WO2003066532A1 - Procede de recuperation d'un agent emulsifiant fluorochimique - Google Patents

Procede de recuperation d'un agent emulsifiant fluorochimique Download PDF

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Publication number
WO2003066532A1
WO2003066532A1 PCT/JP2003/000658 JP0300658W WO03066532A1 WO 2003066532 A1 WO2003066532 A1 WO 2003066532A1 JP 0300658 W JP0300658 W JP 0300658W WO 03066532 A1 WO03066532 A1 WO 03066532A1
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WIPO (PCT)
Prior art keywords
fluorine
wastewater
emulsifier
aqueous solution
layered double
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PCT/JP2003/000658
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English (en)
Japanese (ja)
Inventor
Hiroshi Funaki
Masataka Eda
Hiroki Kamiya
Kota Omori
Takeshi Kamiya
Yasuki Miura
Koichi Yanase
Original Assignee
Jemco Inc.
Asahi Glass Company, Limited
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Application filed by Jemco Inc., Asahi Glass Company, Limited filed Critical Jemco Inc.
Priority to AU2003203382A priority Critical patent/AU2003203382A1/en
Publication of WO2003066532A1 publication Critical patent/WO2003066532A1/fr

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D17/00—Separation of liquids, not provided for elsewhere, e.g. by thermal diffusion
    • B01D17/02—Separation of non-miscible liquids
    • B01D17/0202—Separation of non-miscible liquids by ab- or adsorption
    • 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
    • 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
    • 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
    • C02F2101/30—Organic compounds
    • C02F2101/301—Detergents, surfactants
    • 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
    • C02F2101/30—Organic compounds
    • C02F2101/36—Organic compounds containing halogen
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
    • C02F2103/34—Nature of the water, waste water, sewage or sludge to be treated from industrial activities not provided for in groups C02F2103/12 - C02F2103/32
    • C02F2103/36—Nature of the water, waste water, sewage or sludge to be treated from industrial activities not provided for in groups C02F2103/12 - C02F2103/32 from the manufacture of organic compounds
    • C02F2103/38—Polymers

