WO2013145373A1 - Water treatment method - Google Patents

Water treatment method Download PDF

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Publication number
WO2013145373A1
WO2013145373A1 PCT/JP2012/073194 JP2012073194W WO2013145373A1 WO 2013145373 A1 WO2013145373 A1 WO 2013145373A1 JP 2012073194 W JP2012073194 W JP 2012073194W WO 2013145373 A1 WO2013145373 A1 WO 2013145373A1
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Prior art keywords
filter
calcium
solid
water treatment
water
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PCT/JP2012/073194
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French (fr)
Japanese (ja)
Inventor
深谷　太郎
厚 山崎
剣治 堤
伊知郎 山梨
河野　龍興
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株式会社 東芝
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Publication of WO2013145373A1 publication Critical patent/WO2013145373A1/en

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    • 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
    • C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
    • C02F1/5236—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using inorganic agents
    • C02F1/5245—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using inorganic agents using basic salts, e.g. of aluminium and iron
    • 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
    • C02F1/48—Treatment of water, waste water, or sewage with magnetic or electric fields
    • C02F1/488—Treatment of water, waste water, or sewage with magnetic or electric fields for separation of magnetic materials, e.g. magnetic flocculation
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00—Nature of the contaminant
    • C02F2101/10—Inorganic compounds
    • C02F2101/12—Halogens or halogen-containing compounds
    • C02F2101/14—Fluorine or fluorine-containing compounds

Definitions

  • Embodiments of the present invention relate to a water treatment method.
  • fluoride ions contained in the waste water are reacted with calcium carbonate to form calcium fluoride on the surface thereof, and the calcium fluoride is precipitated by scraping the calcium fluoride. This is a technique for removing fluoride ions.
  • An object of the embodiment is to provide a water treatment method capable of quickly removing fluoride ions in water and easily removing the generated fluorine compound.
  • the calcium-containing inorganic solid is brought into contact with water containing fluoride ions to precipitate calcium fluoride, and the precipitated calcium fluoride and the calcium-containing inorganic solid are separated by a solid-liquid separation device equipped with a filter.
  • B In the water treatment method in which solid-liquid separation is performed, B ⁇ 50 ⁇ m, and 0.2 ⁇ B /, where A is the mode of pore diameter of the filter and B is the volume-converted average particle diameter of the calcium-containing inorganic solid.
  • a water treatment method characterized by A ⁇ 10 can be provided.
  • FIG. 1 is a configuration block diagram showing a water treatment apparatus according to the first embodiment.
  • FIG. 2 is a configuration block diagram showing a water treatment apparatus according to the second embodiment.
  • FIG. 3 is a configuration block diagram showing a water treatment apparatus according to the third embodiment.
  • FIG. 4 is a configuration block diagram showing a water treatment device according to the fourth embodiment.
  • FIG. 5 is a characteristic diagram showing the relationship between the pore diameter and the pore volume by the filter in the water treatment apparatus according to the second embodiment.
  • FIG. 6 is a characteristic diagram showing the relationship between the pore diameter and the pore volume between calcium carbide particles in the water treatment apparatus according to the second embodiment.
  • the calcium-containing inorganic solid according to the embodiment may contain calcium and be insoluble in water. Insoluble in water means that the solubility in water is 10 g or less (25 ° C.) per 1000 ml.
  • the calcium-containing inorganic solid may be natural ore or a single purified one.
  • Natural ores include, for example, aragonite, urexite, melilite, onfasite, uvalite, scheelite, velovskite, hedenburgite, zoisite, fisheye stone, dolomite, creedite, peamontite, spar stone, dihydrate gypsum, titanite , Charoite, anorthite, diopside, ash iron pyroxene, johansen pyroxene, tremolite, rhodonite, pigeon pyroxene, horn blend, augite, becrotite, vesuvianite, fake stone, calcite, meteorite, montmorillonite, actinolite, epidote, clinozoite, Apatite is mentioned.
  • calcium carbonate for example, calcium carbonate, calcium sulfite, calcium hydroxide, calcium sulfate, calcium titanate, and calcium tungstate can be mentioned.
  • calcium carbonate having a low solubility in water and ore eg, aragonite, dolomite
  • the substance which does not have a hydrate or a hydroxyl group is preferable. This is because a substance having a hydrate or a hydroxyl group is softer than other substances and may clog the pores of the filter.
  • the above particles are finely crushed using an arbitrary pulverizer and classified to produce a calcium-containing inorganic solid having a predetermined particle size.
  • the pulverization method include a ball mill, a Henschel mixer, and a roll.
  • the average particle diameter is calculated based on the result measured by the laser diffraction method.
  • a trade name: SALD-DS21 type measuring device manufactured by Shimadzu Corporation can be used as an apparatus using a laser diffraction method.
  • an average particle diameter is a volume conversion average particle diameter.
  • the average particle diameter B thus determined is set to 50 ⁇ m or less, and B / A is 0 with respect to the mode value (peak value where the frequency is greatest in the distribution map) A of the filter pore diameter described later.
  • the present applicant has experimentally confirmed that the precipitated diameter of calcium fluoride deposited on the surface of the calcium-containing inorganic solid is approximately 0.1 to 2 ⁇ m. That is, even when this calcium fluoride remains deposited on the surface of the calcium-containing inorganic solid or peels off and separates into calcium fluoride and the calcium-containing inorganic solid, it is easy to separate into solid and liquid with a filter having a specific pore size. Thus, the particle size of the calcium-containing inorganic solid is limited. That is, by filtering calcium fluoride together with this calcium-containing inorganic solid, calcium fluoride is trapped in the gaps between the calcium-containing inorganic solids, and fluorine can be removed.
  • the material of the filter in the present embodiment is not particularly limited, and examples thereof include a filter cloth, a metal mesh, a porous ceramic, and a porous polymer.
  • a filter cloth is preferable, for example, a material such as polypropylene, nylon, polyester, and knitted with double weave, twill weave, plain weave, satin weave, or the like is used.
  • MF membrane microfiltration membrane
  • the inorganic solid when using a pseudo membrane in which an inorganic solid is laminated on the filter described later, the inorganic solid is pressure-bonded to the filter by water pressure at the time of lamination, causing a partial elastic deformation, and the distance from the adjacent particles is reduced. This is because the performance is improved because the pore size is reduced.
  • the pore diameter of the filter may be known in advance, such as a metal mesh sieve, but if not known, it is measured by a mercury intrusion method.
  • This mercury pressure method uses the high surface tension of mercury to apply pressure to cause mercury to penetrate into the pores of the powder, and obtains the specific surface area and pore distribution from the pressure and the amount of mercury that is injected. It is.
  • the pore diameter of the filter can be determined using, for example, an automatic porosimeter autopore IV9500 series manufactured by Shimadzu Corporation. At this time, the mode diameter is used as the hole diameter of the filter cloth.
  • the horizontal axis is a pore diameter and the vertical axis is a plot of a differential value of the amount of accumulated mercury that is press-fitted
  • the peak pore diameter of the pore size distribution is defined as a mode diameter (mode value) A.
  • inorganic filters insoluble in water may be laminated on the filter to form a pseudo filter, and calcium fluoride and calcium-containing inorganic solid may be solid-liquid separated with this pseudo filter.
  • the pore diameter between the particles corresponds to the pore diameter of the pseudo filter, and can be determined using, for example, an automatic porosimeter autopore IV9500 series manufactured by Shimadzu Corporation.
  • the pore distribution obtained at this time can be defined as the pore diameter between particles.
  • two peaks of a porous pore diameter and a pore diameter between particles are obtained. In this case, a peak having a large pore diameter can be defined as a pore diameter between particles.
  • the representative pore diameter C of the pseudo filter is a mode value as in the filter.
  • the inorganic solid is preferably a magnetic material. This is because the magnetic substance can be reused by removing only the magnetic substance from the mixed slurry of the magnetic substance, calcium fluoride, and calcium-containing inorganic solid by magnetic separation.
  • Ferromagnetic materials can be generally used as magnetic materials, such as iron, iron-based alloys, magnetite (magnetite), titanite (ilmenite), pyrrhotite (pilotite), magnesia ferrite, manganese magnesium ferrite, manganese zinc. Ferrite, cobalt ferrite, nickel ferrite, nickel zinc ferrite, barium ferrite, copper zinc ferrite and the like can be used.
  • Magnetite Fe 3 O 4
  • magnetite Fe 3 O 4
  • a resin may be coated or a surface treatment may be performed with a silane coupling agent. Particularly preferred is to perform a resin or modification with a low surface tension.
  • a silicone resin or a fluororesin can be used as the resin.
  • Silicone resin is a polymer compound made of organopolysiloxane, and there are two types, one-pack type and two-pack type. For example, there are KE series and KR series which are products of Shin-Etsu Chemical Co., Ltd.
  • the fluororesin is a general term for polymers containing fluorine in the resin.
  • polytetrafluoroethylene PTFE
  • tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer PFA
  • tetrafluoroethylene-hexafluoropropylene copolymer tetrafluoroethylene-hexafluoropropylene copolymer.
  • FEP tetrafluoroethylene-ethylene copolymer
  • ETFE polyvinylidene fluoride
  • ECTFE chlorotrifluoroethylene-ethylene copolymer
  • PCTFE polychlorotrifluoroethylene
  • PVF polyvinyl fluoride Rides
  • a resin obtained by copolymerizing these resins with an epoxy resin, polyimide, polyamide or the like is used to improve the adhesion with the magnetic particles. By using these resins, it is easy to separate the magnetic substance and the solid substance, and the reproduction of the magnetic substance is facilitated.
  • this calcium-containing inorganic solid is obtained by classifying a mixed slurry of calcium fluoride and calcium-containing inorganic solid in which calcium ion-containing inorganic solid is mixed with wastewater containing fluoride ions, and a slurry containing relatively large particles and small particles
  • the slurry may be divided into slurries containing a large amount of particles, and a slurry containing large particles may be laminated on the filter to form a pseudo filter.
  • the method of classifying the mixed slurry can be performed using, for example, gravity or centrifugal force.
  • gravity the slurry is introduced into a settling tank, and after a certain settling time, the slurry containing large particles and the slurry containing small particles are pulled out from the upper part and the lower part, respectively.
  • a slurry can be made.
  • centrifugal force a cyclone can be used, the slurry introduced into the cyclone is classified by centrifugal force, and large particles are classified from the lower part of the cyclone, and small particles are classified from the upper part of the cyclone. Slurries having different particle sizes can be made.
  • the solid-liquid separation device may have an arbitrary structure, but it is preferable to use a filter in which the filter is parallel to the ground and the water flow is performed in a downward flow. At this time, the water flow direction is perpendicular to the ground, that is, the same direction as gravity, and it is easy to maintain the shape of the pseudo filter laminated on the filter.
  • the water treatment method using magnetic particles for water treatment includes a first method of solid-liquid separation with a filter after mixing calcium-containing solids with wastewater containing fluoride ions, containing calcium
  • the second method of solid-liquid separation with a pseudo filter in which solids are laminated the third method of separating a slurry having large particles from the mixture, and the solid-liquid separation with a pseudo filter in which the solids are laminated, and the pseudo in which magnetic materials are laminated
  • a fourth method in which solid-liquid separation is performed with a filter, and the magnetic material is regenerated and reused.
  • FIG. 1 shows a first water treatment device.
