JPH09168737A - Adsorbent for surfactant and adsorption method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To recover and remove a surfactant from a solution such as wastewater containing the surfactant simply, inexpensively, and sufficiently. SOLUTION: An adsorbent includes, for example, a crosslinked polymer having a polyoxyalkylene chain. By contacting the adsorbent with a solution, a surfactant is adsorbed. An especially preferable crosslinked polymer is a polymer in which polyalkylene glycol is crosslinked or a polymer obtained by polymerizing a monomeric component such as a (meth)acrylate monomer which is expressed by CH2 =CR-CO-(X)n-Y (where R is hydrogen atom or methyl group, X is 1-5 C oxyalkylene group, Y is oxyalkylphenyl group having 1-3 substituents of hydrogen atom, 1-5C alkoxyl group, phenoxy group, or 1-9C alkyl group, and (n) is a positive number 3-100 on average).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an adsorbent for adsorbing a surfactant contained in a solution, and an adsorption method. More specifically, the present invention relates to an adsorbent and an adsorption method suitable for collecting and removing the surfactant from a solution such as a waste liquid containing the surfactant.

[0002]

BACKGROUND OF THE INVENTION Surfactants, such as nonionic surfactants, are used in the production of polymers by suspension polymerization. And when the reactor used for suspension polymerization is washed with water,
Aqueous effluent that contains a high concentration of surfactants and cannot be discharged directly is discharged. Therefore, conventionally, as a method of treating the aqueous waste liquid, a method of injecting it into a boiler to evaporate water and incinerating a surfactant, a method of treating with activated sludge and the like have been carried out.

However, in the above incineration method,
Large amounts of water contained in the aqueous effluent must be evaporated. Therefore, there are drawbacks that the processing takes time and the processing cost becomes high. Further, the above method using activated sludge has a drawback that it is not possible to treat a large amount of aqueous waste liquid at one time in a short time.

On the other hand, it is known that when an anionic or cationic water-soluble resin is added to an aqueous solution containing a surfactant, a part of the surfactant in the aqueous solution is aggregated. Therefore, it is possible to reduce the concentration of the surfactant in the aqueous waste liquid by adding the water-soluble resin to the aqueous waste liquid containing the surfactant and causing the surfactant to aggregate.

[0005]

However, the above water-soluble resin has a small effect of aggregating the surfactant.
Therefore, the above treatment method cannot sufficiently reduce the concentration of the surfactant in the aqueous waste liquid to such an extent that it can be discharged. Moreover, in the above treatment method, the aggregated surfactant becomes colloidal, which makes it difficult to separate it by filtration.
The processing operation becomes complicated. In addition, the above water-soluble resin is generally expensive, resulting in high processing cost.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to easily, inexpensively and sufficiently prepare a surfactant from a solution such as a waste liquid containing the surfactant. Another object of the present invention is to provide an adsorbent that can be collected and removed, and an adsorption method.

[0007]

Means for Solving the Problems In order to achieve the above-mentioned object, the inventors of the present application have made extensive studies on an adsorbent for a surfactant and an adsorption method. As a result, for example, an adsorbent containing a cross-linked polymer having a polyoxyalkylene chain, the surfactant contained in the solution, while finding that it can be sufficiently removed, by contacting the waste liquid to the adsorbent, The inventors have found that a surfactant can be easily and sufficiently adsorbed, and have completed the present invention.

That is, the adsorbent of the invention according to claim 1 comprises a cross-linked polymer in order to solve the above problems,
It is characterized in that it can adsorb 0.01 g / g or more of a surfactant.

According to the above structure, the adsorbent can efficiently adsorb the surfactant in the solution, for example.

In order to solve the above-mentioned problems, the adsorbent of the invention of claim 2 is the adsorbent of claim 1, wherein
The crosslinked polymer is characterized by having a polyoxyalkylene chain.

According to the above constitution, the adsorbent contains the cross-linked polymer having a polyoxyalkylene chain, and therefore has excellent adsorption ability to the surfactant. This allows
Since the adsorbent can efficiently adsorb the surfactant in the solution, for example, the surfactant can be sufficiently removed. In addition, since the surfactant can be removed only by filtering the adsorbent after adsorbing the surfactant on the adsorbent, the operation is simple.

In order to solve the above-mentioned problems, the adsorbent of the invention of claim 3 is the adsorbent of claim 1 or 2, wherein the crosslinked polymer is a polyalkylene glycol crosslinked. It is characterized by that.

According to the above construction, the adsorbent is more excellent in its adsorption ability for the surfactant, and therefore the surfactant can be removed more sufficiently. Further, the crosslinked polymer can be produced at low cost by cross-linking a polyalkylene glycol such as polyethylene glycol. Therefore, the cost of the crosslinked polymer becomes low and the solution can be processed at low cost.

In order to solve the above-mentioned problems, the adsorbent of the invention of claim 4 is the adsorbent of claim 1 or 2, wherein the cross-linked polymer is represented by the general formula (1) CH ₂ = CR- CO- (X) _n -Y (1) (In the formula, R represents a hydrogen atom or a methyl group, and X is
Represents an oxyalkylene group having 1 to 5 carbon atoms, and Y represents 1 to 1 as a hydrogen atom, an alkoxy group having 1 to 5 carbon atoms, a phenoxy group, or an alkyl group having 1 to 9 carbon atoms as a substituent;
It is obtained by polymerizing a monomer component containing a (meth) acrylic acid ester-based monomer represented by 3 represents an oxyalkylphenyl group, and n represents a positive number of 3 to 100 on average. It is characterized by being a thing.

According to the above constitution, the adsorbent is more excellent in the adsorption ability for the surfactant, and therefore the surfactant can be removed more sufficiently. Further, the crosslinked polymer can be produced at low cost by polymerizing a (meth) acrylic acid ester-based monomer in the presence of a crosslinking agent. Therefore, the cost of the crosslinked polymer becomes low and the solution can be processed at low cost.

In order to solve the above problems, the adsorption method of the invention of claim 5 is an adsorption method of adsorbing a surfactant contained in a solution, which comprises a crosslinked polymer having a polyoxyalkylene chain. It is characterized in that an adsorbent is brought into contact with the solution.

