited, but is preferably at least one of nitrogen and argon from the viewpoint of production and the like, and particularly preferably nitrogen from the viewpoint of production cost and the like.
　臭素の添加の際の反応器内の酸素濃度は６％以下が好ましいが、４％以下がより好ましく、２％以下がさらに好ましく、１％以下が特に好ましい。臭素の反応の際の反応器内の酸素濃度が６％を超えると、反応系内の臭素酸の生成量が増加する場合がある。 酸 素 The oxygen concentration in the reactor when adding bromine is preferably 6% or less, more preferably 4% or less, further preferably 2% or less, and particularly preferably 1% or less. If the oxygen concentration in the reactor during the reaction of bromine exceeds 6%, the amount of bromic acid generated in the reaction system may increase.
　臭素の添加率は、正浸透膜用殺菌剤全体の量に対して２５重量％以下であることが好ましく、１重量％以上２０重量％以下であることがより好ましい。臭素の添加率が正浸透膜用殺菌剤全体の量に対して２５重量％を超えると、反応系内の臭素酸の生成量が増加する場合がある。１重量％未満であると、殺菌力が劣る場合がある。 (4) The bromine addition rate is preferably 25% by weight or less, more preferably 1% by weight or more and 20% by weight or less based on the total amount of the fungicide for forward osmosis membranes. If the bromine addition rate exceeds 25% by weight based on the total amount of the fungicide for the forward osmosis membrane, the amount of bromic acid generated in the reaction system may increase. If it is less than 1% by weight, the bactericidal activity may be poor.
　臭素添加の際の反応温度は、０℃以上２５℃以下の範囲に制御することが好ましいが、製造コスト等の面から、０℃以上１５℃以下の範囲に制御することがより好ましい。臭素添加の際の反応温度が２５℃を超えると、反応系内の臭素酸の生成量が増加する場合があり、０℃未満であると、凍結する場合がある。 (4) The reaction temperature at the time of adding bromine is preferably controlled in the range of 0 ° C. or more and 25 ° C. or less, but is more preferably controlled in the range of 0 ° C. or more and 15 ° C. or less from the viewpoint of production cost and the like. If the reaction temperature at the time of adding bromine exceeds 25 ° C., the amount of bromic acid generated in the reaction system may increase, and if it is lower than 0 ° C., it may freeze.
　以下、実施例および比較例を挙げ、本発明をより具体的に詳細に説明するが、本発明は、以下の実施例に限定されるものではない。 Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.
＜実施例１＞
　ＴＤＳ１００ｐｐｍ、溶解性シリカ１５ｐｐｍを含む工業用水について、図１に記載の水処理装置を用いて濃縮処理を実施した。逆浸透膜処理装置によって、ＴＤＳ８％まで濃縮した。この濃縮水を正浸透膜処理装置（正浸透膜：ＨＰ５２３０（東洋紡製））に供給し、さらに誘引溶液として３０重量％塩化マグネシウム溶液を供給し、ＴＤＳ２０％のＦＯ濃縮水を得た。正浸透膜処理によって希釈された希薄塩化マグネシウム溶液は、溶解性シリカ除去装置にそのまま添加した。正浸透膜処理に用いたエネルギーコストを算出した。結果を表１に示す。 <Example 1>
An industrial water containing 100 ppm of TDS and 15 ppm of soluble silica was subjected to a concentration treatment using the water treatment apparatus shown in FIG. The TDS was concentrated to 8% by a reverse osmosis membrane treatment device. This concentrated water was supplied to a forward osmosis membrane treatment device (forward osmosis membrane: HP5230 (manufactured by Toyobo)), and a 30% by weight magnesium chloride solution was further supplied as an attraction solution to obtain a FO concentrated water having a TDS of 20%. The diluted magnesium chloride solution diluted by the forward osmosis membrane treatment was directly added to a soluble silica removing device. The energy cost used for the forward osmosis membrane treatment was calculated. Table 1 shows the results.
＜比較例１＞
　実施例１で用いた水処理装置において、正浸透膜処理装置の代わりにエバポレータを用いた濃縮操作を実施し、同じくＴＤＳ２０％の濃縮水を得た。エバポレータに用いたエネルギーコストを算出し、実施例１と比較した。結果を表１に示す。 <Comparative Example 1>
In the water treatment apparatus used in Example 1, a concentration operation using an evaporator was performed in place of the forward osmosis membrane treatment apparatus, and a concentrated water having a TDS of 20% was also obtained. The energy cost used for the evaporator was calculated and compared with Example 1. Table 1 shows the results.
＜比較例２＞
　実施例１で用いた水処理装置において、正浸透膜処理装置の誘引溶液として、３０重量％炭酸アンモニウム溶液を用い、同じくＴＤＳ２０％の濃縮水を得た。正浸透膜処理によって希釈された希薄炭酸アンモニウム溶液は、再生装置に送り、熱による再生を実施した（再生工程）。正浸透膜処理に用いたエネルギーコストを算出した（再生工程に供したエネルギーを含む）。結果を表１に示す。 <Comparative Example 2>
In the water treatment apparatus used in Example 1, a 30% by weight ammonium carbonate solution was used as an attraction solution for the forward osmosis membrane treatment apparatus, and a TDS 20% concentrated water was also obtained. The diluted ammonium carbonate solution diluted by the forward osmosis membrane treatment was sent to a regenerating device, and regenerated by heat (regeneration step). The energy cost used for the forward osmosis membrane treatment was calculated (including the energy used for the regeneration step). Table 1 shows the results.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　このように、実施例１の処理方法により、比較例１，２の処理方法に比べて、低いエネルギーコストで濃縮することができ、溶解性シリカおよび硬度成分のうち少なくとも１つを含む被処理水を低コストで処理することができることがわかった。 As described above, the treatment method of Example 1 can be concentrated at a lower energy cost than the treatment methods of Comparative Examples 1 and 2, and the water to be treated containing at least one of the soluble silica and the hardness component. Can be processed at low cost.