  • the water treatment apparatus 1 is a first water treatment apparatus that mixes calcium-containing inorganic solids containing calcium with wastewater containing fluoride ions, and then performs solid-liquid separation with a filter.
  • the water treatment apparatus 1 has a calcium-containing inorganic solid storage tank (hereinafter referred to as a storage tank) 2, a mixing tank 3, a solid-liquid separation apparatus 4, a raw water supply source and a drainage storage tank (not shown), and these devices. And the apparatus are connected to each other by a plurality of piping lines.
  • the storage tank 2 has a stirring screw 7a inside, supplies calcium-containing inorganic solids from a calcium-containing inorganic solid supply port (not shown), and supplies tap water from a tap-water supply port (not shown).
  • the slurry solution is stored. Further, depending on the state of the raw water, a chemical solution can be injected from a pH adjusting solution tank (not shown) to adjust the pH.
  • As the pH adjusting liquid hydrochloric acid, sulfuric acid, sodium hydroxide or the like is used.
  • the mixing tank 3 has a stirring screw 7b that stirs the water to be treated, and wastewater that becomes the water to be treated is introduced from a raw water supply source (not shown) via the piping line 6c, and temporarily stores the water to be treated. It is supposed to leave.
  • the water to be treated is mixed with the calcium-containing inorganic solid supplied from the piping line 6a, reacts with fluoride ions contained in the water to be treated to generate calcium fluoride, and calcium fluoride and the calcium-containing inorganic solid.
  • a mixed slurry is prepared.
  • a detection signal is input to the input unit of the controller (not shown) from the measuring instrument and sensor described above, and control signals are output from the output unit of the controller to the pumps 5a and 5b, respectively, so that their operations are controlled. Yes.
  • the entire water treatment apparatus 1 is comprehensively controlled by a controller (not shown).
  • the solid-liquid separator 4 has a filter 8 inside and is divided into upper and lower spaces. In the space above the solid-liquid separator 4, the mixed slurry is sent from the pump 5 b and the piping line 6 b and is separated into solid and liquid by the filter 8.
  • the mode A of the pore diameter of the filter 8 is 1 ⁇ m or less, and can be suitably used when the relationship with the average particle diameter B of the calcium-containing inorganic solid is 2 ⁇ B / A.
  • the calcium-containing inorganic solid is not particularly limited and may be appropriately selected.
  • the filter 8 should be fine, and for example, an MF film may be used.
  • the liquid subjected to the solid-liquid separation is discharged from the space below the solid-liquid separation device 4 through the piping line 6d and sent to a treated water storage tank (not shown). Moreover, wash water is sent to the upper part through a pipe line 6e from a backwash water tank (not shown), and concentrated water of calcium fluoride and calcium-containing inorganic solid is discharged from the pipe line 6f.
  • the water to be treated and the calcium-containing inorganic solid are mixed in the mixing tank 3, and fluoride ions in water are taken into the surface of the calcium-containing inorganic solid particles to precipitate calcium fluoride on the surface.
  • the addition amount of the calcium-containing inorganic solid particles is not particularly limited, but it is necessary to add at least 1/2 of the number of moles of fluoride ions in water, and it is preferable to add at least the same number as the number of moles of fluoride ions.
  • the slurry containing calcium fluoride and calcium-containing inorganic solid is transferred to the solid-liquid separator 4.
  • the filter 8 satisfying 0.2 ⁇ B / A ⁇ 10 is assumed, where A is the mode of pore diameter of the filter 8 and B is the average particle diameter in terms of volume of the calcium-containing inorganic solid. It is set in advance and the slurry is filtered. At this time, if the filter 8 is level with the ground, fluoride ions and calcium-containing inorganic solids are laminated on the filter.
  • B / A is set to 0.2 ⁇ B / A ⁇ 10
  • the generated calcium fluoride can be suitably laminated with the calcium-containing inorganic solid.
  • the liquid obtained by solid-liquid separation by the solid-liquid separation device 4 is discharged from the lower part of the solid-liquid separation device 4 and sent to a treated water tank (not shown).
  • backwash water is passed from the upper side of the solid-liquid separator 4 to remove the calcium fluoride and calcium-containing inorganic solid deposited on the filter 8 to regenerate the filter 8.
  • the backwash water may be tap water, but may be supplied from a treated water tank (not shown).
  • the 2nd water treatment apparatus 1A is demonstrated with reference to FIG. However, the same members as those in FIG. A valve 11 is interposed in the pipe 6a on the downstream side of the pump 5a.
  • the piping line 6b on the downstream side of the pump 5b and the valve 11 are connected by a piping line 6g.
  • the second water treatment apparatus 1 ⁇ / b> A has piping lines 6 a and 6 g sent from the storage tank 2 connected to the mixing tank 3 and the solid-liquid separation apparatus 4, respectively.
  • the pipe lines 6a and 6g are respectively used in a process of obtaining calcium fluoride by reacting with fluoride ions in the mixing tank 3, and a process of obtaining a precoat layer (pseudo filter) by laminating calcium-containing inorganic solids on the filter 8. used.
  • the valve 11 is switched and the calcium-containing inorganic solid is removed via the piping lines 6g and 6b.
  • the contained slurry is supplied to the solid-liquid separator 4, and a precoat layer made of the slurry containing calcium-containing inorganic solid is formed on the filter 8.
  • the thickness of the precoat layer at this time is not particularly limited as long as no pressure loss is applied, but is specifically about 0.5 to 10 mm.
  • the pore diameter C between the particles of the calcium-containing inorganic solid is C ⁇ A and 0.2 ⁇ B / C ⁇ 10 (provided that B: calcium-containing inorganic solid).
  • the 3rd water treatment apparatus 1B is demonstrated with reference to FIG. However, the same members as those in FIG. Reference numeral 12 in the figure denotes a cyclone (centrifuge).
  • the side near the bottom of the mixing tank 3 and the side near the top of the cyclone 12 are connected by a piping line 6h with a pump 5b interposed.
  • a lower pot 13 for temporarily storing particles having a large particle diameter is disposed below the cyclone 12.
  • a large particle-containing slurry storage tank 15 is connected to the lower portion of the lower pot 13 through a piping line 6 i with a valve 14 interposed.
  • the storage tank 15 includes a stirring screw 7c. Waste water containing particles having a large particle diameter is sent from the cyclone 12 to the large particle-containing slurry reservoir 16 through the piping line 6i.
  • the small particle containing slurry storage tank 16 is connected to the upper part of the cyclone 12 via the piping line 6j.
  • the storage tank 16 includes a stirring screw 7d.
  • the side near the bottom of the large particle-containing storage tank 15 and the upper part of the solid-liquid separator 4 are connected by a piping line 6k with a pump 5c interposed.
  • the side near the bottom of the small particle-containing slurry storage tank 16 and the piping line 6k on the downstream side of the pump 5c are connected to a piping line 61 having a pump 5d interposed therebetween.
  • the third water treatment device 1B first, water is passed from the large particle size-containing slurry storage tank 15 to the solid-liquid separation device 3, and the large particle size is laminated on the filter 8 to form a precoat layer (not shown). To do. Thereafter, a slurry having small particle diameters is passed through the precoat layer (pseudo filter) for water treatment.
  • the 4th water treatment apparatus 1C is demonstrated with reference to FIG. However, the same members as those in FIG.
  • a separation tank 21 is connected to the upper side of the solid-liquid separator 4 via a piping line 6f.
  • the separation tank 21 is provided with a cylindrical portion 23 containing a permanent magnet 22 and a stirring screw 7e.
  • the permanent magnet 22 is driven up and down by an air cylinder (not shown) so that the magnetic field inside the separation tank 21 can be turned ON / OFF.
  • the side near the bottom of the separation tank 21 and the side near the bottom of the magnetic substance storage tank 24 provided with the stirring screw 7f are connected via a piping line 6m with a pump 5e interposed therebetween.
  • the piping line 6b on the downstream side of the pump 5b and the magnetic substance storage tank 24 are connected by a piping line 6n interposed with a pump 5f.
  • the operation of the water treatment apparatus 1C having such a configuration is as follows. First, before passing the mixed slurry of calcium fluoride and calcium-containing inorganic solid through the solid-liquid separator 4, a precoat layer (pseudo filter) in which a magnetic material is laminated on the filter 8 of the solid-liquid separator 4 is formed. . Next, the mixed slurry is passed through the solid-liquid separator 4 to perform solid-liquid separation, and the treated water is discharged through the piping line 6d. Subsequently, backwash water is supplied from the piping line 6e, and the magnetic substance and inorganic solid deposited on the filter 8 are washed away and transferred to the separation tank 21 from the piping line 6f.
  • the mixture of the magnetic substance and the inorganic solid transferred to the separation tank 21 is mixed by the stirring screw 7e, and the magnetic substance and the inorganic solid are separated.
  • the air cylinder is driven, the permanent magnet 22 is put into the cylindrical portion 23 to turn on the magnetic field, and only the magnetic material is recovered on the outer periphery of the cylindrical portion 23.
  • the inorganic solid separated from the piping line 6o is discharged, and the cleaning of the magnetic material is completed.
  • the air cylinder while supplying tap water from a tap water supply port (not shown) to the separation tank 21, the air cylinder is driven to pull out the permanent magnet 22 to the outside of the cylindrical portion 23, thereby turning off the magnetic field.
  • the magnetic material recovered in the cylindrical portion 23 is mixed with the supplied tap water to form a slurry, which is sent to the magnetic material storage tank 24 through the piping line 6m and reused.
  • Example 1 A water treatment test was conducted using the water treatment apparatus of FIG. As simulated waste water, water containing 1000 mg / L hydrofluoric acid was prepared. As the filter 8, a microfiltration (MF) membrane made of cellulose acetate was used, and as the calcium-containing inorganic solid, powder obtained by pulverizing calcite with a ball mill and selecting with a wind force was used. The pore size of the MF membrane was 1 ⁇ m (catalog value), and the ratio (B / A) of the volume-converted average particle size B of the calcium-containing inorganic solid to the mode value of the pore size of the filter 8 was 10.
  • MF microfiltration
  • Example 2 A water treatment test was conducted using the water treatment apparatus of FIG. As simulated waste water, water containing 1000 mg / L hydrofluoric acid was prepared. In addition, a filter cloth made of polypropylene was prepared for the filter, and pore distribution measurement was performed using a trade name: Autopore 9520 (pore distribution measuring device) manufactured by Shimadzu Corporation. As a result, a pore distribution as shown in FIG. 5 was obtained. It was. From this result, it was found that the pore diameter A of the filter 8 was 6.4 ⁇ m (mode). Further, as a calcium-containing inorganic solid, a calcium carbonate reagent manufactured by Wako Pure Chemical Industries, Ltd.
  • the pore size between the calcium carbonate particles was measured using a trade name: Autopore 9520 (pore distribution measuring device) manufactured by Shimadzu Corporation, and the result of FIG. 6 was obtained. From this result, it was confirmed that the pore diameter C between the particles was 1.37 ⁇ m. That is, C ⁇ A, and the ratio of the average particle diameter B to the pore diameter C between the particles (B / C) was 3.9.
  • the simulated waste water and calcium carbonate having the same mole equivalent as the fluoride ions in the simulated waste water were added and stirred for 10 minutes.
  • the pH in the mixing tank rose to 7.3.
  • the valve 11 was operated, and water containing calcium carbonate was passed through the solid-liquid separator 4 and laminated on the filter to prepare a precoat layer (pseudo filter) having a thickness of about 1 mm.
