WO2000027510A1 - Method for filtration with membrane - Google Patents

Method for filtration with membrane Download PDF

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Publication number
WO2000027510A1
WO2000027510A1 PCT/JP1999/006227 JP9906227W WO0027510A1 WO 2000027510 A1 WO2000027510 A1 WO 2000027510A1 JP 9906227 W JP9906227 W JP 9906227W WO 0027510 A1 WO0027510 A1 WO 0027510A1
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WIPO (PCT)
Prior art keywords
ozone
filtration
water
membrane
amount
Prior art date
Application number
PCT/JP1999/006227
Other languages
French (fr)
Japanese (ja)
Inventor
Takehiko Otoyo
Toru Ota
Original Assignee
Asahi Kasei Kogyo Kabushiki Kaisha
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
Application filed by Asahi Kasei Kogyo Kabushiki Kaisha filed Critical Asahi Kasei Kogyo Kabushiki Kaisha
Priority to AU10795/00A priority Critical patent/AU1079500A/en
Publication of WO2000027510A1 publication Critical patent/WO2000027510A1/en

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Classifications

    • 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
    • B01D61/14—Ultrafiltration; Microfiltration
    • B01D61/22—Controlling or regulating
    • 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
    • B01D61/14—Ultrafiltration; Microfiltration
    • B01D61/145—Ultrafiltration
    • 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
    • B01D61/14—Ultrafiltration; Microfiltration
    • B01D61/147—Microfiltration
    • 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
    • B01D61/14—Ultrafiltration; Microfiltration
    • B01D61/16—Feed pretreatment
    • 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
    • C02F1/444—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by ultrafiltration or microfiltration
    • 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
    • C02F1/72—Treatment of water, waste water, or sewage by oxidation
    • C02F1/78—Treatment of water, waste water, or sewage by oxidation with ozone
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2311/00—Details relating to membrane separation process operations and control
    • B01D2311/04—Specific process operations in the feed stream; Feed pretreatment

Definitions

  • the present invention relates to a membrane filtration method using ozone in the field of water treatment such as water supply, sewage, industrial wastewater, domestic wastewater, and human wastewater.
  • Typical treatment methods for conventional water purification treatment include coagulation sedimentation-sand sand filtration-chlorine disinfection, coagulation sedimentation-sand filtration-activated carbon-chlorine disinfection or coagulation sedimentation-sand filtration-ozone-activated carbon-chlorine disinfection.
  • Typical treatment methods for the discharge and reuse of sewage such as human waste and domestic wastewater or industrial wastewater are as follows: first settling tank-aeration-final settling tank-chlorination, first settling tank-aeration. One final sedimentation basin, one coagulation sedimentation, one sand filtration and one chlorine disinfection have been performed.
  • water sources such as water storage dams are being developed as countermeasures against water due to increased demand for domestic water, disorderly deforestation, and abnormal weather.
  • the quality of water sources has deteriorated, and it has become impossible to obtain good drinking water with the conventional methods as described above, which has become a serious problem.
  • sewage such as human waste and domestic wastewater or organic wastewater from factories is discharged after removing various suspended substances and organic components contained by the above-mentioned method.
  • attention has been paid to environmental issues, and such effluents are required to be treated to improve water quality even higher.
  • it has been proposed to reuse sewage and wastewater as water resources for effective use of water For example, various uses are considered, such as park fountains and scenic landscapes, water for water use, miscellaneous water, industrial water, etc. Sewage and drainage have begun to be actually used, especially for landscape views and water for hydrophilic use.
  • the organic matter in the raw water clogs the membrane or is adsorbed by the network inside the membrane, so the filtration flux of the resulting membrane is a fraction of the filtration flux of the clear water. It decreased to several tenths, the membrane filtration cost increased, and the practicality was low from an economic viewpoint.
  • Japanese Patent Application Publication No. Hei 4-110185 proposes performing tangent filtration by adding ozone as an oxidizing gas upstream of the membrane to prevent clogging of the membrane.
  • an oxidizing gas such as ozone as described above, the permeation flux at the time of membrane filtration is several times larger than when ozone is not used, and the installation area of the filtration membrane is reduced and water treatment is performed.
  • the economics for the project are also improved.
  • ozone a great deal of electricity is required to generate ozone, so it is important from an economic point of view how to use the generated ozone effectively.
  • the ozone concentration of the raw water is controlled to a predetermined value.However, in this method, the clarity of the raw water fluctuates, the required amount of ozone decreases, and excessive When ozone was added, the required amount of ozone increased, and the clogging of the membrane gradually progressed, so that a predetermined permeation flux could not be obtained. In addition, excessive addition of ozone was not only economically disadvantageous, but also caused problems such as blocking of activated carbon used in a later step and death of biological activated carbon organisms.
  • An object of the present invention is to perform a high-level treatment of purified water and an advanced sewage by using a membrane. In this case, it is possible to obtain a sufficient quality of treated water, and to effectively use ozone to reduce the amount of added ozone. It is an object of the present invention to provide a practical filtration method for obtaining a high filtration flux.
  • the present invention is a.
  • the amount of ozone to be injected into raw water based on the value of the permeation flux, membrane module inlet pressure or average transmembrane pressure during filtration or backwashing
  • the method comprising controlling It is.
  • FIG. 1 is a flowchart showing an example of the filtration method of the present invention.
  • FIG. 2 is a diagram showing one embodiment of the filtration method of the present invention.
  • FIG. 3 is a diagram showing another embodiment of the filtration method of the present invention.
  • FIG. 4 is a diagram showing another embodiment of the filtration method of the present invention.
  • FIG. 5 is a diagram showing another embodiment of the filtration method of the present invention.
  • the present invention relates to a method of adding ozone to raw water and then performing filtration using a filtration membrane, wherein the ozone is injected into the raw water.
  • the raw water referred to in the present invention is river water, underground water, lake water, lake water, storage water, groundwater and other clean water, human waste water, sewage primary treatment water, sewage secondary treatment water, industrial wastewater, domestic wastewater, pools, baths, Water storage in a water tank for raising aquatic animals, pulp and paper production wastewater, leachate landfill leachate, and the like.
  • the ozone to be added may be ozone alone, ozonized air, or ozone-dissolved water.
  • Ozone is introduced through an ejector, a line mixing method, a diffuser tube, a U-tube, or the like.
  • the source of ozone may be air or oxygen.
  • oxygen it may be oxygen produced by pressure-casing adsorption (PSA) or may be made from liquefied oxygen.
  • PSA pressure-casing adsorption
  • the filtration method using a membrane may be a cross-flow filtration method (circulation filtration method) or a dead-end filtration method (total filtration method).
  • Membrane filtration methods include constant flow filtration and constant pressure filtration. Either method may be used, either the pressurizing method or the depressurizing method may be used, and the external pressure method or the internal pressure method may be used.
  • a method of filtering by allowing ozone to be present up to the membrane surface, or a method of consuming ozone before the filtration treatment by the membrane and then performing filtration may be used.
  • the best method can be selected depending on the condition of the raw water.
  • ozone can be decomposed by adding a reducing agent such as sodium thiosulfate or activated carbon treatment, for example, by installing a retention tank to remove ozone before the filtration process.
  • De-ozone treatment such as, may be performed.
  • ozone passing through the membrane repeatedly attacks the organic substances attached to the membrane, so that the membrane is always self-cleaned and filtered. As a result, a higher permeation flux can be obtained.
  • the concentration of ozone added to raw water to kill microorganisms and remove odorous substances is generally 0.5 ppm or more, depending on the quality of raw water. If the ozone concentration is too high, the economic efficiency is reduced. Therefore, ozone having a concentration of preferably about 0.05 to 50 ppm, more preferably 0.1 to 30 ppm is added.
  • addition of hydrogen peroxide, ultraviolet irradiation, or a promoted oxidation catalyst such as titanium oxide may be used in combination for the purpose of enhancing the oxidizing power of ozone and promoting accelerated oxidation.
  • control of the amount of ozone added to the raw water to an appropriate value is performed based on the permeation flux, the pressure at the membrane module inlet, or the average transmembrane pressure during filtration or backwashing described below.
  • ozone when controlling the amount of ozone to be injected based on the value of the permeation flux at the time of filtration or backwashing at constant pressure filtration, if the permeation flux value falls below a preset value, ozone Increase the amount of ozone added, and in the opposite case reduce or stop adding ozone.
  • the pressure at the membrane module inlet during filtration or backwashing When controlling the amount of ozone to be injected based on the value or the average transmembrane pressure, the value should be larger than the preset value of the membrane module inlet pressure or the value of the average transmembrane pressure. In such cases, increase the amount of ozone added, and in the opposite case, reduce or stop the addition of ozone.
  • Methods for controlling the amount of ozone to be added include, for example, detecting the absolute value or the rate of change of time with respect to the above-mentioned value, which is the basis for control, and adjusting the current or voltage of the ozone generator, or the amount of ozone at the inlet. Is adjusted. Although manual control is possible, it is practical and preferable to calculate the above value and feed it back as an ozone control signal to automatically control the injected ozone amount or concentration.
  • an ozone-resistant membrane is used in a process in which ozone is present up to the membrane surface, but in a process in which ozone is removed before the filtration treatment by the membrane, the membrane is used. You don't have to worry about ozone resistance.
  • the ozone-resistant membrane is not particularly limited as long as it is a filtration membrane that is not deteriorated by ozone.
  • examples thereof include an inorganic membrane such as an ozone-resistant ceramic, a polyvinylidene fluoride (PVDF) membrane, and a polytetrafluoroethylene (PTFE) membrane.
  • Organic membranes such as a membrane, an ethylene-tetrafluoroethylene copolymer (ETFE) membrane, and a fluorine-based resin membrane such as a tetrafluoroethylene-perfluoroalkylvinylester copolymer (PFA) membrane can be applied.
  • PFA tetrafluoroethylene-perfluoroalkylvinylester copolymer
  • a polyolefin film such as a polyethylene film or a polypropylene film, a polysulfone film, a polyacrylonitrile film, a cellulose acetate film, a polycarbonate film, a polyamide film, etc., in addition to the film of the above materials, Can be applied.
  • Examples of the shape of the membrane include a flat membrane, a spiral membrane, a pleated membrane, a hollow fiber membrane, and a tubular membrane, but a hollow fiber membrane is preferred.
  • the pore size of the membrane As the pore size of the membrane, the pore size range of the ultrafiltration (UF) membrane to the microfiltration (MF) membrane can be used, but the microfiltration (MF) membrane is used because the permeation flux of the membrane is basically high.
  • the pore size of the membrane is preferably from 0.001 to 1 ⁇ , and from 0.05 to 1 ⁇ m.
  • the pore size of the membrane When performing membrane filtration, when the pore size of the membrane is in the microfiltration (MF) region, the pore size increases, and suspended substances (SS) and bacteria in the raw water enter the membrane. Therefore, in the case of raw water with a high concentration of suspended solids and bacteria, a high permeation flux will require many ozone injections.
  • a coagulant such as polyaluminum chloride (PACL), bansulfate, ferrous chloride and ferric chloride, and an adsorbent such as activated carbon can be used prior to ozone addition.
  • PCL polyaluminum chloride
  • adsorbent such as activated carbon
  • the flocculant and the adsorbent may be added to an ozonated water tank that stores raw water, or may be added by a line mixing method in a pipe that guides raw water to a place where ozone is added.
  • the amount of the flocculant added must be such that the suspended solids contained in the raw water can be flocculated, and generally 1 to 100 mg per liter of the raw water, and more preferably. Is 2 to 5 O mg per liter of raw water.
  • the membrane module used is selected from known internal pressure type modules and external pressure type modules.
  • the external pressure type module for example, a module having a module structure as described in WO97108993 can be used.
  • Backwashing backwashing
  • air publishing are effective physical cleaning methods.
  • Backwashing is a method in which filtration is stopped for a certain time, filtration is stopped, and washing is performed by flowing a washing solution from the permeate side of the membrane. It is preferable to use filtered water that has passed through the membrane as the washing liquid.
  • Air bubbling After filtration for a certain period of time, filtration is stopped, gas is sent to the membrane surface, and the membrane is washed by vibrating the membrane surface.
  • ozone present on the membrane surface, the organic substances adsorbed on the membrane surface are decomposed by ozone and become non-adsorbent, and thus block the pores of the membrane.
  • Non-adsorbent substances organic and inorganic substances
  • Air bubbling is very effective as a method of cleaning the membrane.
  • Air publishing may be used in combination with backwashing, followed by filtration and air bubbling-backwashing, or filtration and backwashing and air bubbling, or filtration (backwashing at the same time as vacuuming). You may.
  • the air bubbling time is preferably from 1 second to 6 minutes. If it is shorter than 1 second, the effect of air-bubbling is reduced, and if it is longer than 6 minutes, filtration is not performed during air bubbling, and the amount of filtered water is undesirably reduced.
  • FIG. 1 is a flowchart showing an example of the filtration method of the present invention.
  • ozone is added to raw water 1 to perform ozone treatment 2, and suspended substances and organic substances in the raw water 1 are decomposed by ozone.
  • the permeation flux, the membrane module inlet pressure or the average transmembrane pressure difference is detected, and the amount of ozone injected into the raw water is controlled based on the detected values.
  • the permeation flux can be measured by measuring the amount of filtrate permeated through the membrane or the backwash water with a flow meter 16.
  • the pressure at the inlet of the membrane module can be measured by a pressure gauge 13 provided at the inlet of the membrane module at the time of filtration, and can be measured by the pressure gauge 15 at the time of backwashing.
  • the average transmembrane pressure is measured using a pressure gauge 13 provided at the membrane module inlet, a pressure gauge 14 provided at the membrane module circulating water outlet, and a pressure gauge provided at the membrane module filtration water outlet. It is a value calculated from the pressure measured in 15 by the following formula.
  • the average transmembrane pressure is a value calculated by the following formula.
  • Fig. 1 shows only the basic process.
  • a treatment such as an activated carbon treatment or a reverse osmosis membrane treatment may be performed at a subsequent stage.
  • the ozonized air generated by the ozone generator 4 is added to the raw water 1 by the ozone injection means (ejector 1) 5 and supplied to the ozonated water tank 6, and then the ozonized water is Is supplied to the membrane module 9 by the supply means (pump) 8 and filtered.