＜実施例２＞
　ＴＤＳ１００ｐｐｍ、溶解性シリカ１５ｐｐｍを含む工業用水について、図３に記載の水処理装置を用いて濃縮処理を実施した。逆浸透膜処理装置によって、ＴＤＳ８％まで濃縮した。この濃縮水を正浸透膜処理装置（正浸透膜：ＨＰ５２３０（東洋紡製））に供給し、さらに誘引溶液として３０重量％塩化マグネシウム溶液を供給し、ＴＤＳ２０％のＦＯ濃縮水を得た。正浸透膜処理によって希釈された希薄塩化マグネシウム溶液の一部は、溶解性シリカ除去装置にそのまま添加し、残りは、図６の構成の濃縮装置を用いて塩化マグネシウム３０％まで濃縮し、正浸透膜処理装置の誘引溶液として再利用した。正浸透膜処理に用いたエネルギーコストを算出した。結果を表２に示す。 <Example 2>
Concentration treatment was performed on industrial water containing 100 ppm of TDS and 15 ppm of soluble silica using the water treatment apparatus shown in FIG. The TDS was concentrated to 8% by a reverse osmosis membrane treatment device. This concentrated water was supplied to a forward osmosis membrane treatment device (forward osmosis membrane: HP5230 (manufactured by Toyobo)), and a 30% by weight magnesium chloride solution was further supplied as an attraction solution to obtain a FO concentrated water having a TDS of 20%. A part of the diluted magnesium chloride solution diluted by the forward osmosis membrane treatment is directly added to a soluble silica removing device, and the rest is concentrated to 30% of magnesium chloride using a concentrating device having the configuration shown in FIG. It was reused as an attracting solution for the membrane treatment device. The energy cost used for the forward osmosis membrane treatment was calculated. Table 2 shows the results.
＜比較例３＞
　実施例２で用いた水処理装置において、正浸透膜処理装置の代わりにエバポレータを用いた濃縮操作を実施し、同じくＴＤＳ２０％の濃縮水を得た。エバポレータに用いたエネルギーコストを算出し、実施例２と比較した。結果を表２に示す。 <Comparative Example 3>
In the water treatment apparatus used in Example 2, a concentration operation using an evaporator was performed in place of the forward osmosis membrane treatment apparatus, and a concentrated water having a TDS of 20% was also obtained. The energy cost used for the evaporator was calculated and compared with Example 2. Table 2 shows the results.
＜比較例４＞
　実施例２で用いた水処理装置において、正浸透膜処理装置の誘引溶液として、３０重量％炭酸アンモニウム溶液を用い、同じくＴＤＳ２０％の濃縮水を得た。正浸透膜処理によって希釈された希薄炭酸アンモニウム溶液は、再生装置に送り、熱による再生を実施した（再生工程）。正浸透膜処理に用いたエネルギーコストを算出した（再生工程に供したエネルギーを含む）。結果を表２に示す。 <Comparative Example 4>
In the water treatment apparatus used in Example 2, a 30% by weight ammonium carbonate solution was used as an attraction solution for the forward osmosis membrane treatment apparatus, and a TDS 20% concentrated water was also obtained. The diluted ammonium carbonate solution diluted by the forward osmosis membrane treatment was sent to a regenerating device, and regenerated by heat (regeneration step). The energy cost used for the forward osmosis membrane treatment was calculated (including the energy used for the regeneration step). Table 2 shows the results.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　このように、実施例２の処理方法により、比較例３，４の処理方法に比べて、低いエネルギーコストで濃縮することができ、溶解性シリカおよび硬度成分のうち少なくとも１つを含む被処理水を低コストで処理することができることがわかった。 As described above, the treatment method of Example 2 can be concentrated at a lower energy cost than the treatment methods of Comparative Examples 3 and 4, and the water to be treated containing at least one of the soluble silica and the hardness component. Can be processed at low cost.
