JP4904476B2 - Surfactant collection and recovery agent - Google Patents

Description

  The present invention relates to a surfactant collecting / recovering agent.

  Fluorosurfactant has the unique property of repelling water and oil. Utilizing this property, for example, it is used for a wide range of applications in a wide range of other fields such as a surface treatment agent for frying pan, a water repellent such as wax, a digestive agent for digestion and the like.

  However, a fluorosurfactant having a perfluoroalkyl group such as perfluorooctanoic acid is a hardly decomposable substance and does not readily decompose even when released into the environment. It is desirable not to discharge it. In view of the reuse of the separated and recovered perfluorooctanoic acid, the higher the concentration of the separated and recovered solution is, the more convenient for reuse.

  As a method for separating and recovering perfluorooctanoic acid, a method using a commercially available anion exchange resin has been reported (Patent Document 1). However, in these methods, the adsorption limit of perfluorooctanoic acid to an anion exchange resin is small, and it has been difficult to selectively adsorb and concentrate a fluorosurfactant efficiently. In addition, there is a disadvantage that a high concentration alkaline solution is required to desorb and recover after adsorption.

JP 2002-59160 A

  An object of the present invention is to provide a collection / recovery agent that can efficiently and selectively collect and recover a surfactant contained in a medium, preferably a fluorosurfactant.

  The present inventors can efficiently and selectively collect a surfactant contained in a medium, preferably a fluorosurfactant, by using a collection / recovery agent obtained by introducing a thiazine dye into a carrier. The present inventors have found that it can be recovered, and have completed the present invention.

That is, the present invention relates to (1) a surfactant collection / recovery agent obtained by introducing a thiazine dye into a carrier through a covalent bond .

  The present invention also relates to (2) the collection / recovery agent according to (1), wherein the thiazine colorant is methylene blue.

  The present invention also relates to (3) the collection / recovery agent according to (1) or (2) above, wherein the surfactant is a fluorosurfactant.

  The present invention also relates to (4) the collection / recovery agent according to any one of (1) to (3), wherein the surfactant is a fluorine-based anionic surfactant.

  The present invention also relates to (5) the collection / recovery agent according to any one of (1) to (4), wherein the carrier is polymer particles.

  According to the present invention, it is possible to provide a collection / recovery agent that can efficiently and selectively collect and recover a surfactant contained in a medium, preferably a fluorine-based surfactant.

  Hereinafter, embodiments of the present invention will be described in detail.

  The collection / recovery agent of the present invention is obtained by introducing a thiazine dye into a carrier.

Examples of the thiazine dyes used in the present invention include methylene blue and methylene green, as well as thionine trimethylthionin, dimethylthionin, monomethylthionin, thionine, and methyl violet. Among these, surfactants Methylene blue is preferred from the standpoint of efficiently collecting the water. The structural formula of methylene blue is represented by the following formula.

  The collection / recovery agent of the present invention obtained by introducing the above methylene blue into a carrier is not an adsorption by an ion exchange action using a conventional anion exchange resin, but a hydrophobic group (for example, a perfluoroalkyl group) of a surfactant. Adsorbed by a hydrophobic bond between a fluorine chain or the like and a hydrophobic portion (for example, a benzene ring) in the molecular structure of methylene blue.

  In the present invention, the surfactant to be collected and collected is not particularly limited as long as it is a compound having both a hydrophobic part and a hydrophilic part in the same molecule and is soluble in water. Highly fluorinated surfactant is preferred.