  • the ozonized water is Is supplied to the membrane module 9 by the supply means (pump) 8 and filtered.
  • filtration is performed by cross-flow filtration, raw water that does not pass through the filtration membrane is returned to the ozonated water tank 6 as circulating water as shown by a broken line in FIG.
  • all of the ozone-treated water supplied to the membrane module 9 permeates through the membrane, and the filtrate is stored in the filtrate tank 10.
  • the amount of ozone injected into the raw water is controlled based on one of the permeation flux, the inlet pressure of the membrane module, or the average transmembrane pressure.
  • a pressure gauge 13 at the raw water inlet a pressure gauge 15 at the filtered water outlet, a pressure gauge 14 at the circulating water outlet, and a flow meter 16 at the filtered water outlet of the membrane module 9 It can be provided.
  • 12 denotes a raw water supply means (pump)
  • 20 denotes a backwash pump
  • 21 denotes an activated carbon treatment tank.
  • the current or voltage of the ozone generator 4 is adjusted to change the ozone generation amount, thereby controlling the ozone addition amount or ozone concentration in the ejector 15.
  • the amount of ozone injected into the ejector 5 is increased, and when the permeation flux increases, ozone injection is stopped.
  • the injected ozone amount can be controlled by reducing the injected ozone amount in the ejector 5.
  • the amount of ozone injected into the ejector 15 increases, and conversely, if the pressure at the inlet of the filtration membrane decreases,
  • the amount of injected ozone can be controlled by stopping the injection of ozone or decreasing the amount of injected ozone in the ejector 15.
  • the amount of injection ⁇ zone in the ejector 15 increases, and conversely, if the inlet pressure of the filtration membrane decreases,
  • the amount of injected ozone can be controlled by reducing the ozone injection force and the injected ozone amount in the ejector 15.
  • raw water 1 is first supplied to an ozonated water tank 6, and Except for injecting ozonized air into a part (circulating water) of raw water extracted from the treated water tank 6 by the circulation means (pump) 7 and returning it to the ozone water treatment tank 6 again, There is no difference from the filtration method of 2.
  • ozone can be continuously injected into the circulating water from the ozonated water tank 6. The amount of injected ozone is controlled in the same manner as in the filtration method of FIG.
  • the circulating water amount of the pump 7 is preferably 0.2 to 10 times the supply amount of the raw water 1.
  • ozonized air is injected into the raw water 1 by the ejector 5, supplied to the ozonated water tank 6, and a part of the ozonized raw water is extracted by the pump 7 and mixed with the raw water 1.
  • ozonized air is injected again by the ejector 15 there.
  • Figure 5 shows an example of a process for removing ozone prior to filtration by a membrane.
  • the chemical Prior to supplying the ozonated water from the ozonated water tank 6 to the hollow fiber membrane module 9 via the pump 8, the chemical is added from the chemical tank 18 via the pump 17 while mixing with the static mixer 19. Removes ozone. Except for this point, it is the same as the filtration method of FIG.
  • an external pressure type module was prepared in which 1,800 hollow fiber membranes were accommodated in a PVC (polyvinyl chloride) casing having a diameter of 3 inches. This module has a membrane area of 7.0 m 2 and a clear water permeation flux of 1.8 m per hour. At this time, the module filtration pressure was 0.5 kgf / cm 2 .
  • the filtration was carried out by a constant permeation flux filtration of a cross flow system (circulation filtration system).
  • a cross flow system circulation filtration system
  • the ozone treated water tank 6 1.5 m 3 / h.
  • the ozonated water from the tank 6 via the pump 8 is supplied in an amount per hour 2.
  • the concentration of ozone remaining in the filtered water in the filtered water tank 10 was from 0.2 ppm to 0.3 ppm.
  • the activated carbon treatment tank used was designed so that LV was 25 OmZ days and SV was 1 O / Hr.
  • the injection of ozone is performed by calculating the difference between the initial setting value of the membrane module inlet pressure and the actual membrane module inlet pressure, feeding back the signal to the ozone generator 4, and automatically controlling the injected ozone amount. went.
  • Membrane module inlet 0. 80 kg / cm 2 an initial setting value of the pressure, to set the injection amount of ozone at that time 2. O g, each time the membrane module inlet pressure 0. 05 k gZc m 2 rises, The injected ozone volume was increased by 0.3 g, and when the membrane module inlet pressure was less than the initial set value, the operation was continued with the ozone injection reduced.
  • the filtration flux level was maintained at the initial value of 1.5 m / h for 2 months, during which time there was no increase in the pressure at the inlet of the membrane module.
  • the COD chemical oxygen demand
  • the turbidity was 0.02 °
  • Escherichia coli and general bacteria were not detected, and other items were drinking water. As well as meeting the criteria.
  • Example 2 Except for injecting a fixed amount of 2.0 g of ozonized air per hour into raw water 1 with ozone amount and not controlling the amount of added ozone, the same conditions as in Example 1 except for the cross-floor opening method (circulating filtration method) ) was performed. At this time, the residual ozone concentration in the filtered water was 0.3 to 0.3 ppm.
  • Example 1 filtration and backwashing and washing operations were repeated to perform air publishing.
  • the pressure at the inlet of the membrane module increased by 0.5 kg / cm 2 in two months.
  • the filtration was carried out by a constant permeation flux filtration of a cross flow system (circulation filtration system).
  • the raw water 1, to together is supplied in an amount per hour 1.
  • 5 m 3 from the ozone-treated water tank 6 withdrawn by a pump 7, the O Zon generator 4, Ozonated air was injected as an ozone amount of 2.0 g to 2.4 g / h through the ejector 15.
  • the ozonated water from the tank 6 via the pump 8 is supplied in an amount per hour 2.
  • 5 m 3 is taken out by the flux, back film ozonated water tank 6 by not ozonated water per hour 1 m 3, such to transmit.
  • the residual ozone concentration in the filtered water was 0.2 ppm to 0.3 ppm.
  • the activated carbon treatment tank used was designed so that LV was 25 OmZ days and SV was 1 O / Hr.
  • the permeation flux level was maintained at the initial value of 1.5 m / h for 2 months, and there was no increase in the membrane module inlet pressure during that time.
  • the COD (chemical oxygen demand) value was 0.4 mg / L
  • the turbidity was 0.02 degrees
  • Escherichia coli and general bacteria were not detected.
  • the standard for drinking water was sufficiently satisfied.
  • Raw water 1 has a turbidity of 10 degrees, a COD (chemical oxygen demand) value of 13 to 20 mg Z liter, a BOD (biological oxygen demand) value of 20 to 30 mg Z liter, and a secondary sewage water temperature of 25 ° C.
  • COD chemical oxygen demand
  • BOD biological oxygen demand
  • the filtration was carried out by a constant permeation flux filtration of a cross flow system (circulation filtration system).
  • the residual ozone concentration in the filtered water at this time is 0.1 to 0 Injecting ozone, the difference between the initial set value of the average transmembrane pressure and the actual average transmembrane pressure was calculated, and the signal was fed back to the ozone generator 4.
  • the initial setting of the membrane module differential pressure was set to 0.5 kg / cm 2 , and the amount of injected ozone was set to 10.0 g at that time. each time the differential pressure is increased 0. 05 k gZc m 2, the injection amount of ozone is increased by 0.
  • the filtration flux level was maintained at the initial value of 1. Om / hour for 2 months, and there was no increase in the average transmembrane pressure during this period.
  • Raw water 1 has a turbidity of 10 degrees, a COD (chemical oxygen demand) value of 13 to 20 mg liter, a BOD (biological oxygen demand) value of 20 to 3 OmgZ liter, and a water temperature of 25 ° C.
  • the raw water ⁇ ozone treatment ⁇ filtration treatment with an ozone resistant membrane was sequentially performed using the apparatus shown in Fig. 4.
  • the ozone generator 4 Into the water 1, the ozone generator 4, after the ozonized air per hour 10 g to 1 1. 5 g injected as amount of ozone through the Ezekuta one 5, the ozonated water tank 6 of the hourly 1. Om 3 It supplies an amount, extracting raw water from the ozone treated water tank 6 hour 4. 0 m 3 by the pump 7 and, after mixing with raw water in the raw water 1 supply line was injected ozone through the E Zekuta 5. Further, the ozonized water was supplied from the ozonated water tank 6 via the pump 8 to the same PVDF hollow fiber membrane module used in Example 1 at an initial module inlet pressure of 0.9 kg / cm 2. was supplied so as to, the module is taken out of the drainage in filtered water outlet pressure 0.
  • Injecting ozone is a method of calculating the difference between the initial value of the membrane permeation flux and the actual membrane permeation flux and feeding back the signal to the ozone generator 4 to automatically control the amount of ozone to be injected.
  • I went in. Set the initial value of the membrane permeation flux to 1.0 m 3 / hr and the amount of injected ozone at that time to 10.0 g, and inject ozone every time the membrane permeation flux decreases by 0.1 m 3 hr. The amount was increased by 0.3 g, and if the permeation flux exceeded the initial setting, the operation was continued with the ozone injection reduced.
  • the operating conditions were 2 Nm / hour after 10 minutes of filtration. This operation was repeated by supplying air from the lower part of the module, performing air bubbling for 60 seconds, and performing backwashing using backwater by the backwashing pump 20 for 20 seconds. During backwashing and air bubbling, the pump 8 was stopped and the automatic valve 11 was closed to stop the supply of raw water.However, the pump 7 and the ozone generator 4 were constantly operated, and the injection of ozone was continued. . In this case, 5. Om 3 of water per hour was withdrawn from the ozonated water tank 6 by the pump 7 and ozone was injected through the ejector 15.
  • the membrane module inlet pressure 0. 9Kg / cm 2
  • the average filter medium differential pressure is 0. 55 Kg / cm 2
  • the initial level of Wataruconnection can be maintained to 2 months, transparently flux drainage amount therebetween There was no decline.
  • the quality of the obtained drainage water was 0.05 ° C, the ⁇ 00 value was 12 mgZ liter, the BOD value was lmg, and the water quality was sufficient for landscape water and hydrophilic water.
  • Turbidity is 10 degrees as raw water 1
  • COD chemical oxygen demand
  • BOD biological oxygen demand
  • water temperature is 25
  • Raw water-> ozone treatment-de-ozone treatment-> filtration treatment using a membrane was sequentially performed using the secondary treatment water at ° C and the apparatus shown in Fig. 5.
  • Hollow fiber microfiltration (MF) made of HDPE (high-density polyethylene) with a pore diameter of 0.1 ⁇ m, an inner diameter of 0.7 stroke ⁇ , and an outer diameter of 1.25 mm0, prepared based on JP-A-3-42025 as a membrane A membrane was used.
  • An external pressure type module was prepared in which 1800 hollow fiber membranes were housed in a 3 inch diameter PVC (polyvinyl chloride) casing. This module has a membrane area of 7.0 m 2 and a clear water permeation flux of 1.8 m 3 per hour. Yule filtration pressure was 0. 5Kg f / cm 2.
  • the raw water 1, to the ozonated water tank 6, is supplied with monitor, the raw water from the ozonated water tank 6 hour 4. 0 in 3 withdrawn by the pump 7 in an amount per hour 0. 7 m 3, an ozone generator From 4, 10 g to 11 l / h of ozonized air were injected as an ozone amount via ejector 15. Further, the pump ozone treated water from the ozonated water tank 6 via the pump 8, prior to supply an amount per hour 0. 7m 3 to the hollow fiber membrane module manufactured by the HDPE, the Chio sulfate Natoriumu solution, from the tank 1 8 7 g was added per hour in terms of sodium thiosulfate while stirring and mixing with a static mixer 19 through 17. The drainage was drawn off at 0.7 m / h. At this time, the residual ozone concentration at the inlet of the membrane module was 0 ppm.
  • the injection of ozone is performed by calculating the difference between the initial setting value of the membrane module inlet pressure and the actual membrane module inlet pressure, feeding back the signal to the ozone generator 4, and automatically controlling the injection ozone amount.
  • I went.
  • the initial setting of the membrane module inlet pressure was set at 0.80 kgZc and the amount of injected ozone at that time was set at 10 Og, and the membrane module inlet pressure was 0.05 kg / cm. Each time it increased, the amount of injected ozone was increased by 0.3 g, and when the inlet pressure of the membrane module became less than the initial setting, the operation was continued with the injection of ozone decreased.
  • the operating conditions were 2 Nm / hour after 10 minutes of filtration.
  • the operation of supplying air from the lower part of the module, performing air publishing for 60 seconds, and performing backwashing with the backwash pump 20 using drainage for 20 seconds was repeated.
  • the pump 8 was stopped and the automatic valve 11 was closed to stop the supply of raw water.
  • the pump 7 and the ozone generator 4 were constantly operated, and the injection of ozone was continued.
  • the pump 17 for adding the sodium thiosulfate aqueous solution was also stopped at the same time.
  • the permeation flux level was 1.0 m / h, the initial value. For two months, during which time there was no increase in the membrane module inlet pressure.
  • the quality of the obtained drainage water is 0.05 degree, turbidity is 0.05 mg, COD (chemical oxygen demand) value is SmgZ litre, and 8 ⁇ 0 value is 1 111 8 / l, which is enough for landscape water and hydrophilic water The water quality was excellent.
  • Example 7 (invention)
  • the ozone injection is calculated by calculating the difference between the initial set value of the membrane module inlet pressure during backwashing and the actual membrane module inlet pressure during backwash, and the signal is fed back to the ozone generator 4 for injection.
  • the procedure was performed under the same conditions as in Example 1 except that the method was used to automatically control the amount of ozone.
  • the initial setting of the membrane module inlet pressure during backwashing is set to 1.60 kcm 2 , and the amount of injected ozone at that time is set to 2.
  • the COD (chemical oxygen demand) value was 0.4 mg / L
  • the turbidity was 0.02 degrees
  • E. coli and general bacteria were not detected.
  • the items also fully satisfied the criteria for drinking water.
  • the injection of ozone is calculated by calculating the difference between the initial setting of the average transmembrane pressure difference during backwashing and the actual average transmembrane pressure difference during backwashing, and the signal is fed back to the ozone generator 4 for injection.
  • the procedure was performed under the same conditions as in Example 4, except that the method was used to automatically control the amount of ozone.