［安定化次亜臭素酸組成物（組成物１）の調製］
　窒素雰囲気下で、液体臭素：１６．９重量％（ｗｔ％）、スルファミン酸：１０．７重量％、水酸化ナトリウム：１２．９重量％、水酸化カリウム：３．９４重量％、水：残分を混合して、安定化次亜臭素酸組成物（組成物１）を調製した。安定化次亜臭素酸組成物のｐＨは１４、全塩素濃度は７．５重量％であった。全塩素濃度は、ＨＡＣＨ社の多項目水質分析計ＤＲ／４０００を用いて、全塩素測定法（ＤＰＤ（ジエチル－ｐ－フェニレンジアミン）法）により測定した値（ｍｇ／Ｌ　ａｓＣｌ２）である。安定化次亜臭素酸組成物の詳細な調製方法は以下の通りである。 [Preparation of stabilized hypobromite composition (composition 1)]
Under a nitrogen atmosphere, liquid bromine: 16.9% by weight (wt%), sulfamic acid: 10.7% by weight, sodium hydroxide: 12.9% by weight, potassium hydroxide: 3.94% by weight, water: residual The stabilized components were mixed to prepare a stabilized hypobromite composition (composition 1). The pH of the stabilized hypobromite composition was 14, and the total chlorine concentration was 7.5% by weight. The total chlorine concentration is a value (mg / LasCl 2 ) measured by a total chlorine measurement method (DPD (diethyl-p-phenylenediamine) method) using a multi-item water quality analyzer DR / 4000 manufactured by HACH. The detailed preparation method of the stabilized hypobromite composition is as follows.
　反応容器内の酸素濃度が１％に維持されるように、窒素ガスの流量をマスフローコントローラでコントロールしながら連続注入で封入した２Ｌの４つ口フラスコに１４３６ｇの水、３６１ｇの水酸化ナトリウムを加え混合し、次いで３００ｇのスルファミン酸を加え混合した後、反応液の温度が０～１５℃になるように冷却を維持しながら、４７３ｇの液体臭素を加え、さらに４８％水酸化カリウム溶液２３０ｇを加え、組成物全体の量に対する重量比でスルファミン酸１０．７％、臭素１６．９％、臭素の当量に対するスルファミン酸の当量比が１．０４である、目的の安定化次亜臭素酸組成物（組成物１）を得た。生じた溶液のｐＨは、ガラス電極法にて測定したところ、１４であった。生じた溶液の臭素含有率は、臭素をヨウ化カリウムによりヨウ素に転換後、チオ硫酸ナトリウムを用いて酸化還元滴定する方法により測定したところ１６．９％であり、理論含有率（１６．９％）の１００．０％であった。また、臭素反応の際の反応容器内の酸素濃度は、株式会社ジコー製の「酸素モニタＪＫＯ－０２　ＬＪＤＩＩ」を用いて測定した。なお、臭素酸濃度は５ｍｇ／ｋｇ未満であった。 1436 g of water and 361 g of sodium hydroxide were added to a 2 L four-necked flask sealed by continuous injection while controlling the flow rate of nitrogen gas with a mass flow controller so that the oxygen concentration in the reaction vessel was maintained at 1%. After mixing and then adding 300 g of sulfamic acid and mixing, 473 g of liquid bromine was added while maintaining cooling so that the temperature of the reaction solution became 0 to 15 ° C., and 230 g of a 48% potassium hydroxide solution was further added. The intended stabilized hypobromite composition (10.7% by weight relative to the total amount of the composition, 16.9% bromine, and the equivalent ratio of sulfamic acid to the equivalent of bromine is 1.04) Composition 1) was obtained. The pH of the resulting solution was 14, as measured by the glass electrode method. The bromine content of the resulting solution was measured by a method of converting bromine to iodine with potassium iodide and then performing redox titration with sodium thiosulfate, and found to be 16.9%. The theoretical content was 16.9% ) Was 100.0%. The oxygen concentration in the reaction vessel during the bromine reaction was measured using “Oxygen Monitor JKO-02 @ LJDII” manufactured by Jiko Corporation. The bromate concentration was less than 5 mg / kg.
　なお、ｐＨの測定は、以下の条件で行った。
　　電極タイプ：ガラス電極式
　　ｐＨ測定計：東亜ディーケーケー社製、ＩＯＬ－３０型
　　電極の校正：関東化学社製中性リン酸塩ｐＨ（６．８６）標準液（第２種）、同社製ホウ酸塩ｐＨ（９．１８）標準液（第２種）の２点校正で行った
　　測定温度：２５℃
　　測定値：測定液に電極を浸漬し、安定後の値を測定値とし、３回測定の平均値 The pH was measured under the following conditions.
Electrode type: Glass electrode type pH meter: Toa DKK, IOL-30 type Calibration of electrode: Neutral phosphate pH (6.86) standard solution (2nd class), Kanto Chemical Co., boric acid Performed by two-point calibration of salt pH (9.18) standard solution (second type) Measurement temperature: 25 ° C
Measured value: The electrode was immersed in the test solution, and the value after stabilization was taken as the measured value, the average of three measurements
［安定化次亜塩素酸組成物（組成物２）の調製］
　１２％次亜塩素酸ナトリウム水溶液：５０重量％、スルファミン酸：１２重量％、水酸化ナトリウム：８重量％、水：残分を混合して、安定化次亜塩素酸組成物（組成物２）を調製した。組成物２のｐＨは１３．７、全塩素濃度は、６．２重量％であった。 [Preparation of stabilized hypochlorous acid composition (composition 2)]
A 12% aqueous sodium hypochlorite solution: 50% by weight, sulfamic acid: 12% by weight, sodium hydroxide: 8% by weight, water: the residue is mixed, and the stabilized hypochlorous acid composition (Composition 2) Was prepared. Composition 2 had a pH of 13.7 and a total chlorine concentration of 6.2% by weight.