Definitions

  • the present invention relates to a method for recovering a fluorine-containing emulsifier using a layered double hydroxide.
  • Patent Document 1 Japanese Patent Publication No. 47_51233 describes a method of coagulating and washing an emulsion polymerization latex, collecting an emulsifier as an aqueous solution, concentrating the solution, and recovering the fluorine-containing emulsifier with an organic solvent. The text also describes a method for recovering the fluorine-containing emulsifier using an anion exchange resin.
  • Patent Document 2 (US Pat. No. 4,282,162) describes a method in which a diluted aqueous solution of an emulsifier is brought into contact with a weakly basic anion exchange resin in the pH range of 0 to 7 to adsorb the emulsifier and desorb it with aqueous ammonia. ing.
  • Patent Document 3 discloses that nonionic or cationic surfactant is added to flocculated waste water of a fluorine-containing polymer, and polytetrafluoroethylene (hereinafter, referred to as PTFE) fine particles in the flocculated waste water.
  • PTFE polytetrafluoroethylene
  • Patent Literature 4 Japanese Patent Application Laid-Open No. 55-120630
  • Patent Literature 5 US Pat. No. 4,436,9266
  • Patent Literature 6 disclose condensing PTFE wastewater by ultrafiltration and use it for PTFE production It describes a method of recovering a part of the fluorine-containing emulsifier, and then adsorbing and recovering the fluorine-containing emulsifier by IER.
  • Patent Document 2 Patent Document 7 (Japanese Patent Application Laid-Open No. 55-104651) and Patent Document 8 (DE 2903981) describe that perfluorooctanoic acid ammonium is adsorbed on IER, and then acid and organic solvent are added. A method for desorbing and recovering perfluorooctanoic acid using a mixture of the above is disclosed. .
  • Patent Document 9 (WO 99/62858) describes that (Alkyl vinyl ether) Copolymer (hereinafter, referred to as PFA) is adjusted to pH 6 to 7.5 by adding lime water to the coagulated wastewater, and then metal salts such as aluminum chloride and iron chloride are added. After coagulating the unagglomerated PFA and mechanically separating and removing the aggregates, the pH of the obtained wastewater is adjusted to 7 or less with sulfuric acid, and the fluorine-containing emulsifier using strong basic IER A method for adsorbing and recovering is described.
  • PFA Alkyl vinyl ether copolymer
  • Patent Document 10 Japanese Patent Application Laid-Open No. 2000-61231 discloses a method of desorbing a fluorine-containing emulsifier adsorbed on an ion-exchange resin using a mixed solution of water, an alkali and an organic solvent. Is described.
  • Non-Patent Document 1 (Chemical Proceedings of the 76th Annual Meeting of the Chemical Society of Japan, Published on March 15, 2001, p. 600) and Non-Patent Document 2 (Chemical Society of Japan No. 80 Proceedings of the Annual Meeting of the Autumn Meeting, published on September 7, 2001, page 41), reported that perfluoroctanoic acid and its ammonium salt were synthesized using layered double hydroxides of aluminum and zinc. Techniques for inserting and fixing have been reported.
  • SS component suspended solids in coagulated wastewater, including non-coagulated fluorine-containing polymer
  • SS component suspended solids in coagulated wastewater, including non-coagulated fluorine-containing polymer
  • the removal of the SS component has a great effect on the recovery efficiency of the fluorine-containing emulsifier, and there are still many problems in the actual operation, such as no effective SS component removal method has been found. ing.
  • the present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method for efficiently recovering a fluorine-containing emulsifier from a coagulated drainage of a fluorine-containing polymer containing an SS component by a simple method. . Disclosure of the invention
  • the present invention provides a fluorine-containing polymer obtained by polymerizing at least one fluorine-containing monomer in an aqueous medium containing a fluorine-containing emulsifier.
  • a mixed aqueous solution containing a trivalent metal ion is added, and the pH of the wastewater at the time of adding the mixed water solution is adjusted by the divalent metal ion and the trivalent metal ion contained in the mixed aqueous solution.
  • a divalent metal aqueous solution containing a divalent metal ion and a trivalent metal aqueous solution containing a trivalent metal ion may be added to the wastewater.
  • the present invention provides a wastewater after separating a fluorine-containing polymer obtained by polymerizing at least one fluorine-containing monomer in an aqueous medium containing a fluorine-containing emulsifier, wherein the wastewater has a floating solid content and a floating solid content.
  • a method for recovering a fluorine-containing emulsifier is provided.
  • the present invention provides a wastewater after separating a fluorine-containing polymer obtained by polymerizing at least one fluorine-containing monomer in an aqueous medium containing a fluorine-containing emulsifier, wherein the wastewater has a floating solid content and a floating solid content.
  • a method for recovering the fluorine-containing emulsifier from wastewater comprising: a mixed aqueous solution containing a divalent metal-trivalent metal ion; and an anion different from the anion constituting the fluorine-containing emulsifier, and By mixing the divalent metal ion and the trivalent metal ion with a reaction solution maintained at a value that forms a layered double hydroxide, an anion different from the anion constituting the fluorine-containing emulsifier is formed between the layers.
  • a perfluoroalkanoic acid a perfluoroalkanesulfonic acid having 5 to 13 carbon atoms, or an acid in which a part of fluorine in these compounds is substituted by chlorine or hydrogen
  • perfluoroalkanoic acid ⁇ -hydroperfluoroalkanoic acid, ⁇ -chloroperfluoroalkanoic acid, and perfluoroalkanesulfonic acid having 5 to 13 carbon atoms Salts
  • These may have a linear or branched structure, or a mixture thereof.
  • the molecule may contain an etheric oxygen atom.
  • the salt of the acid is preferably an alkali metal salt such as a lithium salt, a sodium salt or a potassium salt or an ammonium salt, more preferably an ammonium salt or a sodium salt, and most preferably an ammonium salt.
  • the acid include perfluoropentanoic acid and perfluorohexanoic acid.
  • Perfluoroheptanoic acid perfluorooctanoic acid, perfluorononanoic acid, perfluorodecanoic acid, perfluorododecanoic acid, ⁇ -hydroperfluoroheptanoic acid, ⁇ -hydro ⁇ Ref J octanoic acid, ⁇ -hi , ⁇ -cloper perfluoroheptanoic acid, ⁇ -cloper perfluorooctanoic acid, ⁇ monocloper perfluorononanoic acid, etc.
  • Perfluorohexanesulfonic acid perfluoroheptansulfonic acid, perfluorooctanesulfonic acid, perfluorononanesulfonic acid, perfluorodensulfonic acid, and the like.
  • ammonium salt examples include ammonium perfluoropentanoate, ammonium perfluorohexanoate, ammonium perfluoroheptanoate, ammonium perfluorooctanoate (hereinafter referred to as APFO), and perfluorononan.
  • Ammonium acid perfluorodecanoic acid ammonium, perfluorododecanoic acid ammonium, ⁇ -hydroperfluoroheptanoic acid ammonium, ⁇ -hyd mouth perfluorooctanoic acid ammonium, ⁇ -hydroperfluoro Nonammonium ammonium, ⁇ -cloper perfluoroheptanoate ammonium, ⁇ -cloper perfluorooctanoic acid ammonium, ⁇ -cloper perfluorononanoic acid ammonium, etc.
  • ammonium perfluorohexane sulfonate ammonium perfluoroheptane sulfonate, ammonium perfluorooctane sulfonate, ammonium perfluorononane sulfonate, ammonium perfluorodecane sulfonate, and the like.
  • lithium salts include lithium perfluoropentanoate and perfluoropentanoate.
  • CF 3 CF 2 CF 2 OCF (CF 3 ) COOL i CF 3 CF 2 CF 2 OCF (CF 3 ) CF 2 OCF (CF 3 ) COOL i, CF 3 CF 2 CF 2 0 [CF (CF 3 ) CF 2 0] 2 CF (CF 3 ) COOL i, CF 3 CF 2 CF 20 [CF (CF 3 ) CF 20 ] 3 CF (CF 3 ) COOL i CF 3 CF 2 CF 2 CF 2 CF 2 ⁇ CF (CF 3 ) COOL i etc.
  • Specific examples of the sodium salt include sodium perfluoropentanoate, sodium perfluorohexanoate, sodium perfluoroheptanoate, sodium perfluorooctanoate, sodium perfluorononanoate, sodium perfluorononanoate, Sodium, sodium perfluorododecanoate, ⁇ _hydroperfluoro
  • CF 3 CF 2 CF 2 OCF (CF 3 ) COON a CF 3 CF 2 CF 2 OCF (CF 3 ) CF 2 OCF (CF 3 ) COON a
  • potassium salts include potassium perfluoropentanoate, potassium perfluorohexanoate, potassium perfluoroheptanoate, potassium perfluorooctanoate, potassium perfluorononanoate, and perfluolonate.
  • potassium perfluoronate and potassium perfluorodecane sulfonate As the fluorine-containing emulsifier in the present invention, an ammonium salt of perfluoroalkanoic acid having 6 to 12 carbon atoms is particularly preferable, and ammonium perfluoroheptanoate, APFO, ammonium perfluorononanoate, or perfluorodenoic acid. Ammonia is more preferred, and APFO is most preferred.
  • the coagulated wastewater from the production process of the polymer of the fluorine-containing monomer or the production process of the copolymer of the fluorine-containing monomer and the monomer other than the fluorine-containing monomer is used.
  • the coagulated waste water from the above-mentioned manufacturing process refers to at least one fluorine-containing monomer or at least one fluorine-containing monomer and a monomer other than the fluorine-containing monomer in an aqueous medium containing a fluorine-containing emulsifier.
  • the wastewater after the fluorine-containing polymer is agglomerated by salting out or the like from the aqueous dispersion of the fluorine-containing polymer obtained by emulsion polymerization or aqueous dispersion polymerization to separate the fluorine-containing polymer that is the object of production.
  • the polymer The washing wastewater and the absorbing liquid that captures the fluorine-containing emulsifier in the exhaust gas generated by drying and baking of the polymer are also included in the wastewater of the present invention.
  • the wastewater contains the fluorine-containing emulsifier used during the polymerization of the fluorine-containing monomer.
  • the flocculated wastewater also contains SS components such as non-aggregated fluorine-containing polymers in addition to the fluorine-containing emulsifier.
  • SS components such as non-aggregated fluorine-containing polymers in addition to the fluorine-containing emulsifier.
  • coagulation wastewater after emulsion polymerization is particularly suitable.
  • description will be made with reference to coagulated wastewater as a typical example of the wastewater in the present invention.
  • TFE tetrafluoroethylene