  • the initial setting value of the average transmembrane pressure during backwashing 0. 5 5 k gZc m 2, to set the injection O zone down amount at that time to 1 0. 0 g, the film between the average pressure difference at the time of backwashing 0. every time 05 kg Roh cm 2 rises, if the injection amount of ozone is increased by 0. 3 g, an average transmembrane pressure during backwashing is less than the initial set value, reduce the injection of ozone And continued driving.
  • the filtration flux level was maintained at the initial value of 1.0 m 3 / h for 2 months, and there was no increase in the average transmembrane pressure during this period.
  • the water quality of the obtained drainage water was 0.05 ° C, the COD value was 12 mgZ liter, the BOD value was 1 mgZ liter, and the water quality was sufficient for landscape water and hydrophilic water.
  • Example 9 (invention)
  • the ozone injection is calculated by calculating the difference between the initial set value of the membrane permeation flux during backwashing and the actual membrane permeation flux during backwashing, and the signal is fed back to the ozone generator 4 for injection.
  • the procedure was carried out under the same conditions as in Example 5, except that the method was used to automatically control the amount of ozone.
  • the initial setting of the membrane permeation flux during backwashing 1. 5 m 3 hr, to set the injection amount of ozone when its 1 0. 0 g, membrane permeation flux during backwashing 0. lm 3 / hr reduced
  • the amount of injected ozone was increased by 0.3 g, and when the membrane permeation flux during backwash exceeded the initial set value, the operation was continued with the injection of ozone decreased.
  • the inlet pressure of the membrane module was 0.9 kg / cm 2
  • the average transmembrane pressure was 0.55 kg / cm 2
  • the initial level could be maintained for 2 months. None.
  • the water quality of the obtained drainage water was 0.05 degree, the COD value was 12 rag / liter, and the BOD value was 1 mgZ liter, which was sufficient for landscape water and hydrophilic water.
  • the present invention relates to a filtration method capable of obtaining a sufficient treated water quality and a filtration flux without depending on the properties of raw water, the type and content of organic matter, in performing advanced treatment of purified water and advanced treatment of sewage using ozone. Can be provided.
  • the amount of ozone injected can be controlled while monitoring the filtration status.Therefore, it is necessary to maintain a high filtration flux with a small amount of ozone added. Can be. It is possible to provide long-term stable filtration by feeding back the monitored value and automatically controlling the process of adjusting the amount of ozone to be added.
  • the present invention can provide a practical and economical filtration method that does not require a special measuring device for control.

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Abstract

A method for filtration with membranes wherein ozone is added to original water (1) to treat the water with ozone (2) and thereby decompose suspended substances and organic substances contained in the original water and then filtration treatment (3) is carried out, which comprises controlling the amount of ozone to be injected to the original water on the basis of a flux of permeated water, a pressure of the inlet of a membrane module or an average inter-membrane pressure difference during filtration or backwash operation. Such control of the amount of ozone provides satisfactory quality of treated water and effective utilization of ozone, and thus leads to a high flux of filtered water with a small amount of ozone added. A flux of permeated water and a pressure of the inlet of a membrane module are measured by means of a flow meter (16) and a pressure gauge (13 or 15) respectively, and an average inter-membrane pressure difference is calculated from measured values of pressure gauges (13, 14 and 15).

Description

明 細 書 膜濾過方法 技術分野  Description Membrane filtration method Technical field
本発明は、 上水 ·下水，工業排水 ·家庭排水 ·屎尿水等の水処理分野における、 オゾンを用いた膜濾過方法に関するものである。  The present invention relates to a membrane filtration method using ozone in the field of water treatment such as water supply, sewage, industrial wastewater, domestic wastewater, and human wastewater.
背景技術 Background art
従来の浄水処理の代表的な処理方法としては、 凝集沈殿一砂濾過一塩素消毒、 凝集沈殿一砂濾過一活性炭一塩素消毒又は凝集沈殿一砂濾過一オゾン一活性炭一 塩素消毒などが行われている。 また、 屎尿や家庭用排水などの下水又は工場排水 などの放流や再利用のための代表的な処理方法としては、 最初沈殿池一曝気ー最 終沈殿池一塩素消毒や、 最初沈殿池一曝気一最終沈殿池一凝集沈殿一砂濾過一塩 素消毒などが行われてきた。  Typical treatment methods for conventional water purification treatment include coagulation sedimentation-sand sand filtration-chlorine disinfection, coagulation sedimentation-sand filtration-activated carbon-chlorine disinfection or coagulation sedimentation-sand filtration-ozone-activated carbon-chlorine disinfection. I have. Typical treatment methods for the discharge and reuse of sewage such as human waste and domestic wastewater or industrial wastewater are as follows: first settling tank-aeration-final settling tank-chlorination, first settling tank-aeration. One final sedimentation basin, one coagulation sedimentation, one sand filtration and one chlorine disinfection have been performed.
—方、 生活用水の需要増大や無秩序な森林伐採、 異常気象等による渴水に対す る対応策として貯水ダム等の水源開発が行われている。 しかし、 近年水源水質の 悪化が進行し、 前述のような従来の方法では必ずしも良好な飲料水が得られなく なってきており、 深刻な問題になってきている。 一方、 屎尿や家庭用排水などの 下水又は工場からの有機性排水などは、 含有されている種々の懸濁物質や有機性 成分を前述のような方法で取り除いてから放流されている。 しかし、 近年環境問 題が注目されるにつれ、 このような放流水においても、 より高度に水質を向上さ せるような処理が要求されてきている。 さらには、 水の有効利用のため、 下水や 排水を水資源として再利用することが提案されている。 例えば公園の噴水や修景、 親水用水、 雑用水、 工業用水等、 多種の用途が考えられており、 特に修景、 親水 用水としては下水や排水が実際に利用され始めている。  On the other hand, water sources such as water storage dams are being developed as countermeasures against water due to increased demand for domestic water, disorderly deforestation, and abnormal weather. However, in recent years, the quality of water sources has deteriorated, and it has become impossible to obtain good drinking water with the conventional methods as described above, which has become a serious problem. On the other hand, sewage such as human waste and domestic wastewater or organic wastewater from factories is discharged after removing various suspended substances and organic components contained by the above-mentioned method. However, in recent years, attention has been paid to environmental issues, and such effluents are required to be treated to improve water quality even higher. Furthermore, it has been proposed to reuse sewage and wastewater as water resources for effective use of water. For example, various uses are considered, such as park fountains and scenic landscapes, water for water use, miscellaneous water, industrial water, etc. Sewage and drainage have begun to be actually used, especially for landscape views and water for hydrophilic use.
このような高度の浄水処理、 卞排水処理を目的として、 最近、 限外濾過膜や精 密濾過膜による膜濾過処理が種々提案されてきている。 しかし、 このような膜に よる濾過処理は、 膜の目詰まりによる濾過流束の低下が問題となっており、 膜の 目詰まりの防止が大きな課題である。 すなわち、 このような水を膜で濾過すると、 原水中に含まれる懸濁物質や使用する膜の孔径以上の大きさの有機物は膜で阻止 され、 いわゆる濃度分極やケーキ層を発生させる。 それと同時に、 原水中の有機 物は膜を目詰まりさせたり、 又は膜内部の網状組織に吸着されるため、 得られる 膜の濾過流束は清澄水の濾過流束に比べて数分の一から数十分の一にまで低下し、 膜濾過コストが高くなり、 経済的な観点からは実用性が低レ、ものであつた。 Various types of membrane filtration using ultrafiltration membranes or precision filtration membranes have recently been proposed for the purpose of such advanced water purification and Byeon wastewater treatment. However, in such a filtration treatment using a membrane, there is a problem in that the filtration flux is reduced due to membrane clogging, and prevention of membrane clogging is a major issue. That is, if such water is filtered through a membrane, Suspended substances contained in the raw water and organic substances having a size larger than the pore size of the membrane used are blocked by the membrane, so-called concentration polarization and a cake layer are generated. At the same time, the organic matter in the raw water clogs the membrane or is adsorbed by the network inside the membrane, so the filtration flux of the resulting membrane is a fraction of the filtration flux of the clear water. It decreased to several tenths, the membrane filtration cost increased, and the practicality was low from an economic viewpoint.
そのため膜濾過法では、 膜の目詰まり防止を目的としてクロスフ口一濾過法 (循環濾過法、 タンジェント濾過法） を用いることが提案されている。 さらに特 開平 4一 1 0 8 5 1 8号公報には、 膜の目詰まりの防止のため、 膜の上流側に酸 化ガスとしてオゾンを添加し、 タンジェント濾過を行うことが提案されている。 上記のようにオゾンなどの酸化ガスを併用することにより、 膜濾過時の透過流 束が、 オゾンを併用しない場合に比べて数倍大きくなり、 濾過膜の設置面積が小 さくなるとともに、 水処理のための経済性も向上する。 しかしながら、 オゾンを 用いる場合、 オゾンの発生には多大の電力が必要になることから、 発生したォゾ ンを如何に有効に利用するかが経済性の観点から重要である。  For this reason, it has been proposed to use a cross-floor monofiltration method (circulation filtration method, tangent filtration method) to prevent membrane clogging in the membrane filtration method. Furthermore, Japanese Patent Application Publication No. Hei 4-110185 proposes performing tangent filtration by adding ozone as an oxidizing gas upstream of the membrane to prevent clogging of the membrane. By using an oxidizing gas such as ozone as described above, the permeation flux at the time of membrane filtration is several times larger than when ozone is not used, and the installation area of the filtration membrane is reduced and water treatment is performed. The economics for the project are also improved. However, when using ozone, a great deal of electricity is required to generate ozone, so it is important from an economic point of view how to use the generated ozone effectively.
従来、 オゾンを用いて水処理を行う場合、 原水のオゾン濃度を所定の値になる ように制御するが、 この方法では、 原水の清澄性が変動し、 必要オゾン量が低下 して、 過剰にオゾンを添加することになつたり、 必要オゾン量が増加して、 徐々 に膜の目詰まりが進行して、 所定の透過流束が得られなくなるという問題があつ た。 また、 過剰にオゾンを添加すると、 経済的に不利なだけではなく、 後段のェ 程に使用される活性炭のプロッキングが起こったり、 生物活性炭の生物が死んだ りする問題があった。  Conventionally, when water treatment is performed using ozone, the ozone concentration of the raw water is controlled to a predetermined value.However, in this method, the clarity of the raw water fluctuates, the required amount of ozone decreases, and excessive When ozone was added, the required amount of ozone increased, and the clogging of the membrane gradually progressed, so that a predetermined permeation flux could not be obtained. In addition, excessive addition of ozone was not only economically disadvantageous, but also caused problems such as blocking of activated carbon used in a later step and death of biological activated carbon organisms.
発明の開示 Disclosure of the invention
本発明の目的は、 膜を用いて浄水の高度処理や下排水の高度処理を行うにあた り、 十分な処理水質を得ることができ、 かつオゾンを有効に利用して低いオゾン 添加量で高い濾過流束を得る、 実用的な濾過方法を提供することにある。  An object of the present invention is to perform a high-level treatment of purified water and an advanced sewage by using a membrane. In this case, it is possible to obtain a sufficient quality of treated water, and to effectively use ozone to reduce the amount of added ozone. It is an object of the present invention to provide a practical filtration method for obtaining a high filtration flux.
本発明は、 '  The present invention
( 1 ) オゾンを添加した水の膜濾過方法において、 濾過時又は逆洗時の、 透 過流束、 膜モジュール入口圧力又は平均膜間差圧の値に基づいて、 原水に注入す るオゾン量を制御することを含む上記方法 である。 (1) In the membrane filtration method of water to which ozone has been added, the amount of ozone to be injected into raw water based on the value of the permeation flux, membrane module inlet pressure or average transmembrane pressure during filtration or backwashing The method comprising controlling It is.
本発明の膜濾過方法の他の態様を挙げると、  According to another embodiment of the membrane filtration method of the present invention,
( 2 ) —定圧力濾過において、 濾過又は逆洗時の、 透過流束の値に基づいて、 注入するオゾン量を制御する上記 （1 ) の膜濾過方法、  (2) The membrane filtration method according to (1), wherein the amount of ozone to be injected is controlled based on the value of permeation flux at the time of filtration or backwashing in constant pressure filtration.
( 3 ) 一定透過流束濾過において、 濾過又は逆洗時の、 膜モジュール入口圧 力の値に基づいて、 注入するオゾン量を制御する上記 （1 ) の膜濾過方法、  (3) The membrane filtration method according to the above (1), wherein the amount of ozone to be injected is controlled based on the value of the pressure at the membrane module inlet at the time of filtration or backwashing in constant flux filtration.
( 4 ) 一定透過流束濾過において、 濾過又は逆洗時の、 平均膜間差圧の値に 基づいて、 注入するオゾン量を制御する上記 （1 ) の膜濾過方法、  (4) In the constant permeation flux filtration, the membrane filtration method according to the above (1), wherein the amount of ozone to be injected is controlled based on the value of the average transmembrane pressure during filtration or backwashing.
などである。 And so on.
図面の簡単な説明 BRIEF DESCRIPTION OF THE FIGURES
図 1は、 本発明の濾過方法の例を示すフロー図である。 FIG. 1 is a flowchart showing an example of the filtration method of the present invention.
図 2は、 本発明の濾過方法の一実施態様を示す図である。 FIG. 2 is a diagram showing one embodiment of the filtration method of the present invention.
図 3は、 本発明の濾過方法の他の実施態様を示す図である。 FIG. 3 is a diagram showing another embodiment of the filtration method of the present invention.
図 4は、 本発明の濾過方法の他の実施態様を示す図である。 FIG. 4 is a diagram showing another embodiment of the filtration method of the present invention.
図 5は、 本発明の濾過方法の他の実施態様を示す図である。 FIG. 5 is a diagram showing another embodiment of the filtration method of the present invention.
発明を実施するための最良の形態 BEST MODE FOR CARRYING OUT THE INVENTION
本発明は、 原水にオゾンを添加した後、 濾過膜を用いて濾過を行う方法におい て、 原水に注入するォゾン量を制御する方法に関する。  The present invention relates to a method of adding ozone to raw water and then performing filtration using a filtration membrane, wherein the ozone is injected into the raw water.