According to the above method, since the adsorbent containing the crosslinked polymer having a polyoxyalkylene chain is used,
The surfactant contained in the solution can be efficiently adsorbed. Therefore, the surfactant can be sufficiently removed. The cross-linked polymer can be produced at low cost by cross-linking a polyalkylene glycol such as polyethylene glycol, or by polymerizing a (meth) acrylic acid ester-based monomer in the presence of a cross-linking agent. it can. As a result, since the adsorbent is inexpensive, the surfactant can be removed inexpensively. Further, since the adsorbent to which the surfactant has been adsorbed is precipitated, the surfactant can be removed only by filtering thereafter.

Hereinafter, the present invention will be described in detail. The crosslinked polymer contained in the adsorbent of the present invention is, for example, a polymer having a polyoxyalkylene chain and having a crosslinkage. That is, the crosslinked polymer is, for example, a polymer having a polyoxyalkylene chain in the main chain and having a crosslink bond, or a polymer having a polyoxyalkylene chain in the side chain and having a crosslink bond.

The crosslinked polymer having a polyoxyalkylene chain as the main chain is not particularly limited, but a crosslinked polymer obtained by crosslinking polyalkylene glycol (hereinafter referred to as polyalkylene glycol crosslinked body) is used. It is particularly preferable because it has excellent surfactant adsorption performance.

The above polyalkylene glycol includes:
It is not particularly limited, and examples thereof include polyethylene glycol, polypropylene glycol, polybutylene glycol and the like. Moreover, the polyalkylene glycol may be a copolymer of two or more kinds of alkylene glycols. These polyalkylene glycols may be used alone, or two or more kinds may be appropriately mixed and used. Of the above-exemplified compounds, polyethylene glycol is particularly preferable because it is inexpensive and the adsorption performance of the crosslinked polyalkylene glycol to the surfactant is good. The molecular weight of the polyalkylene glycol is not particularly limited and may be determined according to the desired physical properties of the adsorbent.

A crosslinked polyalkylene glycol is obtained by crosslinking the above polyalkylene glycol. The method for crosslinking the polyalkylene glycol is not particularly limited. That is, for example, the polyalkylene glycol may be irradiated with γ rays. When irradiating the polyalkylene glycol with γ-rays, it is preferable that the polyalkylene glycol is dissolved in a solvent such as water so that the crosslinking reaction can be easily controlled, and then the solution is in a solution state. The amount of the solvent used is not particularly limited, and may be set in consideration of the ease of controlling the crosslinking reaction, economy, reaction yield, and the like. The amount of γ-rays to be irradiated may be appropriately selected according to the type and amount of polyalkylene glycol.

The reaction product obtained by the crosslinking reaction of polyalkylene glycol may be dried under reduced pressure, if necessary. The polyalkylene glycol cross-linked product, which is a dried product, can be used as it is, but may be further pulverized if necessary using a pulverizer such as a hammer mill or a jet mill. That is, the crosslinked polyalkylene glycol may be granulated into a predetermined shape, and may have various shapes such as an irregular crushed shape, a spherical shape, a scale shape, a fibrous shape, a rod shape, and a lump shape.

The cross-linked polymer having a polyoxyalkylene chain as a side chain is not particularly limited, but it is a monomer containing a (meth) acrylic acid ester monomer represented by the general formula (1). A cross-linked polymer obtained by polymerizing a monomer component is particularly preferable because it has excellent surfactant adsorption performance.

In the above-mentioned (meth) acrylic acid ester-based monomer, in the general formula (1), the substituent represented by R is a hydrogen atom or a methyl group, and the oxyalkylene group represented by X is The number of carbon atoms is 1 to 5, and the number of repeating oxyalkylene groups represented by n is 3 to 1 on average.
00 is a positive number, and the terminal group represented by Y is a hydrogen atom, an alkoxy group having 1 to 5 carbon atoms, a phenoxy group,
Alternatively, it is an oxyalkylphenyl group having 1 to 3 alkyl groups having 1 to 9 carbon atoms as a substituent.

Examples of the (meth) acrylic acid ester-based monomer include methoxy polyethylene glycol mono (meth) acrylate, methoxy polyethylene glycol / polypropylene glycol mono (meth) acrylate, methoxy polyethylene glycol / polybutylene glycol mono (meth). ) Acrylate, ethoxy polyethylene glycol mono (meth) acrylate, ethoxy polyethylene glycol / polypropylene glycol mono (meth) acrylate, ethoxy polyethylene glycol / polybutylene glycol mono (meth) acrylate, phenoxy polyethylene glycol mono (meth) acrylate, benzyloxy polyethylene glycol Mono (meth) acrylate etc. are mentioned. These compounds may be used alone or in combination of two or more.