＜実施例３＞
　ＦＯ被処理水として、全蒸発残留物（ＴＤＳ）８重量％まで濃縮した工業排水を用い、誘引溶液を３０重量％ＭｇＣｌ２水溶液とし、正浸透膜処理を実施した。ＦＯ濃縮水出口の流量がＦＯ被処理水入口の５０％になるように（濃縮倍率２倍）、誘引溶液の流量を調整した。正浸透膜（ＦＯ膜）としては、酢酸セルロース製ＦＯ膜（ＨＰＣ３２０５、東洋紡製）を用いた。ＦＯ被処理水中に、正浸透膜用殺菌剤として安定化次亜臭素酸組成物（組成物１）を、ＦＯ被処理水入口で全塩素濃度１ｐｐｍＣｌとなるように添加した。本運転を計２００時間継続し、正浸透膜処理装置のＦＯ被処理水入口－ＦＯ濃縮水出口の圧力損失（通水差圧）および殺菌剤の阻止率を評価した。なお、運転開始直後の通水差圧は０．０２ＭＰａであった。結果を表３に示す。
　　殺菌剤の阻止率［%］＝（１－（希薄誘引溶液流量×希薄誘引溶液全塩素濃度／ＦＯ被処理水流量×ＦＯ被処理水全塩素濃度）） <Example 3>
Industrial effluent concentrated to a total evaporation residue (TDS) of 8% by weight was used as the FO water to be treated, and the attracting solution was a 30% by weight aqueous MgCl 2 solution, and a forward osmosis membrane treatment was performed. The flow rate of the attracting solution was adjusted so that the flow rate at the outlet of the FO concentrated water was 50% of the inlet of the FO treated water (concentration ratio was 2 times). As the forward osmosis membrane (FO membrane), an FO membrane made of cellulose acetate (HPC3205, manufactured by Toyobo) was used. A stabilized hypobromite composition (composition 1) was added as a fungicide for a forward osmosis membrane to the FO water to be treated so as to have a total chlorine concentration of 1 ppmCl at the inlet of the FO water to be treated. This operation was continued for a total of 200 hours, and the pressure loss (differential water pressure) between the inlet of the FO treated water and the outlet of the FO concentrated water of the forward osmosis membrane treatment apparatus and the rejection rate of the germicide were evaluated. The water flow differential pressure immediately after the start of operation was 0.02 MPa. Table 3 shows the results.
Disinfectant rejection [%] = (1- (diluted attracting solution flow rate × diluted attracting solution total chlorine concentration / FO treated water flow rate × FO treated water total chlorine concentration))
＜実施例４＞
　ＦＯ被処理水中に、正浸透膜用殺菌剤として安定化次亜臭素酸組成物（組成物１）の代わりに、安定化次亜塩素酸組成物（組成物２；クロロスルファミン酸）を、ＦＯ被処理水入口で全塩素濃度１ｐｐｍＣｌとなるように添加した以外は、実施例３と同様にして正浸透膜処理を実施した。結果を表３に示す。 <Example 4>
Instead of the stabilized hypobromite composition (composition 1) as a fungicide for a forward osmosis membrane, a stabilized hypochlorous acid composition (composition 2; chlorosulfamic acid) was added to the FO treated water. A forward osmosis membrane treatment was performed in the same manner as in Example 3 except that the total chlorine concentration was 1 ppmCl at the inlet of the water to be treated. Table 3 shows the results.
＜比較例５＞
　ＦＯ被処理水中に、正浸透膜用殺菌剤として安定化次亜臭素酸組成物（組成物１）の代わりに、塩素系殺菌剤である次亜塩素酸ナトリウムを、ＦＯ被処理水入口で遊離塩素濃度１ｐｐｍＣｌとなるように添加した以外は、実施例３と同様にして正浸透膜処理を実施した。結果を表３に示す。 <Comparative Example 5>
In the FO treated water, sodium hypochlorite, which is a chlorine-based disinfectant, is released at the FO treated water inlet instead of the stabilized hypobromite composition (Composition 1) as a forward osmosis membrane disinfectant. A forward osmosis membrane treatment was carried out in the same manner as in Example 3 except that the chlorine concentration was 1 ppmCl. Table 3 shows the results.
＜比較例６＞
　ＦＯ被処理水中に、正浸透膜用殺菌剤として安定化次亜臭素酸組成物（組成物１）の代わりに、有機系殺菌剤である５－クロロ－２－メチル－４－イソチアゾリン－３－オンを、ＦＯ被処理水入口においてＴＯＣで１０ｐｐｍとなるように添加した以外は、実施例３と同様にして正浸透膜処理を実施した。結果を表３に示す。 <Comparative Example 6>
Instead of the stabilized hypobromite composition (Composition 1) as a fungicide for a forward osmosis membrane, 5-chloro-2-methyl-4-isothiazoline-3- as an organic fungicide is used in the FO treated water. A forward osmosis membrane treatment was carried out in the same manner as in Example 3, except that ON was added at the inlet of the FO treated water at a TOC of 10 ppm. Table 3 shows the results.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
［結果］
　実施例３では、正浸透膜の通水差圧の上昇を抑制することができた。殺菌剤も９９%以上が阻止された。実施例４でも同様の傾向だが、通水差圧はやや上昇した。比較例５，６では、通水差圧が＞０．２ＭＰａとなり、膜の許容通水差圧（０．２ＭＰａ）を超えた。殺菌剤阻止率も８５％以下であり、希薄誘引溶液中への殺菌有効成分のリークが確認された。 [result]
In Example 3, it was possible to suppress an increase in the differential pressure of water passing through the forward osmosis membrane. Fungicides were also blocked by more than 99%. Example 4 has the same tendency, but the pressure difference in water flow slightly increased. In Comparative Examples 5 and 6, the water pressure difference was> 0.2 MPa, which exceeded the allowable water pressure difference (0.2 MPa) of the membrane. The fungicide rejection was also 85% or less, and leakage of the fungicidal active ingredient into the diluted attractant solution was confirmed.
