WO2015076370A1 - Biopolymer-adsorbing composition and water treatment method using same - Google Patents

Abstract

Provided is a biopolymer-adsorbing composition which has excellent adsorbability of a biopolymer that is present in water to be treated. This biopolymer-adsorbing composition contains a chemisorptive functional group-containing polymer (A) and a hydrophilic matrix polymer (B). The hydrophilic matrix polymer (B) is not ion-changing, and the polymer (A) is dispersed in the polymer (B) at an average dispersion diameter of 10,000 nm or less.

Description

Biopolymer adsorptive composition and water treatment method using the same Related applications

This application claims the priority of Japanese Patent Application No. 2013-243149 filed on November 25, 2013, which is incorporated herein by reference in its entirety as a part of this application.

The present invention relates to a biopolymer adsorptive composition that can adsorb dissolved organic substances that are contaminants in water treatment such as raw water, and is particularly excellent in the adsorptivity of biopolymers present in water.

When water treatment is performed on raw water obtained from a natural environment or an artificial environment, dissolved organic carbon (DOC) exists in such raw water. According to Patent Document 1 (Japanese Patent Publication No. 10-504995), DOC is a term encompassing organic carbon, organic colorants, and natural organic substances, and is an organic compound formed by decomposition of plant residues. It is also a term encompassing compounds such as humic acid and fulvic acid, which are mixtures of these compounds, and the main compounds and materials constituting DOC are soluble and cannot be easily separated from water. In Patent Document 1, a. Adding an ion exchange resin to water containing dissolved organic carbon; b. Dispersing the resin in the water to allow adsorption of the dissolved organic carbon onto the resin; and c. It proposes a method for removing dissolved organic carbon from water by separating the resin loaded with the dissolved organic carbon from the water.

In addition, humic substances such as humic acid and fulvic acid exist in raw water such as rivers, and such humic substances are problematic as pollutants in water treatment.
For example, in Patent Document 2 (Japanese Patent Application Laid-Open No. 2005-238174), humic substances account for 30 to 80% of dissolved organic matter (DOM) in rivers and lake water, It has been pointed out that it is also included in domestic wastewater, sewage facility wastewater, and agricultural facility wastewater such as barns, which contributes to environmental pollution. And in order to remove a humic substance effectively, the humic substance removal agent characterized by using as a main component the titanium carrying | support porous body which carry | supports titanium in a porous body is disclosed.

Patent Document 3 (Japanese Patent Application Laid-Open No. 2008-246365) discloses a method for treating humic substance-containing water, in which fine particles made of a cationic or nonionic polymer that swells in water and does not substantially dissolve in water are described above. Disclosed is a method for treating humic-containing water characterized by having a step of adding to humic-containing water. According to this method, cationic property that swells in humic-containing water and does not substantially dissolve in water is disclosed. Or, by adding fine particles of nonionic polymer, humic substances can be efficiently removed from water containing humic substances without the need for activated carbon treatment that causes problems such as clogging problems, water flow to ion exchange resin columns, membrane treatment, etc. can do.

On the other hand, in recent years, detailed analysis on fouling substances in membrane filtration has been made, and in Non-Patent Document 1, the causative substance of irreversible fouling is a dissolved organic substance having a relatively higher hydrophilicity than humic substances or the like. It has been reported that biopolymers such as proteins are the main cause.

Japanese National Patent Publication No. 10-504995 JP 2005-238174 A JP 2008-246365 A

However, although the invention of Patent Document 1 investigates dissolved organic carbon (DOC) in general, since DOC contains a wide variety of organic carbon substances including humic acid and fulvic acid, specific pollutants are included. The water treatment cannot be performed efficiently by adsorbing water.
In the inventions of Patent Documents 2 and 3, although adsorption performance for humic substances in water is reported, if organic carbon substances other than humic substances are important as pollutants in water treatment, those substances It is not clear about the adsorptivity to.