The above-mentioned monomer component may be composed of only a (meth) acrylic acid ester-based monomer, but if necessary, a monomer copolymerizable with the monomer (hereinafter referred to as a copolymer). (Also referred to as a polymerized monomer). The copolymerization monomer is not particularly limited, and various compounds can be used. Examples of the above-mentioned copolymerizable monomers include unsaturated monocarboxylic acid-based monomers such as acrylic acid, methacrylic acid, crotonic acid, and neutralized products or partially neutralized products thereof; maleic acid, fumaric acid, Itaconic acid, citraconic acid, and unsaturated dicarboxylic acid type monomers such as neutralized products and partially neutralized products thereof; vinyl sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, styrene sulfonic acid, 2-acrylamido-2 -Methylpropane sulfonic acid, sulfoethyl (meth) acrylate, sulfopropyl (meth)
Acrylate, 2-hydroxysulfopropyl (meth)
Unsaturated sulfonic acid-based monomers such as acrylate, sulfoethylmaleimide, 3-allyloxy-2-hydroxypropanesulfonic acid, and neutralized or partially neutralized products thereof;
Amide-based monomers such as (meth) acrylamide, isopropylacrylamide, t-butyl (meth) acrylamide; hydrophobic monomers such as (meth) acrylic acid ester, styrene, 2-methylstyrene, vinyl acetate; 2-hydroxy Ethyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, allyl alcohol,
Polyethylene glycol monoallyl ether, polypropylene glycol monoallyl ether, 3-methyl-3
-Buten-1-ol (isoprenol), polyethylene glycol monoisoprenol ether, polypropylene glycol monoisoprenol ether, 3-methyl-2-buten-1-ol (prenol), polyethylene glycol monoprenol ether, polypropylene glycol monopren Nol ether, 2-methyl-3
-Buten-2-ol (isoprene alcohol), polyethylene glycol monoisoprene alcohol ether, polypropylene glycol monoisoprene alcohol ether, N-methylol (meth) acrylamide,
Unsaturated hydroxyl group-containing monomers such as glycerol mono (meth) acrylate, glycerol monoallyl ether and vinyl alcohol; cationic monomers such as dimethylaminoethyl (meth) acrylate and dimethylaminopropyl (meth) acrylamide; (meth) Nitrile-based monomers such as acrylonitrile; phosphorus-containing monomers such as (meth) acrylamidomethanephosphonic acid, (meth) acrylamidomethanephosphonic acid methyl ester, and 2- (meth) acrylamido-2-methylpropanephosphonic acid. To be Further, the unsaturated monocarboxylic acid-based monomer, unsaturated dicarboxylic acid-based monomer, and the neutralized product or partially neutralized product of the unsaturated sulfonic acid-based monomer are monovalent monovalent compounds. It is obtained by neutralizing with a metal, a divalent metal, ammonia, or an organic amine. These copolymerizable monomers may be used alone, or two or more kinds may be appropriately mixed and used. Of these, unsaturated monocarboxylic acid-based monomers, unsaturated sulfonic acid-based monomers, and mixtures thereof are particularly preferred because of their excellent copolymerizability and low cost. The amount of the copolymerizable monomer is not particularly limited as long as it does not impair the physical properties of the adsorbent.

A solvent can be used when the above-mentioned monomer components are polymerized. Examples of the solvent include liquids in which monomer components are soluble, for example, water and hydrophilic organic solvents that are uniformly mixed with water. Examples of the organic solvent include methyl alcohol and ethyl alcohol. Examples include lower alcohols having 1 to 4 carbon atoms, lower ketones such as acetone, dimethylformamide, dimethylsulfoxide, and the like. These solvents may be used alone or as a mixture of two or more. The mixing ratio in the case of mixing two or more kinds of solvents may be appropriately set in consideration of the kind of the (meth) acrylic acid ester-based monomer. Further, when the polymerization reaction is carried out by the reverse phase suspension polymerization method (described later), a hydrophobic organic solvent can be used.

The amount of the above solvent used, that is, the concentration of the monomer component in the solvent (hereinafter referred to as the monomer concentration) is not particularly limited, but it is easy to control the polymerization reaction, is economical, Taking the reaction yield into consideration, the monomer concentration is 20
It may be set to be in the range of not less than wt% and not more than the saturated concentration, preferably in the range of 30 wt% to 95 wt%, and more preferably in the range of 55 wt% to 80 wt%.
When the monomer concentration is less than 20% by weight, the amount of the solvent used becomes excessive and the economical efficiency and the reaction yield are reduced.
Not preferred. When the monomer concentration is equal to or higher than the saturation concentration, the polymerization reaction becomes non-uniform and it becomes difficult to remove the reaction heat of the polymerization reaction (polymerization heat), which is not preferable.

In the present invention, a crosslinking agent can be used when polymerizing the monomer components. Examples of the cross-linking agent include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate,
Propylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol di (meth) acrylate, N, N-methylenebisacrylamide, isocyanuric Acid compounds such as triallyl acid and trimethylolpropane diallyl ether having two or more ethylenically unsaturated groups in one molecule; ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, glycerin, polyglycerin, propylene glycol, diethanolamine, tri Ethanolamine, polypropylene glycol, polyvinyl alcohol, pentaerythritol, sorbit, sorbitan, glue Polyhydric alcohols such as glucose, mannitol, mannitol, sucrose, glucose; ethylene glycol diglycidyl ether, glycerin diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol Examples thereof include polyepoxy compounds such as diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane diglycidyl ether, trimethylolpropane triglycidyl ether, and glycerin triglycidyl ether. These cross-linking agents may be used alone, or two or more of them may be appropriately mixed and used.

By using a cross-linking agent, the cross-linking density of the resulting cross-linked polymer can be controlled to any value.
Among the above-mentioned crosslinking agents, polyethylene glycol di (meth) acrylate is particularly preferable. Further, the number of added moles of ethylene oxide (hereinafter referred to as EO) constituting polyethylene glycol di (meth) acrylate is preferably in the range of 4 to 100 moles, and from the viewpoint of crosslinking efficiency, 5 to 50 moles. The range is particularly preferable.

Even when a compound other than polyethylene glycol di (meth) acrylate is used as the crosslinking agent, it is preferable to use polyethylene glycol di (meth) acrylate together with the compound.

The molar ratio of the cross-linking agent to the above monomer component is preferably in the range of 1 × 10 ^{−5 to} 5 × 10 ⁻² , and 5 ×.
The range of 10 ^{−4 to} 2 × 10 ⁻² is particularly preferable. When the molar ratio of the cross-linking agent is less than 1 × 10 ⁻⁵ , the cross-linking density of the obtained cross-linked polymer becomes too small, and the adsorbing performance of the adsorbent decreases, which is not preferable. The molar ratio of the cross-linking agent is 5
When it is larger than × 10 ^-2 , the crosslinked density of the obtained crosslinked polymer becomes too high, and the adsorption performance of the adsorbent decreases, which is not preferable.

When a polyhydric alcohol is used as a crosslinking agent, the reaction product obtained after the polymerization reaction is 15
It is preferable to perform heat treatment at 0 ° C to 250 ° C. Also,
When a polyepoxy compound is used as the cross-linking agent, it is preferable to heat-treat the obtained reaction product at 50 ° C to 250 ° C after the polymerization reaction.