　このように、殺菌剤として、安定化次亜臭素酸組成物または安定化次亜塩素酸組成物を用いることにより、殺菌剤が正浸透膜を透過するのを抑制し、希薄誘引溶液の再利用が可能となることがわかった。 As described above, by using a stabilized hypobromous acid composition or a stabilized hypochlorous acid composition as a disinfectant, the disinfectant is prevented from passing through the forward osmosis membrane, and the diluted attractant solution is reused. Was found to be possible.
　１，３，５，７　水処理装置、８　正浸透膜処理システム、９　水処理システム、１０，１１４，２００　前処理装置、１２，１１８　逆浸透膜処理装置、１４，２０２　正浸透膜処理装置、１６　被処理水配管（ＦＯ被処理水配管）、１８　前処理水配管、２０　濃縮水配管、２２　透過水配管、２４，３２　誘引溶液配管、２６，３６　希薄誘引溶液配管、２８　ＦＯ濃縮水配管、３０　誘引溶液調製槽、３４，３４０，３４２，３４４，３４６，３４８，３５０　濃縮装置、３８　濃縮誘引溶液配管、４０　希釈液配管、４２，７８　１段目半透膜処理装置、４４，８０　２段目半透膜処理装置、４６，８２　３段目半透膜処理装置、４８，８４　一次側、５０，８６　二次側、５２，８８　半透膜、５４，５６，５８，６０，６２，６４，６６，６８，９０，９２，９４，９６，９８，１００，１０２，１０４，１２２，１２４　配管、７０，７２，７４，１０６　ポンプ、１１０　正浸透膜、１１２　殺菌剤添加配管、１１６　濁質除去装置、１２０　被処理水配管、１２６　ＲＯ透過水配管、１２８　逆洗排水配管、２０４　誘引溶液槽、２０６　加熱装置。 1,3,5,7 water treatment device, 8 forward osmosis membrane treatment system, 9 water treatment system, 10, 114, 200 pretreatment device, 12, 118 reverse osmosis membrane treatment device, 14, 202 forward osmosis membrane treatment device, 16 treated water piping (FO treated water piping), 18 pretreated water piping, 20 concentrated water piping, 22 permeated water piping, 24, 32 induced solution piping, 26, 36 diluted attracting solution piping, 28 FO concentrated water piping, 30 ° attracting solution preparation tank, 34,340,342,344,346,348,350６ ， concentrating device, 38 concentrating attracting solution piping, 40 diluting solution piping, 42,78 first stage semipermeable membrane treatment device, 44,80 2 stage Semi-permeable membrane processing device, 46, 82 {third-stage semi-permeable membrane device, 48, 84} primary side, 50, 86 secondary side, 52, 88} semi-permeable membrane, 54, 56, 58, 60, 62 64, 66, 68, 90, 92, 94, 96, 98, 100, 102, 104, 122, 124 pipe, 70, 72, 74, 106 pump, 110 forward osmosis membrane, 112 disinfectant addition pipe, 116 suspension Removal device, 120 treated water piping, 126 RO permeated water piping, 128 backwash drainage piping, 204 induced solution tank, 206 heating device.

Claims (24)

  1. 　溶解性シリカおよび硬度成分のうち少なくとも１つを含む被処理水の処理を行う水処理装置であって、
    　溶解性シリカ除去手段および硬度成分除去手段のうちいずれか１つを備える前処理手段と、
    　前記前処理手段で得られた前処理水を濃縮処理する濃縮処理手段と、
    　前記濃縮処理手段で得られた濃縮水を正浸透膜処理する正浸透膜処理手段と、
    　を備え、
    　前記正浸透膜処理手段で使用された希薄誘引溶液が前記前処理手段で使用されることを特徴とする、水処理装置。     A water treatment apparatus for treating water to be treated containing at least one of soluble silica and a hardness component,
    A pretreatment means comprising any one of a soluble silica removing means and a hardness component removing means,
    Concentration treatment means for concentration treatment of the pretreated water obtained by the pretreatment means,
    Forward osmosis membrane treatment means for forward osmosis membrane treatment of the concentrated water obtained by the concentration treatment means,
    With
    The water treatment apparatus, wherein the diluted attracting solution used in the forward osmosis membrane treatment means is used in the pretreatment means.
  2. 　請求項１に記載の水処理装置であって、
    　前記濃縮処理手段は、逆浸透膜処理手段であることを特徴とする、水処理装置。     The water treatment device according to claim 1,
    The water treatment apparatus, wherein the concentration treatment means is a reverse osmosis membrane treatment means.