  The fluorosurfactant is not particularly limited as long as it is a surfactant having a fluorine atom, and includes a fluorine atom as a hydrophobic portion and a hydrophilic portion such as a cationic group, an anionic group, a hydroxyl group, and an ether bond as a hydrophilic portion. Compounds having a perfluoroalkyl group, such as perfluoroalkyl group-containing carboxylic acid, perfluoroalkyl group-containing sulfonic acid, perfluoroalkyl group-containing phosphoric acid (ester), perfluoroalkyl group-containing oxide adduct, perfluoroalkyl group-containing ammonium, etc. The compound which has an alkyl group is mentioned. Among these, fluorine-based anionic surfactants such as a perfluoroalkyl group-containing carboxylic acid having a carboxylic acid group as a hydrophilic portion and a perfluoroalkyl group-containing sulfonic acid having an acidic group such as a sulfonic acid group are preferable. Such a fluorine-based anionic surfactant has a hydrophobic bond between a perfluoroalkyl group and a benzene ring of methylene blue, as well as interactions due to charges such as the amino group of methylene blue and the carboxylic acid group and sulfonic acid group of the fluorine-based anionic surfactant. This is preferable in that the amount collected is improved (see the schematic diagram of adsorption of perfluorooctanoic acid and methylene blue shown in FIG. 1). In FIG. 1, for the sake of simplification, the description of the fluorine atom of the perfluoroalkyl group part that is hydrophobically bonded to the methylene blue benzene ring is omitted. For this reason, conventional ion exchange can be performed by using the collection / recovery agent of the present invention for fluoroanionic surfactants having a carboxylic acid group or sulfonic acid group such as perfluorooctanoic acid or perfluorooctanesulfonic acid. About 9 times the amount (weight standard) can be adsorbed compared to the resin. In addition, when the collection / recovery agent of the present invention is used, recovery with a low-concentration alkaline aqueous solution becomes possible.

  The carrier used in the present invention is not particularly limited as long as it does not dissolve in the surfactant sample to be collected and collected, and examples thereof include styrene-divinylbenzene, acrylate, methacrylate, polyvinyl alcohol, and cellulose. Can be mentioned. The carrier used in the present invention is preferably a polymer particle, and the polymer particle has a functional group such as a hydroxyl group, an epoxy group, a halogen group such as chloro or bromo, etc., from the viewpoint of facilitating introduction of a thiazine dye. Polymer particles having a group are preferred, and polymer particles having an epoxy group are more preferred.

  As a method for synthesizing the polymer particles, known methods such as suspension polymerization, dispersion polymerization, soap-free polymerization and the like are used. From the viewpoint of ease of polymerization, aqueous suspension polymerization is more preferable. However, it is not limited to this.

  In the present invention, the polymer particles can be formed by a copolymerization reaction of a polymerizable carbon-carbon double bond of a non-crosslinkable polymerizable monomer and a crosslinkable polymerizable monomer.

  The non-crosslinkable polymerizable monomer is a monomer having one polymerizable carbon-carbon double bond in one molecule. Styrenic, acrylic and methacrylic non-crosslinkable polymerizable monomers may be mentioned. Examples of derivatives of these non-crosslinkable polymerizable monomers include derivatives having a hydroxyl group, a glycidyl group, a halogen and the like.

  As the derivative of styrene having a halogen, one in which a hydrogen atom of styrene is substituted with an atom such as chlorine or bromine and a side chain of an aromatic ring such as chloromethylstyrene is preferred. For example, chloromethyl styrene, dichloromethyl styrene, trichloromethyl styrene, tetrachloromethyl styrene, pentachloromethyl styrene, monoethyl chlorostyrene, diethyl chlorostyrene, triethyl chlorostyrene, tetraethyl chlorostyrene, pentaethyl chlorostyrene, monopropyl chlorostyrene , Dipropylchlorostyrene, tripropylchlorostyrene, tetrapropylchlorostyrene, pentapropylchlorostyrene, monobutylchlorostyrene, dibutylchlorostyrene, tributylchlorostyrene, tetrabutylchlorostyrene, pentabutylchlorostyrene, etc. And halogenated derivatives, etc. Examples of the derivative of the acrylic ester having halogen include chloromethyl methacrylate, chloroethyl methacrylate, chlorobutyltyl methacrylate, and the like.

  Examples of styrene derivatives having a glycidyl group include vinyl benzyl glycidyl ether and vinyl benzyl glycidyl ester. Examples of the acrylic acid and methacrylic acid derivatives having a glycidyl group include glycidyl acrylate, glycidyl methacrylate, glycidyl clonate, glycidyl itaconate, glycidyl fumarate, glycidyl malate, and the like.