  • CF 2 CFC 1
  • CFH CF 2
  • CFH CH 2
  • CF 2 CH 2 (vinylidene fluoride , Here
  • fluorine-containing monomers may be used alone or in combination of two or more. In the present invention, at least one of the fluorine-containing monomers is preferably TFE.
  • Examples of monomers other than the fluorine-containing monomer include vinyl esters such as vinyl acetate, vinyl ethers such as ethyl vinyl ether, cyclohexyl vinyl ether, and hydroxybutyl vinyl ether, monomers having a cyclic structure such as norpolenene and norponadiene, and methylaryl. Examples thereof include aryl ethers such as ether, ethylene (hereinafter, referred to as E), propylene (hereinafter, referred to as P), and olefins such as isobutylene. These monomers other than the fluorine-containing monomer may be used alone or in combination of two or more.
  • examples of the fluorine-containing polymer include PTFE, TFEZP copolymer, TFEZP / VdF copolymer, TFE / HFP copolymer, TFEZPPVE copolymer, EZTFE copolymer, and polyvinylidene fluoride.
  • PTFE PTFE, TFE / P copolymer, TFEZP ZV dF copolymer or TFEZPPVE copolymer, most preferably PTFE.
  • the fluorine-containing polymer in the present invention may be of one type or two or more types.
  • a layered double hydroxide is formed using divalent metal ions and trivalent metal ions, and is contained in the coagulated wastewater.
  • the layered double hydroxide is separated from the coagulated wastewater through a step of encapsulating a fluorine-containing emulsifier between the layers of the layered double hydroxide (an emulsifier fixing step).
  • the coprecipitation method is a method in which a metal ion is added to a solution in which the recovery anion is dissolved to form a layered double hydroxide and, at the same time, the anion is included between the layers of the layered double hydroxide. is there.
  • a layered double hydroxide having a structure in which anions other than the target anion (eg, chloride ion, hydroxide ion, carbonate ion, etc.) are included between the layered double hydroxide layers is prepared in advance.
  • This is a method in which the layered double hydroxide is added to a solution in which the recovery target anion is dissolved, and the recovery target anion is included between the layers so as to replace the already included anion.
  • a layered double hydroxide containing carbonate ions between the layers is synthesized, and the solid from which the internal carbonate ions are removed at a high temperature of 400 to 500 ° C is used as the anion adsorbent.
  • This is a method in which the desired anion is included in the layered double hydroxide by adding it to a liquid in which the recovery target anion is dissolved.
  • any of the coprecipitation method, the ion exchange method, and the reconstruction method can be used.
  • a divalent metal ion and a trivalent metal ion are used to generate a layered double hydroxide in any of the coprecipitation method, the ion exchange method, and the reconstruction method.
  • the trivalent metal (metal that becomes trivalent ion when ionized) and divalent metal (metal that becomes divalent ion when ionized) used to form the layered double hydroxide are the trivalent metals.
  • the range of pH at which metal ions form hydroxides and the divalent metal If the pH ranges at which ON forms hydroxides overlap, or if these pH ranges are close, layered double hydroxides can be formed.
  • divalent metals examples include beryllium, cadmium, cobalt, chromium, copper (II), iron (11), magnesium, manganese (11), nickel, lead, platinum, palladium, zinc, tin, calcium, and the like.
  • trivalent metals include aluminum, bismuth, cerium, chromium, iron (111), gallium, indium, manganese (111), titanium, and thallium.
  • the hydroxide formation pH of the trivalent metal and the divalent metal is as follows.
  • Beryllium 6.5 or more, Cadmium: 8 to 13; Cobalt: 7.5 to 13; Chromium: 7 or more; Copper (II): 5 to 13; Iron (II): 7 or more; Magnesium: 1 0 or more, manganese (II): 8.5 to 13, nickel: 7 to 13.5, lead: 7 to 12, platinum: 7 or more, palladium: 3.5 to 13, zinc: 7-1 2, Tin: 2 ⁇ 10, Calcium: 12.5 or more
  • the trivalent metal ion is preferably a metal ion selected from aluminum, chromium, manganese (111), and gallium.
  • Aluminum ions are particularly preferred.
  • divalent metal ions magnesium, calcium, zinc, nickel, copper (11), iron (11) , Manganese (11), and ions of metals selected from cobalt are preferred, zinc or magnesium ions are more preferred, and magnesium ions are even more preferred.
  • a preferable divalent metal (magnesium, zinc) and a preferable trivalent metal (aluminum) will be mainly described.
  • the metal ions added to the coagulated wastewater to produce layered double hydroxides can be made from any raw material, but due to the availability and environmental impact, hydration of chlorides and chlorides Are preferred.
  • aluminum ion aluminum chloride, aluminum chloride hexahydrate, aluminum sulfate, or aluminum nitrate is preferably used, and aluminum chloride or aluminum chloride hexahydrate is more preferable. It is preferable to use magnesium chloride, magnesium chloride hexahydrate, magnesium nitrate hexahydrate, magnesium nitrate, magnesium oxide, magnesium sulfate, magnesium sulfate heptahydrate, or magnesium carbonate as a raw material for magnesium ion.
  • magnesium chloride or magnesium chloride hexahydrate is preferred.
  • a raw material for zinc ion it is preferable to use zinc chloride, zinc nitrate hexahydrate, zinc oxide, zinc sulfate, or zinc sulfate heptahydrate, and zinc chloride is particularly preferable.
  • the initial concentration of the fluorine-containing emulsifier to be recovered in the coagulated wastewater is preferably from 1 ppm (by mass, the same applies hereinafter) to 10% by mass, more preferably from 10 ppm to 10% by mass. , And more preferably 10 ppm or more and 1 mass% or less, particularly preferably 50 ppm or more and 0.5 mass% or less.
  • the efficiency of capturing the fluorine-containing emulsifier by the layered double hydroxide in the coagulated wastewater will decrease.
  • a simpler and more efficient method such as precipitation of the fluorine-containing emulsifier by changing pH can be used.
  • the initial concentration of the fluorine-containing emulsifier in the wastewater refers to the concentration before the pretreatment step when the pretreatment step is performed, and the emulsifier fixing step is performed without performing the pretreatment step In this case, it refers to the concentration before the emulsifier fixing step.
  • the substances that can become suspended solids include the metal salt used for salting out and coagulation of the fluorine-containing polymer and / or the substance that precipitates due to a change in pH of the coagulation wastewater and the temperature drop of Z or coagulation wastewater or Examples include substances that precipitate due to a rise in temperature.
  • the SS component include unagglomerated fluorine-containing polymer dispersed particles, agglomerated fluorine-containing polymer particles, foreign substances mixed in a wastewater treatment route, and metal salts precipitated on the acidic side. s If the S component remains in the coagulated wastewater, it does not adversely affect the recovery and recovery rate of the fluorine-containing emulsifier, but separates and regenerates the fluorine-containing emulsifier from the layered double hydroxide containing the fluorine-containing emulsifier between layers Efficiency at the time of this is reduced. Therefore, it is important to remove the SS component to 1% by mass or less before forming the layered double hydroxide. The SS component in the coagulated wastewater is more preferably removed to 0.3% by mass or less, particularly preferably to 0.05% by mass or less.
  • a pretreatment step for coagulating and removing the SS component contained in the wastewater after the polymerization of the fluorine-containing polymer may be performed prior to the emulsifier fixing step.
  • an inorganic acid is added to the wastewater to adjust its pH to 1 or more and less than 6.
  • the pH is 6 or more, the aggregation efficiency of the SS component is reduced.
  • the SS component is aggregated at a pH of 6 or more, fine aggregates are formed, and the separation tends to be difficult.
  • the pH of the wastewater is adjusted to 2 or more and less than 4.
  • Fluorine-containing emulsifiers tend to change from the salt form to the acid form when the pH is adjusted low.
  • the inorganic acid used for adjusting the pH of the wastewater one or more selected from the group consisting of sulfuric acid, nitric acid and hydrochloric acid is more preferred, and hydrochloric acid is most preferred.
  • these inorganic acids, particularly hydrochloric acid are used, the efficiency of recovering the fluorine-containing emulsifier and the Z- or acid-form fluorine-containing emulsifier into the layered double hydroxide in the subsequent emulsifier fixing step is improved.
  • a metal chloride or a hydrate of the metal chloride having a solubility in water of 25 T of 5% by mass or more is added.
  • the SS component contained in the wastewater is aggregated and removed.
  • the metal chloride used has a solubility of 25 in water of 5% by mass or more. This is because if the solubility is less than 5% by mass, the amount of metal chloride required for aggregation may not be dissolved.
  • the solubility is preferably at least 20% by mass, more preferably at least 40% by mass.
  • the metal chloride acts as a flocculant for the SS component.
  • a chloride of a polyvalent metal is preferable. Chloride of polyvalent metal has large cohesive force of SS component.
  • the metal chloride is more preferably at least one selected from the group consisting of aluminum chloride, aluminum chloride hexahydrate, aluminum chloride, ferrous chloride and ferric chloride.
  • the solubility of aluminum chloride, ferrous chloride and ferric chloride in water at 25 ° C is 46.8% by mass, 64.5% by mass and 91.9% by mass, respectively.
  • Aluminum chloride hexahydrate is 80% by weight.
  • Polyaluminum chloride can be mixed with water at any ratio.
  • the amount of the metal chloride to be added is preferably 10 ppm or more and less than 500 ppm, more preferably 10 ppm or more and less than 200 ppm, per mass of the wastewater. If the amount of the metal chloride is less than 10 ppm, the removal of the SS component tends to be insufficient. When the addition amount of the metal chloride is 500 ppm or more, the sedimentation of the aggregates is reduced, and the aggregate becomes sticky and hardly undergoes solid-liquid separation. Further, chloride ions derived from the metal chloride are removed. However, it tends to inhibit the fluorine-containing emulsifier from being included in the layered double hydroxide in the subsequent emulsifier fixing step.