  3. 　溶解性シリカおよび硬度成分のうち少なくとも１つを含む被処理水の処理を行う水処理装置であって、
    　溶解性シリカ除去手段および硬度成分除去手段のうちいずれか１つを備える前処理手段と、
    　前記前処理手段で得られた前処理水を濃縮処理する第１濃縮処理手段と、
    　前記第１濃縮処理手段で得られた濃縮水を正浸透膜処理する正浸透膜処理手段と、
    　前記正浸透膜処理手段で使用された希薄誘引溶液の一部を濃縮処理する第２濃縮処理手段と、
    　を備え、
    　前記正浸透膜処理手段で使用された希薄誘引溶液の一部が前記前処理手段で使用され、前記第２濃縮手段で濃縮された濃縮誘引溶液が前記正浸透膜処理手段における誘引溶液として再度使用されることを特徴とする水処理装置。     A water treatment apparatus for treating water to be treated containing at least one of soluble silica and a hardness component,
    A pretreatment means comprising any one of a soluble silica removing means and a hardness component removing means,
    First concentration treatment means for concentration treatment of the pretreated water obtained by the pretreatment means,
    Forward osmosis membrane treatment means for subjecting the concentrated water obtained by the first concentration treatment means to forward osmosis membrane treatment,
    Second concentration treatment means for concentration treatment of a part of the diluted attracting solution used in the forward osmosis membrane treatment means,
    With
    Part of the diluted attracting solution used in the forward osmosis membrane treatment means is used in the pretreatment means, and the concentrated attractant solution concentrated in the second concentration means is reused as the attractant solution in the forward osmosis membrane treatment means. A water treatment apparatus characterized by being performed.
  4. 　請求項３に記載の水処理装置であって、
    　前記第２濃縮処理手段は、半透膜を用いる濃縮処理手段であることを特徴とする水処理装置。     The water treatment device according to claim 3,
    The said 2nd concentration processing means is a concentration processing means using a semipermeable membrane, The water treatment apparatus characterized by the above-mentioned.
  5. 　請求項３または４に記載の水処理装置であって、
    　前記第１濃縮処理手段は、逆浸透膜処理手段であることを特徴とする水処理装置。     The water treatment device according to claim 3 or 4,
    The said 1st concentration processing means is a reverse osmosis membrane processing means, The water treatment apparatus characterized by the above-mentioned.
  6. 　請求項１～５のいずれか１項に記載の水処理装置であって、
    　前記正浸透膜処理手段で用いる誘引溶液がマグネシウム塩水溶液であり、前記正浸透膜処理手段で使用されたマグネシウム塩希薄水溶液が、前記溶解性シリカ除去手段で使用されることを特徴とする水処理装置。     The water treatment apparatus according to any one of claims 1 to 5, wherein
    Water treatment, wherein the attracting solution used in the forward osmosis membrane treatment means is a magnesium salt aqueous solution, and the magnesium salt dilute aqueous solution used in the forward osmosis membrane treatment means is used in the soluble silica removing means. apparatus.
  7. 　請求項１～５のいずれか１項に記載の水処理装置であって、
    　前記正浸透膜処理手段で用いる誘引溶液がアルカリ剤水溶液であり、前記正浸透膜処理手段で使用されたアルカリ剤希薄水溶液が、前記硬度成分除去手段で使用されることを特徴とする水処理装置。     The water treatment apparatus according to any one of claims 1 to 5, wherein
    A water treatment apparatus, wherein the attracting solution used in the forward osmosis membrane processing means is an aqueous solution of an alkali agent, and the diluted aqueous solution of the alkali agent used in the forward osmosis membrane processing means is used in the hardness component removing means. .
  8. 　請求項１～５のいずれか１項に記載の水処理装置であって、
    　前記正浸透膜処理手段で用いる誘引溶液が酸水溶液または塩化ナトリウム水溶液であり、前記正浸透膜処理手段で使用された酸希薄水溶液または塩化ナトリウム希薄水溶液が、前記硬度成分除去手段で使用されることを特徴とする水処理装置。     The water treatment apparatus according to any one of claims 1 to 5, wherein
    The attracting solution used in the forward osmosis membrane treatment means is an acid aqueous solution or an aqueous sodium chloride solution, and the acid dilute aqueous solution or the sodium chloride dilute aqueous solution used in the forward osmosis membrane treatment means is used in the hardness component removing means. A water treatment apparatus characterized by the above-mentioned.
  9. 　溶解性シリカおよび硬度成分のうち少なくとも１つを含む被処理水の処理を行う水処理方法であって、
    　溶解性シリカ除去工程および硬度成分除去工程のうちいずれか１つを含む前処理工程と、
    　前記前処理工程で得られた前処理水を濃縮処理する濃縮処理工程と、
    　前記濃縮処理工程で得られた濃縮水を正浸透膜処理する正浸透膜処理工程と、
    　を含み、
    　前記正浸透膜処理工程で使用した希薄誘引溶液を前記前処理工程で使用することを特徴とする、水処理方法。     A water treatment method for treating treated water containing at least one of soluble silica and a hardness component,
    A pretreatment step including any one of a soluble silica removal step and a hardness component removal step,
    A concentration treatment step of concentration treatment of the pretreated water obtained in the pretreatment step,
    A forward osmosis membrane treatment step of treating the concentrated water obtained in the concentration treatment step with a forward osmosis membrane,
    Including
    A water treatment method, wherein the dilute attractant used in the forward osmosis membrane treatment step is used in the pretreatment step.