  Examples of the styrene derivative having a hydroxyl group include styrene having 1 to 5 hydroxyl groups, and may have a hydrocarbon group other than the hydroxyl group. For example, monohydroxystyrene, dihydroxystyrene, trihydroxystyrene, tetrahydroxystyrene, pentahydroxystyrene, monomethylhydroxystyrene, dimethylhydroxystyrene, trimethylhydroxystyrene, tetramethylhydroxystyrene, pentamethylhydroxystyrene, monoethylhydroxystyrene, diethylhydroxy Styrene, triethylhydroxystyrene, tetraethylhydroxystyrene, pentaethylhydroxystyrene, monopropylhydroxystyrene, dipropylhydroxystyrene, tripropylhydroxystyrene, tetrapropylhydroxystyrene, pentapropylhydroxystyrene, monobutylhydroxystyrene, dibutylhydroxystyrene, tributyl Rokishisuchiren, tetrabutyl hydroxystyrene, penta butyl hydroxy styrene. Examples of the derivatives of acrylic acid and methacrylic acid having a hydroxyl group include hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, 2-hydroxy-3-phenyloxypropyl acrylate, 2-hydroxyethyl acrylate, 4 -Hydroxybutyl acrylate, neopentyl glycol monoacrylate, tetramethylol methane triacrylate, etc., 2-hydroxyethyl, hydroxypropyl methacrylate, hydroxybutyl methacrylate, 2-hydroxy-3-phenyloxypropyl methacrylate and 2- Hydroxyethyl methacrylate, 4-hydroxybutyl methacrylate, neopentyl glycol monomethacrylate, tetramethylol methane trimethacrylate, etc. It is. Examples of styrene derivatives having a glycidyl group include vinyl benzyl glycidyl ether and vinyl benzyl glycidyl ester. Examples of the acrylic acid and methacrylic acid derivatives having a glycidyl group include glycidyl acrylate, glycidyl methacrylate, glycidyl clonate, glycidyl itaconate, glycidyl fumarate, glycidyl malate, and the like.

  Among the non-crosslinkable polymerizable monomers, a non-crosslinkable polymerizable monomer having a hydroxyl group, a glycidyl group, a halogen group, or the like is preferable in terms of facilitating introduction of a thiazine-based dye, and has a glycidyl group. Non-crosslinkable polymerizable monomers are more preferred.

  The crosslinkable polymerizable monomer may be any monomer as long as it has two or more polymerizable groups in one molecule. Examples of the monomer having two polymerizable groups in one molecule include divinylbenzene, glycol and methacrylic acid or acrylic acid diesters such as ethylene glycol dimethacrylate, ethylene glycol diacrylate, propylene glycol dimethacrylate, and propylene. Glycol diacrylate, 1,3-butylene glycol dimethacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol dimethacrylate, 1,4-butanediol diacrylate, 1,5- Pentanediol dimethacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol dimethacrylate, 1,6-hexanediol diacrylate, neopentyl glycol dimethacrylate, neopentylglyco Diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, polyethylene glycol dimethacrylate, polyethylene glycol diacrylate, tripropylene glycol dimethacrylate, tripropylene glycol diacrylate, trimethylolpropane dimethacrylate , Trimethylolpropane diacrylate, tetramethylolmethane dimethacrylate, tetramethylolmethane diacrylate, polypropylene glycol dimethacrylate, polypropylene glycol diacrylate, and the like. Examples of the monomer having three or more polymerizable groups in one molecule include trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, trimethylolethane trimethacrylate, trimethylolethane triacrylate, and tetramethylolmethane trimethacrylate. , Tetramethylol methane triacrylate, pentaerythritol trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetramethacrylate, pentaerythritol tetraacrylate and the like. However, the present invention is not limited to these specific examples, and several of them can be mixed.

  Among the crosslinkable polymerizable monomers, diesters of glycol and methacrylic acid, diesters of glycol and acrylic acid, trimethylolpropane methacrylate, trimethylolpropane triacrylate, etc. are easy to collect / recovery with water. In particular, a methacrylate-based crosslinkable polymerizable monomer is more preferable because it is not hydrolyzed and has high durability.

  By copolymerizing 90 to 30% by weight of the non-crosslinkable polymerizable monomer and 10 to 70% by weight of the crosslinkable polymerizable monomer, polymer particles can be obtained. When the amount of the crosslinkable polymerizable monomer is less than 10% by weight, the mechanical strength of the polymer particles obtained is poor, durability in repeated use tends to be inferior, and stable collection / recovery operation tends to be impossible. . In addition, when the amount of the crosslinkable polymerizable monomer exceeds 70% by weight, it tends to be difficult to adjust the pore diameter of the polymer particles. As the monomer, other known non-crosslinkable polymerizable monomers and crosslinkable polymerizable monomers can be copolymerized.