  • the waste water is preferably stirred.
  • the stirring method is not particularly limited, but a method that does not mechanically break the aggregate particles by stirring is preferable.
  • a stirring blade of such a stirring device a stirring blade capable of uniformly mixing the entire drainage at low speed is preferable, and one type selected from the group consisting of a full zone blade, a max blend blade, and an anchor blade is preferable.
  • the G value during stirring by the stirring blade is preferably 1 to 300 s- 1 , more preferably 5 to 250 s- 1, and most preferably 10 to 200 s-11.
  • the G value refers to a value derived by the following equation (1). G... (1)
  • a general solid-liquid separation method can be adopted as a method for removing the aggregate of the SS component which has been aggregated by adding the metal chloride or the hydrate of the metal chloride to the wastewater.
  • the filtration is preferably performed under pressure. Further, it is preferable that the wastewater containing the aggregate is allowed to stand, the aggregate is settled, and the supernatant is filtered to remove the aggregate. Thickeners or screw decanters are most preferable in terms of facility maintenance.
  • the content of the SS component in the coagulated wastewater can be reduced to about 0.01 to 45 ppm, more preferably 0.01 to 45 ppm. It can be 20 ppm, most preferably 0.01 to 10 ppm. It is not preferable to reduce the S S component to less than 0.01 ppm because the amount of the metal chloride added increases.
  • the pretreatment step of adding the metal chloride or its hydrate to the wastewater to coagulate the SS component a part of the fluorine-containing emulsifier contained in the wastewater coagulates together with the SS component. As a result, the recovery efficiency of the fluorine-containing emulsifier may be reduced.
  • the fluorine-containing emulsifier coagulated together with the SS component from the coagulated material into the wastewater by increasing the pH of the waste water after coagulating the SS component.
  • the pH range is desirably from 8 to less than 11, more desirably from 9 to less than 10. If the pH of the wastewater is less than 8, the elution efficiency of the fluorine-containing emulsifier decreases, and if the pH becomes 11 or more, the re-dispersion of the aggregated SS component is likely to occur. Further, when increasing the pH of the wastewater, it is preferable to add sodium hydroxide and Z or a hydroxide hydration agent.
  • the coagulated waste water or the coagulated waste water that has completed the pretreatment step is led to an emulsifier fixing step of fixing the fluorine-containing emulsifier to the layered double hydroxide by a coprecipitation method, an ion exchange method, or a reconstruction method.
  • the emulsifier fixing step of the coprecipitation method the pH of the coagulated waste water or the coagulated waste water after the pretreatment step is converted into a layered divalent metal ion and a trivalent metal ion used for forming a layered double hydroxide.
  • the layered double hydroxide is formed by adding divalent metal ions and trivalent metal ions while maintaining the value at which double hydroxides are formed.
  • the layered double hydroxide contains the fluorine-containing emulsifier contained in the coagulated wastewater between the layers.
  • a mixed aqueous solution containing both divalent metal ions and trivalent metal ions may be added to the coagulated wastewater, and a divalent metal aqueous solution containing divalent metal ions and a trivalent metal aqueous solution containing trivalent metal ions are respectively added to the wastewater. It may be added separately to the coagulated wastewater.
  • the divalent and trivalent metal ions used to generate the layered double hydroxide may be prepared by adding each aqueous solution individually, but a mixed solution of divalent and trivalent metal ions is prepared. It is more preferable to add them.
  • the pH of the coagulated wastewater is adjusted to a value at which the divalent metal ion and the trivalent metal ion used to form the layered double hydroxide form a layered double hydroxide.
  • the pH of the coagulated wastewater is adjusted by adding hydrochloric acid and / or Z or acid and / or Z or nitric acid if the coagulated wastewater is alkaline, and potassium hydroxide and / or Z or hydroxylated if the coagulated wastewater is acidic. This is done by adding sodium.
  • pH is set to 6 Adjust the pH to 9 or less, and when using aluminum ion as the trivalent metal ion and magnesium ion (hydroxide formation pH 10 to 14) as the divalent metal ion, adjust the PH to 9 or more and less than 11 Adjustment is preferred.
  • the pH is preferably adjusted to 6 or more and 9 or less.
  • the molar ratio of divalent metal ions to trivalent metal ions added to the coagulated wastewater is in the range of 10:90 to 90:10, preferably 50:50 to 8 3: It is 17.
  • the recovery ratio of the fluorine-containing emulsifier is highest in the range of 2 mol times to 4 mol times, and the ratio of divalent metal ions to trivalent metal ions is 2 mol.
  • the amount is less than 2 times or more than 4 times, the fluorine-containing emulsifier can be recovered, but the recovery rate decreases.
  • trivalent metal ions play a role as a adsorption site for the fluorine-containing emulsifier, and divalent metal ions serve as a spacer for maintaining the distance between the adsorption sites. Therefore, when the molecular size of the fluorine-containing emulsifier is larger than that of the adsorption site, by keeping the distance between the adsorption sites, all the adsorption sites, that is, trivalent metal ions can effectively adsorb the fluorine-containing emulsifier. If this distance is insufficient, trivalent metal ions that do not function as adsorption sites are present in the layered double hydroxide, which is inefficient.
  • the amount of the trivalent metal ion to be added to the coagulated wastewater is 1 mol or more and 30 mol or less, more preferably 1 mol, based on the fluorine-containing emulsifier in the coagulated wastewater. Not less than 5 mole times.
  • the amount of the metal ion used is less than the above range, the recovery of the fluorine-containing emulsifier is insufficient, and when the amount is more than the above range, the mixed aqueous solution, or the aqueous trivalent metal solution and the aqueous divalent metal solution are used. As the amount increases, the concentration of the fluorine-containing emulsifier relatively decreases, and the recovery rate does not become sufficiently high.
  • the concentrations of the divalent metal ion and the trivalent metal ion in the mixed aqueous solution or the trivalent metal aqueous solution and the divalent metal aqueous solution are each preferably from 0.1 mol ZL to 2 mol. If the metal ion concentration is smaller than the above range, the amount of the aqueous solution required for adding the required amount of metal ion increases, and the result is large. As a result, the concentration of the fluorine-containing emulsifier decreases, and the recovery efficiency decreases.
  • the metal ion concentration exceeds the above range, when the mixed aqueous solution, or the trivalent metal aqueous solution and / or the divalent metal aqueous solution is acidic, the addition of these aqueous solutions causes a part of the coagulated wastewater to be removed.
  • the PH locally deviates from the optimum range for forming the layered double hydroxide, and the added metal ions are not effectively used for forming the layered double hydroxide.
  • the method of adding metal ions to the coagulated wastewater is not particularly limited, but the added metal ion, such as dropping the mixed aqueous solution containing the metal ions or the trivalent metal aqueous solution and the divalent metal aqueous solution into the coagulated wastewater, is used. It is preferable to use a method in which the particles are instantaneously diffused in the system.
  • the stirring method is not particularly limited, but is preferably a method that does not mechanically destroy the aggregate particles generated by the stirring.
  • a stirring blade of such a stirring device a stirring blade capable of uniformly mixing the entire drainage at a low speed is preferable, and one type selected from the group consisting of a full zone blade, a max blend blade, and an anchor blade is preferable.
  • G value during stirring at the stirring blade 1 to 3 0 0 s-1 is rather preferred, more preferably 5 ⁇ 2 5 0 s- 1, 1 0 ⁇ 2 0 0 s 1 is most preferred.
  • the G value is a value derived from the equation (1).
  • the aqueous solution containing metal ions is dropped into the coagulated wastewater in a sealable reaction vessel.
  • an inert gas such as nitrogen gas or argon gas. It is preferable to seal the reaction vessel after bubbling or expelling carbonate ions and / or carbon dioxide gas with an inert gas. This is to prevent the layered double hydroxide from reacting with the carbonate ion and hindering the recovery of the fluorine-containing emulsifier.
  • the flow rate of the inert gas when publishing is performed is preferably 0.1 Nm 3 / m 3 'h: L 0 Nm 3 / m 3 ' h, and 0.1 Nm 3 Zm 3 l!
  • the layered double hydroxide is efficiently formed at a reaction temperature of 5 ° C to 50 ° C, and more preferably at a temperature of 10 ° C to 45 ° C. If the reaction temperature is lower or higher than this, the recovery of the fluorine-containing emulsifier by the layered double hydroxide will decrease. In particular, since the recovery at lower temperatures is significantly reduced, it is preferable to equip the reactor with a temperature controller.
  • the dropping of the aqueous solution containing the metal ions into the coagulated wastewater is performed over a period of 10 minutes or more and 3 hours or less. If the aqueous solution containing metal ions is added in a shorter time than this, the aqueous solution containing metal ions is acidic, so that a part of the coagulated wastewater is optimal for forming a layered double hydroxide locally. Outside the range of H, metal ions may not be effectively used for forming layered double hydroxides.
  • the mixed aqueous solution may be added to a reactor to which coagulated waste water is continuously supplied.
  • the layered double hydroxide is continuously generated.
  • the residence time of the coagulated wastewater in the reactor is preferably in the range of 10 minutes to 3 hours.