  • the treatment liquid whose fluorine concentration is reduced to 7 mg / L from the piping line 6d.
  • Example 3 Using the same calcium-containing inorganic solid and filter as in Example 2, the test was conducted with the water treatment apparatus of FIG.
  • the simulated waste water and calcium carbonate having the same mole equivalent as the fluoride ions in the simulated waste water were added to the mixing tank 3 and stirred for 10 minutes, the pH in the mixing tank rose to 7.3.
  • the liquid mixture in the mixing tank is passed through the cyclone 12 using the pump 5b, and the slurry having different average particle diameters is supplied to the large particle-containing slurry storage tank 15 and the small particle-containing slurry storage tank 16, respectively. did.
  • the pore diameter between the particles of the large particle-containing slurry reservoir 15 was examined, it was 4.0 ⁇ m and C ⁇ A.
  • the average particle size of the small particles was 0.8 ⁇ m, and B / C was 0.2. Thereafter, the particles in the large particle-containing slurry storage tank 15 were supplied to the solid-liquid separator 4 and laminated to form a precoat layer (pseudo filter). When the small particle-containing slurry was subjected to solid-liquid separation with this precoat layer, a treatment liquid having a fluorine concentration reduced to 7 mg / L was obtained from the piping line 6d.
  • Example 4 A water treatment test was conducted using the water treatment apparatus of FIG. As simulated waste water, water containing 1000 mg / L hydrofluoric acid was prepared. Further, manganese magnesium ferrite having an average particle diameter of 14 ⁇ m was prepared as a magnetic material, and the pore diameter between the magnetic particles was measured to be 4.7 ⁇ m. The same filter as in Example 2 was used. In addition, a powder obtained by grinding dolomite as a calcium-containing inorganic solid with a ball mill and selecting with a wind force was used. The average particle size of dolomite was 10 ⁇ m, and the interparticle pore size was 2.3 ⁇ m. C ⁇ A and B / C was 4.3.
  • the simulated waste water and dolomite having the same molar equivalent as the fluoride ions in the simulated waste water were added to the mixing tank 3 and stirred for 15 minutes. As a result, the pH in the mixing tank rose to 7.0. Further, the ferrite slurry was passed through the solid-liquid separator 4 in advance to form a precoat layer (pseudo filter) having a thickness of 1 mm.
  • a treatment liquid having a fluorine concentration reduced to 13 mg / L was obtained from the piping line 6d. .

Abstract

This water treatment method causes the precipitation of calcium fluoride by contacting water containing fluorine ions to a calcium-containing inorganic solid, and causes solid/liquid separation of the precipitated calcium fluoride and the calcium-containing inorganic solid by means of a solid/liquid separation device (4) provided with a filter (8). The water treatment method is characterized in that when the mode value for the pore diameters in the filter (8) is A and the volume-converted average particle size of the calcium-containing inorganic solid is B, B ≤ 50 μm and 0.2 ≤ B/A ≤ 10.

Description

水処理方法Water treatment method
　本発明の実施形態は、水処理方法に関する。 Embodiments of the present invention relate to a water treatment method.
　近時、工業の発達や人口の増加により水資源の有効利用が求められるようになってきている。水資源の有効利用を図るためには、工業排水や生活排水などのような各種の排水を浄化して再利用することが重要である。排水を浄化するためには、水中に含まれる水不溶物や不純物を分離除去する必要がある。排水を浄化する方法として、例えば膜分離法、遠心分離法、活性炭吸着法、オゾン処理法、凝集剤添加による浮遊物質の沈殿除去法がある。これらの水処理方法を用いて、排水に含まれるリンやフッ素などの環境に及ぼす影響の大きい化学物質を除去し、また水中に分散した油類やクレイなどを除去することができる。　
　従来、炭酸カルシウムを用いたフッ素含有排水の処理方法が知られている。この処理方法は、排水に含まれるフッ化物イオンを炭酸カルシウムと反応させてその表面にフッ化カルシウムを生成させ、そのフッ化カルシウムを削ることにより炭酸カルシウムを析出させ、再度反応を進行させてフッ化物イオンを除去する技術である。 Recently, the effective use of water resources has been required due to industrial development and population growth. In order to effectively use water resources, it is important to purify and reuse various wastewaters such as industrial wastewater and domestic wastewater. In order to purify the wastewater, it is necessary to separate and remove water insoluble matters and impurities contained in the water. Examples of methods for purifying wastewater include membrane separation methods, centrifugal separation methods, activated carbon adsorption methods, ozone treatment methods, and suspended matter precipitation removal methods by adding flocculants. By using these water treatment methods, chemical substances having a great influence on the environment such as phosphorus and fluorine contained in the wastewater can be removed, and oils and clays dispersed in water can be removed.
Conventionally, a method for treating fluorine-containing wastewater using calcium carbonate is known. In this treatment method, fluoride ions contained in the waste water are reacted with calcium carbonate to form calcium fluoride on the surface thereof, and the calcium fluoride is precipitated by scraping the calcium fluoride. This is a technique for removing fluoride ions.
特開２００５－３０５２７９号公報JP 2005-305279 A
　しかし、上述した従来方法では、炭酸カルシウムの表面に析出するフッ化カルシウムを除去するエネルギーが必要になるだけでなく、炭酸カルシウム表面から剥離した微細なフッ化カルシウムの除去が困難になるという問題があった。　
　実施形態の目的は、水中のフッ化物イオンを速やかに除去し、かつ生成したフッ素化合物の除去を容易に行うことのできる水処理方法を提供することである。 However, the above-described conventional method not only requires energy to remove calcium fluoride deposited on the surface of calcium carbonate, but also has a problem that it is difficult to remove fine calcium fluoride peeled off from the calcium carbonate surface. there were.
An object of the embodiment is to provide a water treatment method capable of quickly removing fluoride ions in water and easily removing the generated fluorine compound.
　実施形態によれば、フッ化物イオンを含有する水にカルシウム含有無機固体を接触させてフッ化カルシウムを析出させ、析出したフッ化カルシウムとカルシウム含有無機固体を、フィルターを備えた固液分離装置により固液分離を行う水処理方法において、前記フィルターの細孔径の最頻値をＡ，前記カルシウム含有無機固体の体積換算平均粒子径をＢとした時に、Ｂ≦５０μｍ、かつ０．２≦Ｂ／Ａ≦１０であることを特徴とする水処理方法を提供できる。 According to the embodiment, the calcium-containing inorganic solid is brought into contact with water containing fluoride ions to precipitate calcium fluoride, and the precipitated calcium fluoride and the calcium-containing inorganic solid are separated by a solid-liquid separation device equipped with a filter. In the water treatment method in which solid-liquid separation is performed, B ≦ 50 μm, and 0.2 ≦ B /, where A is the mode of pore diameter of the filter and B is the volume-converted average particle diameter of the calcium-containing inorganic solid. A water treatment method characterized by A ≦ 10 can be provided.
図１は、第１の実施形態に係る水処理装置を示す構成ブロック図である。FIG. 1 is a configuration block diagram showing a water treatment apparatus according to the first embodiment. 図２は、第２の実施形態に係る水処理装置を示す構成ブロック図である。FIG. 2 is a configuration block diagram showing a water treatment apparatus according to the second embodiment. 図３は、第３の実施形態に係る水処理装置を示す構成ブロック図である。FIG. 3 is a configuration block diagram showing a water treatment apparatus according to the third embodiment. 図４は、第４の実施形態に係る水処理装置を示す構成ブロック図である。FIG. 4 is a configuration block diagram showing a water treatment device according to the fourth embodiment. 図５は、第２の実施形態に係る水処理装置におけるフィルターによる細孔径と細孔体積との関係を示す特性図である。FIG. 5 is a characteristic diagram showing the relationship between the pore diameter and the pore volume by the filter in the water treatment apparatus according to the second embodiment. 図６は、第２の実施形態に係る水処理装置における炭化カルシウムの粒子間の孔径と細孔体積との関係を示す特性図である。FIG. 6 is a characteristic diagram showing the relationship between the pore diameter and the pore volume between calcium carbide particles in the water treatment apparatus according to the second embodiment.
　以下、実施形態に係る水処理方法ついて説明する。　
　（１）実施形態に関わるカルシウム含有無機固体は、カルシウムを含み、水に不溶なものであればよい。水に不溶とは、水への溶解度が、１０００ｍｌ当たり１０ｇ以下（２５℃）であることを意味する。カルシウム含有無機固体としては、天然鉱石や単一の精製したものでも構わない。天然鉱石としては、例えば、アラゴナイト、ウレキサイト、メリライト、オンファサイト、ウバロバイト、灰重石、ベロブスカイト、ヘデンバージャイト、ゾイサイト、魚眼石、ドロマイト、クリード石、ピーモンタイト、スパー石、二水石膏、チタナイト、チャロアイト、灰長石、透輝石、灰鉄輝石、ヨハンセン輝石、トレモライト、ロードナイト、ピジョン輝石、ホルンブレンド、オージャイト、ベクロタイト、ベスビアナイト、逸見石、カルサイト、霰石、モンモリロナイト、アクチノライト、エピドート、クリノゾイサイト、アパタイトが挙げられる。精製したものであれば、例えば、炭酸カルシウム、亜硫酸カルシウム、水酸化カルシウム、硫酸カルシウム、チタン酸カルシウム、タングステン酸カルシウムが挙げられる。この中でも水への溶解度が小さい炭酸カルシウムや、炭酸カルシウムを主成分とする鉱石（例えばアラゴナイト、ドロマイト）が好ましい。また、水和物や水酸基を有しない物質が好ましい。水和物や水酸基を有する物質であると他の物質に比べて柔らかい特徴を持ち、フィルターの孔に詰まってしまう場合があるからである。 Hereinafter, the water treatment method according to the embodiment will be described.
(1) The calcium-containing inorganic solid according to the embodiment may contain calcium and be insoluble in water. Insoluble in water means that the solubility in water is 10 g or less (25 ° C.) per 1000 ml. The calcium-containing inorganic solid may be natural ore or a single purified one. Natural ores include, for example, aragonite, urexite, melilite, onfasite, uvalite, scheelite, velovskite, hedenburgite, zoisite, fisheye stone, dolomite, creedite, peamontite, spar stone, dihydrate gypsum, titanite , Charoite, anorthite, diopside, ash iron pyroxene, johansen pyroxene, tremolite, rhodonite, pigeon pyroxene, horn blend, augite, becrotite, vesuvianite, fake stone, calcite, meteorite, montmorillonite, actinolite, epidote, clinozoite, Apatite is mentioned. If it is purified, for example, calcium carbonate, calcium sulfite, calcium hydroxide, calcium sulfate, calcium titanate, and calcium tungstate can be mentioned. Of these, calcium carbonate having a low solubility in water and ore (eg, aragonite, dolomite) containing calcium carbonate as a main component are preferable. Moreover, the substance which does not have a hydrate or a hydroxyl group is preferable. This is because a substance having a hydrate or a hydroxyl group is softer than other substances and may clog the pores of the filter.