本発明でいう原水とは、 河川水、 伏流水、 湖沼水、 貯水、 地下水などの上水原 水、 屎尿水、 下水一次処理水、 下水二次処理水、 工業排水、 家庭排水、 プール、 浴場、 水生動物を飼育する水槽等の貯水、 紙パルプ製造排水、 ゴミ埋め立て地浸 出水等が挙げられる。  The raw water referred to in the present invention is river water, underground water, lake water, lake water, storage water, groundwater and other clean water, human waste water, sewage primary treatment water, sewage secondary treatment water, industrial wastewater, domestic wastewater, pools, baths, Water storage in a water tank for raising aquatic animals, pulp and paper production wastewater, leachate landfill leachate, and the like.
添加するオゾンは、 オゾン単体、 オゾン化空気、 又はオゾン溶解水でもよく、 オゾンの導入は、 ェゼクタ一、 ラインミキシング法、 散気管、 U—チューブ等を 介して行う。  The ozone to be added may be ozone alone, ozonized air, or ozone-dissolved water. Ozone is introduced through an ejector, a line mixing method, a diffuser tube, a U-tube, or the like.
また、 オゾンの原料は、 空気でも、 酸素でもよい。 酸素の場合は、 圧カスイン グ吸着 （P S A) で製造された酸素でもよく、 液化酸素から作ってもよい。  Also, the source of ozone may be air or oxygen. In the case of oxygen, it may be oxygen produced by pressure-casing adsorption (PSA) or may be made from liquefied oxygen.
膜による濾過方法は、 クロスフロー濾過法 （循環濾過法） でも、 デッドエンド 濾過法 （全量濾過法） でもよい。 膜濾過方式としては、 定流速濾過、 定圧濾過の どちらでもよく、 加圧方式、 減圧方式のどちらでもよく、 また、 外圧方式、 内圧 方式のどちらでもよい。 The filtration method using a membrane may be a cross-flow filtration method (circulation filtration method) or a dead-end filtration method (total filtration method). Membrane filtration methods include constant flow filtration and constant pressure filtration. Either method may be used, either the pressurizing method or the depressurizing method may be used, and the external pressure method or the internal pressure method may be used.
また、 オゾンを膜面まで存在させて濾過する方法でも、 膜による濾過処理の前 段でオゾンを消費させたのち濾過する方法でもよい。 原水の状態によって、 最適 の方法を選べばよい。  Also, a method of filtering by allowing ozone to be present up to the membrane surface, or a method of consuming ozone before the filtration treatment by the membrane and then performing filtration may be used. The best method can be selected depending on the condition of the raw water.
積極的に膜面の残留オゾンをゼロにしたい場合は、 濾過処理の前段で、 例えば、 滞留槽を設けてバツキによりオゾンを除く、 チォ硫酸ナトリゥム等の還元剤添加 又は活性炭処理によりオゾンを分解させる、 などの脱オゾン処理を行えばよい。 オゾン存在下で濾過を行う場合は、 膜を通過するオゾンが膜に付着した有機物 を繰り返し攻撃するため、 膜は常時自己洗浄されながら濾過を行うことになる。 その結果、 より高い透過流束を得ることができる。 このようにオゾン存在下で濾 過する際は、 濾過速度の上昇を図るために濾過水に 0 . 0 5 ppm 以上のオゾン が残留するように、 原水にオゾンを添加するのが好ましい。  If it is desired to positively reduce the residual ozone on the membrane surface, ozone can be decomposed by adding a reducing agent such as sodium thiosulfate or activated carbon treatment, for example, by installing a retention tank to remove ozone before the filtration process. De-ozone treatment such as, may be performed. When filtration is performed in the presence of ozone, the ozone passing through the membrane repeatedly attacks the organic substances attached to the membrane, so that the membrane is always self-cleaned and filtered. As a result, a higher permeation flux can be obtained. When the filtration is performed in the presence of ozone as described above, it is preferable to add ozone to the raw water so that ozone of 0.05 ppm or more remains in the filtered water in order to increase the filtration rate.
一方、 微生物類を殺菌し、 臭気物質を除去するための原水へのオゾン添加濃度 は、 原水水質にもよるが一般に 0 . 5 p p m以上である。 オゾン濃度が高すぎる と経済性が低下することになるので、 好ましくは 0 . 0 5〜5 0 ppm 程度、 更 に好ましくは 0 . l〜3 0 ppm の濃度のオゾンを添加する。  On the other hand, the concentration of ozone added to raw water to kill microorganisms and remove odorous substances is generally 0.5 ppm or more, depending on the quality of raw water. If the ozone concentration is too high, the economic efficiency is reduced. Therefore, ozone having a concentration of preferably about 0.05 to 50 ppm, more preferably 0.1 to 30 ppm is added.
原水とオゾンとの接触時間は、 特に留意する必要はないが、 通常、 1秒〜 3 0 分の接触時間が一般的である。  It is not necessary to pay special attention to the contact time between raw water and ozone, but usually, a contact time of 1 second to 30 minutes is generally used.
オゾンによる原水処理において、 オゾンの酸化力をより強め、 促進酸化をより 良く行う目的で、 過酸化水素の添加や紫外線照射、 又は酸化チタン等の促進酸化 触媒を併用してもよい。  In the treatment of raw water with ozone, addition of hydrogen peroxide, ultraviolet irradiation, or a promoted oxidation catalyst such as titanium oxide may be used in combination for the purpose of enhancing the oxidizing power of ozone and promoting accelerated oxidation.
原水に添加するオゾン量の適正値への制御は、 濾過時又は後述する逆洗時に、 透過流束、 膜モジュール入口圧力又は平均膜間差圧の値に基づいて行う。  The control of the amount of ozone added to the raw water to an appropriate value is performed based on the permeation flux, the pressure at the membrane module inlet, or the average transmembrane pressure during filtration or backwashing described below.
例えば、 一定圧力濾過において、 濾過又は逆洗時の透過流束の値に基づいて注 入するオゾン量を制御する場合 ίま、 あらかじめ設定された値よりも透過流束の値 が低下したときにはオゾンの添加量を増やし、 逆の場合はオゾンの添加を減らす か中止する。  For example, when controlling the amount of ozone to be injected based on the value of the permeation flux at the time of filtration or backwashing at constant pressure filtration, if the permeation flux value falls below a preset value, ozone Increase the amount of ozone added, and in the opposite case reduce or stop adding ozone.
また、 一定透過流束濾過において、 濾過又は逆洗時の膜モジュール入口圧力の 値、 又は平均膜間差圧の値に基づいて注入するオゾン量を制御する場合は、 あら かじめ設定された膜モジュール入口圧力の値、 又は平均膜間差圧の値よりも値が 大きくなつたときにはオゾンの添加量を増やし、 逆の場合はオゾンの添加を減ら すか中止する。 Also, in constant flux filtration, the pressure at the membrane module inlet during filtration or backwashing When controlling the amount of ozone to be injected based on the value or the average transmembrane pressure, the value should be larger than the preset value of the membrane module inlet pressure or the value of the average transmembrane pressure. In such cases, increase the amount of ozone added, and in the opposite case, reduce or stop the addition of ozone.
添加するオゾン量を制御する方法としては、 例えば制御の基礎となる上記の値 の絶対値又は時間変化率を検出し、 オゾン発生機の電流又は電圧を調整するか、 又は注入口でのオゾン量を調整する方法が挙げられる。 手動による制御も可能で あるが、 上記の値を演算処理してオゾン量制御信号としてフィードバックし、 注 入ォゾン量又は濃度を自動制御する方法が実用的で好ましレ、。  Methods for controlling the amount of ozone to be added include, for example, detecting the absolute value or the rate of change of time with respect to the above-mentioned value, which is the basis for control, and adjusting the current or voltage of the ozone generator, or the amount of ozone at the inlet. Is adjusted. Although manual control is possible, it is practical and preferable to calculate the above value and feed it back as an ozone control signal to automatically control the injected ozone amount or concentration.
濾過処理に使用される膜としては、 オゾンが膜面まで存在するプロセスにおい ては、 オゾン耐性のある膜が使用されるが、 膜による濾過処理の前段でオゾンが 除去されるプロセスにおいては、 膜のオゾン耐性にこだわる必要はない。  As a membrane used for the filtration treatment, an ozone-resistant membrane is used in a process in which ozone is present up to the membrane surface, but in a process in which ozone is removed before the filtration treatment by the membrane, the membrane is used. You don't have to worry about ozone resistance.
オゾン耐性膜としては、 オゾンにより劣化しない濾過膜であれば特に限定され ないが、 例えば、 オゾン耐性を有するセラミック等の無機膜、 ポリフッ化ビニリ デン （PVDF) 膜、 ポリ四フッ化工チレン （PTFE) 膜、 エチレンーテトラ フルォロエチレン共重合体 （ETFE) 膜、 四フッ化工チレン一パ一フルォロア ルキルビ二ルェ一テル共重合樹脂 （PFA) 膜等のフッ素系樹脂膜等の有機膜を 適用することができる。 なかでもポリフッ化ビニリデン （PVDF) 膜の使用が 好ましい。  The ozone-resistant membrane is not particularly limited as long as it is a filtration membrane that is not deteriorated by ozone. Examples thereof include an inorganic membrane such as an ozone-resistant ceramic, a polyvinylidene fluoride (PVDF) membrane, and a polytetrafluoroethylene (PTFE) membrane. Organic membranes such as a membrane, an ethylene-tetrafluoroethylene copolymer (ETFE) membrane, and a fluorine-based resin membrane such as a tetrafluoroethylene-perfluoroalkylvinylester copolymer (PFA) membrane can be applied. Of these, the use of polyvinylidene fluoride (PVDF) membrane is preferred.
—方、 オゾン耐性が必要でない場合は、 上記材質の膜に加えて、 ポリエチレン 膜、 ポリプロピレン膜等のポリオレフイン膜、 ポリスルフォン膜、 ポリアクリロ 二トリル膜、 酢酸セルロース膜、 ポリカーボネート膜、 ポリアミ ド膜等を適用す ることができる。  If ozone resistance is not required, a polyolefin film such as a polyethylene film or a polypropylene film, a polysulfone film, a polyacrylonitrile film, a cellulose acetate film, a polycarbonate film, a polyamide film, etc., in addition to the film of the above materials, Can be applied.
膜の形状としては、 平膜、 スパイラル膜、 プリーツ膜、 中空糸膜、 チューブラ —膜等があるが、 中空糸膜が好ましい。  Examples of the shape of the membrane include a flat membrane, a spiral membrane, a pleated membrane, a hollow fiber membrane, and a tubular membrane, but a hollow fiber membrane is preferred.
膜の孔径としては、 限外濾過 （UF) 膜から精密濾過 （MF) 膜の孔径域を 使用し得るが、 膜の透過流束が基本的に高い点から精密濾過 （MF) 膜を使用す るのが好ましい。 例えば、 膜の孔径は 0. 00 1〜1 μπαが好ましく、 0. 0 5 〜 1 μ m 更に子まし ヽ。 膜濾過を行うに際し、 膜の孔径が精密濾過 （M F ) 領域となると孔径が大きく なるため、 原水中の懸濁物質 （S S ) やバクテリア等が膜内に侵入する。 従って、 懸濁物質やバクテリアが多い原水の場合には、 高い透過流束を得るには多くのォ ゾン注入が必要になる。 As the pore size of the membrane, the pore size range of the ultrafiltration (UF) membrane to the microfiltration (MF) membrane can be used, but the microfiltration (MF) membrane is used because the permeation flux of the membrane is basically high. Preferably. For example, the pore size of the membrane is preferably from 0.001 to 1 μπα, and from 0.05 to 1 μm. When performing membrane filtration, when the pore size of the membrane is in the microfiltration (MF) region, the pore size increases, and suspended substances (SS) and bacteria in the raw water enter the membrane. Therefore, in the case of raw water with a high concentration of suspended solids and bacteria, a high permeation flux will require many ozone injections.
このオゾン添加量を低減する目的で、 オゾン添加に先立ちポリ塩化アルミニゥ ム （P A C L ) 、 硫酸バン土、 塩化第一鉄、 塩化第二鉄等の凝集剤、 活性炭など の吸着剤を使用してもよい。  In order to reduce the amount of ozone added, a coagulant such as polyaluminum chloride (PACL), bansulfate, ferrous chloride and ferric chloride, and an adsorbent such as activated carbon can be used prior to ozone addition. Good.
凝集剤及び吸着剤は、 原水を貯めるオゾン処理水タンクに添加してもよいし、 又は、 原水をオゾン添加を行う所に誘導する管の途中にラインミキシング方式で 添加してもよレ、。  The flocculant and the adsorbent may be added to an ozonated water tank that stores raw water, or may be added by a line mixing method in a pipe that guides raw water to a place where ozone is added.
凝集剤の添加量は、 原水中に含まれる懸濁物質を凝集できる量である必要があ り、 一般的に原水の 1 リットル中に 1〜 1 0 0 m gであればよく、 さらに好まし くは原水の 1リツトル中に 2〜5 O m gであればよレ、。  The amount of the flocculant added must be such that the suspended solids contained in the raw water can be flocculated, and generally 1 to 100 mg per liter of the raw water, and more preferably. Is 2 to 5 O mg per liter of raw water.
濾過方法によって、 使用する膜モジュールは、 公知の内圧型モジュール及び外 圧型モジュールから選ばれる。 外圧型モジュールとしては、 例えば、 W0 9 7 1 0 8 9 3に記載されているようなモジュール構造のものが使用できる。  Depending on the filtration method, the membrane module used is selected from known internal pressure type modules and external pressure type modules. As the external pressure type module, for example, a module having a module structure as described in WO97108993 can be used.
濾過膜の濾過性能を維持するために、 定期的に膜モジュールを物理洗浄するの が好ましい。 物理洗浄法としては、 逆流洗浄 （逆洗） とエアーパブリングが効果 的である。  In order to maintain the filtration performance of the filtration membrane, it is preferable to periodically physically clean the membrane module. Backwashing (backwashing) and air publishing are effective physical cleaning methods.
逆流洗浄は、 一定時間の濾過の後、 濾過を中止して、 膜の透過液側から洗浄液 を流して洗浄を行うという方法である。 洗浄液として、 膜を透過した濾水を用い るのが好ましい。  Backwashing is a method in which filtration is stopped for a certain time, filtration is stopped, and washing is performed by flowing a washing solution from the permeate side of the membrane. It is preferable to use filtered water that has passed through the membrane as the washing liquid.