In particular, in the titanium-supporting porous material of Patent Document 2, the pores already used cannot be further used because they are taken in by utilizing a capillary phenomenon using a porous structure. Further, the particles of Patent Document 3 have an extremely large swelling property such that the particle size in water is about 10 to 200 times (that is, 1000 to 200000%) with respect to the particle size when not swollen with water. Therefore, the handleability at the time of adsorption treatment is poor, and there is a problem that the liquid permeability is lowered due to the adhesion of particles particularly in a closed environment.

An object of the present invention is to provide a biopolymer adsorbing composition capable of adsorbing dissolved organic substances that are contaminants in water treatment, and particularly capable of adsorbing at least a biopolymer efficiently.

As a result of intensive studies to achieve the above object, the inventors of the present invention have found that (i) a conventionally used ion exchange resin hardly adsorbs a biopolymer, and (ii) a hydrophilic matrix. A composition in which a polymer having a chemisorbable functional group is combined with a polymer in a state having a predetermined average dispersion diameter is surprisingly not only capable of adsorbing dissolved organic matter, but particularly among them. The present inventors have found that it has excellent adsorptivity to biopolymers and has reached the present invention.

That is, the present invention is a composition comprising a chemisorbable functional group-containing polymer (A) and a hydrophilic matrix polymer (B),
The hydrophilic matrix polymer (B) is non-ion exchangeable,
The polymer (A) is a biopolymer adsorptive composition that is dispersed in the polymer (B) with an average dispersion diameter of 10000 nm or less and that is excellent in the adsorptivity of the biopolymer present in the water to be treated.

In the biopolymer adsorbing composition, for example, the ion exchange capacity may be 0.1 mmol / g or more.

For example, the chemisorbable functional group in the chemisorbable functional group-containing polymer (A) forms at least one bond selected from the group consisting of a hydrogen bond, an ionic bond, and a chelate bond with respect to the biopolymer. May have a function. For example, such a chemisorbable functional group may be a chemisorbable functional group containing at least one element selected from the group consisting of N, S, P, and O. Preferably, the chemisorbable functional group-containing polymer (A) is a cationic polymer.
Cationic polymers include, for example, polyethyleneimine, polyallylamine, polyvinylamine, polypyridine, polyvinylpyridine, polyamino acid, polydiallyldimethylammonium halide, polyvinylbenzyltrimethylammonium halide, polydiacryldimethylammonium halide, polydimethylaminoethyl methacrylate hydrochloride, It may be at least one selected from the group consisting of polynucleotides and salts thereof.

On the other hand, the hydrophilic matrix polymer (B) includes polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyvinyl acetal, polyvinyl alkyl alcohol, polyalkylene glycol, polyvinyl alkyl ether, polyalkylene oxide, poly (meth) acrylamide, polyamide, It may be at least one selected from polyvinylpyrrolidone, cellulose derivatives, dextrin, chitin, and chitosan. In particular, the hydrophilic matrix polymer (B) is preferably at least one selected from polyvinyl alcohol and ethylene-vinyl alcohol copolymers.

In the biopolymer adsorbing composition, the ratio (mass ratio) between the chemically adsorbing functional group-containing polymer (A) and the matrix polymer (B) is, for example, polymer (A) / polymer (B) = It may be about 1/99 to 70/30.

Preferably, the weight loss when the boiling test is performed on the biopolymer adsorbing composition may be 20% by mass or less. Moreover, 50% or more of the adsorptive retention may be obtained when the biopolymer adsorbing composition is immersed in warm water at 60 ° C. for 1 week.

The present invention includes, as another embodiment, a water treatment method comprising at least an adsorption step of bringing the water to be treated containing a biopolymer into contact with the biopolymer adsorbing composition and adsorbing at least the biopolymer.

The water treatment method may further include a filtration step of membrane-filtering the adsorption treated water obtained by the adsorption step.

It should be noted that any combination of at least two components disclosed in the claims and / or the specification and / or the drawings is included in the present invention. In particular, any combination of two or more of the claims recited in the claims is included in the present invention.