In the present invention, when the thiazine dye is introduced by an ether bond after the production of the polymer particles, the polymer particles preferably have a functional group such as a hydroxyl group, a glycidyl group, or a halogen. In order to produce such polymer particles, polymerization is carried out using at least one kind of non-crosslinkable polymerizable monomer having a hydroxyl group, a glycidyl group, a halogen or the like as the non-crosslinkable polymerizable monomer, or a polymer For example, a method of introducing a glycidyl group or the like by reacting epichlorohydrin or the like after the production of the particles can be mentioned. The thiazine dye may be introduced into the polymer particles by an ester bond in addition to the ether bond, but an ether bond is preferable from the viewpoint of durability.
In the polymerization, the non-crosslinkable polymerizable monomer and the crosslinkable polymerizable monomer may be an inert organic solvent such as dimethyl sulfoxide, xylene, toluene, dioxane, N, N-dimethylformamide, N, N. -Dissolved in dimethylacetamide, acetone, tetrahydrofuran, etc.

  Further, it is preferable to use a dispersant such as gelatin, polyvinyl alcohol, methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, or hydroxyapatite in order to stabilize the oil droplets of the monomer in the dispersion medium.

  The polymerization reaction between the non-crosslinkable polymerizable monomer and the crosslinkable polymerizable monomer is preferably performed in an aqueous medium. The amount of the aqueous medium is basically determined in order to emulsify and disperse the oil droplets of the monomer, which is the base of the polymer particles, to a desired size, and depends on the type and amount of the monomer. However, it is preferably 80 to 400 parts by weight with respect to 100 parts by weight of the monomer having a polymerizable group. If the amount is less than 80 parts by weight, the viscosity of the emulsified dispersion tends to increase, making it difficult to adjust the desired oil droplets. If the amount exceeds 400 parts by weight, the yield of polymer particles per production batch will be poor, and productivity will be reduced. There are problems such as decline.

Some of the above dispersants do not sufficiently exhibit their functions by themselves, and it is effective to add a dispersion aid. As the dispersion aid, generally known cationic surfactants, anionic surfactants, and nonionic surfactants are used, and among these, anionic surfactants are particularly preferable. Examples of the anionic surfactant include sodium alkylbenzene sulfonate, sodium α-olefin sulfonate, sodium alkyl sulfonate, and metal salts thereof. The anionic surfactant is preferably added in an amount of 1 × 10 ^{−4 to} 0.1% by weight based on the aqueous medium. If it is less than 1 × 10 ⁻⁴ % by weight, the function as a dispersion aid tends to be difficult to be exhibited. There is a tendency that cannot be done.

  As the polymerization initiator used in the polymerization of the non-crosslinkable polymerizable monomer and the crosslinkable polymerizable monomer, a peroxide radical initiator and an azo radical initiator are preferable, for example, benzoyl peroxide, 2-ethylhexyl perbenzoate, acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, lauroyl peroxide, ditert-butyl peroxide, cumene hydroperoxide, methyl ethyl ketone peroxide, 4,4,6-trimethylcyclohexanone, ditert-butyl Peroxyketal, cyclohexanone peroxide, methylcyclohexanone peroxide, acetylacetone peroxide, cyclohexanone di-tert-butylperoxyketal, acetone di-tert-butylperoxyketal, diisopropylhydroperoxide 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), (1-phenylethyl) azodiphenylmethane, 2,2 '-Azobis (4-methoxy-2,4-dimethylvaleronitrile), dimethyl 2,2'-azobisisobutyrate, 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis ( 1-cyclohexanecarbonitrile), 2- (carbamoylazo) isobutyronitrile, 2,2′-azobis (2,4,4-trimethylpentane), 2-phenylazo-2,4-dimethyl-4-methoxyvaleronitrile, 2 Azo polymerization initiators such as 2′-azobis (2-methylpropane).

  The radical polymerization initiator is used in an amount of 0.05 to 10 parts by weight based on 100 parts by weight of the monomer having one polymerizable group. If the amount used is less than 0.05 parts by weight, the polymerization time becomes long, and unreacted monomers tend to remain in the polymer particles, which is not preferable. On the other hand, when the amount used exceeds 10 parts by weight, not only the polymerization initiator is wasted, but also heat generation control during polymerization tends to be difficult and problems such as insufficient molecular chain length tend to occur.