エアーバブリングは、 一定時間の濾過の後、 濾過を中止して膜面に気体を送り 込み、 膜面を振動させることにより膜の洗浄を行うものである。 膜面にオゾンが 存在する場合は、 膜面に吸着する有機物がオゾンにより分解され、 非吸着性にな つているため、 膜の孔を閉塞す ¾非吸着性の物質 （有機物、 無機物） がエアーバ プリングにより有効にふるい落とされ、 大きな洗浄効果が得られる。 したがって、 オゾン存在下で膜濾過する方法においては、 膜の洗浄方法としてエアーバプリン グは非常に有効である。 エアーパブリングは、 逆流洗浄と併用してもよく、 濾過一エアーバブリングー 逆流洗浄の順でもよいし、 濾過一逆流洗浄一エアーバブリング、 又は濾過一 （ェ ァーバプリングと同時に逆流洗浄） の順で行ってもよい。 In air bubbling, after filtration for a certain period of time, filtration is stopped, gas is sent to the membrane surface, and the membrane is washed by vibrating the membrane surface. When ozone is present on the membrane surface, the organic substances adsorbed on the membrane surface are decomposed by ozone and become non-adsorbent, and thus block the pores of the membrane. ¾ Non-adsorbent substances (organic and inorganic substances) are air-barred. It is effectively sifted off by the pulling, and a great cleaning effect is obtained. Therefore, in the method of membrane filtration in the presence of ozone, air bubbling is very effective as a method of cleaning the membrane. Air publishing may be used in combination with backwashing, followed by filtration and air bubbling-backwashing, or filtration and backwashing and air bubbling, or filtration (backwashing at the same time as vacuuming). You may.
エアーバブリングの時間は 1秒以上 6分以内が好ましい。 1秒より短いとエア —バブリングの効果が少なくなり、 また 6分より長いと、 エアーバブリング中は 濾過を行わないため濾過水量が少なくなり好ましくない。  The air bubbling time is preferably from 1 second to 6 minutes. If it is shorter than 1 second, the effect of air-bubbling is reduced, and if it is longer than 6 minutes, filtration is not performed during air bubbling, and the amount of filtered water is undesirably reduced.
以下、 図面を参照して本発明の濾過方法を説明する。  Hereinafter, the filtration method of the present invention will be described with reference to the drawings.
図 1は、 本発明の濾過方法の例を示すフロー図である。 図 1において、 原水 1 にオゾンを添加してオゾン処理 2し、 該原水 1中の懸濁物質や有機物をオゾンに より分解する。 その後、 膜を用いて濾過処理 3を行うにあたり、 透過流束、 膜モ ジュール入口圧力又は平均膜間差圧の値を検知し、 その値に基づいて原水に注入 するオゾン量を制御する。  FIG. 1 is a flowchart showing an example of the filtration method of the present invention. In FIG. 1, ozone is added to raw water 1 to perform ozone treatment 2, and suspended substances and organic substances in the raw water 1 are decomposed by ozone. After that, when performing the filtration treatment 3 using the membrane, the permeation flux, the membrane module inlet pressure or the average transmembrane pressure difference is detected, and the amount of ozone injected into the raw water is controlled based on the detected values.
透過流束は、 膜を透過した濾水量又は逆洗水を流量計 1 6により測定すること ができる。  The permeation flux can be measured by measuring the amount of filtrate permeated through the membrane or the backwash water with a flow meter 16.
膜モジュール入口圧力は、 濾過時は膜モジュール入口に設けた圧力計 1 3によ り測定することができ、 逆洗時は圧力計 1 5により測定することができる。 平均膜間差圧は、 クロスフロー濾過の場合は、 膜モジュール入口に設けた圧力 計 1 3、 膜モジュール循環水出口に設けた圧力計 1 4、 及び膜モジュール濾水出 口に設けた圧力計 1 5により測定される圧力から、 以下の計算式により算出され る値である。  The pressure at the inlet of the membrane module can be measured by a pressure gauge 13 provided at the inlet of the membrane module at the time of filtration, and can be measured by the pressure gauge 15 at the time of backwashing. In the case of cross-flow filtration, the average transmembrane pressure is measured using a pressure gauge 13 provided at the membrane module inlet, a pressure gauge 14 provided at the membrane module circulating water outlet, and a pressure gauge provided at the membrane module filtration water outlet. It is a value calculated from the pressure measured in 15 by the following formula.
平均膜間差圧 = (膜モジュール入口圧力 +膜モジュール循環水出口圧力） Z 2 一膜モジュール濾水出口圧力 Average transmembrane pressure = (membrane module inlet pressure + membrane module circulating water outlet pressure) Z 2 Single membrane module filtrate outlet pressure
デッドエンド濾過の場合は、 平均膜間差圧は以下の計算式により算出される値 である。  In the case of dead-end filtration, the average transmembrane pressure is a value calculated by the following formula.
平均膜間差圧 == (膜モジュール入口圧力一膜モジュール濾水出口圧力） また、 逆洗時においては、 平-均膜間差圧は以下の計算式により算出される値で ある。  Average transmembrane pressure == (pressure at the inlet of the membrane module-pressure at the outlet of the drainage of the membrane module) In backwashing, the average transmembrane pressure is a value calculated by the following formula.
平均膜間差圧 == (逆洗水モジュール入口圧力一逆洗水出口圧力）  Average transmembrane pressure == (backwash water module inlet pressure-backwash water outlet pressure)
図 1には基本的なプロセスのみを示しており、 必要に応じて膜による濾過処理 の後段に活性炭処理や逆浸透膜処理などの処理を行ってもよい。 Fig. 1 shows only the basic process. A treatment such as an activated carbon treatment or a reverse osmosis membrane treatment may be performed at a subsequent stage.
図 2に例示する方法は、 オゾン発生機 4で発生したオゾン化空気をオゾン注入 手段 （ェゼクタ一） 5により原水 1に添加して、 オゾン処理水タンク 6に供給し た後、 そのオゾン処理水を供給手段 （ポンプ） 8により膜モジュール 9に供給し、 濾過する方法である。 濾過をクロスフロー濾過で行う場合は、 濾過膜を透過しな い原水が循環水として図 2に破線で示すようにオゾン処理水タンク 6に戻される。 デッドエンド濾過で濾過する場合は、 膜モジュール 9に供給されるオゾン処理水 はすべて膜を透過し、 濾過水が濾過水タンク 1 0に貯められる。  In the method illustrated in FIG. 2, the ozonized air generated by the ozone generator 4 is added to the raw water 1 by the ozone injection means (ejector 1) 5 and supplied to the ozonated water tank 6, and then the ozonized water is Is supplied to the membrane module 9 by the supply means (pump) 8 and filtered. When filtration is performed by cross-flow filtration, raw water that does not pass through the filtration membrane is returned to the ozonated water tank 6 as circulating water as shown by a broken line in FIG. In the case of performing filtration by dead-end filtration, all of the ozone-treated water supplied to the membrane module 9 permeates through the membrane, and the filtrate is stored in the filtrate tank 10.
図 2において、 原水への注入オゾン量は、 透過流束、 膜モジュール入口圧力又 は平均膜間差圧のいずれか一つの値に基づいてコントロールされる。 これらの値 を測定 ·検出するために、 膜モジュール 9の原水入口に圧力計 1 3、 濾水出口に 圧力計 1 5、 循環水出口に圧力計 1 4、 濾水出口に流量計 1 6を設けることがで きる。 なお、 1 1は自動弁、 1 2は原水供給手段 （ポンプ） 、 2 0は逆洗ポンプ、 2 1は活性炭処理槽を表す。 ここで測定された値に基づいて、 オゾン発生機 4の 電流又は電圧を調整し、 オゾン発生量を変化させることなどにより、 ェゼクタ一 5におけるオゾン添加量又はオゾン濃度を制御する。  In Fig. 2, the amount of ozone injected into the raw water is controlled based on one of the permeation flux, the inlet pressure of the membrane module, or the average transmembrane pressure. To measure and detect these values, a pressure gauge 13 at the raw water inlet, a pressure gauge 15 at the filtered water outlet, a pressure gauge 14 at the circulating water outlet, and a flow meter 16 at the filtered water outlet of the membrane module 9 It can be provided. In addition, 11 denotes an automatic valve, 12 denotes a raw water supply means (pump), 20 denotes a backwash pump, and 21 denotes an activated carbon treatment tank. Based on the measured values, the current or voltage of the ozone generator 4 is adjusted to change the ozone generation amount, thereby controlling the ozone addition amount or ozone concentration in the ejector 15.
例えば、 一定圧力濾過を継続して行う時に、 透過流束が低下した場合には、 ェ ゼクター 5における注入オゾン量を増加させ、 逆に透過流束が増加した場合には、 オゾンの注入を中止するか、 ェゼクター 5における注入オゾン量を低下させるこ とにより注入オゾン量を制御できる。  For example, when the permeation flux decreases during continuous filtration under constant pressure, the amount of ozone injected into the ejector 5 is increased, and when the permeation flux increases, ozone injection is stopped. Alternatively, the injected ozone amount can be controlled by reducing the injected ozone amount in the ejector 5.
同様に、 一定透過流束濾過を継続して行う時に、 濾過膜入口圧力が増加した場 合には、 ェゼクタ一 5における注入オゾン量を増加させ、 逆に濾過膜入口圧力が 低下した場合には、 オゾンの注入を中止するか、 ェゼクタ一 5における注入ォゾ ン量を低下させることにより注入オゾン量を制御できる。  Similarly, when performing continuous permeation flux filtration, if the pressure at the inlet of the filtration membrane increases, the amount of ozone injected into the ejector 15 increases, and conversely, if the pressure at the inlet of the filtration membrane decreases, The amount of injected ozone can be controlled by stopping the injection of ozone or decreasing the amount of injected ozone in the ejector 15.
また、 一定透過流束濾過を継続して行う時に、 平均膜間差圧が増加した場合に は、 ェゼクタ一 5における注入^ゾン量を増加させ、 逆に濾過膜入口圧力が低下 した場合には、 オゾンの注入を中止する力、 ェゼクタ一 5における注入オゾン量 を低下させることにより注入オゾン量を制御できる。  If the average transmembrane pressure increases during continuous permeate flux filtration, the amount of injection ^ zone in the ejector 15 increases, and conversely, if the inlet pressure of the filtration membrane decreases, The amount of injected ozone can be controlled by reducing the ozone injection force and the injected ozone amount in the ejector 15.
図 3に例示する方法は、 原水 1をまずオゾン処理水タンク 6に供給し、 オゾン 処理水タンク 6から循環手段 （ポンプ） 7により抜き出した原水の一部 （循環 水） にオゾン化空気を注入し、 再びオゾン水処理タンク 6に戻す方法によりォゾ ン処理を行う以外は、 図 2の濾過方法と異なる点はない。 In the method illustrated in FIG. 3, raw water 1 is first supplied to an ozonated water tank 6, and Except for injecting ozonized air into a part (circulating water) of raw water extracted from the treated water tank 6 by the circulation means (pump) 7 and returning it to the ozone water treatment tank 6 again, There is no difference from the filtration method of 2.
逆流洗浄やエアーバブリングなどの洗浄操作で膜濾過が停止している間は、 ォ ゾン処理水タンク 6の水量に連動した自動弁 1 1により原水供給は停止するが、 ポンプ 7は常に稼働し、 必要に応じて、 オゾン処理水タンク 6からの循環水にォ ゾンを注入し続けることができる。 その注入オゾン量は、 図 2の濾過方法と同様 にして制御される。  While membrane filtration is stopped by a washing operation such as backwashing or air bubbling, the supply of raw water is stopped by the automatic valve 11 that is linked to the amount of water in the ozonated water tank 6, but the pump 7 is always running. If necessary, ozone can be continuously injected into the circulating water from the ozonated water tank 6. The amount of injected ozone is controlled in the same manner as in the filtration method of FIG.
オゾン処理のためにオゾン処理水タンク 6中の水の一部を抜き出し、 オゾン処 理した後再びオゾン処理水タンク 6に戻すポンプ 7の循環水量は、 大きいほどォ ゾン化空気との接触が多くなるので好ましいが、 あまりに大きいとエネルギー口 スとなるので好ましくない。 通常ポンプ 7の循環水量は、 原水 1の供給量の 0 . 2倍から 1 0倍が好ましい。  A part of the water in the ozonated water tank 6 is extracted for ozone treatment, and after returning to the ozonated water tank 6 after ozone treatment, the larger the amount of circulating water in the pump 7, the greater the contact with the ozonized air. However, if it is too large, it is not preferable because it becomes an energy source. Usually, the circulating water amount of the pump 7 is preferably 0.2 to 10 times the supply amount of the raw water 1.
図 4に例示する方法は、 原水 1にェゼクター 5によりオゾン化空気を注入し、 オゾン処理水タンク 6に供給し、 そのオゾン処理された原水の一部をポンプ 7に より抜き出して原水 1と混合し、 そこに再びェゼクタ一 5によりオゾン化空気を 注入する以外は、 図 3の濾過方法と異なる点はない。  In the method illustrated in Fig. 4, ozonized air is injected into the raw water 1 by the ejector 5, supplied to the ozonated water tank 6, and a part of the ozonized raw water is extracted by the pump 7 and mixed with the raw water 1. There is no difference from the filtration method of Fig. 3 except that ozonized air is injected again by the ejector 15 there.
図 5は、 膜による濾過処理の前段で、 オゾンを除去するプロセスの例である。 オゾン処理水をオゾン処理水タンク 6からポンプ 8を介して中空糸膜モジュール 9へ供給するに先立って、 薬液タンク 1 8からポンプ 1 7を介してスタティック ミキサー 1 9で混合しながら薬液を添加し、 オゾンを除去する。 この点以外は、 図 3の濾過方法と同じである。  Figure 5 shows an example of a process for removing ozone prior to filtration by a membrane. Prior to supplying the ozonated water from the ozonated water tank 6 to the hollow fiber membrane module 9 via the pump 8, the chemical is added from the chemical tank 18 via the pump 17 while mixing with the static mixer 19. Removes ozone. Except for this point, it is the same as the filtration method of FIG.