The above-mentioned cross-linked polymer is prepared by mixing the monomer component in the presence of a cross-linking agent, a solvent, and a polymerization initiator in a known manner such as a solution polymerization method, a suspension polymerization method or a reverse phase suspension polymerization method. It is obtained by polymerization using a polymerization method. Further, polymerization is performed using a so-called casting polymerization method, thin film polymerization method, spray polymerization method, or a polymerization method in which a double-arm type kneader is used as a reactor, and the reaction product is polymerized while being fragmented by the shearing force of the kneader. By doing so, a crosslinked polymer can also be obtained.

The above-mentioned polymerization initiator is not particularly limited, but examples thereof include hydrogen peroxide; persulfates such as sodium persulfate, ammonium persulfate and potassium persulfate; 2,2′-azobis (2 -Amidinopropane) dihydrochloride, water-soluble azo compounds such as 4,4'-azobis (4-cyanovaleric acid); 2,2'-azobisisobutyronitrile, 2,2'-azobis (4-methoxy) -2,4-dimethylvaleronitrile) and other oil-soluble azo compounds; and radical polymerization initiators such as benzoyl peroxide, lauroyl peroxide, peracetic acid, benzoyl peroxide, cumene hydroperoxide, and other organic peroxides. To be These polymerization initiators may be used alone, or two or more of them may be used as an appropriate mixture. Further, a reducing agent that accelerates the decomposition of these polymerization initiators may be used in combination, and a combination of both may be used as a redox initiator.
The reducing agent is not particularly limited, but examples thereof include (bis) sulfite (salt) such as sodium bisulfite, L-ascorbic acid (salt), reducing metal (salt such as ferrous salt). ), Amines and the like. Incidentally, instead of using the polymerization initiator, the polymerization reaction may be carried out by irradiating the reaction system with radiation, electron beams, ultraviolet rays or the like.

As the dispersant for dispersing the aqueous solution of the monomer component in the hydrophobic organic solvent when performing the reverse phase suspension polymerization method, for example, sorbitan fatty acid ester, sucrose fatty acid ester, glycerin fatty acid ester, poly Glycerin fatty acid ester, cellulose ester such as ethyl cellulose, cellulose acetate, cellulose ether, α
Examples include carboxyl group-containing polymers such as olefin-maleic anhydride copolymers. The hydrophobic organic solvent is not particularly limited.

The reaction temperature depends on the kind and combination of the (meth) acrylic acid ester-based monomer, the copolymerization monomer, the cross-linking agent, the solvent, the polymerization initiator, and the amount used, but the reaction is completed. Moreover, it is preferable that the temperature is relatively low so that the molecular weight of the obtained crosslinked polymer becomes large. The reaction temperature is
For example, the range of 20 ° C to 100 ° C is suitable. still,
The reaction time is not particularly limited and may be appropriately set depending on the reaction temperature and the like. Also, the reactor such as a polymerization vessel for carrying out the above-mentioned polymerization reaction is not particularly limited, but the reaction product obtained after the polymerization reaction can be easily crushed (described later). The so-called double-arm kneader is preferable.

The reaction system may be agitated or allowed to stand at the time of carrying out the polymerization reaction. That is, the reaction system may be subjected to stirring polymerization, static polymerization, or a combination of stirring polymerization and static polymerization. Of these, static polymerization is most preferable. By carrying out static polymerization, a crosslinked polymer having excellent adsorption performance, that is, an adsorbent can be efficiently produced. When performing static polymerization, it is preferable to crush the reaction product obtained after the polymerization reaction.

The reaction product obtained by the polymerization reaction is used as it is or, if necessary, as a sulfite salt, a hydrogen sulfite salt, a pyrosulfite salt, a dithionite salt, a nitrite salt, a phosphite salt, and hypophosphorous acid. An oxygen-containing reducing inorganic salt such as a salt is added to reduce the amount of residual monomer in the reaction product, and then the product is dried using a dryer or the like. The drying temperature is 100 ° C to 1
60 degreeC is preferable and 120 degreeC-140 degreeC is more preferable. Further, it is particularly preferable to dry under reduced pressure (dry under reduced pressure) or to dry under an inert gas stream.
The crosslinked polymer which is a dried product is pulverized as necessary using a pulverizer such as a hammer mill or a jet mill. When the drying temperature is lower than 100 ° C, it takes time to dry the reaction product sufficiently, which is not preferable. If the drying temperature exceeds 160 ° C, the crosslinked polymer obtained by drying tends to deteriorate due to heat, and the adsorption characteristics of the crosslinked polymer, that is, the adsorbent, tends to deteriorate.

The adsorbent in the present invention, that is, the above-mentioned cross-linked polymer may be granulated into a predetermined shape.
Irregular crushed shape, spherical shape, scale shape, fiber shape, rod shape, lump shape, etc.
It may have various shapes. Further, the cross-linked polymer has 1
It may be a secondary particle or a granulated body of primary particles. The average particle size of the crosslinked polymer may be appropriately set in consideration of the types of both monomers used and the use of the adsorbent, and for example, several μm to several hundreds μm is preferable. The method for granulating the crosslinked polymer is not particularly limited as long as the adsorption characteristics such as the absorption capacity are satisfied.

Further, the crosslinked polymer may be subjected to various treatments or modifications (modifications) on its surface in order to improve its adsorption characteristics such as liquid permeability, dispersibility and absorption rate. . That is, the crosslinked polymer may be subjected to, for example, a surface treatment for introducing a crosslinked structure near the surface of the crosslinked polymer.

The surface cross-linking agent used in the above surface treatment can react with the carboxyl group and / or the carboxylate group when the cross-linked polymer contains the carboxyl group and / or the carboxylate group, for example. A compound having two or more functional groups in the molecule is suitable. Examples of the surface cross-linking agent include glycerin,
Polyhydric alcohols such as ethylene glycol and pentaerythritol; polyepoxy compounds such as ethylene glycol diglycidyl ether; polyamines such as ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine and polyethyleneimine; glutaraldehyde, Polyvalent aldehydes such as glyoxal; and polyvalent metal salts such as (poly) aluminum chloride, magnesium chloride, calcium chloride, aluminum sulfate, magnesium sulfate and calcium sulfate. These surface cross-linking agents may be used alone, or two or more of them may be appropriately mixed and used.