　上記の粒子を、任意の粉砕機を用いて細かく砕き、分級をして所定の粒子径を有するカルシウム含有無機固体を製造する。粉砕の方法としては、例えばボールミル、ヘンシェルミキサー、ロールが挙げられる。また、平均粒子径は、レーザー回折法により測定した結果に基づいて算出される。具体的には、レーザー回折法を利用した機器として株式会社島津製作所製の商品名：ＳＡＬＤ－ＤＳ２１型測定装置を用いることができる。なお、平均粒子径とは体積換算平均粒子径のことである。このようにして求められた平均粒子径Ｂが５０μｍ以下になるようにし、かつ後述するフィルターの孔径の最頻値（分布図で頻度が最も大きくなるピーク値）Ａに対し、Ｂ／Ａが０．２～１０の値となるように調整する。ここで、Ｂ／Ａが０．２より小さいと、生成フッ化カルシウムとカルシウム含有無機固体がフィルターで捕捉されないか、又は緻密に積層して固液分離が困難になる。Ｂ／Ａが１０より大きいと、生成フッ化カルシウムがフィルターを通過したり目詰まりを起こしたりして、適切な水処理を行うことが困難である。また、平均粒子径が５０μｍよりも大きい場合においても、生成フッ化カルシウムがフィルターを通過したり目詰まりを起こしたりする。 The above particles are finely crushed using an arbitrary pulverizer and classified to produce a calcium-containing inorganic solid having a predetermined particle size. Examples of the pulverization method include a ball mill, a Henschel mixer, and a roll. The average particle diameter is calculated based on the result measured by the laser diffraction method. Specifically, a trade name: SALD-DS21 type measuring device manufactured by Shimadzu Corporation can be used as an apparatus using a laser diffraction method. In addition, an average particle diameter is a volume conversion average particle diameter. The average particle diameter B thus determined is set to 50 μm or less, and B / A is 0 with respect to the mode value (peak value where the frequency is greatest in the distribution map) A of the filter pore diameter described later. Adjust to a value between 2 and 10. Here, when B / A is smaller than 0.2, the produced calcium fluoride and the calcium-containing inorganic solid are not captured by the filter, or are densely laminated and solid-liquid separation becomes difficult. When B / A is larger than 10, the generated calcium fluoride passes through the filter or is clogged, and it is difficult to perform appropriate water treatment. Even when the average particle size is larger than 50 μm, the generated calcium fluoride passes through the filter or causes clogging.
　本実施形態においては、本出願人は、カルシウム含有無機固体表面に析出するフッ化カルシウムの析出径が概ね０．１～２μｍであることを実験的に確認している。即ち、このフッ化カルシウムがカルシウム含有無機固体の表面に析出したままか、または剥がれ落ちてフッ化カルシウムとカルシウム含有無機固体に分かれた場合においても、特定の孔径を有するフィルターで固液分離しやすいようにカルシウム含有無機固体の粒子径を制限している。即ち、このカルシウム含有無機固体と共にフッ化カルシウムを濾過することにより、カルシウム含有無機固体間の隙間にフッ化カルシウムがトラップされ、フッ素の除去が可能になる。 In this embodiment, the present applicant has experimentally confirmed that the precipitated diameter of calcium fluoride deposited on the surface of the calcium-containing inorganic solid is approximately 0.1 to 2 μm. That is, even when this calcium fluoride remains deposited on the surface of the calcium-containing inorganic solid or peels off and separates into calcium fluoride and the calcium-containing inorganic solid, it is easy to separate into solid and liquid with a filter having a specific pore size. Thus, the particle size of the calcium-containing inorganic solid is limited. That is, by filtering calcium fluoride together with this calcium-containing inorganic solid, calcium fluoride is trapped in the gaps between the calcium-containing inorganic solids, and fluorine can be removed.
　（２）本実施形態におけるフィルターの材質は特に制限されるものではなく、例えば、ろ布や金属メッシュ、多孔質セラミック、多孔質ポリマーが挙げられる。この中でも、ろ布が好ましく、例えばポリプロピレン、ナイロン、ポリエステルなどの材質で、二重織、綾織、平織、朱子織などで編んだものが用いられる。この中でも、柔らかいろ布や高分子からなる精密ろ過膜（ＭＦ膜）などを用いると、フッ化カルシウムなどを好適に捕獲することができる。上記フィルターによれば、後述するフィルター上に無機固体を積層する擬似膜を用いる場合、積層時に無機固体が水圧でフィルターに圧着され一部弾性変形を起こし、隣の粒子との距離が縮まり、粒子間孔径が小さくなるために性能が向上するからである。 (2) The material of the filter in the present embodiment is not particularly limited, and examples thereof include a filter cloth, a metal mesh, a porous ceramic, and a porous polymer. Among these, a filter cloth is preferable, for example, a material such as polypropylene, nylon, polyester, and knitted with double weave, twill weave, plain weave, satin weave, or the like is used. Among these, when a microfiltration membrane (MF membrane) made of a soft filter cloth or a polymer is used, calcium fluoride or the like can be suitably captured. According to the above filter, when using a pseudo membrane in which an inorganic solid is laminated on the filter described later, the inorganic solid is pressure-bonded to the filter by water pressure at the time of lamination, causing a partial elastic deformation, and the distance from the adjacent particles is reduced. This is because the performance is improved because the pore size is reduced.
　フィルターの孔径は、例えば金属メッシュの篩のように予め既知のものであれば良いが、不明な場合は水銀圧入法により測定する。この水銀圧力法は、水銀の表面張力が大きいことを利用して粉体の細孔に水銀を浸入させるために圧力を加え、圧力と圧入された水銀量から比表面積や細孔分布を求める方法である。フィルターの孔径は、例えば島津製作所製の自動ポロシメータオートポアＩＶ９５００シリーズを用いて求めることができる。この時のろ布の孔径は最頻径を用いる。ここで、横軸を孔径、縦軸を圧入された積算水銀量の微分値をプロットした時に、孔径分布のピークの孔径を最頻径（最頻値）Ａと定義する。 The pore diameter of the filter may be known in advance, such as a metal mesh sieve, but if not known, it is measured by a mercury intrusion method. This mercury pressure method uses the high surface tension of mercury to apply pressure to cause mercury to penetrate into the pores of the powder, and obtains the specific surface area and pore distribution from the pressure and the amount of mercury that is injected. It is. The pore diameter of the filter can be determined using, for example, an automatic porosimeter autopore IV9500 series manufactured by Shimadzu Corporation. At this time, the mode diameter is used as the hole diameter of the filter cloth. Here, when the horizontal axis is a pore diameter and the vertical axis is a plot of a differential value of the amount of accumulated mercury that is press-fitted, the peak pore diameter of the pore size distribution is defined as a mode diameter (mode value) A.
　また、前記フィルター上に水に不溶の無機粒子を積層させて、擬似フィルターとし、この擬似フィルターでフッ化カルシウムとカルシウム含有無機固体を固液分離しても良い。前記擬似フィルターの孔径に相当するのが粒子間の孔径であり、例えば島津製作所製の自動ポロシメータオートポアＩＶ９５００シリーズを用いて求めることができる。この時に得られる細孔分布が粒子間の孔径と定義できる。但し、無機粒子がポーラス構造であると、ポーラス細孔径と粒子間の孔径の二つのピークが得られるが、この場合孔径の大きいピークが粒子間の孔径と定義できる。また、この擬似フィルターの代表孔径Ｃは、フィルターと同様に最頻値とする。この擬似フィルターの孔径の最頻値Ｃとフィルターの孔径の最頻値ＡはＣ＜Ａであることが好ましい。この値であると、フッ化カルシウムなどの細かい粒子がフィルターまで届かず、フィルターの寿命を延ばすことができるからである。また無機固体を積層しない時と同様に、０．２≦Ｂ／Ｃ≦１０であることが好ましい。 Further, inorganic filters insoluble in water may be laminated on the filter to form a pseudo filter, and calcium fluoride and calcium-containing inorganic solid may be solid-liquid separated with this pseudo filter. The pore diameter between the particles corresponds to the pore diameter of the pseudo filter, and can be determined using, for example, an automatic porosimeter autopore IV9500 series manufactured by Shimadzu Corporation. The pore distribution obtained at this time can be defined as the pore diameter between particles. However, when the inorganic particles have a porous structure, two peaks of a porous pore diameter and a pore diameter between particles are obtained. In this case, a peak having a large pore diameter can be defined as a pore diameter between particles. Further, the representative pore diameter C of the pseudo filter is a mode value as in the filter. The mode C of the pore diameter of the pseudo filter and the mode A of the filter pore diameter are preferably C <A. This is because fine particles such as calcium fluoride do not reach the filter at this value, and the life of the filter can be extended. Moreover, it is preferable that it is 0.2 <= B / C <= 10 similarly to when not laminating inorganic solids.
　（３）前記無機固体は磁性体であることが好ましい。磁性体であると、磁気分離により磁性体とフッ化カルシウム，カルシウム含有無機固体の混合スラリーから、磁性体だけを取り除き、再利用することができるからである。　
　磁性体としては強磁性物質を全般的に用いることができ、例えば鉄、鉄基合金、磁鉄鉱（マグネタイト）、チタン鉄鉱（イルメナイト）、磁硫鉄鉱（ピロータイト）、マグネシアフェライト、マンガンマグネシウムフェライト、マンガン亜鉛フェライト、コバルトフェライト、ニッケルフェライト、ニッケル亜鉛フェライト、バリウムフェライト、銅亜鉛フェライトなどを用いることができる。これらのうち水中での安定性に優れたマグネタイト、マグネシアフェライト、マンガンマグネシウムフェライトなどのフェライト系化合物を用いることが最も好ましい。マグネタイト（Ｆｅ３Ｏ４）は、安価であるだけでなく、水中でも磁性体として安定した性質を示し、毒性のない安全な元素ばかりで構成されているため、水処理に使用するのに適している。 (3) The inorganic solid is preferably a magnetic material. This is because the magnetic substance can be reused by removing only the magnetic substance from the mixed slurry of the magnetic substance, calcium fluoride, and calcium-containing inorganic solid by magnetic separation.
Ferromagnetic materials can be generally used as magnetic materials, such as iron, iron-based alloys, magnetite (magnetite), titanite (ilmenite), pyrrhotite (pilotite), magnesia ferrite, manganese magnesium ferrite, manganese zinc. Ferrite, cobalt ferrite, nickel ferrite, nickel zinc ferrite, barium ferrite, copper zinc ferrite and the like can be used. Of these, it is most preferable to use a ferrite-based compound such as magnetite, magnesia ferrite, or manganese magnesium ferrite having excellent stability in water. Magnetite (Fe 3 O 4 ) is not only inexpensive, but also exhibits stable properties as a magnetic substance in water and is composed of only safe and non-toxic elements, so it is suitable for use in water treatment. Yes.
　これらの磁性体は単体で用いても良いが、何らかの方法で凝集体として用いてもよい。また、必要により、樹脂を被覆したり、シランカップリング剤で表面処理をしても良い。特に好ましいのは、表面張力の低い樹脂または修飾を行うことである。前記樹脂としては、例えばシリコーン樹脂またはフッ素樹脂を用いることができる。シリコーン樹脂は、オルガノポリシロキサンからなる高分子化合物であり、一液型と二液型の２つがある。例えば信越化学工業株式会社の製品であるＫＥシリーズやＫＲシリーズが挙げられる。 These magnetic materials may be used alone, or may be used as an aggregate by any method. Further, if necessary, a resin may be coated or a surface treatment may be performed with a silane coupling agent. Particularly preferred is to perform a resin or modification with a low surface tension. As the resin, for example, a silicone resin or a fluororesin can be used. Silicone resin is a polymer compound made of organopolysiloxane, and there are two types, one-pack type and two-pack type. For example, there are KE series and KR series which are products of Shin-Etsu Chemical Co., Ltd.