  • a reaction solution in which the divalent metal ion and the trivalent metal ion maintain pH at a value at which a layered double hydroxide is formed The layered double hydroxide is generated by mixing the divalent metal ion and the mixed aqueous solution containing the trivalent metal ion.
  • a reaction solution containing an anion other than the anion to be recovered an anion constituting the fluorine-containing emulsifier
  • the anion contained in the reaction solution include chloride ion, hydroxide ion, carbonate ion and the like. Particularly, carbonate ion is preferable.
  • a mixed aqueous solution containing metal ions is used as the anion other than the recovery purpose anion.
  • the layered double hydroxide generated in the layered double hydroxide generation step is mixed with the coagulated wastewater or the coagulated wastewater that has been subjected to the pretreatment step.
  • the pH of the wastewater is maintained at a value at which the divalent metal ion and the trivalent metal ion form a layered double hydroxide.
  • a layered double hydroxide containing the fluorine-containing emulsifier contained in the wastewater between layers is generated.
  • the reconstruction method first, in the step of forming a sintered body, in the same manner as in the step of forming a layered double hydroxide in the ion exchange method, the layered composite containing anions other than the anion to be recovered is included in the reaction solution. After the hydroxide is generated, the obtained layered double hydroxide is fired to obtain a sintered body from which the anion contained in the layered double hydroxide has been removed.
  • the calcined product generated in the layered double hydroxide generation step is mixed with the coagulated waste water or the coagulated waste water having undergone the pretreatment step.
  • the pH of the wastewater is maintained at a value at which the divalent metal ion and the trivalent metal ion form a layered double hydroxide.
  • a layered double hydroxide containing a fluorine-containing emulsifier contained in the wastewater between layers is generated.
  • the adjustment of the pH of the reaction solution in the step of forming a layered double hydroxide in the ion exchange method and the adjustment of the pH of the reaction solution in the step of forming a fired body in the reconstruction method are performed by adjusting the pH of the coagulated wastewater in the coprecipitation method. Can be performed in the same manner as the adjustment of
  • the molar ratio of divalent metal ion: trivalent metal ion added to the reaction solution is 10:90 to It is preferably in the range of 90:10, more preferably 50:50 to 83:17.
  • the ratio of divalent metal ions to trivalent metal ions is in the range of 2 mol times to 4 mol times, and the recovery rate of the fluorine-containing emulsifier is highest, and the ratio of divalent metal ions to trivalent metal ions is high.
  • the amount is less than 2 times or more than 4 times, the fluorine-containing emulsifier can be recovered, but the recovery rate decreases.
  • a mixture containing the divalent metal ion and the trivalent metal ion added to the reaction solution.
  • the metal ion concentration in the combined aqueous solution is preferably not less than 0.01 lmo 1 and not more than 211101 / L for each of the divalent metal ion and the trivalent metal ion. If the metal ion concentration is less than this, the amount of water increases when the required metal ions are added, and in particular, the ion exchange method and the reconstruction method require more water to separate the layered double hydroxide produced. They tend to be less economical with effort. If the metal ion concentration exceeds the above upper limit, the mixed aqueous solution is acidic.
  • an optimum p is set so that a part of the reaction solution locally forms a layered double hydroxide.
  • a layered double hydroxide can be generated by adding a mixed aqueous solution having an appropriate concentration range again.
  • the method for adding metal ions to the reaction solution is not particularly limited, but a method in which the added metal ions are instantaneously diffused in the system, such as by dropping a mixed aqueous solution containing metal ions into the reaction solution, is preferable. .
  • the reaction solution is preferably stirred in the same manner as in the emulsifier fixing step in the coprecipitation method.
  • the layered double hydroxide is efficiently formed at a reaction temperature of 5 ° C. to 50 ° C., and more preferably at a temperature of 10 to 45 ° C. If the reaction temperature is lower or higher than this, the recovery of the fluorine-containing emulsifier by the layered double hydroxide will decrease. In particular, since the recovery at lower temperatures is significantly reduced, it is preferable to equip the reactor with a temperature controller.
  • the dropwise addition of the mixed aqueous solution to the reaction solution is performed over a period of 10 minutes to 3 hours.
  • the mixed aqueous solution is added in a shorter time, the mixed aqueous solution is acidic, and a part of the reaction solution deviates from the optimum pH range for locally forming a layered double hydroxide, Metal ions may not be effectively used for forming the layered double hydroxide.
  • the mixed aqueous solution is added to a reactor where the reaction solution is continuously supplied.
  • a layered double hydroxide is continuously produced.
  • the residence time of the coagulated wastewater in the reactor is preferably in the range of 10 minutes to 3 hours.
  • Adjustment of the pH of the coagulated wastewater in the emulsifier fixing step of the ion exchange method and the reconstitution method can be performed in the same manner as the adjustment of the pH of the coagulated wastewater in the coprecipitation method.
  • the ion exchange method and the reconstitution method when the pH of the coagulated wastewater is out of the preferable pH range described above, the coagulated wastewater and the previously generated layered double hydroxide or the calcined body of the layered double hydroxide are separated. When mixed, divalent and trivalent metals are eluted from the layered double hydroxide, and as a result, the recovery efficiency of the fluorine-containing emulsifier is significantly reduced.
  • the amount of the layered double hydroxide or the calcined body of the layered double hydroxide used when mixing with the coagulated wastewater is such that the trivalent metal ion is at least 1 mole times the fluorine-containing emulsifier in the coagulated wastewater.
  • the mixing is preferably performed so as to be 30 mol times or less, and more preferably 1 mol time or more and 5 mol times or less.
  • the flow rate of the inert gas when carrying out the bubbling 0. L Nm 3 / m 3 ⁇ h ⁇ 1 0 Nm 3 Zm 3 'h preferably, 0. 1 Nm 3 / m 3 ⁇ 1! ⁇ 5 Nm a Zm 3 ⁇ h is more preferred. If the gas flow rate is less than this, the removal of carbonate ions and / or carbon dioxide in the system will not be performed sufficiently. If the gas flow rate is greater than this, not only will the water evaporate along with the gas, but also coagulated wastewater due to heat of vaporization.
  • the temperature of the solution decreases, which is not preferable.
  • the fluorine-containing emulsifier is recovered by separating the layered double hydroxide containing a fluorine-containing emulsifier between the layers, which has been generated in the emulsifier fixing step of each of the coprecipitation method, the ion exchange method, and the reconstitution method, from the coagulated wastewater.
  • a method for separating the layered double hydroxide from the coagulated wastewater a well-known solid-liquid separation method can be appropriately used. In particular, one type selected from the group consisting of filtration, decantation, centrifugation and thickener It is more preferable to use the above method.
  • the filtration is also preferably performed under pressure.
  • the method of recovering a fluorine-containing emulsifier from a layered double hydroxide containing a fluorine-containing emulsifier between layers is, for example, a method of dissolving the layered double hydroxide in a mineral acid and extracting the fluorine-containing emulsifier using a fluorine-containing hydrocarbon.
  • Mineral acids used for dissolving the layered double hydroxide include hydrochloric acid, sulfuric acid, nitric acid and the like.
  • the fluorine-containing hydrocarbon used for the extraction of the fluorine-containing emulsifier preferably has 2 or 3 carbon atoms and contains at least one hydrogen atom and at least one fluorine atom. Fluoridylpropane, pendufluorfluorpropane, pendufluordichloropropane and the like.
  • the method of recovering a fluorine-containing emulsifier of the present invention is not limited to the above-mentioned fluorine-containing emulsifier, low-molecular-weight fluorine-containing power such as trifluoroacetic acid, pentafluorofluoropropanoic acid, and the like. It can also be applied to its salts.
  • the concentrations of APFO, perfluorooctanoic acid (hereinafter referred to as PFOA), and sodium perfluorooctanoate were determined by high performance liquid chromatography using a mixed solution of methanol and water as a solvent. It was measured using one mass spectrum method. Species to be detected by this method is per full O Roo Kuta Noe Ichito (C 7 F 1 5 COO I).
  • Example 1 (coprecipitation method, no pretreatment, using mixed aqueous solution)
  • the APFO concentration (initial concentration) of the coagulated waste water (containing 2300 ppm of SS component) after emulsion polymerization of PTFE was 148 ppm by measurement.
  • a 0.2N aqueous sodium hydroxide solution was added to the coagulated wastewater to adjust the pH to 10.0.
  • the liquid temperature was 26 ° C.
  • a mixed aqueous solution of aluminum chloride and magnesium chloride (A1 ion concentration: 0.075mo1ZL, Mg2 + ion: 0L) was added to 1L of coagulated wastewater (APFO content: 0.148g, 0.343mmo1) adjusted to this pH.
  • Example 1 the SS component in the coagulated wastewater was removed before the formation of the layered double hydroxide.
  • Example 2 0.130 g of aluminum chloride hexahydrate was added to 2 L of PTFE coagulated wastewater as in Example 1, and salting out was performed to coagulate uncoagulated PTFE particles and the like.
  • the pH of the coagulated wastewater was adjusted to 10.0 using 0.2 N sodium hydroxide.
  • the SS component concentration of the supernatant of the coagulated waste water was 2 Opm and the APFO concentration (initial concentration) was 141 ppm.