  10. 　請求項９に記載の水処理方法であって、
    　前記濃縮処理工程は、逆浸透膜処理工程であることを特徴とする、水処理方法。     The water treatment method according to claim 9,
    The water treatment method, wherein the concentration treatment step is a reverse osmosis membrane treatment step.
  11. 　溶解性シリカおよび硬度成分のうち少なくとも１つを含む被処理水の処理を行う水処理方法であって、
    　溶解性シリカ除去工程および硬度成分除去工程のうちいずれか１つを含む前処理工程と、
    　前記前処理工程で得られた前処理水を濃縮処理する第１濃縮処理工程と、
    　前記第１濃縮処理工程で得られた濃縮水を正浸透膜処理する正浸透膜処理工程と、
    　前記正浸透膜処理工程で使用された希薄誘引溶液の一部を濃縮処理する第２濃縮処理工程と、
    　を含み、
    　前記正浸透膜処理工程で使用した希薄誘引溶液の一部を前記前処理工程で使用し、前記第２濃縮処理工程で濃縮した濃縮誘引溶液を前記正浸透膜処理工程における誘引溶液として再度使用することを特徴とする水処理方法。     A water treatment method for treating treated water containing at least one of soluble silica and a hardness component,
    A pretreatment step including any one of a soluble silica removal step and a hardness component removal step,
    A first concentration treatment step for concentration treatment of the pretreated water obtained in the pretreatment step,
    A forward osmosis membrane treatment step of subjecting the concentrated water obtained in the first concentration treatment step to forward osmosis membrane treatment,
    A second concentration treatment step of concentration treatment of a part of the diluted attracting solution used in the forward osmosis membrane treatment step,
    Including
    Part of the diluted attracting solution used in the forward osmosis membrane treatment step is used in the pretreatment step, and the concentrated attractant solution concentrated in the second concentration treatment step is reused as the attractant solution in the forward osmosis membrane treatment step. A water treatment method, comprising:
  12. 　請求項１１に記載の水処理方法であって、
    　前記第２濃縮処理工程は、半透膜を用いる濃縮処理工程であることを特徴とする水処理方法。     The water treatment method according to claim 11,
    The water treatment method, wherein the second concentration treatment step is a concentration treatment step using a semipermeable membrane.
  13. 　請求項１１または１２に記載の水処理方法であって、
    　前記第１濃縮処理工程は、逆浸透膜処理工程であることを特徴とする水処理方法。     The water treatment method according to claim 11 or 12,
    The said 1st concentration process is a reverse osmosis membrane process, The water treatment method characterized by the above-mentioned.
  14. 　請求項９～１３のいずれか１項に記載の水処理方法であって、
    　前記正浸透膜処理工程で用いる誘引溶液がマグネシウム塩水溶液であり、前記正浸透膜処理工程で使用したマグネシウム塩希薄水溶液を、前記溶解性シリカ除去工程で使用することを特徴とする水処理方法。     The water treatment method according to any one of claims 9 to 13, wherein
    A water treatment method, wherein the attracting solution used in the forward osmosis membrane treatment step is a magnesium salt aqueous solution, and the magnesium salt dilute aqueous solution used in the forward osmosis membrane treatment step is used in the soluble silica removal step.
  15. 　請求項９～１３のいずれか１項に記載の水処理方法であって、
    　前記正浸透膜処理工程で用いる誘引溶液がアルカリ剤水溶液であり、前記正浸透膜処理工程で使用したアルカリ剤希薄水溶液を、前記硬度成分除去工程で使用することを特徴とする水処理方法。     The water treatment method according to any one of claims 9 to 13, wherein
    A water treatment method, wherein the attraction solution used in the forward osmosis membrane treatment step is an aqueous alkaline solution, and the diluted alkaline agent aqueous solution used in the forward osmosis membrane treatment step is used in the hardness component removing step.
  16. 　請求項９～１３のいずれか１項に記載の水処理方法であって、
    　前記正浸透膜処理工程で用いる誘引溶液が酸水溶液または塩化ナトリウム水溶液であり、前記正浸透膜処理工程で使用した酸希薄水溶液または塩化ナトリウム希薄水溶液を、前記硬度成分除去工程で使用することを特徴とする水処理方法。     The water treatment method according to any one of claims 9 to 13, wherein
    The attracting solution used in the forward osmosis membrane treatment step is an acid aqueous solution or a sodium chloride aqueous solution, and the acid dilute aqueous solution or sodium chloride dilute aqueous solution used in the forward osmosis membrane treatment step is used in the hardness component removing step. Water treatment method.
  17. 　被処理水と、前記被処理水よりも高濃度の誘引溶液とを、正浸透膜を介して接触させることによって、濃縮水と希薄誘引溶液とを得る正浸透膜処理工程を含み、
    　前記被処理水中に、臭素系酸化剤または塩素系酸化剤とスルファミン酸化合物とを含む殺菌剤を存在させることを特徴とする正浸透膜処理方法。     The water to be treated and the attracting solution having a higher concentration than the water to be treated are brought into contact with each other via a forward osmosis membrane, thereby comprising a forward osmosis membrane treatment step of obtaining a concentrated water and a diluted attracting solution.