　前記フッ素樹脂は、樹脂中にフッ素を含む高分子の総称であり、例えばポリテトラフルオロエチレン(ＰＴＦＥ)，テトラフルオロエチレン－パーフルオロアルキルビニルエーテル共重合体(ＰＦＡ)，テトラフルオロエチレン－ヘキサフルオロプロピレン共重合体(ＦＥＰ)，テトラフルオロエチレン－エチレン共重合体(ＥＴＦＥ)，ポリビニリデンフルオライド(ＰＶＤＦ)，クロロトリフルオロエチレン－エチレン共重合体(ＥＣＴＦＥ)，ポリクロロトリフルオロエチレン(ＰＣＴＦＥ)，ポリビニルフルオライド(ＰＶＦ)及びこれらの複合体を含むものである。必要に応じて、これらの樹脂とエポキシ樹脂やポリイミド、ポリアミドなどを共重合させたものを使用し、磁性体粒子との接着性を改善する。これらの樹脂を用いることにより、磁性体と固形物の分離が容易になり、磁性体の再生が容易になる。 The fluororesin is a general term for polymers containing fluorine in the resin. For example, polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer. Polymer (FEP), tetrafluoroethylene-ethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), chlorotrifluoroethylene-ethylene copolymer (ECTFE), polychlorotrifluoroethylene (PCTFE), polyvinyl fluoride Rides (PVF) and their composites are included. If necessary, a resin obtained by copolymerizing these resins with an epoxy resin, polyimide, polyamide or the like is used to improve the adhesion with the magnetic particles. By using these resins, it is easy to separate the magnetic substance and the solid substance, and the reproduction of the magnetic substance is facilitated.
　（４）カルシウム含有無機固体を用いた場合、前述したフッ化物イオン含有排水に混合したカルシウム含有無機固体と同じものを用いることができる。このようなカルシウム含有無機固体を用いると、通水時に水中に残存しているフッ化物イオンとカルシウム含有無機固体の接触効率が高くなり、フッ素の除去効率が高まる効果がある。 (4) When a calcium-containing inorganic solid is used, the same calcium-containing inorganic solid mixed in the fluoride ion-containing waste water described above can be used. When such a calcium-containing inorganic solid is used, the contact efficiency between fluoride ions remaining in water during water flow and the calcium-containing inorganic solid is increased, and the fluorine removal efficiency is increased.
　また、このカルシウム含有無機固体は、フッ化物イオンを含有する排水にカルシウム含有無機固体を混合したフッ化カルシウム、カルシウム含有無機固体の混合スラリーを分級し、比較的大粒子を含有するスラリーと小粒子を含有するスラリーに分け、このうち大粒子を含有するスラリーをフィルター上に積層して擬似フィルターとしても良い。 In addition, this calcium-containing inorganic solid is obtained by classifying a mixed slurry of calcium fluoride and calcium-containing inorganic solid in which calcium ion-containing inorganic solid is mixed with wastewater containing fluoride ions, and a slurry containing relatively large particles and small particles The slurry may be divided into slurries containing a large amount of particles, and a slurry containing large particles may be laminated on the filter to form a pseudo filter.
　前記混合スラリーを分級する方法は、例えば重力や遠心力を用いて行うことができる。重力を用いる方法によれば、沈降分離槽にスラリーを導入させ、一定の沈降時間の後、上部・下部からそれぞれ大粒子を含有するスラリー及び小粒子を含有するスラリーを引き抜くことで、異なる粒子径を有するスラリーを作ることができる。また、遠心力を用いる方法によれば、サイクロンを用いることができ、サイクロンに導入するスラリーを遠心力で分級して、大きい粒子をサイクロン下部から、小さい粒子をサイクロン上部から取り出すことにより分級して異なる粒子径を有するスラリーを作製することができる。 The method of classifying the mixed slurry can be performed using, for example, gravity or centrifugal force. According to the method using gravity, the slurry is introduced into a settling tank, and after a certain settling time, the slurry containing large particles and the slurry containing small particles are pulled out from the upper part and the lower part, respectively. A slurry can be made. In addition, according to the method using centrifugal force, a cyclone can be used, the slurry introduced into the cyclone is classified by centrifugal force, and large particles are classified from the lower part of the cyclone, and small particles are classified from the upper part of the cyclone. Slurries having different particle sizes can be made.
　（５）これらの粒子の粒子間の孔径分布において、最頻値をＤ１、９０％径をＤ２、１０％径をＤ３とした時、ｌｏｇＤ２－ｌｏｇＤ１ ＜ ｌｏｇＤ１－ｌｏｇＤ３であることが好ましい。換言すれば、これは、磁性体の粒子間の孔径の分布において、最頻値よりも小さい領域の分布幅が最頻値よりも大きい領域の分布幅より大きいことを意味する。従って、このような粒子間の孔径分布を持つものは、最頻値よりも小さい孔径を多く有する。このように小さい孔径を多く有すると、例えばフッ化カルシウムのような小さい粒子を捕捉することができ、さらに捕捉した小さい粒子が孔径を狭めるので、さらに小さい粒子を取り除くことができる。逆に最頻値よりも大きな粒子間の孔径を多く有すると、最初にフッ化カルシウムのような小さい粒子を捕捉する確率が低下し、小さな粒子の捕捉率が低下する場合がある。 (5) In the pore size distribution between these particles, when the mode is D1, the 90% diameter is D2, and the 10% diameter is D3, logD2-logD1 <logD1-logD3 is preferable. In other words, this means that the distribution width of the region smaller than the mode value is larger than the distribution width of the region larger than the mode value in the pore diameter distribution between the magnetic particles. Accordingly, those having such a pore size distribution between particles have many pore sizes smaller than the mode value. When there are many such small pore diameters, for example, small particles such as calcium fluoride can be captured, and since the captured small particles narrow the pore diameter, even smaller particles can be removed. Conversely, if there are many pore sizes between particles larger than the mode value, the probability of capturing small particles such as calcium fluoride first decreases, and the capture rate of small particles may decrease.
　（６）本実施形態に係る固液分離装置は特に任意の構造で構わないが、好ましくはフィルターが地面と水平なろ過器を用い、通水は下向流で行うことが好ましい。この時、通水方向は地面と垂直、即ち重力と同じ向きになり、フィルター上に積層した擬似フィルターの形を維持しやすいからである。 (6) The solid-liquid separation device according to the present embodiment may have an arbitrary structure, but it is preferable to use a filter in which the filter is parallel to the ground and the water flow is performed in a downward flow. At this time, the water flow direction is perpendicular to the ground, that is, the same direction as gravity, and it is easy to maintain the shape of the pseudo filter laminated on the filter.
　以下、添付の図面を参照して種々の実施の形態をそれぞれ説明する。　
　本実施形態の水処理用磁性体粒子を用いる水処理方法には、フッ化物イオンを含有する排水にカルシウムを含有する固体を混合した後に、フィルターで固液分離する第１の方法、カルシウムを含有する固体を積層した擬似フィルターで固液分離する第２の方法、混合物から大きな粒子を有するスラリーを分離し、これを積層した擬似フィルターで固液分離する第３の方法、磁性体を積層した擬似フィルターで固液分離し、磁性体を再生して再利用する第４の方法が挙げられる。 Hereinafter, various embodiments will be described with reference to the accompanying drawings.
The water treatment method using magnetic particles for water treatment according to the present embodiment includes a first method of solid-liquid separation with a filter after mixing calcium-containing solids with wastewater containing fluoride ions, containing calcium The second method of solid-liquid separation with a pseudo filter in which solids are laminated, the third method of separating a slurry having large particles from the mixture, and the solid-liquid separation with a pseudo filter in which the solids are laminated, and the pseudo in which magnetic materials are laminated There is a fourth method in which solid-liquid separation is performed with a filter, and the magnetic material is regenerated and reused.
　次に、本実施形態に係る水処理方法異用いられる水処理装置について説明する。　
　（第１の水処理装置）　
　図１は、第１の水処理装置を示す。　
　本実施形態の水処理装置１は、フッ化物イオンを含有する排水にカルシウムを含有するカルシウム含有無機固体を混合した後に、フィルターで固液分離する第１の水処理装置である。水処理装置１は、カルシウム含有無機固体貯留槽（以下、貯留槽と呼ぶ）２、混合槽３、固液分離装置４、図示しない原水供給源および排水貯留槽を有しており、これらの機器及び装置が複数の配管ラインにより互いに接続されている。 Next, a water treatment apparatus used differently from the water treatment method according to the present embodiment will be described.
(First water treatment device)
FIG. 1 shows a first water treatment device.
The water treatment apparatus 1 according to the present embodiment is a first water treatment apparatus that mixes calcium-containing inorganic solids containing calcium with wastewater containing fluoride ions, and then performs solid-liquid separation with a filter. The water treatment apparatus 1 has a calcium-containing inorganic solid storage tank (hereinafter referred to as a storage tank) 2, a mixing tank 3, a solid-liquid separation apparatus 4, a raw water supply source and a drainage storage tank (not shown), and these devices. And the apparatus are connected to each other by a plurality of piping lines.
　ポンプ５ａ、図示しない計測器及びセンサを介装した配管ライン６ａは、貯留槽２と混合槽３を接続している。貯留槽２は、内部に攪拌スクリュウ７ａを有し、図示しないカルシウム含有無機固体供給口からカルシウム含有無機固体を供給するとともに、図示しない水道水供給口から水道水を供給して、カルシウム含有無機固体のスラリー溶液を溜めておく機能を有する。また、原水の状態によっては、図示しないｐＨ調整液タンクから薬液を注入し、ｐＨを調整することができる。ｐＨ調整液としては、塩酸、硫酸、水酸化ナトリウムなどが用いられる。 A piping line 6 a interposing a pump 5 a, a measuring instrument (not shown) and a sensor connects the storage tank 2 and the mixing tank 3. The storage tank 2 has a stirring screw 7a inside, supplies calcium-containing inorganic solids from a calcium-containing inorganic solid supply port (not shown), and supplies tap water from a tap-water supply port (not shown). The slurry solution is stored. Further, depending on the state of the raw water, a chemical solution can be injected from a pH adjusting solution tank (not shown) to adjust the pH. As the pH adjusting liquid, hydrochloric acid, sulfuric acid, sodium hydroxide or the like is used.
　ポンプ５ｂ、図示しない計測器及びセンサを介装した配管ライン６ｂは、混合槽３と固液分離装置４を接続している。混合槽３は、被処理水を撹拌する撹拌スクリュウ７ｂを有し、図示しない原水供給源から配管ライン６ｃを介して被処理水となる排水が導入され、被処理水を一時的に貯留しておくようになっている。その間に、被処理水は配管ライン６ａから供給されるカルシウム含有無機固体と混合され、被処理水中に含まれるフッ化物イオンと反応し、フッ化カルシウムを生成させ、フッ化カルシウムとカルシウム含有無機固体の混合スラリーを作製する。 A piping line 6b provided with a pump 5b, a measuring instrument and a sensor (not shown) connects the mixing tank 3 and the solid-liquid separation device 4. The mixing tank 3 has a stirring screw 7b that stirs the water to be treated, and wastewater that becomes the water to be treated is introduced from a raw water supply source (not shown) via the piping line 6c, and temporarily stores the water to be treated. It is supposed to leave. In the meantime, the water to be treated is mixed with the calcium-containing inorganic solid supplied from the piping line 6a, reacts with fluoride ions contained in the water to be treated to generate calcium fluoride, and calcium fluoride and the calcium-containing inorganic solid. A mixed slurry is prepared.