  • APFO was recovered in the same manner as in Example 1 using the supernatant obtained in this way (coagulated wastewater from which the SS component had been removed in advance).
  • a mixed aqueous solution of aluminum chloride and magnesium chloride was added to 1 L of the coagulated waste water (APFO content: 0.141 g, 0.327 mmo 1) from which the S S component was removed.
  • Example 1 the same operation was performed except that the coagulated wastewater after polymerization of TFE / HF P / Vd copolymer (33 component 530 111, APFO initial concentration 580 Ppm) was used instead of the coagulated wastewater after PTFE polymerization. went.
  • a mixed aqueous solution of aluminum chloride and magnesium chloride added to 1 L of this coagulated wastewater (? 0 content 0.580 g, 1.35 mmo 1) [ ⁇ + ion concentration 0.075 mol 1 ZL, Mg 2+ ion 0. [15mo1ZL] was 89.7mL [total amount of A1 ions: 6.73mmo1; total amount of Mg ions: 13.5mmo1].
  • the APFO concentration in the filtrate after removing the precipitate of the layered double hydroxide containing APFO is 8 ppm And eight? 0 recovery was 98.6%.
  • Table 1 The conditions and results of this example are shown in Table 1 below.
  • Example 2 The same operation was performed as in Example 1, except that the coagulated wastewater after TFE / E copolymer polymerization (SS component 460 ppm, APFO initial concentration 320 ppm) was used instead of the coagulated wastewater after PTFE polymerization. .
  • a mixed aqueous solution of aluminum chloride and magnesium chloride added to 1 L of this coagulated waste water [A + ion concentration 0.075 mo I ZL, Mg ion 0.1 51110 1/1 ⁇ ] was 49.5 mL [total amount of AI st ion 3.7 lmmo 1 and total Mg ion 7.43 mmo 1].
  • the APFO concentration in the filtrate after removing the precipitate of the APFO-containing layered double hydroxide was 6 ppm, and the 80 recovery was 98. 1%.
  • Table 1 The conditions and results of this example are shown in Table 1 below.
  • Example 1 the magnesium ions added to the coagulated wastewater were changed to zinc ions.
  • a 0.2 N aqueous sodium hydroxide solution was added to the same coagulated waste water after emulsion polymerization of PTFE as used in Example 1 to adjust the pH to 7.0.
  • the liquid temperature was 26 ⁇ .
  • 1 L of the coagulated wastewater (APFO content 0.148 g, 0.343 mmo 1) after pH adjustment was added to a mixed aqueous solution of aluminum chloride and zinc chloride [A 1 ion concentration 0.07 5 mol ZL, Zn ion 0 1.5 mol / L]
  • About 4.58 mL total amount of Al 3t ions 0.343 mmol, total amount of Zn 2+ ions 0.686 mmol] was dropped over 2 hours.
  • the coagulated wastewater was bubbled with nitrogen gas at a constant flow rate of 1 Nm 3 Zm 3 ′ h to remove dissolved carbonate ions and carbon dioxide in the aqueous solution.
  • a 0.2 N aqueous sodium hydroxide solution was appropriately added dropwise to adjust the pH to 6.5 or more and 7.5 or less.
  • the very pale milky liquid started to aggregate and started to form a white precipitate.
  • Example 5 the SS component in the coagulated wastewater was removed before the formation of the layered double hydroxide.
  • Example 1 After removing the SS component from the PTFE coagulated wastewater as in Example 1 in the same manner as in Example 2, using the operating conditions shown in Table 1, a layered double hydroxide was generated according to the operating procedure in Example 5. Then, when the APFO was recovered, the recovery rate of APFO was 98.6%.
  • Table 1 The conditions and results of this example are shown in Table 1 below.
  • Example 3 the magnesium ions added to the coagulated wastewater were changed to zinc ions.
  • the layered double hydroxide was generated according to the operating procedure of Example 3, and the APFO was recovered.
  • the pH of the coagulated wastewater was adjusted to 7.0, and the pH was adjusted to 6.5 or more and 7.5 or less during the dropwise addition of the mixed aqueous solution of aluminum chloride and zinc chloride.
  • the recovery rate of APFO was 98.8%. Table 1 shows the conditions and results of this example.
  • Example 4 the magnesium ions added to the coagulated wastewater were changed to zinc ions.
  • the layered double hydroxide was prepared according to the operating procedure of Example 4 using the operating conditions shown in Table 1.
  • the material was generated and the APFO was collected.
  • the pH of the coagulated wastewater was adjusted to 7.0, and the pH was adjusted to 6.5 or more and 7.5 or less during the dropwise addition of the mixed aqueous solution of aluminum chloride and zinc chloride.
  • the recovery rate of APFO was 98.4%.
  • Table 1 shows the conditions and results of this example.
  • APFO was recovered in the same manner as in Example 1, except that a hydroxide hydration power was used instead of sodium hydroxide as the alkaline aqueous solution for pH adjustment. As a result, the recovery rate of AP FO was 98.6%.
  • the conditions and results of this example are shown in Table 1 below.
  • Example 10 (Coprecipitation method, no pretreatment, use of mixed aqueous solution, low pH of coagulation wastewater)
  • the pH of coagulation wastewater was adjusted to 7.0, and the pH during dripping was 6.8 or more.
  • the AP FO was collected by adjusting it to 2 or less.
  • the concentration (initial concentration) of APFO was measured to be 148 ppm in the coagulated wastewater (containing 2300 ppm of SS component) after emulsion polymerization of PTFE.
  • a 0.2N aqueous sodium hydroxide solution was added to the flocculated wastewater to adjust the pH to 7.0.
  • the liquid temperature was 26 ° C.
  • a mixed aqueous solution of aluminum chloride and magnesium chloride [octane concentration 075 mol ZL, Mg ion 0 L] was added to 1 L of the coagulated wastewater (AP FO content 0.148 g, 0.343 mmo 1) whose pH was adjusted.
  • the dried precipitate was analyzed by differential thermogravimetric analysis (DTA), infrared absorption spectrum (IR), and XRD.
  • DTA differential thermogravimetric analysis
  • IR infrared absorption spectrum
  • XRD X-ray diffraction
  • Example 11 (Coprecipitation method, no pretreatment, use of mixed aqueous solution, no pH adjustment of coagulated wastewater)
  • pH adjustment of coagulated wastewater was not performed before adding the mixed aqueous solution containing metal ions.
  • the mixed aqueous solution was added all at once without dripping, and the pH of the coagulated wastewater was not adjusted during the addition of the mixed aqueous solution.
  • Example 7 TFE / HFP / VdF2 530 None 580 Al Zn 1 2 7 2 NaOH 7 98.8
  • Example 8 TFE / E 460 None 320 Al Zn 1 2 7 2 NaOH 5 98.4
  • Example 9 PTFE 2300 None 148 Al Mg 5 10 10 2 KOH 2 98.6
  • Example 10 PTFE 2300 None 148 Al Mg 5 10 7 2 NaOH 108 26.7
  • Example 1 1 PTFE 2300 None 1 48 Al Mg 5 100 NaOH 138 6.76
  • the concentration of APF ⁇ was measured on the coagulated wastewater (? Concentration 2300 mass 111) after emulsion polymerization of PTFE and was 148 ppm.
  • a 0.2 N aqueous sodium hydroxide solution was added to adjust the pH to 10.0.
  • the liquid temperature was 26 ° C.
  • This coagulated wastewater is added at a constant flow rate of 4.5 LZ to a tightly closed 5 L glass reactor equipped with two metering pumps, a pH meter, a stirrer, and a capacity meter using a metering pump. I let it.
  • the glass reactor was set to be automatically adjusted by a volume meter so that the internal volume became 3 L.
  • the residence time of the coagulated wastewater in the glass reactor was 40 minutes.
  • the aqueous solution discharged from the reactor was stored in another 10-L container made of polyethylene.
  • a mixed aqueous solution of aluminum chloride and magnesium chloride [A1 ion concentration 0.075 mol / L, Mg2 + ion 0.15 mol1 / L] was continuously added to this glass reactor at a constant flow rate of 103 mLZ. .
  • the pH was adjusted to 9.8 or more and 10.2 or less by appropriately adding 0.2 N aqueous sodium hydroxide solution.
  • Example 13 (coprecipitation method, no pretreatment, use of mixed aqueous solution, large pH of coagulated wastewater)
  • the pH of the coagulated wastewater was changed to 11.
  • the concentration of APFO in the coagulated waste water after the emulsion polymerization of PTFE was 148 ppm, which was the same as in Example 1.
  • a 0.2 N aqueous solution of sodium hydroxide was added to the coagulated wastewater to adjust the pH to 11.0.
  • the liquid temperature was 26 ° C.
  • the coagulated waste water was bubbled with nitrogen gas at a constant flow rate of 1 Nm 3 Zm h to remove dissolved carbon ions and carbon dioxide gas from the aqueous solution.
  • a 0.2N aqueous sodium hydroxide solution was appropriately added dropwise to adjust the pH to 10.8 or more and 11.2 or less.
  • the extremely thin milky white liquid began to aggregate and began to form a white precipitate.
  • the formation of the precipitate was completed.
  • Example 14 (Coprecipitation method, no pretreatment, use of mixed aqueous solution, large pH of coagulated wastewater)
  • concentration of APFO was measured to be 148 ppm in the post-coagulated wastewater after emulsion polymerization of PTFE.
  • a 0.2 N aqueous sodium hydroxide solution was added to the coagulated wastewater to adjust the pH to 10.0.
  • the liquid temperature was 26 ° C. Then adjust this pH.
  • the coagulated wastewater was bubbled with nitrogen gas at a constant flow rate of 1 Nm 3 Zm 3 ′ h to remove dissolved carbonate ions and carbon dioxide gas in the system. Also during dropwise G value using Anne force part was continued stirring such that the 100 s 1. Dropping was performed at room temperature (about 25 ° C), and no special temperature control was performed. Approximately 2 minutes after the start of the dropwise addition of the mixed aqueous solution, the coagulated wastewater began to become cloudy, and a white precipitate was generated over time. When the dropping of the mixed aqueous solution was completed and the stirring was stopped, the white precipitate started to settle. It settled out completely in about 5 minutes, and the supernatant was colorless and transparent.
  • the precipitate was collected by filtration through a membrane filter having an average diameter of 3 m, and the precipitate was dried together with the filter paper at 70 ° C for 15 hours.
  • DTA differential thermal mass spectrometry
  • IR infrared absorption spectrum
  • XRD X-ray diffraction
  • Example 16 (Coprecipitation method, no pretreatment, use of mixed aqueous solution, small amount of metal ions added)
  • the type of coagulation wastewater was changed, and addition of metal ions to AP FO contained in coagulation wastewater The amount was changed and AP FO was collected.