以下に、 本発明を例を用いてより詳細に説明するが、 これらの例は本発明を何 ら限定するものと解釈されるべきではない。  Hereinafter, the present invention will be described in more detail with reference to examples, but these examples should not be construed as limiting the present invention.
例 1 (本発明） Example 1 (the present invention)
原水 1として、 濁度が 5〜 6度、 C O D (化学的酸素要求量） 値が 4 m g / リットル、 水温が 1 2 °Cの河川表流水を用い、 図 2に示す装置を用いて、 原水→ オゾン処理→オゾン耐性膜による濾過処理を順次実施し、 さらに後段で活性炭処 理を行った。 オゾン耐性膜としては、 特開平 3— 21 5535号公報に基づいて作製した、 孔径 0. 1 / 111、 内径が0. 7讓 φ、 外径力 Si. 25πιηιφの PVDF (ポリフッ 化ビ-リデン） 製の中空糸状精密濾過 （MF) 膜を使用した。 WO 971089 3に基づいて、 この中空糸膜 1 800本を 3インチ径の P VC (ポリ塩化ビニ ル） ケ一シングに納めた外圧型モジュールを作製した。 このモジュールは、 膜面 積が 7. 0m2、 清澄水透過流束が毎時 1. 8 m。の時、 モジュール濾過圧が、 0. 5 Kg f /c m 2であった。 As raw water 1, river surface water with a turbidity of 5 to 6 degrees, a COD (chemical oxygen demand) value of 4 mg / liter, and a water temperature of 12 ° C was used. → Ozone treatment → Filtration treatment with an ozone resistant membrane was sequentially performed, followed by activated carbon treatment at a later stage. As the ozone-resistant film, a PVDF (polyfluoridene fluoride) having a pore diameter of 0.1 / 111, an inner diameter of 0.7 sq.φ, and an outer diameter force of Si. 25πιηιφ was manufactured based on JP-A-3-215535. Hollow fiber microfiltration (MF) membrane was used. Based on WO 9710893, an external pressure type module was prepared in which 1,800 hollow fiber membranes were accommodated in a PVC (polyvinyl chloride) casing having a diameter of 3 inches. This module has a membrane area of 7.0 m 2 and a clear water permeation flux of 1.8 m per hour. At this time, the module filtration pressure was 0.5 kgf / cm 2 .
濾過はクロスフロー方式 （循環濾過方式） の一定透過流束濾過を行った。 上記原水 1に、 オゾン発生機 4から、 オゾン注入手段であるェゼクタ一 5を 介して、 オゾン化空気をオゾン量として毎時 2. 0 g〜3. O g注入した後、 ォ ゾン処理水タンク 6へ毎時 1. 5m3の量で供給した。 さらに、 オゾン処理水を タンク 6からポンプ 8を介して、 中空糸膜モジュール 9に毎時 2. 5m3の量で 供給し、 濾水を毎時 1. 5m3の流束で取り出すとともに、 膜を透過しないォゾ ン処理水を毎時 1 m3でオゾン処理水タンク 6に戻した。 この時の濾過水タンク 10中の濾過水中残留オゾン濃度は 0. 2 p pm〜0. 3 p pmであった。 活性 炭処理槽は LVが 25 OmZ日、 S Vが 1 O/H rになるよう設計したものを用 いた。 The filtration was carried out by a constant permeation flux filtration of a cross flow system (circulation filtration system). After injecting 2.0 g to 3.O g / hour of ozonized air into the raw water 1 from the ozone generator 4 through the ejector 15 as an ozone injection means as an ozone amount, the ozone treated water tank 6 1.5 m 3 / h. Further, the ozonated water from the tank 6 via the pump 8, is supplied in an amount per hour 2. 5 m 3 to the hollow fiber membrane module 9, it is taken out at a flux per hour 1. 5 m 3 drainage, through the membrane returning to ozonated water tank 6 in the non O zone emissions treated water per hour 1 m 3. At this time, the concentration of ozone remaining in the filtered water in the filtered water tank 10 was from 0.2 ppm to 0.3 ppm. The activated carbon treatment tank used was designed so that LV was 25 OmZ days and SV was 1 O / Hr.
オゾンの注入は、 膜モジュール入口圧力の初期設定値と実際の膜モジュール入 口圧力との差を演算処理して、 その信号をオゾン発生機 4にフィードバックし、 注入オゾン量を自動制御する方法で行った。 膜モジュール入口圧力の初期設定値 を 0. 80 k g/c m2、 その時の注入オゾン量を 2. O gに設定し、 膜モジュ ール入口圧力が 0. 05 k gZc m2上昇するごとに、 注入オゾン量を 0. 3 g ずつ増加させ、 膜モジュール入口圧力が初期設定値未満となる場合は、 オゾンの 注入を減少させて運転を続けた。 The injection of ozone is performed by calculating the difference between the initial setting value of the membrane module inlet pressure and the actual membrane module inlet pressure, feeding back the signal to the ozone generator 4, and automatically controlling the injected ozone amount. went. Membrane module inlet 0. 80 kg / cm 2 an initial setting value of the pressure, to set the injection amount of ozone at that time 2. O g, each time the membrane module inlet pressure 0. 05 k gZc m 2 rises, The injected ozone volume was increased by 0.3 g, and when the membrane module inlet pressure was less than the initial set value, the operation was continued with the ozone injection reduced.
運転条件は濾過を 10分行った後、 逆洗ポンプ 20により濾水を利用して逆流 洗浄を 1 5秒間行うという操作を繰り返し、 1 2時間毎に毎時 2 Nm 3の空気を モジュール下部から供給してエアーパブリングを 1 20秒間行った。 After operating conditions went 10 minutes filtered and the backwash pump 20 by utilizing a filtered water repeatedly an operation of performing backwashing 1 5 seconds, supplying 1 of every 2 hours per hour 2 Nm 3 air from the module lower Then, air publishing was performed for 120 seconds.
その結果、 濾過流束のレベルが初期値の毎時 1. 5m°で 2ヶ月間に亘つて維 持でき、 その間、 膜モジュール入口圧力上昇は無かった。 活性炭処理槽出の水の分析を行った結果、 COD (化学的酸素要求量） 値は 0. 4mgZL、 濁度は 0. 02度、 大腸菌、 一般細菌は検出されず、 その他の項目 も飲料水としての基準を十分に満たしていた。 As a result, the filtration flux level was maintained at the initial value of 1.5 m / h for 2 months, during which time there was no increase in the pressure at the inlet of the membrane module. As a result of analyzing the water from the activated carbon treatment tank, the COD (chemical oxygen demand) was 0.4 mg ZL, the turbidity was 0.02 °, Escherichia coli and general bacteria were not detected, and other items were drinking water. As well as meeting the criteria.
例 2 (比較例） Example 2 (Comparative example)
原水 1に、 オゾン化空気をオゾン量として毎時 2. 0 gの一定量を注入して、 添加オゾン量の制御を行わない以外は、 例 1と同じ条件でクロスフ口一方式 （循 環濾過方式） の一定透過流束濾過を行った。 この時の濾過水中の残留オゾン濃度 は 0. O p pm〜0. 3 p pmであった。  Except for injecting a fixed amount of 2.0 g of ozonized air per hour into raw water 1 with ozone amount and not controlling the amount of added ozone, the same conditions as in Example 1 except for the cross-floor opening method (circulating filtration method) ) Was performed. At this time, the residual ozone concentration in the filtered water was 0.3 to 0.3 ppm.
さらに、 例 1 と同様に、 濾過と逆洗洗浄操作を繰り返し、 エアーパブリングを 行った。 透過流束のレベルを初期値の毎時 1. 5 m3に維持させた結果、 2ヶ月 間で、 膜モジュール入口圧力が 0. 5KgZcm2上昇した。 Further, as in Example 1, filtration and backwashing and washing operations were repeated to perform air publishing. As a result of maintaining the permeation flux level at the initial value of 1.5 m 3 / h, the pressure at the inlet of the membrane module increased by 0.5 kg / cm 2 in two months.
例 3 (本発明） Example 3 (invention)
原水 1として、 濁度が 3〜4度、 COD (化学的酸素要求量） 値が 2mgZ リッ トル、 水温が 1 2°Cの河川表流水を用い、 図 3に示す装置を用いて、 原水→ オゾン処理→オゾン耐性膜による濾過処理を順次実施し、 さらに後段に活性炭処 理を行った。  As raw water 1, river surface water with turbidity of 3 to 4 degrees, COD (chemical oxygen demand) of 2 mgZ liter, and water temperature of 12 ° C was used. Ozone treatment → Filtration treatment with an ozone-resistant membrane was sequentially performed, followed by activated carbon treatment at a later stage.
濾過はクロスフロー方式 （循環濾過方式） の一定透過流束濾過を行った。  The filtration was carried out by a constant permeation flux filtration of a cross flow system (circulation filtration system).
上記原水 1を、 オゾン処理水タンク 6へ毎時 1. 5m3の量で供給するととも に、 オゾン処理水タンク 6から毎時 4. 5m3の原水をポンプ 7で抜き出し、 ォ ゾン発生機 4から、 ェゼクタ一 5を介して、 オゾン化空気をオゾン量として毎時 2. 0 g〜2. 4 g注入した。 さらに、 オゾン処理水をタンク 6からポンプ 8を 介して、 例 1で用いたのと同じ PVDF製中空糸膜モジュールに毎時 2. 5m3 の量で供給し、 濾水を毎時 1. 5m3の流束で取り出すとともに、 膜を透過しな いオゾン処理水を毎時 1 m 3でオゾン処理水タンク 6に戻した。 この時の濾過水 中の残留オゾン濃度は 0. 2 p pm〜0. 3 p p mであった。 活性炭処理槽は L Vが 25 OmZ日、 S Vが 1 O/H rになるよう設計したものを用いた。 The raw water 1, to together is supplied in an amount per hour 1. 5 m 3 to ozonated water tank 6, the raw water per hour 4. 5 m 3 from the ozone-treated water tank 6 withdrawn by a pump 7, the O Zon generator 4, Ozonated air was injected as an ozone amount of 2.0 g to 2.4 g / h through the ejector 15. Further, the ozonated water from the tank 6 via the pump 8, is supplied in an amount per hour 2. 5 m 3 in the same PVDF hollow fiber membrane module as used in Example 1, drainage and per hour 1. 5 m 3 is taken out by the flux, back film ozonated water tank 6 by not ozonated water per hour 1 m 3, such to transmit. At this time, the residual ozone concentration in the filtered water was 0.2 ppm to 0.3 ppm. The activated carbon treatment tank used was designed so that LV was 25 OmZ days and SV was 1 O / Hr.
注入オゾンの制御は、 例 1と同様に行った。  The control of the injected ozone was performed in the same manner as in Example 1.
運転条件は濾過を 10分行った後逆洗ポンプ 20により濾水を利用して逆流洗 浄を 1 5秒間行うという操作を繰り返し、 1 2時間毎に毎時 2 Nm3の空気をモ ジュール下部から供給してエアーバプリングを 1 20秒間行った。 逆流洗浄及び エア一バブリングの間は、 ポンプ 8は停止するとともに自動弁 1 1を閉じて、 原 水の供給を停止したが、 供給ポンプ、 オゾン発生機は常時稼働させ、 オゾンの注 入を続けた。 Operating conditions repeat an operation of using the drainage perform backflow washing 1 5 seconds by the backwash pump 20 after 10 minutes filtered, motor air per hour 2 Nm 3 per 2 hour Air supply was performed from the lower part of the joule for 120 seconds. During backwashing and air bubbling, the pump 8 was stopped and the automatic valve 11 was closed to stop the supply of raw water.However, the supply pump and ozone generator were always running, and the injection of ozone was continued. Was.
その結果、 透過流束のレベルが初期値の毎時 1. 5m"で 2ヶ月間に亘つて維 持でき、 その間、 膜モジュール入口圧力の上昇は無かった。  As a result, the permeation flux level was maintained at the initial value of 1.5 m / h for 2 months, and there was no increase in the membrane module inlet pressure during that time.
活性炭処理槽出の水の分析を行った結果、 COD (化学的酸素要求量） 値は 0. 4mg/L, 濁度は 0. 02度、 大腸菌、 一般細菌は検出されず、 その他の項目 も飲料水としての基準を十分に満たしていた。  As a result of analyzing the water from the activated carbon treatment tank, the COD (chemical oxygen demand) value was 0.4 mg / L, the turbidity was 0.02 degrees, Escherichia coli and general bacteria were not detected. The standard for drinking water was sufficiently satisfied.
例 4 (本発明） Example 4 (invention)
原水 1として濁度が 10度、 COD (化学的酸素要求量） 値が 1 3〜20mg Zリットル、 B O D (生物的酸素要求量） 値が 20〜30mgZリットル、 水温 が 25 °Cの下水二次処理水を用い、 図 4に示す装置を用いて原水→オゾン処理→ オゾン耐性膜による濾過処理を順次実施した。  Raw water 1 has a turbidity of 10 degrees, a COD (chemical oxygen demand) value of 13 to 20 mg Z liter, a BOD (biological oxygen demand) value of 20 to 30 mg Z liter, and a secondary sewage water temperature of 25 ° C. Using treated water, raw water → ozone treatment → filtration treatment with an ozone-resistant membrane was sequentially performed using the apparatus shown in Fig. 4.
濾過はクロスフロー方式 （循環濾過方式） の一定透過流束濾過を行った。  The filtration was carried out by a constant permeation flux filtration of a cross flow system (circulation filtration system).