　前述した計測器及びセンサから図示しない制御器の入力部に検出信号が入り、当該制御器の出力部からポンプ５ａ，５ｂにそれぞれ制御信号が出され、それらの動作が制御されるようになっている。このように水処理装置１の全体は図示しない制御器によって統括的にコントロールされるようになっている。 A detection signal is input to the input unit of the controller (not shown) from the measuring instrument and sensor described above, and control signals are output from the output unit of the controller to the pumps 5a and 5b, respectively, so that their operations are controlled. Yes. As described above, the entire water treatment apparatus 1 is comprehensively controlled by a controller (not shown).
　固液分離装置４は、内部にフィルター８を有し、上下のスペースに分割されている。固液分離装置４の上部のスペースには、ポンプ５ｂと配管ライン６ｂより混合スラリーが送られ、フィルター８で固液分離される。前記フィルター８の孔径の最頻値Ａは１μｍ以下であり、カルシウム含有無機固体の平均粒子径Ｂとの関係が２≦Ｂ／Ａのときに好適に使用することができる。前記カルシウム含有無機固体としては、特に制限されることはなく、適宜選択すればよい。また、フィルター８は目の細かいものがよく、例えばＭＦ膜などを用いると良い。 The solid-liquid separator 4 has a filter 8 inside and is divided into upper and lower spaces. In the space above the solid-liquid separator 4, the mixed slurry is sent from the pump 5 b and the piping line 6 b and is separated into solid and liquid by the filter 8. The mode A of the pore diameter of the filter 8 is 1 μm or less, and can be suitably used when the relationship with the average particle diameter B of the calcium-containing inorganic solid is 2 ≦ B / A. The calcium-containing inorganic solid is not particularly limited and may be appropriately selected. The filter 8 should be fine, and for example, an MF film may be used.
　固液分離された液体は、固液分離装置４の下部のスペースから配管ライン６ｄにより排出され、図示しない処理水貯留槽へ送られる。また、上部には図示しない逆洗水タンクから配管ライン６ｅを介して洗浄水が送られ、配管ライン６ｆからフッ化カルシウムとカルシウム含有無機固体の濃縮水が排出される。 The liquid subjected to the solid-liquid separation is discharged from the space below the solid-liquid separation device 4 through the piping line 6d and sent to a treated water storage tank (not shown). Moreover, wash water is sent to the upper part through a pipe line 6e from a backwash water tank (not shown), and concentrated water of calcium fluoride and calcium-containing inorganic solid is discharged from the pipe line 6f.
　次に、図１を参照して上記の装置を用いた水処理方法を説明する。　
　まず、混合槽３内で被処理水とカルシウム含有無機固体を混合し、カルシウム含有無機固体粒子表面に水中のフッ化物イオンを取り込み、表面にフッ化カルシウムを析出させる。カルシウム含有無機固体粒子の添加量は特に問わないが、水中のフッ化物イオンのモル数の１／２以上を入れる必要があり、好ましくはフッ化物イオンのモル数と同量以上入れるのがよい。 Next, a water treatment method using the above apparatus will be described with reference to FIG.
First, the water to be treated and the calcium-containing inorganic solid are mixed in the mixing tank 3, and fluoride ions in water are taken into the surface of the calcium-containing inorganic solid particles to precipitate calcium fluoride on the surface. The addition amount of the calcium-containing inorganic solid particles is not particularly limited, but it is necessary to add at least 1/2 of the number of moles of fluoride ions in water, and it is preferable to add at least the same number as the number of moles of fluoride ions.
　次いで、このフッ化カルシウムとカルシウム含有無機固体を含むスラリーを、固液分離装置４へ移送する。固液分離装置内には、フィルター８の細孔径の最頻値をＡ，カルシウム含有無機固体の体積換算平均粒子径をＢとした時に、０．２≦Ｂ／Ａ≦１０であるフィルター８を予めセットしておき、前記スラリーを濾過処理する。この時、フィルター８が地面と水平であると、フィルター上にフッ化物イオンとカルシウム含有無機固体が積層される。Ｂ／Ａを０．２≦Ｂ／Ａ≦１０にした時には、生成したフッ化カルシウムが、カルシウム含有無機固体と共に積層し、好適に取ることができる。 Next, the slurry containing calcium fluoride and calcium-containing inorganic solid is transferred to the solid-liquid separator 4. In the solid-liquid separator, the filter 8 satisfying 0.2 ≦ B / A ≦ 10 is assumed, where A is the mode of pore diameter of the filter 8 and B is the average particle diameter in terms of volume of the calcium-containing inorganic solid. It is set in advance and the slurry is filtered. At this time, if the filter 8 is level with the ground, fluoride ions and calcium-containing inorganic solids are laminated on the filter. When B / A is set to 0.2 ≦ B / A ≦ 10, the generated calcium fluoride can be suitably laminated with the calcium-containing inorganic solid.
　固液分離装置４で固液分離して得られた液体は、固液分離装置４の下部から排出され、図示しない処理水槽に送られる。また、固液分離装置４の上側の側部から、逆洗水を通水し、フィルター８上に堆積したフッ化カルシウムとカルシウム含有無機固体を除去して、フィルター８を再生する。前記逆洗水は、水道水を用いても良いが、図示しない処理水タンクから供給しても構わない。　
　このように特定の大きさのカルシウム含有無機固体と特定の孔径を有するフィルター８を用いることにより、特別な処理を必要とせず、水中のフッ化物イオンを除去することができる。 The liquid obtained by solid-liquid separation by the solid-liquid separation device 4 is discharged from the lower part of the solid-liquid separation device 4 and sent to a treated water tank (not shown). In addition, backwash water is passed from the upper side of the solid-liquid separator 4 to remove the calcium fluoride and calcium-containing inorganic solid deposited on the filter 8 to regenerate the filter 8. The backwash water may be tap water, but may be supplied from a treated water tank (not shown).
As described above, by using the calcium-containing inorganic solid having a specific size and the filter 8 having a specific pore size, it is possible to remove fluoride ions in water without requiring any special treatment.
　（第２の水処理装置）　
　第２の水処理装置１Ａについて図２を参照して説明する。但し、図１と同部材は同符号を付して説明を省略する。　
　ポンプ５ａの下流側の配管６ａには、バルブ１１が介装されている。前記ポンプ５ｂの下流側の配管ライン６ｂとバルブ１１とは、配管ライン６ｇにより接続されている。第２の水処理装置１Ａは、図１の水処理装置１と異なり、貯留槽２から送られる配管ライン６ａ，６ｇは、夫々混合槽３と固液分離装置４に繋がっている。前記配管ライン６ａ，６ｇは、夫々混合槽３でフッ化物イオンと反応させてフッ化カルシウムを得る工程と、フィルター８上にカルシウム含有無機固体を積層させ、プレコート層（擬似フィルター）を得る工程に使用される。 (Second water treatment device)
The 2nd water treatment apparatus 1A is demonstrated with reference to FIG. However, the same members as those in FIG.
A valve 11 is interposed in the pipe 6a on the downstream side of the pump 5a. The piping line 6b on the downstream side of the pump 5b and the valve 11 are connected by a piping line 6g. Unlike the water treatment apparatus 1 in FIG. 1, the second water treatment apparatus 1 </ b> A has piping lines 6 a and 6 g sent from the storage tank 2 connected to the mixing tank 3 and the solid-liquid separation apparatus 4, respectively. The pipe lines 6a and 6g are respectively used in a process of obtaining calcium fluoride by reacting with fluoride ions in the mixing tank 3, and a process of obtaining a precoat layer (pseudo filter) by laminating calcium-containing inorganic solids on the filter 8. used.
　混合槽３で得られたフッ化カルシウムとカルシウム含有無機固体を含んだスラリーを固液分離装置８に通水する前に、バルブ１１を切り替えて配管ライン６ｇ，６ｂを介してカルシウム含有無機固体を含んだスラリーを固液分離装置４に供給し、フィルター８上にカルシウム含有無機固体を含んだスラリーによるプレコート層を形成する。この時のプレコート層の厚さは、圧力損失がかからない程度であれば特に問わないが、具体的には０．５～１０ｍｍ程度にする。この時に、このカルシウム含有無機固体の粒子間の孔径Ｃがフィルター８の孔径Ａと比較して、Ｃ＜Ａであり、０．２≦Ｂ／Ｃ≦１０（但し、Ｂ：カルシウム含有無機固体の体積換算平均粒子径）となるようにカルシウム含有無機固体とフィルター８を調整すると、好適にフッ化カルシウムおよびカルシウム含有無機固体を除去することができる。 Before the slurry containing calcium fluoride and calcium-containing inorganic solid obtained in the mixing tank 3 is passed through the solid-liquid separator 8, the valve 11 is switched and the calcium-containing inorganic solid is removed via the piping lines 6g and 6b. The contained slurry is supplied to the solid-liquid separator 4, and a precoat layer made of the slurry containing calcium-containing inorganic solid is formed on the filter 8. The thickness of the precoat layer at this time is not particularly limited as long as no pressure loss is applied, but is specifically about 0.5 to 10 mm. At this time, the pore diameter C between the particles of the calcium-containing inorganic solid is C <A and 0.2 ≦ B / C ≦ 10 (provided that B: calcium-containing inorganic solid When the calcium-containing inorganic solid and the filter 8 are adjusted so as to have a volume-converted average particle diameter, the calcium fluoride and the calcium-containing inorganic solid can be suitably removed.
（第３の水処理装置）　
　第３の水処理装置１Ｂについて図３を参照して説明する。但し、図１と同部材は同符号を付して説明を省略する。　
　図中の符号１２はサイクロン（遠心分離装置）を示す。前記混合槽３の底部寄りの側部とサイクロン１２の上部寄りの側部は、ポンプ５ｂを介装した配管ライン６ｈにより接続されている。サイクロン１２の下部には、粒子径の大きい粒子を一時的に溜める下部ポット１３が配置されている。下部ポット１３の下部には、バルブ１４を介装した配管ライン６ｉを介して大粒子含有スラリー貯留槽１５が接続されている。この貯留槽１５は攪拌スクリュウ７ｃを備えている。粒子径の大きい粒子を含む排水は、配管ライン６ｉによりサイクロン１２から大粒子含有スラリー貯留槽１６に送られる。 (Third water treatment device)
The 3rd water treatment apparatus 1B is demonstrated with reference to FIG. However, the same members as those in FIG.
Reference numeral 12 in the figure denotes a cyclone (centrifuge). The side near the bottom of the mixing tank 3 and the side near the top of the cyclone 12 are connected by a piping line 6h with a pump 5b interposed. A lower pot 13 for temporarily storing particles having a large particle diameter is disposed below the cyclone 12. A large particle-containing slurry storage tank 15 is connected to the lower portion of the lower pot 13 through a piping line 6 i with a valve 14 interposed. The storage tank 15 includes a stirring screw 7c. Waste water containing particles having a large particle diameter is sent from the cyclone 12 to the large particle-containing slurry reservoir 16 through the piping line 6i.