  • a mixed aqueous solution of magnesium chloride and aluminum chloride 2. 2mL (Mg ion 0. 325mmo1, Al 3t ion 0.162mmo1 contained.
  • Example 15 The same operation as in Example 15 was performed, except that A1 ion was added dropwise over 7 minutes to the amount of APFO over 8 minutes (0.13 hours).
  • the pH of the coagulated wastewater was kept at 10 using 0.2 mol ZL of sodium hydroxide.
  • the supernatant was separated by filtration and analyzed in the same manner as in Example 15 to quantify the concentration of anion for the purpose of adsorption.
  • the AP FO concentration of the coagulated waste water (containing 40 ppm of SS component) after emulsion polymerization of PTFE was 148 ppm.
  • a 0.2N aqueous sodium hydroxide solution was added to the flocculated wastewater to adjust the pH to 10.0.
  • the liquid temperature was 26.
  • a mixed aqueous solution of aluminum chloride and magnesium chloride [A 1 ion concentration 0.075mo 1 / L, Mg 2+ ion] was added to 1 L of coagulated wastewater (APFO content 0.148 g, 0.343 mmo 1) whose pH was adjusted. 0.
  • Example 17 To the same coagulated waste water used in Example 17 was added a 0.2 N aqueous sodium hydroxide solution to adjust the pH to 7.0. The liquid temperature was 26. Next, a mixed aqueous solution of aluminum chloride and zinc chloride [A 1 ion concentration 0.075 mol / l] was added to 1 L of the concentrated wastewater (APFO content 0.148 g, 0.343 mmo 1) whose pH was adjusted. L, Z n " Ion 0.075 mol ZL] About 4.58 mL [A + total ion 0.343 mmol, total Zn ion 0.343 mmol] was added dropwise over 2 hours. During the dropping, stirring was continued using an anchor blade so that the G value became 100 s- 1 .
  • the coagulated waste water was bubbled with nitrogen gas at a constant flow rate of 1 Nm 3 Zm 3 ′ h to remove dissolved carbon ions and carbon dioxide gas in the aqueous solution.
  • a 0.2N aqueous sodium hydroxide solution was appropriately added dropwise to adjust the pH to 6.5 or more and 7.5 or less.
  • a very pale milky liquid began to aggregate and began to form a white precipitate.
  • a 0.2N aqueous sodium hydroxide solution was appropriately added dropwise to adjust the pH to 9.8 or more and 10.2 or less.
  • a white precipitate began to form.
  • Two hours after the start of the dropwise addition of the mixed aqueous solution the formation of the precipitate was completed.
  • the aqueous solution containing this precipitate is Added over 30 minutes to the coagulated wastewater (SS content 400 ppm, APFO concentration 148 ppm) after emulsion polymerization of PT FE, adjusted to pH 10.0 by adding 0.2N aqueous sodium hydroxide solution did.
  • the weight of the precipitate after calcination was 14 Omg.
  • the calcined product was added to a 0.2 N aqueous solution of sodium hydroxide to adjust the pH to 10.0, and was added to the wastewater after flocculation after PTFE emulsion polymerization (SS content 400 ppm, AP concentration 148 111). did.
  • stirring was continued using an anchor blade so that the G value became 100 s- 1 .
  • the resulting solution was filtered with a m filter.
  • the precipitate was dried together with the filter paper at 70 ° C. for 15 hours.
  • Example 21 (Coprecipitation method, no pretreatment, use of mixed aqueous solution, metal ion ratio 95: 5) 0.2 N sodium hydroxide aqueous solution was added to the same wastewater used in Example 17 to adjust the pH. Adjusted to 10.0. The liquid temperature was 26 ° C.
  • the coagulated wastewater was bubbled with nitrogen gas at a constant flow rate of 1 Nn / m 3 'h to remove dissolved carbon ions and carbon dioxide gas in the aqueous solution.
  • a 0.2N aqueous sodium hydroxide solution was appropriately added dropwise to adjust the pH to 9.8 or more and 10.2 or less.
  • a very pale milky liquid began to aggregate and began to form a white precipitate.
  • Example 22 (Coprecipitation method, no pretreatment, use of mixed aqueous solution, metal ion ratio 5:95) 0.2 N sodium hydroxide aqueous solution was added to the same wastewater used in Example 17 to adjust the pH. Adjusted to 7.0. The liquid temperature was 26 ° C.
  • the pH was adjusted to 6.5 or more and 7.5 or less by appropriately adding a 0.2 N aqueous sodium hydroxide solution during the dropwise addition.
  • a 0.2 N aqueous sodium hydroxide solution Immediately after the dropping of the aqueous solution of zinc chloride and zinc chloride, the very pale milky liquid began to aggregate and began to form a white precipitate.
  • the precipitate was dried together with the filter paper for 15 hours at 70 ° C.
  • the precipitate was analyzed by differential thermogravimetric analysis (DTA;), infrared absorption spectrum (IR), and XRD.
  • a peak attributed to PTFE, a peak attributed to PFOA, and a peak attributed to layered double hydroxide were detected, indicating that this precipitate was formed by precipitation of PTFE and PFOA together with layered double hydroxide.
  • the concentration of APFO was 130 ppm, and thus the recovery of APFO was 11.8%.
  • Example 23 (Coprecipitation method, no pretreatment, use of mixed aqueous solution, coagulated wastewater 0 ° C)
  • the concentration of AP FO in the coagulated waste water (containing 400 ppm of SS component) after emulsion polymerization of PTFE was 148 ppm when measured.
  • 1 L of this wastewater (APFO content: 148 g, 0.343 mmo 1) was placed in a 2 L reactor, and the pH was adjusted to 10.0 by adding a 0.2 N aqueous sodium hydroxide solution.
  • Example 24 (Coprecipitation method, no pretreatment, use of mixed aqueous solution, metal ion dripping time of 5 minutes)
  • the temperature inside the reactor was set to 25 ° C with a warm bath.
  • the same operation was performed except that the time was adjusted to C and the dropping time of the divalent and trivalent metal ions was set to 5 minutes.
  • Analysis of the resulting supernatant showed that the concentration of APFO was 84.2 ppm, and thus the fixation rate of PFOA contained in the layered double hydroxide was 60.3%.
  • Example 25 (Coprecipitation method, no pretreatment, use of mixed aqueous solution, coagulated wastewater at 60 ° C)
  • 1 L of coagulated wastewater used in Example 23 set the temperature at the time of dropping divalent and trivalent metal ions to 60 ° C. Except for adjusting to C, the same operation was performed. Analysis of the resulting supernatant revealed that the APFO concentration was 20.1%, and thus the fixation rate of PFOA contained in the layered double hydroxide was 85.2%.
  • Example 26 (coprecipitation method, with pretreatment, using mixed aqueous solution)
  • the coagulated wastewater after coagulation and separation of PTFE from the aqueous dispersion of PTFE obtained by polymerizing TFE using APFO as an emulsifier contains 400 ppm of SS component mainly composed of non-coagulated PTFE dispersed particles.
  • the concentration of APF0 in the coagulated wastewater was 1668 ppm
  • the pH was 4.5.
  • a 0.2N aqueous sodium hydroxide solution was added to the coagulated wastewater to adjust the pH to 10.0.
  • the liquid temperature was 26.
  • a mixed aqueous solution of aluminum chloride and magnesium chloride [A 1 ion concentration 0.07 5mo 1 ZL Mg ion 0. ⁇ ⁇ ) was added to 10 L of the coagulated wastewater (AP FO content 1.26 g 2.92 mmo 1).
  • AP FO content 1.26 g 2.92 mmo 1).
  • the coagulated waste water was bubbled with nitrogen gas at a constant flow rate of 1 Nm 3 Zm 3 ′ h to remove dissolved carbon ions and carbon dioxide gas in the aqueous solution.
  • a 0.2 N aqueous sodium hydroxide solution was appropriately added dropwise to adjust the pH to 9.8 or more and 10.2 or less.
  • a very pale milky liquid began to aggregate and began to form a white precipitate.
  • the precipitate was subjected to solid-liquid separation, 100 g of 10% by mass hydrochloric acid was added, and the mixture was stirred at room temperature for 3 hours and heated to 70 ° C to separate into an upper aqueous solution and a lower oil layer. .
  • the lower oil layer contained 1.05 g of PFOA, and the recovery of the fluorine-containing emulsifier from the coagulated wastewater before removing the SS component was 65.1%.
  • Example 26 when an AP FO separation operation was performed in the same manner as in Example 26, an oil layer containing 1.02 g of PFOA was obtained, and the recovery from the coagulated wastewater before removing the SS component was 63.2%. .
  • a 0.2N aqueous sodium hydroxide solution was added to distilled water to adjust the pH to 10.0.
  • the liquid temperature was 26 ° C.
  • the solution 1 L aluminum mixed aqueous solution of chloride mug Neshiumu chloride [eight 1 3+ Ion concentration 0. 07 5mo l ZL, Mg ion 0. 1 5MO 1 ZL] about 229 mL [A 1 ion total 1 ⁇ . 2 mm ⁇ 1, Mg ion total amount 34.3 mmo 1] was added dropwise over 2 hours. During the dropwise addition the G value and stirring was continued so that the 1 00 s 1 and have use an anchor blade.
  • coagulated wastewater after coagulation and separation of PTFE from an aqueous dispersion of PTFE obtained by polymerizing TFE using APFO as an emulsifier (SS component 400 ppm, APF ⁇ concentration 168 ppm, The pH was adjusted to 10.0 by adding 0.2 N sodium hydroxide to pH4.5) 10.
  • a 0.2 N aqueous solution of sodium hydroxide was added to distilled water to adjust the pH to 10.0.
  • the liquid temperature was 26 ° C. 1.82 g (17.2 mmo 1) of sodium carbonate was dissolved therein. Then mixed aqueous solution of dilute sodium carbonate solution 1 L aluminum chloride dihydrate ⁇ beam chloride Maguneshiumu [A 1 ion concentration 0. 0 75 mo 1 / L, Mg 3 ⁇ 4 ion 0 - 1 5mo 1 ZL] about 2 2 9 mL [ A 1 Total ion amount 17.2 mm
  • the precipitate of the layered double hydroxide calcined above was added, and the mixture was stirred at room temperature for 1 hour. When the stirring was stopped, the precipitate slowly settled out. Deposit the sediment with an average diameter of 3 im It was collected by filtration with a membrane filter. As a result of analyzing the supernatant, the fixing ratio of APFO to the layered double hydroxide was 54.9%. Further, when the separation of APFO was performed in the same manner as in Example 26, 100 g of 10% by mass hydrochloric acid was added, and the mixture was stirred at room temperature for 3 hours, and the precipitate was not sufficiently dispersed.
  • the mixture was heated to 70 and filtered while hot with a membrane filter having an average diameter of 3 zm, and the lower oil layer was separated.
  • the oil reservoir contained 0.17 g of PFOA, with a recovery of 10.1% from coagulated wastewater.
  • a fluorine-containing emulsifier can be collect