The amount of the surface cross-linking agent used is not particularly limited, but is 0.005% by weight to the cross-linked polymer.
It is preferably in the range of 5% by weight. In addition, the treatment method for performing the above-described surface treatment is not particularly limited. For example, after mixing the powdery cross-linked polymer with the surface cross-linking agent as it is or in the state of a solution dissolved in an appropriate solvent,
Surface treatment may be performed by heating if necessary, and after the crosslinked polymer is dispersed in a hydrophobic organic solvent, a surface crosslinking agent is added to the dispersion, and then, if necessary. Surface treatment may be performed by heating.

Further, the adsorbent may be added with inorganic fine particles such as silica fine particles, and an additive such as a filler made of pulp fiber or the like, if necessary, in order to improve processability and quality performance. May be. The amount of the above additive is
It is not particularly limited, and may be appropriately set depending on, for example, the type of additive. The method for adding the additive is
There is no particular limitation.

The surfactant to be treated according to the invention is preferably in solution. The solution may contain a surfactant, and its composition is not particularly limited. That is, the liquid that is the main component of the solution may be water or an organic solvent,
These mixtures may be used. In addition, components other than the surfactant, such as inorganic salts, may be dissolved in the waste liquid.

As the surfactant which can be adsorbed by the adsorbent,
It is not particularly limited, nonionic surfactant,
Examples thereof include anionic surfactants, cationic surfactants, amphoteric surfactants, polymer surfactants and reactive surfactants. The adsorbent according to the present invention is particularly preferably used for adsorbing a nonionic surfactant among the above surfactants.

Specific examples of nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkylaryl ethers; sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters; fatty acid monoglycerides such as glycerol monolaurate. A polyoxyethylene-polyoxypropylene copolymer; a condensation product obtained by reacting ethylene oxide with an aliphatic amine, an aliphatic amide, or an acid. Two or more kinds of these surfactants may be present in the waste liquid.

The concentration of the surfactant in the solution is not particularly limited, but the adsorbent according to the present invention is
When the surfactant has a relatively high concentration, for example, about 100 ppm, its adsorption property can be remarkably exhibited.

The amount of the adsorbent having the above-mentioned constitution is particularly preferably within the range of 0.01 to 1 part by weight with respect to 100 parts by weight of the waste liquid containing the surfactant. 0.01 used
If the amount is less than parts by weight, the effect of reducing the concentration of the surfactant is insufficient, which is not preferable. On the other hand, if the amount used exceeds 1 part by weight, the effect commensurate with the increase in amount cannot be obtained and the adsorbent is wasted, which is not preferable.

To treat the solution with the adsorbent, the adsorbent may be brought into contact with the solution. The contact method for bringing the adsorbent into contact with the solution is not particularly limited.
That is, for example, when the solution is in a container,
A method in which the adsorbent is directly added (added) to the solution may be used, or a method in which the adsorbent is placed in a tea bag type bag made of a water-permeable material and immersed in the solution may be used. Also,
The contact method may be a method in which an adsorbent is put in a container and a solution is added (added) thereto. Further, the contact method may be a method of passing a solution through the adsorbent. This allows the solution to be processed continuously.

The adsorbent according to the present invention contains a surfactant in an amount of 0.01 g / g or more, preferably 0.01 g / g to 0.
It can be adsorbed within the range of 1 g / g. The adsorbent can adsorb the surfactant in the liquid just by contacting with the solution, but if necessary, both may be stirred and mixed. The temperature of the solution and the contact time when the solution is treated with the adsorbent are not particularly limited.

After treating the solution with the adsorbent, the adsorbent becomes a gel-like insoluble matter. The insoluble matter precipitates after the treatment when the solution is added to the adsorbent or when the adsorbent is added to the solution to perform the treatment. Therefore, the insoluble matter may be separated by filtration from the solution. Incidentally, when the treatment is carried out by a method using a tea bag type bag or a method of passing a solution through an adsorbent, the solution after treatment does not contain a precipitate, so that the filtering operation can be omitted. .

In the solution treated with the adsorbent in this way, the concentration of the surfactant is sufficiently lowered, so that the solution may be discharged as it is. On the other hand, the treated adsorbent may be incinerated or regenerated.

The adsorbent having the above structure may be combined with (combined with) fiber, non-woven fabric, rubber, synthetic resin or the like, and molded into a sheet or fiber to form a composite. it can. The above complex can be particularly preferably used when the method of passing the solution through the adsorbent is adopted.

[0055]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples, but the present invention is not limited thereto. The liquid absorption capacity of the crosslinked polymer is
It was measured by the following method. Moreover, "part" described in the examples and comparative examples indicates "part by weight".

(A) Liquid Absorption Capacity of Crosslinked Polymer About 0.3 g of the crosslinked polymer was uniformly put in a tea bag type bag and immersed in ion-exchanged water. After standing for 3 hours, the tea bag type bag was pulled up and drained for a certain period of time, and then the weight W ₁ (g) of the tea bag type bag was measured. Further, the same operation was performed without using the crosslinked polymer, and the weight W ₀ (g) of the tea bag type bag at that time was measured. And
From these weights W ₁ and W ₀ , the liquid absorption capacity according to the following formula, liquid absorption capacity (g / g) = (weight W ₁ (g) -weight W ₀ (g)) / weight of crosslinked polymer (g) (G / g) was calculated. The liquid absorption ratio is an equilibrium value.

Example 1 In a plastic reactor having an internal volume of 600 ml equipped with a thermometer, a nitrogen gas blowing tube, and a stirrer, 60.4 parts of sodium acrylate as a comonomer, (meth) were added. Methoxy polyethylene glycol acrylate 339.6 parts as an acrylic acid ester-based monomer, ion-exchanged water 593.
0 part and 1.8 parts of polyethylene glycol diacrylate as a crosslinking agent were charged to prepare a reaction liquid. The average number of moles of ethylene oxide added in the above methoxypolyethylene glycol acrylate is 10 moles. The average number of moles of ethylene oxide added to polyethylene glycol diacrylate is 8 moles.

That is, the molar ratio of sodium acrylate and methoxy polyethylene glycol acrylate is
Both were prepared so that it would be 50:50. Further, polyethylene glycol diacrylate was charged so that the ratio with respect to the above-mentioned monomer component was 0.3 mol%.