　サイクロン１２の上部には、配管ライン６ｊを介して小粒子含有スラリー貯留槽１６が接続されている。この貯留槽１６は攪拌スクリュウ７ｄを備えている。前記大粒子含有貯留槽１５の底部寄りの側部と前記固液分離装置４の上部は、ポンプ５ｃを介装した配管ライン６ｋにより接続されている。小粒子含有スラリー貯留槽１６の底部寄りの側部とポンプ５ｃの下流側の配管ライン６ｋは、ポンプ５ｄを介装した配管ライン６１と接続されている。 The small particle containing slurry storage tank 16 is connected to the upper part of the cyclone 12 via the piping line 6j. The storage tank 16 includes a stirring screw 7d. The side near the bottom of the large particle-containing storage tank 15 and the upper part of the solid-liquid separator 4 are connected by a piping line 6k with a pump 5c interposed. The side near the bottom of the small particle-containing slurry storage tank 16 and the piping line 6k on the downstream side of the pump 5c are connected to a piping line 61 having a pump 5d interposed therebetween.
　第３の水処理装置１Ｂにおいては、まず、大粒子径含有スラリー貯留槽１５から固液分離装置３に通水され、大粒子径の粒子がフィルター８上に積層され、図示しないプレコート層を形成する。その後、このプレコート層（疑似フィルター）に小粒子径の粒子を有するスラリーを通水して水処理を行う。 In the third water treatment device 1B, first, water is passed from the large particle size-containing slurry storage tank 15 to the solid-liquid separation device 3, and the large particle size is laminated on the filter 8 to form a precoat layer (not shown). To do. Thereafter, a slurry having small particle diameters is passed through the precoat layer (pseudo filter) for water treatment.
　（第４の水処理装置）　
　第４の水処理装置１Ｃについて図４を参照して説明する。但し、図１と同部材は同符号を付して説明を省略する。　
　固液分離装置４の上部側には、配管ライン６ｆを介して分離槽２１が接続されている。この分離槽２１には、永久磁石２２を内包する円筒部２３及び攪拌スクリュウ７ｅが配置されている。永久磁石２２は、図示しないエアシリンダーにより上下に駆動し、分離槽２１の内部の磁場をＯＮ・ＯＦＦすることができるようになっている。 (Fourth water treatment device)
The 4th water treatment apparatus 1C is demonstrated with reference to FIG. However, the same members as those in FIG.
A separation tank 21 is connected to the upper side of the solid-liquid separator 4 via a piping line 6f. The separation tank 21 is provided with a cylindrical portion 23 containing a permanent magnet 22 and a stirring screw 7e. The permanent magnet 22 is driven up and down by an air cylinder (not shown) so that the magnetic field inside the separation tank 21 can be turned ON / OFF.
　分離槽２１の底部寄りの側部と攪拌スクリュウ７ｆを備えた磁性体貯留槽２４の底部寄りの側部は、ポンプ５ｅを介装した配管ライン６ｍを介して接続されている。前記ポンプ５ｂの下流側の配管ライン６ｂと磁性体貯留槽２４は、ポンプ５ｆを介装した配管ライン６ｎにより接続されている。 The side near the bottom of the separation tank 21 and the side near the bottom of the magnetic substance storage tank 24 provided with the stirring screw 7f are connected via a piping line 6m with a pump 5e interposed therebetween. The piping line 6b on the downstream side of the pump 5b and the magnetic substance storage tank 24 are connected by a piping line 6n interposed with a pump 5f.
　こうした構成の水処理装置１Ｃの動作は次の通りである。　
　まず、フッ化カルシウムとカルシウム含有無機固体の混合スラリーを固液分離装置４に通水する前に、固液分離装置４のフィルター８上に磁性体を積層したプレコート層（疑似フィルター）を形成する。次に、前記混合スラリーを固液分離装置４に通水して固液分離を行い、処理水を配管ライン６ｄにより排出する。つづいて、逆洗水を配管ライン６ｅから供給して、フィルター８上に堆積した磁性体と無機固体を洗い流し、配管ライン６ｆより分離槽２１に移送する。 The operation of the water treatment apparatus 1C having such a configuration is as follows.
First, before passing the mixed slurry of calcium fluoride and calcium-containing inorganic solid through the solid-liquid separator 4, a precoat layer (pseudo filter) in which a magnetic material is laminated on the filter 8 of the solid-liquid separator 4 is formed. . Next, the mixed slurry is passed through the solid-liquid separator 4 to perform solid-liquid separation, and the treated water is discharged through the piping line 6d. Subsequently, backwash water is supplied from the piping line 6e, and the magnetic substance and inorganic solid deposited on the filter 8 are washed away and transferred to the separation tank 21 from the piping line 6f.
　分離槽２１に移送された磁性体と無機固体の混合物は、攪拌スクリュウ７ｅにより混合され、磁性体と無機固体がばらばらにされる。次に、エアシリダーを駆動して永久磁石２２を円筒部２３内に入れて磁場をＯＮにし、円筒部２３の外周に磁性体のみを回収する。その後、配管ライン６ｏから分離した無機固体を排出し、磁性体の洗浄を完了する。つづいて、図示しない水道水供給口から水道水を分離槽２１に供給しつつ、エアシリンダーを駆動して永久磁石２２を円筒部２３の外部に引き抜き、磁場をＯＦＦにする。その結果、円筒部２３に回収されていた磁性体は、供給された水道水と混合してスラリー状になり、配管ライン６ｍを介して磁性体貯留槽２４に送り、再利用する。 The mixture of the magnetic substance and the inorganic solid transferred to the separation tank 21 is mixed by the stirring screw 7e, and the magnetic substance and the inorganic solid are separated. Next, the air cylinder is driven, the permanent magnet 22 is put into the cylindrical portion 23 to turn on the magnetic field, and only the magnetic material is recovered on the outer periphery of the cylindrical portion 23. Thereafter, the inorganic solid separated from the piping line 6o is discharged, and the cleaning of the magnetic material is completed. Subsequently, while supplying tap water from a tap water supply port (not shown) to the separation tank 21, the air cylinder is driven to pull out the permanent magnet 22 to the outside of the cylindrical portion 23, thereby turning off the magnetic field. As a result, the magnetic material recovered in the cylindrical portion 23 is mixed with the supplied tap water to form a slurry, which is sent to the magnetic material storage tank 24 through the piping line 6m and reused.
　以下、具体的な実施例について詳細に説明する。　 Hereinafter, specific examples will be described in detail. *
　（実施例１）　
　図１の水処理装置を用いて、水処理の試験を行った。模擬排水として、１０００ｍｇ／Ｌのフッ化水素酸を含有する水を用意した。また、フィルター８としては酢酸セルロースからなる精密ろ過（ＭＦ）膜を、カルシウム含有無機固体としてはカルサイトをボールミルで粉砕し、風力で選別した粉体を使用した。ＭＦ膜の孔径は１μｍ（カタログ値）であり、カルシウム含有無機固体の体積換算平均粒子径Ｂのフィルター８の細孔径の最頻値に対する比（Ｂ／Ａ）は１０であった。 Example 1
A water treatment test was conducted using the water treatment apparatus of FIG. As simulated waste water, water containing 1000 mg / L hydrofluoric acid was prepared. As the filter 8, a microfiltration (MF) membrane made of cellulose acetate was used, and as the calcium-containing inorganic solid, powder obtained by pulverizing calcite with a ball mill and selecting with a wind force was used. The pore size of the MF membrane was 1 μm (catalog value), and the ratio (B / A) of the volume-converted average particle size B of the calcium-containing inorganic solid to the mode value of the pore size of the filter 8 was 10.
　混合槽３に、模擬排水と該模擬排水中のフッ化物イオンと同モル相当を有するカルサイトを添加し、１０分攪拌したところ、混合槽内のｐＨが７．２まで上昇した。混合槽内の混合液を、ポンプ５ｂを用いて固液分離装置４に供給し、フィルター８で固液分離したところ、配管ライン６ｄからフッ素濃度が９ｍｇ／Ｌに低減された処理液を得た。 In the mixing tank 3, simulated effluent and calcite having the same molar equivalent as the fluoride ion in the simulated effluent were added and stirred for 10 minutes. As a result, the pH in the mixing tank rose to 7.2. When the mixed liquid in the mixing tank was supplied to the solid-liquid separator 4 using the pump 5b and solid-liquid separated by the filter 8, a treatment liquid having a fluorine concentration reduced to 9 mg / L was obtained from the piping line 6d. .
　（実施例２）　
　図２の水処理装置を用いて、水処理の試験を行った。模擬排水として、１０００ｍｇ／Ｌのフッ化水素酸を含有する水を用意した。また、フィルターはポリプロピレンのろ布を用意し、島津製作所製の商品名：オートポア９５２０（細孔分布測定装置）を用いて細孔分布測定を行ったところ、図５のような細孔分布を得た。この結果より、このフィルター８の孔径Ａは６．４μｍ（最頻値）であることがわかった。また、カルシウム含有無機固体として、和光純薬製の炭酸カルシウムの試薬を準備し、ボールミルで粉砕して風力選別を行って粉体を得た。この炭酸カルシウムの粒子間の孔径を、島津製作所製の商品名：オートポア９５２０（細孔分布測定装置）を用いて測定したところ、図６の結果を得た。この結果より、粒子間の孔径Ｃは１．３７μｍであることを確認した。即ち、Ｃ＜Ａであり、粒子間の孔径Ｃに対する平均粒子径Ｂの比（Ｂ／Ｃ）は３．９であった。 (Example 2)
A water treatment test was conducted using the water treatment apparatus of FIG. As simulated waste water, water containing 1000 mg / L hydrofluoric acid was prepared. In addition, a filter cloth made of polypropylene was prepared for the filter, and pore distribution measurement was performed using a trade name: Autopore 9520 (pore distribution measuring device) manufactured by Shimadzu Corporation. As a result, a pore distribution as shown in FIG. 5 was obtained. It was. From this result, it was found that the pore diameter A of the filter 8 was 6.4 μm (mode). Further, as a calcium-containing inorganic solid, a calcium carbonate reagent manufactured by Wako Pure Chemical Industries, Ltd. was prepared, pulverized with a ball mill, and subjected to wind sorting to obtain a powder. The pore size between the calcium carbonate particles was measured using a trade name: Autopore 9520 (pore distribution measuring device) manufactured by Shimadzu Corporation, and the result of FIG. 6 was obtained. From this result, it was confirmed that the pore diameter C between the particles was 1.37 μm. That is, C <A, and the ratio of the average particle diameter B to the pore diameter C between the particles (B / C) was 3.9.
　混合槽３に、模擬排水と、模擬排水中のフッ化物イオンと同モル相当を有する炭酸カルシウムを添加し、１０分攪拌したところ、混合槽内のｐＨが７．３まで上昇した。ここで、バルブ１１を操作し、炭酸カルシウムを含有する水を固液分離装置４に通水し、フィルター上に積層させ厚さ約１ｍｍのプレコート層（疑似フィルター）を作製した。この後、混合槽内の混合液を、ポンプ５ｂを用いて固液分離装置４に供給し、プレコート層で固液分離したところ、配管ライン６ｄからフッ素濃度が７ｍｇ／Ｌに低減された処理液を得た。 In the mixing tank 3, the simulated waste water and calcium carbonate having the same mole equivalent as the fluoride ions in the simulated waste water were added and stirred for 10 minutes. As a result, the pH in the mixing tank rose to 7.3. Here, the valve 11 was operated, and water containing calcium carbonate was passed through the solid-liquid separator 4 and laminated on the filter to prepare a precoat layer (pseudo filter) having a thickness of about 1 mm. Then, when the liquid mixture in the mixing tank is supplied to the solid-liquid separation device 4 using the pump 5b and solid-liquid separated by the precoat layer, the treatment liquid whose fluorine concentration is reduced to 7 mg / L from the piping line 6d. Got.