    A forward osmosis membrane treatment method, wherein a bactericide containing a bromine-based oxidant or a chlorine-based oxidant and a sulfamic acid compound is present in the water to be treated.
  18. 　被処理水と、前記被処理水よりも高濃度の誘引溶液とを、正浸透膜を介して接触させることによって、濃縮水と希薄誘引溶液とを得る正浸透膜処理工程を含み、
    　前記被処理水中に、臭素系酸化剤とスルファミン酸化合物とを含む殺菌剤を存在させることを特徴とする正浸透膜処理方法。     The water to be treated and the attracting solution having a higher concentration than the water to be treated are brought into contact with each other via a forward osmosis membrane, thereby comprising a forward osmosis membrane treatment step of obtaining a concentrated water and a diluted attracting solution.
    A method for treating a forward osmosis membrane, wherein a bactericide containing a bromine-based oxidizing agent and a sulfamic acid compound is present in the water to be treated.
  19. 　被処理水と、前記被処理水よりも高濃度の誘引溶液とを、正浸透膜を介して接触させることによって、濃縮水と希薄誘引溶液とを得る正浸透膜処理工程を含み、
    　前記被処理水中に、臭素とスルファミン酸化合物とを含む殺菌剤を存在させることを特徴とする正浸透膜処理方法。     The water to be treated and the attracting solution having a higher concentration than the water to be treated are brought into contact with each other via a forward osmosis membrane, thereby comprising a forward osmosis membrane treatment step of obtaining a concentrated water and a diluted attracting solution.
    A forward osmosis membrane treatment method, wherein a bactericide containing bromine and a sulfamic acid compound is present in the water to be treated.
  20. 　請求項１７～１９のいずれか１項に記載の正浸透膜処理方法を含み、
    　前記正浸透膜処理工程の前段に、前処理工程および逆浸透膜処理工程を含み、
    　前記正浸透膜処理工程により得られた希薄誘引溶液を、前記前処理工程で使用することを特徴とする水処理方法。     A forward osmosis membrane treatment method according to any one of claims 17 to 19,
    Before the forward osmosis membrane treatment step, including a pretreatment step and a reverse osmosis membrane treatment step,
    A water treatment method, wherein the diluted attracting solution obtained in the forward osmosis membrane treatment step is used in the pretreatment step.
  21. 　被処理水と、前記被処理水よりも高濃度の誘引溶液とを、正浸透膜を介して接触させることによって、濃縮水と希薄誘引溶液とを得る正浸透膜処理手段を備え、
    　前記被処理水中に、臭素系酸化剤または塩素系酸化剤とスルファミン酸化合物とを含む殺菌剤を存在させることを特徴とする正浸透膜処理システム。     The water to be treated and the attracting solution having a higher concentration than the water to be treated are brought into contact with each other via a forward osmosis membrane, so as to have a forward osmosis membrane treatment means for obtaining a concentrated water and a diluted attracting solution,
    A forward osmosis membrane treatment system, wherein a bactericide containing a bromine-based oxidant or a chlorine-based oxidant and a sulfamic acid compound is present in the water to be treated.
  22. 　被処理水と、前記被処理水よりも高濃度の誘引溶液とを、正浸透膜を介して接触させることによって、濃縮水と希薄誘引溶液とを得る正浸透膜処理手段を備え、
    　前記被処理水中に、臭素系酸化剤とスルファミン酸化合物とを含む殺菌剤を存在させることを特徴とする正浸透膜処理システム。     The water to be treated and the attracting solution having a higher concentration than the water to be treated are brought into contact with each other via a forward osmosis membrane, so as to have a forward osmosis membrane treatment means for obtaining a concentrated water and a diluted attracting solution,
    A forward osmosis membrane treatment system, wherein a bactericide containing a bromine-based oxidizing agent and a sulfamic acid compound is present in the water to be treated.
  23. 　被処理水と、前記被処理水よりも高濃度の誘引溶液とを、正浸透膜を介して接触させることによって、濃縮水と希薄誘引溶液とを得る正浸透膜処理手段を備え、
    　前記被処理水中に、臭素とスルファミン酸化合物とを含む殺菌剤を存在させることを特徴とする正浸透膜処理システム。     The water to be treated and the attracting solution having a higher concentration than the water to be treated are brought into contact with each other via a forward osmosis membrane, so as to have a forward osmosis membrane treatment means for obtaining a concentrated water and a diluted attracting solution,
    A forward osmosis membrane treatment system, wherein a bactericide containing bromine and a sulfamic acid compound is present in the water to be treated.
  24. 　請求項２１～２３のいずれか１項に記載の正浸透膜処理システムを備え、
    　前記正浸透膜処理手段の前段に、前処理手段および逆浸透膜処理手段を備え、
    　前記正浸透膜処理手段により得られた希薄誘引溶液が、前記前処理手段で使用されることを特徴とする水処理システム。     A forward osmosis membrane treatment system according to any one of claims 21 to 23,
    In the preceding stage of the forward osmosis membrane treatment means, a pre-treatment means and a reverse osmosis membrane treatment means are provided,
    A water treatment system, wherein the diluted attracting solution obtained by the forward osmosis membrane treatment means is used by the pretreatment means.
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