  The polymer particles are preferably porous in terms of increasing the surface area and increasing the amount of adsorption of the surfactant. For this reason, various solvents are added as a pore regulator during polymerization. This solvent is soluble in the polymerizable monomer and does not dissolve the polymer. Specifically, toluene, xylene, ethylbenzene, diethylbenzene, heptanol, isoamyl alcohol, ethyl acetate, butyl acetate, dimethyl phthalate, phthalate Known compounds such as aliphatic or aromatic esters such as diethyl acid, ethylene glycol monoethyl ether acetate, hexane, octane and decane can be used. These are properly used depending on the type of monomer constituting the polymer to be obtained, and may be used alone or in combination of several types.

  The mixing ratio of these solvents is preferably 5 to 300% by weight, more preferably 20 to 200% by weight, and still more preferably 50 to 100% by weight based on the total amount of the polymerizable monomers in terms of porosity. Is done. If the blending ratio is less than 5% by weight or exceeds 300% by weight, it becomes difficult to obtain desired porosity, and the resulting polymer tends to have poor durability.

  The polymer particles used in the present invention are those obtained by synthesizing the non-crosslinkable polymerizable monomer and the crosslinkable polymerizable monomer by a known aqueous suspension polymerization, and the particle size of the polymer particles is not particularly limited. From the viewpoint of easiness of synthesis, those of about 1 μm to 2 mm are desirable, and more preferably about 5 μm to 800 μm from the viewpoint of ease of classification.

  The collection / recovery agent of the present invention is obtained by introducing a thiazine dye into a carrier. As an example, a method for introducing methylene blue into polymer particles is shown below. In addition, the synthesis example of the collection / recovery agent shown here is an example, and is not limited thereto.

  First, methylene blue is dissolved in a solvent. The solvent is not particularly limited as long as it dissolves methylene blue, and examples thereof include dimethyl sulfoxide, dimethylformamide, pyridine, and tetrahydrofuran. These solvents may be used alone or in combination of two or more, or may be used as an aqueous solution. When methylene blue does not dissolve, it may be dissolved by heating at a temperature below the boiling point of the solvent. The polymer particles are then added to the methylene blue solution. The amount of each component used is preferably in the range of 1 to 5 g of methylene blue and 20 to 500 ml of solvent with respect to 1 g of polymer gel. As a method for introducing methylene blue into the polymer particles, for example, polymer particles having an epoxy group as a functional group are used to react with an epoxy group to introduce methylene blue through an ether bond. Examples of the functional group include a hydroxyl group and a halogen group in addition to the epoxy group.

  In order to facilitate the introduction of methylene blue, the pH may be adjusted. In general, good reaction with the epoxy groups of the polymer particles proceeds in the range of pH 4-11. When the pH is out of the range, the epoxy group is hydrolyzed and the reaction tends to be inhibited. The reaction temperature may be from room temperature to the boiling point of the solvent, but is preferably in the range of 40 to 90 ° C. If it is less than 40 ° C, the reaction tends to be slow, and if it exceeds 90 ° C, the reaction may be difficult to control. The reaction time is 1 to 24 hours, but if it is less than 1 hour, the reaction may not proceed sufficiently.

  After the reaction, polymer particles into which methylene blue has been introduced are collected by filtration, washed with fresh solvent, water, etc., if necessary, and dried.

  The collection / recovery agent of the present invention is preferably introduced with 5 μM to 15 mM of a thiazine dye per gram of carrier, more preferably 0.5 mM to 5 mM.

  The method for collecting and collecting the surfactant contained in the medium using the collection / recovery agent of the present invention is not particularly limited as long as the collection / recovery agent and the surfactant are in contact with each other. For example, the surfactant can be collected by adding the collection / recovery agent of the present invention to a medium containing the surfactant and stirring and mixing as desired. Next, the collection / recovery agent that collected the surfactant by filtration is collected, an alkali such as sodium hydroxide is added, and the surfactant is desorbed from the collection / recovery agent by mixing with stirring as desired. By removing the collection / recovery agent by filtration, the surfactant can be recovered.

  EXAMPLES Hereinafter, although the collection and collection | recovery agent of this invention and its usage method are demonstrated concretely by an Example, this invention is not restrict | limited by the said Example.

Example 1
<Production of collection / recovery agent>
A mixture of 100 g of ethylene glycol dimethacrylate, 100 g of glycidyl methacrylate, 70 g of n-butyl acetate, 130 g of isoamyl alcohol and 0.9 g of azobisisobutyronitrile was added to 2000 g of 0.5 wt% aqueous methylcellulose solution and suspended at 90 ° C. for 10 hours. Polymerized. Then, after cooling this reaction liquid, the produced copolymer was filtered, washed with water, and washed with methanol to obtain polymer particles having an epoxy amount of 3.5 mmol / g and a particle size of 40 to 60 μm.