上記原水 1に、 オゾン発生機 4から、 ェゼクタ一 5を介してオゾン化空気を オゾン量として毎時 10 g〜 1 1. 5 g注入した後、 オゾン処理水タンク 6へ毎 時 1. 0m の量で供給するとともに、 オゾン処理水タンク 6から毎時 4. 0 m 3の原水をポンプ 7で抜き出し、 原水 1の供給ラインで原水と混合した後、 ェ ゼクタ一 5を介してオゾンを注入した。 さらに、 オゾン処理水をオゾン処理水タ ンク 6からポンプ 8を介して、 例 1で用いたのと同じ PVDF製中空糸膜モジュ ールに毎時 2. 0m"の量で供給し、 濾水を毎時 1. Om3の流束で取り出すと ともに、 膜を透過しないオゾン処理水を毎時 1 m。でオゾン処理水タンク 6に戻 した。 この時の濾過水中の残留オゾン濃度は 0. 1〜0. 2 p pmであった。 オゾンの注入は、 平均膜間差圧の初期設定値と実際の平均膜間差圧との差を演 算処理して、 その信号をオゾン宪生機 4にフィードバックし、 注入オゾン量を自 動制御する方法で行った。 膜モジュール差圧の初期設定値を 0. 5 5 k g/ c m2, その時の注入オゾン量を 1 0. 0 gに設定し、 平均膜間差圧が 0. 05 k gZc m2上昇するごとに、 注入オゾン量を 0. 3 gずつ増加させ、 平均膜間 差圧が初期設定値未満となる場合は、 オゾンの注入を減少させて運転を続けた。 運転条件は濾過を 10分行った後、 毎時 2 Nm°の空気をモジュール下部から 供給してエアーパブリングを 60秒間行い、 逆洗ポンプ 20により濾水を利用し て逆流洗浄を 20秒間行うという操作を繰り返した。 逆流洗浄及びエアーバブリ ングの間は、 ポンプ 8は停止するとともに自動弁 1 1を閉じて、 原水の供給を停 止したが、 ポンプ 7、 オゾン発生機 4は常時稼働させ、 オゾンの注入を続けた。 この場合、 オゾン処理水タンク 6から毎時 5. Om の水をポンプ 7で抜き出し、 ェゼクタ一 5を介してォゾンを注入した。 After injecting 10 g to 11.5 g of ozone air per hour as ozone amount from the ozone generator 4 to the raw water 1 through the ejector 5 from the ozone generator 4, the amount of 1.0 m / hour into the ozonized water tank 6 in supplies, extracted raw water per hour 4. 0 m 3 from the ozone treated water tank 6 by the pump 7 and, after mixing with raw water in the raw water 1 supply line was injected ozone through the E injector one 5. Further, ozonated water was supplied from the ozonated water tank 6 via the pump 8 to the same PVDF hollow fiber membrane module used in Example 1 at an amount of 2.0 m / h, and the filtrate was filtered. hour 1. both the retrieved by flux Om 3, and returned to the ozone treated water tank 6 with ozone treated water that does not pass through the membrane per hour 1 m.. the residual ozone concentration in the filtered water at this time is 0.1 to 0 Injecting ozone, the difference between the initial set value of the average transmembrane pressure and the actual average transmembrane pressure was calculated, and the signal was fed back to the ozone generator 4. The initial setting of the membrane module differential pressure was set to 0.5 kg / cm 2 , and the amount of injected ozone was set to 10.0 g at that time. each time the differential pressure is increased 0. 05 k gZc m 2, the injection amount of ozone is increased by 0. 3 g, average transmembrane When the differential pressure was less than the initial set value, the operation was continued with the ozone injection reduced. The operating conditions are as follows: after filtration for 10 minutes, air at 2 Nm ° / h is supplied from the bottom of the module, air publishing is performed for 60 seconds, and backwashing is performed for 20 seconds using filtered water by the backwash pump 20. The operation was repeated. During backwashing and air bubbling, the pump 8 was stopped and the automatic valve 11 was closed to stop the supply of raw water.However, the pump 7 and the ozone generator 4 were constantly operated, and the injection of ozone was continued. . In this case, 5. Om of water per hour was withdrawn from the ozonized water tank 6 by the pump 7, and ozone was injected through the ejector 15.
その結果、 濾過流束のレベルが初期値の毎時 1. Om"で 2ヶ月間に亘つて維 持でき、 この間の平均膜間差圧上昇は無かった。  As a result, the filtration flux level was maintained at the initial value of 1. Om / hour for 2 months, and there was no increase in the average transmembrane pressure during this period.
得られた濾水の水質は、 濁度が 0. 05度、 COD値が 1 2mg/リッ トル、 800値が1 1118//リットルと修景用水、 親水用水として十分な水質であった。 例 5 (本発明） The resulting water drainage, the turbidity 0.05 degrees, COD value 1 2 mg / liter, 800 value was of sufficient quality 1 111 8 / / liter and landscaping water, as a hydrophilic water. Example 5 (invention)
原水 1として濁度が 10度、 COD (化学的酸素要求量） 値が 1 3〜20mg リットル、 BOD (生物的酸素要求量） 値が 20〜3 OmgZリッ トル、 水温 が 25 °Cの下水二次処理水を用い、 図 4に示す装置を用いて原水→オゾン処理→ オゾン耐性膜による濾過処理を順次実施した。  Raw water 1 has a turbidity of 10 degrees, a COD (chemical oxygen demand) value of 13 to 20 mg liter, a BOD (biological oxygen demand) value of 20 to 3 OmgZ liter, and a water temperature of 25 ° C. Using the next treated water, the raw water → ozone treatment → filtration treatment with an ozone resistant membrane was sequentially performed using the apparatus shown in Fig. 4.
濾過はクロスフロー方式 （循環濾過方式） の一定圧力濾過を行った。  Filtration was carried out by cross-flow (circulation filtration) constant-pressure filtration.
上記原水 1に、 オゾン発生機 4から、 ェゼクタ一 5を介してオゾン化空気を オゾン量として毎時 10 g〜 1 1. 5 g注入した後、 オゾン処理水タンク 6へ毎 時 1. Om3の量で供給するとともに、 オゾン処理水タンク 6から毎時 4. 0 m3の原水をポンプ 7で抜き出し、 原水 1の供給ラインで原水と混合した後、 ェ ゼクター 5を介してオゾンを注入した。 さらに、 オゾン処理水をオゾン処理水タ ンク 6からポンプ 8を介して、 例 1で用いたのと同じ PVDF製中空糸膜モジュ —ルに初期のモジュール入口圧力が 0. 9 K g/c m2になるように供給し、 モ ジュール濾水出口圧力を 0. 28 K gZc m2で濾水を取り出すとともに、 モジ ユール循環水出口の圧力を 0 · 04 KgZc m2にして循環水をオゾン処理水タ ンク 6に戻した。 この時の濾水量は毎時 1. Om で、 膜間差圧は 0. 55Kg cm2であった.. この時の濾過水中の残留オゾン濃度は 0. 1〜0. 3 p pm であった。 Into the water 1, the ozone generator 4, after the ozonized air per hour 10 g to 1 1. 5 g injected as amount of ozone through the Ezekuta one 5, the ozonated water tank 6 of the hourly 1. Om 3 It supplies an amount, extracting raw water from the ozone treated water tank 6 hour 4. 0 m 3 by the pump 7 and, after mixing with raw water in the raw water 1 supply line was injected ozone through the E Zekuta 5. Further, the ozonized water was supplied from the ozonated water tank 6 via the pump 8 to the same PVDF hollow fiber membrane module used in Example 1 at an initial module inlet pressure of 0.9 kg / cm 2. was supplied so as to, the module is taken out of the drainage in filtered water outlet pressure 0. 28 K gZc m 2, modular Yule pressure of the circulating water outlet in the 0 · 04 KgZc m 2 circulating water with ozone treated water Returned to tank 6. At this time, the amount of filtered water was 1. Om / hour, and the transmembrane pressure was 0.55 kgcm 2. The residual ozone concentration in the filtered water at this time was 0.1 to 0.3 ppm. Met.
オゾンの注入は、 膜透過流束の初期設定値と実際の膜透過流束との差を演算処 理して、 その信号をオゾン発生機 4にフィードバックし、 注入オゾン量を自動制 御する方法で行った。 膜透過流束の初期設定値を 1. 0m3/h r、 その時の注 入オゾン量を 1 0. 0 gに設定し、 膜透過流束が 0. 1 m3 h r低下するごと に、 注入オゾン量を 0. 3 gずつ増加させ、 膜透過流束が初期設定 を超える場 合は、 オゾンの注入を減少させて運転を続けた。 Injecting ozone is a method of calculating the difference between the initial value of the membrane permeation flux and the actual membrane permeation flux and feeding back the signal to the ozone generator 4 to automatically control the amount of ozone to be injected. I went in. Set the initial value of the membrane permeation flux to 1.0 m 3 / hr and the amount of injected ozone at that time to 10.0 g, and inject ozone every time the membrane permeation flux decreases by 0.1 m 3 hr. The amount was increased by 0.3 g, and if the permeation flux exceeded the initial setting, the operation was continued with the ozone injection reduced.
運転条件は濾過を 10分行った後、 毎時 2 Nm。の空気をモジュール下部から 供給してエアーバプリングを 60秒間行い、 逆洗ポンプ 20により濾水を利用し て逆流洗浄を 20秒間行うという操作を繰り返した。 逆流洗浄及びエアーバブリ ングの間は、 ポンプ 8は停止するとともに自動弁 1 1を閉じて、 原水の供給を停 止したが、 ポンプ 7、 オゾン発生機 4は常時稼働させ、 オゾンの注入を続けた。 この場合、 オゾン処理水タンク 6から毎時 5. Om3の水をポンプ 7で抜き出し、 ェゼクタ一 5を介してオゾンを注入した。 The operating conditions were 2 Nm / hour after 10 minutes of filtration. This operation was repeated by supplying air from the lower part of the module, performing air bubbling for 60 seconds, and performing backwashing using backwater by the backwashing pump 20 for 20 seconds. During backwashing and air bubbling, the pump 8 was stopped and the automatic valve 11 was closed to stop the supply of raw water.However, the pump 7 and the ozone generator 4 were constantly operated, and the injection of ozone was continued. . In this case, 5. Om 3 of water per hour was withdrawn from the ozonated water tank 6 by the pump 7 and ozone was injected through the ejector 15.
その結果、 膜モジュール入口圧力は、 0. 9Kg/cm2、 平均濾材間差圧は 0. 55Kg/cm2で、 初期のレベルを 2ヶ月に亘つて維持でき、 その間の透 過流束濾水量の低下は無かつた。 As a result, the membrane module inlet pressure, 0. 9Kg / cm 2, the average filter medium differential pressure is 0. 55 Kg / cm 2, the initial level of Wataru connexion can be maintained to 2 months, transparently flux drainage amount therebetween There was no decline.
得られた濾水の水質は、 濁度が 0. 05度、 〇00値が1 2m gZリットル、 BOD値が lmgノリツトルと修景用水、 親水用水として十分な水質であった。 例 6 (本発明）  The quality of the obtained drainage water was 0.05 ° C, the 〇00 value was 12 mgZ liter, the BOD value was lmg, and the water quality was sufficient for landscape water and hydrophilic water. Example 6 (invention)
原水 1 として濁度が 1 0度、 COD (化学的酸素要求量） 値が 1 2〜 1 5 mgZリッ トル、 BOD (生物的酸素要求量） 値が 20〜3 Omg/リッ トル、 水温が 25 °Cの下水二次処理水を用い、 図 5に示す装置を用いて、 原水→オゾン 処理—脱オゾン処理→膜による濾過処理を順次実施した。  Turbidity is 10 degrees as raw water 1, COD (chemical oxygen demand) value is 12 to 15 mgZ liter, BOD (biological oxygen demand) value is 20 to 3 Omg / liter, water temperature is 25 Raw water-> ozone treatment-de-ozone treatment-> filtration treatment using a membrane was sequentially performed using the secondary treatment water at ° C and the apparatus shown in Fig. 5.
膜として、 特開平 3— 42025号公報に基づいて作製した孔径 0. 1 μ m、 内径 0. 7画 φ、 外径 1. 25mm0の HDPE (高密度ポリエチレン） 製中空糸 状精密濾過 （MF) 膜を使用した。 この中空糸膜 1 800本を 3インチ径の PV C (ポリ塩化ビニル） ケーシングに納めた外圧型モジュールを作製した。 このモ ジュールは、 膜面積が 7. 0m2、 清澄水透過流束が毎時 1. 8 m 3の時、 モジ ユール濾過圧が 0. 5Kg f /c m2であった。 Hollow fiber microfiltration (MF) made of HDPE (high-density polyethylene) with a pore diameter of 0.1 μm, an inner diameter of 0.7 stroke φ, and an outer diameter of 1.25 mm0, prepared based on JP-A-3-42025 as a membrane A membrane was used. An external pressure type module was prepared in which 1800 hollow fiber membranes were housed in a 3 inch diameter PVC (polyvinyl chloride) casing. This module has a membrane area of 7.0 m 2 and a clear water permeation flux of 1.8 m 3 per hour. Yule filtration pressure was 0. 5Kg f / cm 2.
濾過はデッドエンド方式 （全量濾過方式） の一定透過流束濾過を行った。  Filtration was performed by a constant permeation flux filtration of a dead-end system (a total filtration system).
上記原水 1を、 オゾン処理水タンク 6へ、 毎時 0. 7 m3の量で供給するとと もに、 オゾン処理水タンク 6から毎時 4. 0 in3の原水をポンプ 7で抜き出し、 オゾン発生機 4から、 ェゼクタ一 5を介して、 オゾン化空気をオゾン量として毎 時 10 g〜l l. 5 g注入した。 さらに、 オゾン処理水をオゾン処理水タンク 6 からポンプ 8を介して、 上記 HDPE製中空糸膜モジュールに毎時 0. 7m3の 量で供給するに先だって、 チォ硫酸ナトリゥム水溶液を、 タンク 1 8からポンプ 1 7を介して、 スタティックミキサー 1 9で撹拌混合しながらチォ硫酸ナトリウ ム換算で毎時 7 g添加した。 濾水を毎時 0. 7m で取り出した。 この時の膜モ ジュール入口の残留オゾン濃度は 0 p pmであった。 The raw water 1, to the ozonated water tank 6, is supplied with monitor, the raw water from the ozonated water tank 6 hour 4. 0 in 3 withdrawn by the pump 7 in an amount per hour 0. 7 m 3, an ozone generator From 4, 10 g to 11 l / h of ozonized air were injected as an ozone amount via ejector 15. Further, the pump ozone treated water from the ozonated water tank 6 via the pump 8, prior to supply an amount per hour 0. 7m 3 to the hollow fiber membrane module manufactured by the HDPE, the Chio sulfate Natoriumu solution, from the tank 1 8 7 g was added per hour in terms of sodium thiosulfate while stirring and mixing with a static mixer 19 through 17. The drainage was drawn off at 0.7 m / h. At this time, the residual ozone concentration at the inlet of the membrane module was 0 ppm.