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  • Chemical & Material Sciences (AREA)
  • Hydrology & Water Resources (AREA)
  • Thermal Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Inorganic Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • Water Supply & Treatment (AREA)
  • Organic Chemistry (AREA)
  • Separation Of Suspended Particles By Flocculating Agents (AREA)
  • Removal Of Specific Substances (AREA)
  • Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)

Abstract

L'invention concerne un procédé de récupération d'un agent émulsifiant fluorochimique à partir d'eaux usées provenant de la polymérisation en vue de la production de fluoropolymère. Ces eaux contiennent l'agent émulsifiant fluorochimique. Dans ces eaux usées, la teneur en matières et substances solides en suspension qui peuvent devenir des matières solides en suspension est inférieure ou égale à 1% en poids. Ce procédé consiste à utiliser des ions métalliques divalents et trivalents pour former un hydroxyde composite lamellaire afin de piéger l'agent émulsifiant fluorochimique contenu dans les eaux usées entre des feuilles de l'hydroxyde lamellaire composite . En outre, ce composé consiste à séparer l'hydroxyde composite lamellaire des eaux usées. Ainsi, un agent émulsifiant fluorochimique peut être aisément retiré en vue de sa récupération avec efficacité des eaux usées provenant de la coagulation d'un fluoropolymère.
PCT/JP2003/000658 2002-01-25 2003-01-24 Procede de recuperation d'un agent emulsifiant fluorochimique WO2003066532A1 (fr)

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JP2002-16618 2002-01-25
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JP2002-17536 2002-01-25
JP2002-17543 2002-01-25
JP2002017536 2002-01-25
JP2002017539 2002-01-25
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JP2002017543 2002-01-25
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JP2002368452A JP2003285075A (ja) 2002-01-25 2002-12-19 フッ素含有乳化剤回収方法

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JP4770802B2 (ja) * 2007-06-26 2011-09-14 ダイキン工業株式会社 排水処理方法
WO2012043870A1 (fr) * 2010-10-01 2012-04-05 Daikin Industries, Ltd. Procédé de récupération de tensioactif fluoré
WO2021070446A1 (fr) * 2019-10-11 2021-04-15 日本国土開発株式会社 Procédé de traitement de liquide

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0648742A (ja) * 1992-07-27 1994-02-22 Nitto Chem Ind Co Ltd 層間化合物
JPH10279307A (ja) * 1997-03-31 1998-10-20 Co-Op Chem Co Ltd 層状複水酸化物と糖類の複合体及びその製造方法、並びに糖類の回収材
WO1999062830A1 (fr) * 1998-06-02 1999-12-09 Dyneon Gmbh & Co. Kg Procede pour la recuperation d'acides alcanoiques fluores dans des eaux residuaires
WO2000059629A1 (fr) * 1999-04-06 2000-10-12 Japan Science And Technology Corporation Procede de fabrication de composes intercales d'hydroxyde double stratifies anioniques et produits ainsi fabriques

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0648742A (ja) * 1992-07-27 1994-02-22 Nitto Chem Ind Co Ltd 層間化合物
JPH10279307A (ja) * 1997-03-31 1998-10-20 Co-Op Chem Co Ltd 層状複水酸化物と糖類の複合体及びその製造方法、並びに糖類の回収材
WO1999062830A1 (fr) * 1998-06-02 1999-12-09 Dyneon Gmbh & Co. Kg Procede pour la recuperation d'acides alcanoiques fluores dans des eaux residuaires
WO2000059629A1 (fr) * 1999-04-06 2000-10-12 Japan Science And Technology Corporation Procede de fabrication de composes intercales d'hydroxyde double stratifies anioniques et produits ainsi fabriques

Non-Patent Citations (1)

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Title
KIYOSHI NUNODA: "Perfluoro kaimen kasseizai ion no sangyonai kaishu eno sojo kagobutsu no oyo", CSJ: THE CHEMICAL SOCIETY OF JAPAN, KOEN YOKOSHU, no. 80, 7 September 2001 (2001-09-07), pages 41, XP002968455 *

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