  To the flask, 3.7 g of methylene blue, 50 ml of dimethyl sulfoxide and 50 ml of water were added and dissolved at 60 ° C. with stirring. The above solution in which methylene blue was dissolved was cooled to room temperature, and 1M sodium hydroxide was added to adjust pH to 9. 1 g of the above polymer particles are added and reacted at 75 ° C. for 3 hours, then the gel is filtered, washed with methanol, and dried in a dryer at 60 ° C. for 3 hours to introduce methylene blue into the polymer particles. A collection / recovery agent was prepared.

<Evaluation>
Surfactant collection Perfluorooctanoic acid (fluorosurfactant, manufactured by Daikin Industries, Ltd.) 3.0 × 10 ⁻² M and 1 L of ion-exchanged water are dissolved in a 1.5 L beaker. Next, 0.2 g of the collection / recovery agent prepared above was added, stirred for 5 minutes at 210 rpm, filtered to remove the collection / recovery agent, and the concentration of perfluorooctanoic acid in the filtrate was measured by absorbance. When the concentration of perfluorooctanoic acid collected by the collection / recovery agent (mmol relative to the weight of the collection / recovery agent) was calculated from the difference from the concentration of perfluorooctanoic acid before collection, it was 0.3 mmol / g. Met.

The absorbance was measured using an ultraviolet-visible near-infrared spectrophotometer (manufactured by JASCO Corporation, V-570) under the condition of measurement wavelength: 653 nm (maximum absorption wavelength).
-Recovery of surfactant The collection / recovery agent that collected perfluorooctanoic acid collected by filtration and 1 L of 0.1 M NaOH aqueous solution were placed in a 1.5 L beaker, stirred at 210 rpm for 10 minutes, and then filtered. The concentration of perfluorooctanoic acid in the filtrate (mmol relative to the weight of the collection / recovery agent) was measured by absorbance to be 0.3 mmol / g, and the recovery rate of perfluorooctanoic acid Was 100%.

(Example 2)
The same operation as in Example 1 was conducted except that perfluorooctane sulfonic acid (a fluorosurfactant) was used instead of perfluorooctanoic acid, and the collection / recovery agent was evaluated. The concentration of the collected perfluorooctane sulfonic acid was calculated and found to be 0.24 mmol / g. Further, the concentration of the recovered perfluorooctane sulfonic acid was 0.24 mmol / g, and the recovery rate was 100%.

(Comparative Example 1)
The same operation as in Example 1 was performed except that an ion exchange resin (Amberlite IRA-400, manufactured by Organo Corporation) was used instead of the collection / recovery agent, and evaluation of the collection / recovery of perfluorooctanoic acid was performed. As a result, the concentration of perfluorooctanoic acid collected by the ion exchange resin was 0.034 mmol / g.

  In addition, the recovery rate of perfluorooctanoic acid when using a 0.1M NaOH aqueous solution was 83%, and the recovery rate of perfluorooctanoic acid when using a 0.15M NaOH aqueous solution was 100%.

(Comparative Example 2)
The same operation as in Example 2 was performed except that an ion exchange resin (Amberlite IRA-400, manufactured by Organo Corporation) was used instead of the collection / recovery agent, and evaluation of the collection / recovery of perfluorooctanesulfonic acid was performed. As a result, the concentration of perfluorooctane sulfonic acid collected by the ion exchange resin was 0.0065 mmol / g.

  Further, the recovery rate of perfluorooctane sulfonic acid when using a 0.1 M NaOH aqueous solution was 85%, and the recovery rate of perfluorooctane sulfonic acid when using a 0.15 M NaOH aqueous solution was 100%.

It is an adsorption schematic diagram of perfluorooctanoic acid and methylene blue.

Claims (5)

A surfactant collecting and collecting agent obtained by introducing a thiazine dye into a carrier through a covalent bond .   The collection / recovery agent according to claim 1, wherein the thiazine colorant is methylene blue.   The collection / recovery agent according to claim 1 or 2, wherein the surfactant is a fluorosurfactant.   The collection / recovery agent according to claim 1, wherein the surfactant is a fluorine-based anionic surfactant.   The collection / recovery agent according to any one of claims 1 to 4, wherein the carrier is polymer particles.

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