Next, nitrogen gas was blown into the above reaction solution to expel dissolved oxygen, and the reaction system was replaced with nitrogen gas. Subsequently, the temperature of the reaction solution was raised to 40 ° C. using a water bath, and then 10% by weight 2,2′-azobis (2-amidinopropane) hydrochloride as a polymerization initiator (manufactured by Wako Pure Chemical Industries, Ltd. ; 5.2 parts of a trade name V-50) aqueous solution was added. After stirring and mixing the reaction solution, the stirring was stopped. Then, the polymerization reaction was immediately started. 2,2 '
-Azobis (2-amidinopropane) hydrochloride was added so that the ratio to the monomer component was 0.15 mol%.

In the above polymerization reaction, the temperature of the reaction liquid reached 64 ° C. and reached a peak 46 minutes after the reaction was started. During this time, the temperature of the water bath was appropriately raised so as to be substantially equal to the temperature of the reaction solution. After the temperature of the reaction solution reached the peak, the temperature of the water bath was maintained at 80 ° C., and the reaction solution was aged for 60 minutes. After the aging was completed, the obtained hydrogel polymer was taken out and crushed into fine particles.

The crushed fine hydrous gel polymer was dried at 150 ° C. for 1 hour in a nitrogen stream using a hot air circulation dryer, and then the dried product was crushed using a table crusher and crosslinked. A polymer was obtained. The liquid absorption capacity of the obtained crosslinked polymer was measured by the method described above. As a result, the liquid absorption ratio is 116 g /
g.

Next, polyethylene glycol nonyl phenyl ether, which is a nonionic surfactant, was dissolved in ion-exchanged water. As a result, a 100 ppm aqueous solution of polyethylene glycol nonylphenyl ether was prepared as a solution containing a surfactant. The average number of moles of polyethylene glycol nonyl phenyl ether added is 9 moles.

Then, in a beaker with an internal volume of 100 ml,
50 parts of the above polyethylene glycol nonylphenyl ether aqueous solution was charged, the above crosslinked polymer, that is, 0.1 part of an adsorbent was added, and the mixture was stirred for 5 hours. After the stirring was completed, the adsorbent was precipitated as a gel. Then, the above aqueous solution was filtered to remove the precipitate, and the concentration of polyethylene glycol nonylphenyl ether in the filtrate was measured by high performance liquid chromatography. As a result, the concentration of polyethylene glycol nonyl phenyl ether was 8 ppm. That is, by treating the polyethylene glycol nonylphenyl ether aqueous solution with the adsorbent, the concentration of polyethylene glycol nonylphenyl ether in the aqueous solution was reduced from 100 ppm to 8 ppm. Further, the adsorbent is a polyethylene glycol nonyl phenyl ether as a surfactant, 0.04
It was found that 6 g / g was adsorbed.

Example 2 In a plastic reactor having an internal volume of 600 ml equipped with a thermometer, a nitrogen gas blowing tube, and a stirrer, 26.4 parts of sodium methacrylate as a comonomer, (meth) were added. 573.6 parts of butoxy polyethylene glycol methacrylate as an acrylate monomer, ion-exchanged water as a solvent 39
A reaction solution was prepared by charging 7.6 parts and 0.45 part of polyethylene glycol diacrylate as a crosslinking agent. The average number of moles of ethylene oxide added in the above butoxy polyethylene glycol acrylate is 50.
Is a mole. The average number of moles of ethylene oxide added in polyethylene glycol diacrylate is 8
Is a mole.

That is, both were prepared so that the molar ratio of sodium methacrylate and butoxy polyethylene glycol methacrylate was 50:50. Further, polyethylene glycol diacrylate was charged so that the ratio to the above-mentioned monomer component was 0.2 mol%.

Next, nitrogen gas was blown into the above reaction solution to expel dissolved oxygen, and the reaction system was replaced with nitrogen gas. Subsequently, the temperature of the reaction solution was raised to 50 ° C. using a water bath, and then 10% by weight 2,2′-azobis (2-amidinopropane) hydrochloride as a polymerization initiator (manufactured by Wako Pure Chemical Industries, Ltd. (Trade name: V-50) 2.0 parts of an aqueous solution was added. After stirring and mixing the reaction solution, the stirring was stopped. Then, the polymerization reaction was immediately started. 2,2 '
-Azobis (2-amidinopropane) hydrochloride was added so that the ratio to the monomer component was 0.15 mol%.

In the above polymerization reaction, the temperature of the reaction solution reached 60 ° C. and reached a peak 116 minutes after the reaction was started. During this time, the temperature of the water bath was appropriately raised so as to be substantially equal to the temperature of the reaction solution. After the temperature of the reaction solution reached the peak, the temperature of the water bath was maintained at 80 ° C., and the reaction solution was aged for 60 minutes. After the aging was completed, the obtained hydrogel polymer was taken out and crushed into fine particles.

The crushed fine hydrogel polymer was dried at 150 ° C. for 1 hour in a nitrogen stream using a hot air circulation dryer, and the dried product was crushed using a table crusher and crosslinked. A polymer was obtained. The liquid absorption capacity of the obtained crosslinked polymer was measured by the method described above. As a result, the liquid absorption capacity is 75 g / g
Met.

Then, in the same manner as in Example 1, a 100 ppm aqueous solution of polyethylene glycol nonylphenyl ether was treated by contacting it with the above-mentioned crosslinked polymer, that is, an adsorbent, and then, the concentration of polyethylene glycol nonylphenyl ether in the aqueous solution was treated. Was measured. As a result, the concentration of polyethylene glycol nonyl phenyl ether was 13p.
pm. That is, the adsorbent is polyethylene glycol nonyl phenyl ether at 0.0435 g /
It was found that g was adsorbed.