オゾンの注入は、 膜モジュール入口圧力の初期設定値と実際の膜モジュール入 口圧力との差を演算処理して、 その信号をオゾン発生機 4にフィードバックし、 注入ォゾン量を自動制御する方法で行つた。 膜モジュール入口圧力の初期設定値 を 0. 80 k gZc 、 その時の注入オゾン量を 1 0. O gに設定し、 膜モジ ユール入口圧力が 0. 05 k g/c m。上昇するごとに、 注入オゾン量を 0. 3 gずつ増加させ、 膜モジュール入口圧力が初期設定直未満となる場合は、 オゾン の注入を減少させて運転を続けた。  The injection of ozone is performed by calculating the difference between the initial setting value of the membrane module inlet pressure and the actual membrane module inlet pressure, feeding back the signal to the ozone generator 4, and automatically controlling the injection ozone amount. I went. The initial setting of the membrane module inlet pressure was set at 0.80 kgZc and the amount of injected ozone at that time was set at 10 Og, and the membrane module inlet pressure was 0.05 kg / cm. Each time it increased, the amount of injected ozone was increased by 0.3 g, and when the inlet pressure of the membrane module became less than the initial setting, the operation was continued with the injection of ozone decreased.
運転条件は濾過を 10分行った後、 毎時 2 Nm。の空気をモジュール下部から 供給してエアーパブリングを 60秒間行い、 逆洗ポンプ 20により濾水を利用し て逆流洗浄を 20秒間行うという操作を繰り返した。 逆流洗浄およびエアーバプ リングの間は、 ポンプ 8は停止するとともに自動弁 1 1を閉じて、 原水の供給を 停止したが、 ポンプ 7、 オゾン発生機 4は常時稼働させ、 オゾンの注入を続けた。 この時、 同時に、 チォ硫酸ナトリゥム水溶液を添加するポンプ 1 7も停止した。 その結果、 透過流束のレベルが初期値の毎時 1. 0 m。で 2ヶ月間に亘つて維 持でき、 その間の膜モジュール入口圧力上昇は無かった。  The operating conditions were 2 Nm / hour after 10 minutes of filtration. The operation of supplying air from the lower part of the module, performing air publishing for 60 seconds, and performing backwashing with the backwash pump 20 using drainage for 20 seconds was repeated. During backwashing and air coupling, the pump 8 was stopped and the automatic valve 11 was closed to stop the supply of raw water. However, the pump 7 and the ozone generator 4 were constantly operated, and the injection of ozone was continued. At this time, the pump 17 for adding the sodium thiosulfate aqueous solution was also stopped at the same time. As a result, the permeation flux level was 1.0 m / h, the initial value. For two months, during which time there was no increase in the membrane module inlet pressure.
得られた濾水の水質は、 濁度が 0. 05度、 COD (化学的酸素要求量） 値は SmgZリツトル、 8〇0値が1 1118/リットルと、 修景用水、 親水用水として 十分な水質であった。 例 7 (本発明） The quality of the obtained drainage water is 0.05 degree, turbidity is 0.05 mg, COD (chemical oxygen demand) value is SmgZ litre, and 8〇0 value is 1 111 8 / l, which is enough for landscape water and hydrophilic water The water quality was excellent. Example 7 (invention)
オゾンの注入を、 逆洗時の膜モジュール入口圧力の初期設定値と逆洗時の実 際の膜モジュール入口圧力との差を演算処理して、 その信号をオゾン発生機 4に フィードバックし、 注入オゾン量を自動制御する方法で行った以外は例 1と同じ 条件で行った。 逆洗時の膜モジュール入口圧力の初期設定値を 1. 60 k c m2, その時の注入オゾン量を 2. O gに設定し、 逆洗時の膜モジュール入口 圧力が 0. 0 7 k gZcm"上昇するごとに、 注入オゾン量を 0. 3 gずつ増加 させ、 逆洗時の膜モジュール入口圧力が初期設定値未満となる場合は、 オゾンの 注入を減少させて運転を続けた。 The ozone injection is calculated by calculating the difference between the initial set value of the membrane module inlet pressure during backwashing and the actual membrane module inlet pressure during backwash, and the signal is fed back to the ozone generator 4 for injection. The procedure was performed under the same conditions as in Example 1 except that the method was used to automatically control the amount of ozone. The initial setting of the membrane module inlet pressure during backwashing is set to 1.60 kcm 2 , and the amount of injected ozone at that time is set to 2. Og, and the membrane module inlet pressure during backwashing increases by 0.07 kgZcm ” Each time, the amount of injected ozone was increased by 0.3 g, and when the back pressure of the membrane module at the time of back washing was less than the initial set value, the operation was continued with the ozone injection reduced.
その結果、 濾過流束のレベルが初期値の毎時 1. 5m 3で 2ヶ月間に亘つて維 持でき、 その間、 膜モジュール入口圧力上昇は無かった。 As a result, the level of the filtration flux within 2 months per hour 1. 5 m 3 of the initial value can lifting Wataru connexion Wei, during which the membrane module inlet pressure rise was not.
活性炭処理槽出の水の分析を行った結果、 COD (化学的酸素要求量） 値は 0. 4mg//L, 濁度は 0. 0 2度、 大腸菌、 一般細菌は検出されず、 その他の項目 も飲料水としての基準を十分に満たしていた。 As a result of analyzing the water from the activated carbon treatment tank, the COD (chemical oxygen demand) value was 0.4 mg / L, the turbidity was 0.02 degrees, and E. coli and general bacteria were not detected. The items also fully satisfied the criteria for drinking water.
例 8 (本発明） Example 8 (invention)
オゾンの注入を、 逆洗時の平均膜間差圧の初期設定 と逆洗時の実際の平均膜 間差圧との差を演算処理して、 その信号をオゾン発生機 4にフィードバックし、 注入オゾン量を自動制御する方法で行つた以外は、 例 4と同じ条件でおこなった。 逆洗時の平均膜間差圧の初期設定値を 0. 5 5 k gZc m2、 その時の注入ォゾ ン量を 1 0. 0 gに設定し、 逆洗時の膜間平均差圧が 0. 05 k gノ c m2上昇 するごとに、 注入オゾン量を 0. 3 gずつ増加させ、 逆洗時の平均膜間差圧が初 期設定値未満となる場合は、 オゾンの注入を減少させて運転を続けた。 The injection of ozone is calculated by calculating the difference between the initial setting of the average transmembrane pressure difference during backwashing and the actual average transmembrane pressure difference during backwashing, and the signal is fed back to the ozone generator 4 for injection. The procedure was performed under the same conditions as in Example 4, except that the method was used to automatically control the amount of ozone. The initial setting value of the average transmembrane pressure during backwashing 0. 5 5 k gZc m 2, to set the injection O zone down amount at that time to 1 0. 0 g, the film between the average pressure difference at the time of backwashing 0. every time 05 kg Roh cm 2 rises, if the injection amount of ozone is increased by 0. 3 g, an average transmembrane pressure during backwashing is less than the initial set value, reduce the injection of ozone And continued driving.
その結果、 濾過流束のレベルが初期値の毎時 1. 0 m3で 2ヶ月間に亘つて維 持でき、 この間の平均膜間差圧上昇は無かった。 As a result, the filtration flux level was maintained at the initial value of 1.0 m 3 / h for 2 months, and there was no increase in the average transmembrane pressure during this period.
得られた濾水の水質は、 濁度が 0. 05度、 COD値が 1 2mgZリットル、 BOD値が lmgZリツトルと修景用水、 親水用水として十分な水質であった。 例 9 (本発明）  The water quality of the obtained drainage water was 0.05 ° C, the COD value was 12 mgZ liter, the BOD value was 1 mgZ liter, and the water quality was sufficient for landscape water and hydrophilic water. Example 9 (invention)
オゾンの注入を、 逆洗時の膜透過流束の初期設定値と逆洗時の実際の膜透過流 束との差を演算処理して、 その信号をオゾン発生機 4にフィードバックし、 注入 オゾン量を自動制御する方法で行つた以外は例 5と同じ条件で行つた。 逆洗時の 膜透過流束の初期設定 を 1. 5 m 3 h r、 その時の注入オゾン量を 1 0. 0 g に設定し、 逆洗時の膜透過流束が 0. lm3/h r低下するごとに、 注入オゾン 量を 0. 3 gずつ増加させ、 逆洗時の膜透過流束が初期設定値を超える場合は、 オゾンの注入を減少させて運転を続けた。 The ozone injection is calculated by calculating the difference between the initial set value of the membrane permeation flux during backwashing and the actual membrane permeation flux during backwashing, and the signal is fed back to the ozone generator 4 for injection. The procedure was carried out under the same conditions as in Example 5, except that the method was used to automatically control the amount of ozone. The initial setting of the membrane permeation flux during backwashing 1. 5 m 3 hr, to set the injection amount of ozone when its 1 0. 0 g, membrane permeation flux during backwashing 0. lm 3 / hr reduced Each time, the amount of injected ozone was increased by 0.3 g, and when the membrane permeation flux during backwash exceeded the initial set value, the operation was continued with the injection of ozone decreased.
その結果、 膜モジュール入口圧力は、 0. 9KgZcm2、 平均膜間差圧は、 0. 55KgZcn^で、 初期のレベルを 2ヶ月に亘つて維持でき、 その間の膜 透過流束濾水量の低下は無かつた。 As a result, the inlet pressure of the membrane module was 0.9 kg / cm 2 , the average transmembrane pressure was 0.55 kg / cm 2 , and the initial level could be maintained for 2 months. Nothing.
得られた濾水の水質は、 濁度が 0. 05度、 COD値が 1 2rag/リットル、 BOD値が 1 mgZリットルと修景用水、 親水用水として十分な水質であった。 産業上の利用の可能性  The water quality of the obtained drainage water was 0.05 degree, the COD value was 12 rag / liter, and the BOD value was 1 mgZ liter, which was sufficient for landscape water and hydrophilic water. Industrial applicability
本発明は、 オゾンを用いて浄水の高度処理や下排水高度処理を行うにあたり、 原水の性状、 有機物の種類や含有量に左右されずに充分な処理水質と濾過流束が 得られる濾過方法を提供することができる。  The present invention relates to a filtration method capable of obtaining a sufficient treated water quality and a filtration flux without depending on the properties of raw water, the type and content of organic matter, in performing advanced treatment of purified water and advanced treatment of sewage using ozone. Can be provided.
また、 11莫濾過の前段で原水にオゾンを添加する際に、 濾過状況をモニターしな がら注入オゾン量を制御することができるので、 少ないオゾン添加量で、 高い濾 過流束を維持することができる。 モニターした値をフィードバックし、 添加する オゾン量を調節する工程を自動制御として、 長期間安定した濾過を提供すること が可能である。  In addition, when ozone is added to raw water at the stage prior to 11 megafiltration, the amount of ozone injected can be controlled while monitoring the filtration status.Therefore, it is necessary to maintain a high filtration flux with a small amount of ozone added. Can be. It is possible to provide long-term stable filtration by feeding back the monitored value and automatically controlling the process of adjusting the amount of ozone to be added.
さらに本発明は、 制御のための特殊な測定器を必要としない、 実用的で経済的 な濾過方法を提供することができる。  Further, the present invention can provide a practical and economical filtration method that does not require a special measuring device for control.

Claims

請求の範囲 The scope of the claims
1 . オゾンを添加した水の膜濾過方法において、 濾過時又は逆洗時の、 透過流 束、 膜モジュール入口圧力又は平均膜間差圧の値に基づいて、 原水に注入するォ ゾン量を制御することを含む上記方法。 1. In the membrane filtration method of water to which ozone has been added, the amount of ozone to be injected into raw water is controlled based on the value of permeation flux, membrane module inlet pressure or average transmembrane pressure during filtration or backwashing. The above method comprising:
2 . 一定圧力濾過において、 濾過又は逆洗時の、 透過流束の値に基づいて、 注 入するオゾン量を制御する請求項 1記載の濾過方法。  2. The filtration method according to claim 1, wherein in the constant pressure filtration, the amount of ozone to be injected is controlled based on a value of a permeation flux at the time of filtration or backwashing.
3 . 一定透過流束濾過において、 濾過又は逆洗時の、 膜モジュール入口圧力の 値に基づいて、 注入するオゾン量を制御する請求項 1記載の濾過方法。  3. The filtration method according to claim 1, wherein the amount of ozone to be injected is controlled based on the value of the pressure at the inlet of the membrane module at the time of filtration or backwashing in constant permeate flux filtration.
4 . 一定透過流束濾過において、 濾過又は逆洗時の、 平均膜間差圧の値に基づ いて、 注入するオゾン量を制御する請求項 1記載の濾過方法。  4. The filtration method according to claim 1, wherein the amount of ozone to be injected is controlled based on the value of the average transmembrane pressure at the time of filtration or back washing in constant permeate flux filtration.
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JP2007021408A (en) * 2005-07-19 2007-02-01 Mitsubishi Rayon Eng Co Ltd Water treatment device and method
WO2010110065A1 (en) * 2009-03-27 2010-09-30 メタウォーター株式会社 Process for producing regenerated water and system for producing regenerated water
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JP2005230730A (en) * 2004-02-20 2005-09-02 Kurita Water Ind Ltd Water treatment method and water treatment apparatus
JP2007021408A (en) * 2005-07-19 2007-02-01 Mitsubishi Rayon Eng Co Ltd Water treatment device and method
US8158405B2 (en) 2008-06-30 2012-04-17 General Electric Company Process for concentrating and processing fluid samples
US8546127B2 (en) 2008-06-30 2013-10-01 General Electric Company Bacteria/RNA extraction device
WO2010110065A1 (en) * 2009-03-27 2010-09-30 メタウォーター株式会社 Process for producing regenerated water and system for producing regenerated water
JP2015024409A (en) * 2009-03-27 2015-02-05 メタウォーター株式会社 Reclaimed water production method and reclaimed water production system
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AT516359A1 (en) * 2014-10-01 2016-04-15 Deltacore Gmbh Device for filtering water with a filter arrangement
EP3201139A1 (en) * 2014-10-01 2017-08-09 Deltacore GmbH Device and method for filtering water
AT516359B1 (en) * 2014-10-01 2021-06-15 Deltacore Gmbh Device for the filtration of water with a filter arrangement
EP3201139B1 (en) * 2014-10-01 2023-04-12 Deltacore GmbH Device and method for filtering water

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