　（実施例３）　
　実施例２と同じカルシウム含有無機固体とフィルターを用い、図３の水処理装置で試験を行った。混合槽３に模擬排水と、模擬排水中のフッ化物イオンと同モル相当を有する炭酸カルシウムを添加し、１０分攪拌したところ、混合槽内のｐＨが７．３まで上昇した。ここで、混合槽内の混合液を、ポンプ５ｂを用いてサイクロン１２に通水し、異なる平均粒子径を有するスラリーを、大粒子含有スラリー貯留槽１５、小粒子含有スラリー貯留槽１６に夫々供給した。このうち、大粒子含有スラリー貯留槽１５の粒子の粒子間の孔径を調べたところ、４．０μｍであり、Ｃ＜Ａであった。また小粒子の平均粒子径は０．８μｍであり、Ｂ／Ｃは０．２であった。この後、大粒子含有スラリー貯留槽１５の粒子を固液分離装置４に供給して積層させ、プレコート層（疑似フィルター）を形成した。このプレコート層で小粒子含有スラリーを固液分離したところ、配管ライン６ｄからフッ素濃度が７ｍｇ／Ｌに低減された処理液を得た。 (Example 3)
Using the same calcium-containing inorganic solid and filter as in Example 2, the test was conducted with the water treatment apparatus of FIG. When the simulated waste water and calcium carbonate having the same mole equivalent as the fluoride ions in the simulated waste water were added to the mixing tank 3 and stirred for 10 minutes, the pH in the mixing tank rose to 7.3. Here, the liquid mixture in the mixing tank is passed through the cyclone 12 using the pump 5b, and the slurry having different average particle diameters is supplied to the large particle-containing slurry storage tank 15 and the small particle-containing slurry storage tank 16, respectively. did. Among these, when the pore diameter between the particles of the large particle-containing slurry reservoir 15 was examined, it was 4.0 μm and C <A. The average particle size of the small particles was 0.8 μm, and B / C was 0.2. Thereafter, the particles in the large particle-containing slurry storage tank 15 were supplied to the solid-liquid separator 4 and laminated to form a precoat layer (pseudo filter). When the small particle-containing slurry was subjected to solid-liquid separation with this precoat layer, a treatment liquid having a fluorine concentration reduced to 7 mg / L was obtained from the piping line 6d.
　（実施例４）　
　図４の水処理装置を用いて、水処理の試験を行った。模擬排水として、１０００ｍｇ／Ｌのフッ化水素酸を含有する水を用意した。また、磁性体として平均粒子径１４μｍのマンガンマグネシウムフェライトを準備し、磁性体の粒子間の孔径を測定したところ４．７μｍであった。フィルターは実施例２と同じものを用いた。またカルシウム含有無機固体としてのドロマイトをボールミルで粉砕し、風力で選別した粉体を使用した。ドロマイトの平均粒子径は１０μｍであり、粒子間孔径は２．３μｍであった。Ｃ＜Ａであり、Ｂ／Ｃは４．３であった。 (Example 4)
A water treatment test was conducted using the water treatment apparatus of FIG. As simulated waste water, water containing 1000 mg / L hydrofluoric acid was prepared. Further, manganese magnesium ferrite having an average particle diameter of 14 μm was prepared as a magnetic material, and the pore diameter between the magnetic particles was measured to be 4.7 μm. The same filter as in Example 2 was used. In addition, a powder obtained by grinding dolomite as a calcium-containing inorganic solid with a ball mill and selecting with a wind force was used. The average particle size of dolomite was 10 μm, and the interparticle pore size was 2.3 μm. C <A and B / C was 4.3.
　混合槽３に、模擬排水と、模擬排水中のフッ化物イオンと同モル相当を有するドロマイトを添加し、１５分攪拌したところ、混合槽内のｐＨが７．０まで上昇した。また、フェライトのスラリーを予め固液分離装置４に通水し、厚さ１ｍｍのプレコート層（疑似フィルター）を形成した。混合槽内の混合液を、ポンプ５ｂを用いて固液分離装置４に供給し、プレコート層で固液分離したところ、配管ライン６ｄからフッ素濃度が１３ｍｇ／Ｌに低減された処理液を得た。 The simulated waste water and dolomite having the same molar equivalent as the fluoride ions in the simulated waste water were added to the mixing tank 3 and stirred for 15 minutes. As a result, the pH in the mixing tank rose to 7.0. Further, the ferrite slurry was passed through the solid-liquid separator 4 in advance to form a precoat layer (pseudo filter) having a thickness of 1 mm. When the mixed liquid in the mixing tank was supplied to the solid-liquid separation device 4 using the pump 5b and solid-liquid separated by the precoat layer, a treatment liquid having a fluorine concentration reduced to 13 mg / L was obtained from the piping line 6d. .
　また、固液分離装置４の横の配管ライン６ｅから水道水を供給し、フィルター上にある磁性体と無機固体分を洗浄し、分離槽２１に供給した。次に、攪拌スクリュウ７ｅを動かして磁性体と無機固形分を分離した後、永久磁石２２で磁性体を回収し、無機固形分を配管ライン６ｏから排出した後、水道水を導入して磁性体を回収した。 Further, tap water was supplied from the horizontal piping line 6 e of the solid-liquid separator 4, the magnetic substance and inorganic solids on the filter were washed, and supplied to the separation tank 21. Next, after moving the stirring screw 7e to separate the magnetic material and the inorganic solid content, the magnetic material is recovered by the permanent magnet 22, and the inorganic solid content is discharged from the piping line 6o. Was recovered.
　本発明のいくつかの実施形態を説明したが、これらの実施形態は、例として提示したものであり、発明の範囲を限定することは意図していない。これら新規な実施形態は、その他の様々な形態で実施されることが可能であり、発明の要旨を逸脱しない範囲で、種々の省略、置き換え、変更を行うことができる。これら実施形態やその変形は、発明の範囲や要旨に含まれるとともに、特許請求の範囲に記載された発明とその均等の範囲に含まれる。 Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.
　１，１Ａ，１Ｂ，１Ｃ…水処理装置、２…カルシウム含有貯留槽、３…混合槽、４…固液分離装置、５ａ，５ｂ，５ｃ，５ｄ，５ｅ，５ｆ…ポンプ、６ａ～６ｎ…配管ライン、７ａ～７ｆ…攪拌スクリュウ、８…フィルター、１１…バルブ、１２…サイクロン、１３…下部ポット、１５…大粒子径含有スラリー貯留槽、１６…小粒子径含有スラリー貯留槽、２１…分離槽、２２…永久磁石、２３…円筒部、２４…磁性体槽。 DESCRIPTION OF SYMBOLS 1,1A, 1B, 1C ... Water treatment apparatus, 2 ... Calcium containing storage tank, 3 ... Mixing tank, 4 ... Solid-liquid separator, 5a, 5b, 5c, 5d, 5e, 5f ... Pump, 6a-6n ... Piping Lines, 7a to 7f ... stirring screw, 8 ... filter, 11 ... valve, 12 ... cyclone, 13 ... lower pot, 15 ... large particle diameter containing slurry storage tank, 16 ... small particle diameter containing slurry storage tank, 21 ... separation tank 22 ... Permanent magnet, 23 ... Cylindrical part, 24 ... Magnetic body tank.

Claims (9)

  1. 　フッ化物イオンを含有する水にカルシウム含有無機固体を接触させてフッ化カルシウムを析出させ、析出したフッ化カルシウムとカルシウム含有無機固体を、フィルターを備えた固液分離装置により固液分離を行う水処理方法において、
    　前記フィルターの細孔径の最頻値をＡ，前記カルシウム含有無機固体の体積換算平均粒子径をＢとした時に、Ｂ≦５０μｍ、かつ０．２≦Ｂ／Ａ≦１０であることを特徴とする水処理方法。     Water in which calcium-containing inorganic solid is brought into contact with water containing fluoride ions to precipitate calcium fluoride, and the precipitated calcium fluoride and calcium-containing inorganic solid are subjected to solid-liquid separation by a solid-liquid separation device equipped with a filter. In the processing method,
    B ≦ 50 μm and 0.2 ≦ B / A ≦ 10, where A is the mode of pore diameter of the filter and B is the volume-average particle diameter of the calcium-containing inorganic solid. Water treatment method.
  2. 　前記フィルターの上に予め水に不溶の無機粒子を積層させて疑似フィルターを形成し、前記無機粒子の粒子間の孔径の最頻値Ｃが、Ｃ＜Ａであり、かつ０．２≦Ｂ／Ｃ≦１０を満たすことを特徴とする請求項１に記載の水処理方法。 A pseudo filter is formed by previously laminating inorganic particles insoluble in water on the filter, and the mode C of the pore diameter between the inorganic particles is C <A, and 0.2 ≦ B / The water treatment method according to claim 1, wherein C ≦ 10 is satisfied.
  3. 　前記フィルターの上に積層する無機粒子が、磁性体を含んだ粒子であることを特徴とする請求項２に記載の水処理方法。 The water treatment method according to claim 2, wherein the inorganic particles laminated on the filter are particles containing a magnetic substance.
  4. 　前記フィルターの上に積層する無機粒子が、カルシウム含有無機固体であることを特徴とする請求項２に記載の水処理方法。 The water treatment method according to claim 2, wherein the inorganic particles laminated on the filter are calcium-containing inorganic solids.
  5. 　磁性体の粒子間の孔径の分布は、最頻値より小さい領域の分布幅が最頻値より大きい領域の分布幅よりも大きいことを特徴とする請求項３項記載の水処理方法。 4. The water treatment method according to claim 3, wherein the pore size distribution between the magnetic particles is larger in the distribution width of the region smaller than the mode value than in the region larger than the mode value.
  6. 　前記フィルターの上に積層する無機粒子は、カルシウム含有無機固体を接触させた後の溶液中に含まれる固形物を２つの粒度分布が異なる固形分に分離して得られる、平均粒子径が大きい粒子であることを特徴とする請求項２に記載の水処理方法。 The inorganic particles laminated on the filter are particles having a large average particle diameter obtained by separating solids contained in the solution after contacting the calcium-containing inorganic solid into two solids having different particle size distributions. The water treatment method according to claim 2, wherein:
  7. 　前記フィルターが、布であることを特徴とする請求項１乃至６いずれか１項に記載の水処理方法。 The water treatment method according to any one of claims 1 to 6, wherein the filter is a cloth.
  8. 　前記フィルターが、精密ろ過膜であることを特徴とする請求項１乃至６いずれか１項に記載の水処理方法。 The water treatment method according to any one of claims 1 to 6, wherein the filter is a microfiltration membrane.
  9. 　前記フィルターを有する固液分離装置が、地面と水平なろ過面をもつろ過器であることを特徴とする請求項１乃至６いずれか１項に記載の水処理方法。 The water treatment method according to any one of claims 1 to 6, wherein the solid-liquid separator having the filter is a filter having a filtration surface parallel to the ground.
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