Example 3 In a plastic reactor having an internal volume of 600 ml equipped with a thermometer, a nitrogen gas blowing tube, and a stirrer, 190.8 parts of sodium methacrylate as a comonomer, (meth) were added. 409.2 parts of methoxypolyethylene glycol methacrylate as an acrylate monomer, ion-exchanged water as a solvent 3
A reaction liquid was prepared by charging 83.9 parts and 5.9 parts of polyethylene glycol diacrylate as a crosslinking agent. The average number of moles of ethylene oxide added in the above methoxypolyethylene glycol acrylate is 10
Is a mole. The average number of moles of ethylene oxide added in polyethylene glycol diacrylate is 8
Is a mole.

That is, both were prepared so that the molar ratio of sodium methacrylate and methoxy polyethylene glycol methacrylate was 70:30. Further, polyethylene glycol diacrylate was charged so that the ratio to the above-mentioned monomer component was 0.5 mol%.

Next, nitrogen gas was blown into the above reaction solution to expel dissolved oxygen, and the reaction system was replaced with nitrogen gas. Subsequently, the temperature of the reaction solution was raised to 45 ° C. using a water bath, and then 10% by weight 2,2′-azobis (2-amidinopropane) hydrochloride as a polymerization initiator (manufactured by Wako Pure Chemical Industries, Ltd. ; 10.3 parts of trade name V-50) aqueous solution was added. After stirring and mixing the reaction solution, the stirring was stopped. Then, the polymerization reaction was immediately started. 2,
2'-Azobis (2-amidinopropane) hydrochloride was added so that the ratio to the monomer component was 0.15 mol%.

In the above polymerization reaction, the temperature of the reaction solution reached 93 ° C. and reached a peak 88 minutes after the reaction was started. During this time, the temperature of the water bath was appropriately raised so as to be substantially equal to the temperature of the reaction solution. After the temperature of the reaction solution reached the peak, the temperature of the water bath was maintained at 80 ° C., and the reaction solution was aged for 60 minutes. After the aging was completed, the obtained hydrogel polymer was taken out and crushed into fine particles.

The crushed fine hydrogel polymer was dried at 150 ° C. for 1 hour in a nitrogen stream using a hot air circulation dryer, and the dried product was crushed using a table crusher and crosslinked. A polymer was obtained. The liquid absorption capacity of the obtained crosslinked polymer was measured by the method described above. As a result, the liquid absorption ratio is 116 g /
g.

Then, in the same manner as in Example 1, a 100 ppm aqueous solution of polyethylene glycol nonylphenyl ether was treated by contacting it with the above-mentioned crosslinked polymer, that is, an adsorbent, and then the concentration of polyethylene glycol nonylphenyl ether in the aqueous solution was treated. Was measured. As a result, the concentration of polyethylene glycol nonyl phenyl ether was 24p.
pm. That is, the adsorbent was polyethylene glycol nonyl phenyl ether at 0.038 g / g.
It was found to be adsorbed.

Example 4 In a plastic reactor having an internal volume of 600 ml equipped with a thermometer, a nitrogen gas blowing tube, and a stirrer, 246.8 parts of sodium acrylate as a comonomer, (meth) were added. 153.2 parts of methoxypolyethylene glycol acrylate as an acrylic acid-based monomer, ion-exchanged water 57 as a solvent
A reaction solution was prepared by charging 4.6 parts and 13.5 parts of polyethylene glycol diacrylate as a crosslinking agent. The average number of moles of ethylene oxide added in the above methoxypolyethylene glycol acrylate is 10
Is a mole. The average number of moles of ethylene oxide added in polyethylene glycol diacrylate is 8
Is a mole.

That is, the molar ratio of sodium acrylate and methoxy polyethylene glycol acrylate is
Both were prepared so that it might be 90:10. Further, polyethylene glycol diacrylate was charged so that the ratio with respect to the above-mentioned monomer components would be 1 mol%.

Next, nitrogen gas was blown into the above reaction solution to expel dissolved oxygen, and the reaction system was replaced with nitrogen gas. Subsequently, the temperature of the reaction solution was raised to 40 ° C. using a water bath, and then 10% by weight 2,2′-azobis (2-amidinopropane) hydrochloride as a polymerization initiator (manufactured by Wako Pure Chemical Industries, Ltd. ; Trade name V-50) 11.9 parts of aqueous solution was added. After stirring and mixing the reaction solution, the stirring was stopped. Then, the polymerization reaction was immediately started. 2,
2'-Azobis (2-amidinopropane) hydrochloride was added so that the ratio to the monomer component was 0.15 mol%.

In the above polymerization reaction, the temperature of the reaction solution reached 95 ° C. and reached a peak 33 minutes after the reaction was started. During this time, the temperature of the water bath was appropriately raised so as to be substantially equal to the temperature of the reaction solution. After the temperature of the reaction solution reached the peak, the temperature of the water bath was maintained at 80 ° C., and the reaction solution was aged for 60 minutes. After the aging was completed, the obtained hydrogel polymer was taken out and crushed into fine particles.

The crushed fine hydrogel polymer was dried for 1 hour at 150 ° C. in a nitrogen stream using a hot air circulation dryer, and then the dried product was crushed using a table crusher and crosslinked. A polymer was obtained. The liquid absorption capacity of the obtained crosslinked polymer was measured by the method described above. As a result, the liquid absorption capacity is 86 g / g
Met.

Then, in the same manner as in Example 1, a 100 ppm aqueous solution of polyethylene glycol nonylphenyl ether was contacted with the above-mentioned cross-linked polymer, that is, an adsorbent, and treated, and then the concentration of polyethylene glycol nonylphenyl ether in the aqueous solution was increased. Was measured. As a result, the concentration of polyethylene glycol nonyl phenyl ether was 32 p.
pm. That is, the adsorbent is polyethylene glycol nonyl phenyl ether at 0.034 g / g
It was found to be adsorbed.

Example 5 5 parts of polyethylene glycol as a polyalkylene glycol was placed in a plastic reactor having an internal volume of 100 ml, and 95 parts of ion-exchanged water as a solvent was added and dissolved to obtain an aqueous solution. The polyethylene glycol has a molecular weight of 150,000 to 4
00,000.

Next, 20 KGY of γ rays was added to the above aqueous solution.
Irradiated. After the irradiation was completed, the obtained hydrogel polymer was taken out and crushed into fine particles. The crushed fine hydrogel polymer was dried at 60 ° C. under reduced pressure, and the dried product was crushed using a table crusher to obtain a crosslinked polymer. The liquid absorption capacity of the obtained crosslinked polymer was measured by the method described above.
As a result, the liquid absorption capacity was 31 g / g.

Then, in the same manner as in Example 1, a 100 ppm aqueous solution of polyethylene glycol nonylphenyl ether was treated by contacting it with the above-mentioned crosslinked polymer, that is, an adsorbent, and then the concentration of polyethylene glycol nonylphenyl ether in the aqueous solution was treated. Was measured. As a result, the concentration of polyethylene glycol nonyl phenyl ether was 17 p
pm. That is, the adsorbent is polyethylene glycol nonyl phenyl ether at 0.0415 g /
It was found that g was adsorbed.

[Comparative Example 1] As a comparative adsorbent, a sodium polyacrylate-based crosslinked polymer having a liquid absorption capacity of 96 g / g (water-absorbent resin, manufactured by Nippon Shokubai Co., Ltd .; trade name)
Aqualic GH-2) was used. In the same manner as in Example 1, a 100 ppm aqueous solution of polyethylene glycol nonylphenyl ether was contacted with the comparative adsorbent and treated, and then the concentration of polyethylene glycol nonylphenyl ether in the aqueous solution was measured. As a result, the concentration of polyethylene glycol nonyl phenyl ether was 8
It was 7 ppm and was hardly adsorbed by the comparative adsorbent. In other words, the comparative adsorbent contains 0.0065 g of polyethylene glycol nonyl phenyl ether.
It was found that only / g was adsorbed.

As is clear from Examples 1 to 5, the adsorbents according to this example have excellent adsorption performance for surfactants because the cross-linked polymer has a polyoxyalkylene chain, for example. Therefore, it can be seen that the surfactant can be efficiently removed. That is, the adsorbent is
It can be seen that 0.01 g / g or more of the surfactant can be adsorbed. On the other hand, the comparative adsorbent according to Comparative Example 1 is
Since the crosslinked polymer does not have a polyoxyalkylene chain, it is found that the adsorption performance for the surfactant is poor and the surfactant cannot be removed efficiently.

[0087]

As described above, the adsorbent according to the first aspect of the present invention comprises the cross-linked polymer, and contains the surfactant in an amount of 0.
The composition is capable of adsorbing at least 01 g / g. This allows
The adsorbent has an effect of being able to efficiently adsorb the surfactant in the solution, for example.

As described above, the adsorbent according to a second aspect of the present invention is such that the crosslinked polymer has a polyoxyalkylene chain. According to the above configuration, the adsorbent contains the cross-linked polymer having a polyoxyalkylene chain, and therefore has an excellent ability to adsorb a surfactant. As a result, the adsorbent can efficiently adsorb the surfactant in the solution, for example, so that the surfactant can be sufficiently removed.

The adsorbent according to a third aspect of the present invention has a structure in which the crosslinked polymer is crosslinked with polyalkylene glycol as described above. As a result, the adsorbent has the effect of being able to more sufficiently remove the surfactant.

The adsorbent according to claim 4 is as described above.
The crosslinked polymer is represented by the general formula _{(1) CH 2 = CR-} CO- (X) n -Y ...... (1) ( wherein, R represents a hydrogen atom or a methyl group, X is,
Represents an oxyalkylene group having 1 to 5 carbon atoms, and Y represents 1 to 1 as a hydrogen atom, an alkoxy group having 1 to 5 carbon atoms, a phenoxy group, or an alkyl group having 1 to 9 carbon atoms as a substituent;
It is obtained by polymerizing a monomer component containing a (meth) acrylic acid ester-based monomer represented by 3 represents an oxyalkylphenyl group, and n represents a positive number of 3 to 100 on average. It is a structure that is one. As a result, the adsorbent has the effect of being able to more sufficiently remove the surfactant.

As described above, the adsorption method according to claim 5 is an adsorption method for adsorbing the surfactant contained in the solution, wherein the adsorbent containing the crosslinked polymer having a polyoxyalkylene chain is added to the solution. This is the method of contact. According to the above method, since the adsorbent containing the crosslinked polymer having a polyoxyalkylene chain is used, the surfactant contained in the solution can be efficiently adsorbed. Therefore, the surfactant can be sufficiently removed.

The above-mentioned crosslinked polymer can be produced at low cost by, for example, crosslinking a polyalkylene glycol such as polyethylene glycol or polymerizing a (meth) acrylic acid ester type monomer in the presence of a crosslinking agent. You can As a result, since the adsorbent is inexpensive, the surfactant can be removed inexpensively. Further, since the adsorbent to which the surfactant has been adsorbed is precipitated, the surfactant can be removed only by filtering thereafter. Due to these, there is an effect that the surfactant can be easily and inexpensively and sufficiently recovered and removed from the solution containing the surfactant.

Claims (5)

[Claims] 1. An adsorbent comprising a crosslinked polymer and capable of adsorbing a surfactant in an amount of 0.01 g / g or more. 2. The adsorbent according to claim 1, wherein the crosslinked polymer has a polyoxyalkylene chain. 3. The adsorbent according to claim 1, wherein the crosslinked polymer is formed by crosslinking polyalkylene glycol. 4. The crosslinked polymer has the general formula (1) CH ₂ ═CR—CO— (X) _n —Y (1) (wherein R represents a hydrogen atom or a methyl group, and X represents Is
Represents an oxyalkylene group having 1 to 5 carbon atoms, and Y represents 1 to 1 as a hydrogen atom, an alkoxy group having 1 to 5 carbon atoms, a phenoxy group, or an alkyl group having 1 to 9 carbon atoms as a substituent;
It is obtained by polymerizing a monomer component containing a (meth) acrylic acid ester-based monomer represented by 3 represents an oxyalkylphenyl group, and n represents a positive number of 3 to 100 on average. It is a thing, The thing of Claim 1 or 2 characterized by the above-mentioned.
Adsorbent as described. 5. An adsorption method for adsorbing a surfactant contained in a solution, which comprises contacting the solution with an adsorbent containing a crosslinked polymer having a polyoxyalkylene chain.