In the biopolymer adsorbing composition of the present invention, the chemically adsorbing functional group-containing polymer (A) is dispersed with the hydrophilic matrix polymer (B) with a predetermined dispersion diameter. Biopolymers that were difficult to adsorb can be adsorbed efficiently.
Moreover, in the water treatment method of the present invention, by using a specific biopolymer adsorbent composition as an adsorbent, even in the case of water to be treated containing biopolymer, the biopolymer in the water to be treated can be easily treated. The amount can be reduced.

The present invention will be more clearly understood from the following description of preferred embodiments with reference to the accompanying drawings. However, the embodiments and drawings are merely for illustration and description and should not be used to define the scope of the present invention. The scope of the invention is defined by the appended claims. In the accompanying drawings, the same part number in a plurality of drawings indicates the same part.
It is a TEM photograph of the biopolymer adsorptive composition obtained in Example 2 of the present invention.

Hereinafter, embodiments of the present invention will be described in detail. Note that the embodiments described below do not limit the present invention.

[Biopolymer adsorptive composition]
The biopolymer adsorbing composition of the present invention is a composition comprising at least a chemically adsorbing functional group-containing polymer (A) and a hydrophilic matrix polymer (B).

[Chemically Adsorbing Functional Group-Containing Polymer (A)]
The chemisorbable functional group-containing polymer (A) is at least composed of a structural unit having a chemisorbable functional group, and this structural unit exists in the polymer as a main chain and / or as a side chain. .

The functional group having chemisorbability is a functional group having a capability of forming at least one kind of bond selected from the group consisting of a hydrogen bond, an ionic bond, and a chelate bond (preferably a chelate-forming group, A cationic ion-exchange group, an anion ion-exchange group, etc.), and is not particularly limited as long as it has adsorptivity to a biopolymer.

The functional group may be a chemisorbable functional group containing at least one element selected from the group consisting of N, S, P and O, for example.
Specifically, such functional groups include amino groups (primary amino groups, secondary amino groups, tertiary amino groups), quaternary ammonium groups, iminium groups, imidazole groups, quaternary imidazolium groups, pyridyl groups. Group, quaternary pyridinium group, hydroxyl group, carboxyl group, sulfonate group, sulfonic acid group, sulfonium group, mercapto group, thiourea group, phosphonate group, phosphonic acid group, phosphonium group and the like. They may be present in a salt state. These functional groups may be present alone or in combination of two or more in the polymer (A). These functional groups may be complexed, and in that case, for example, a chelate-forming group such as an iminodiacetic acid group, an aminophosphoric acid group, an amidoxime group, a methylglucamine group, or a dithiocarbamic acid group may be used. Among these, preferred functional groups include amino groups, quaternary ammonium groups, iminium groups, imidazole groups, quaternary imidazolium groups, pyridyl groups, quaternary pyridinium groups, and salts thereof.

The structural unit having such a functional group, for example, polymerizes an ethylenically unsaturated monomer having a functional group (such as allylamine or diallyldimethylammonium halide) or a ring structure-containing monomer capable of forming a functional group (for example, ethyleneimine). May be introduced.

Alternatively, styrene resin, poly (meth) acrylate resin, polysulfone, polyethersulfone, polyetheretherketone, polyphenylene oxide, polyimide, etc. are used as the base resin, and the base resin is sulfonated, hydrolyzed, and aminated. The functional group may be introduced by a known method such as phosphorylation. If necessary, the base resin may have a crosslinkable structural unit such as divinylbenzene.

For example, the chemisorbable functional group-containing polymer (A) is an anion such as polystyrene sulfonic acid (PSS), polyvinyl sulfate (PVS), polyacrylic acid (PAA), polymethacrylic acid (PMA), polymaleic acid, polyamic acid, etc. Polyethyleneimine, polyallylamine, polyvinylamine, polypyridine, polyvinylpyridine, polyamino acid, polydiallyldimethylammonium halide, polyvinylbenzyltrimethylammonium halide, polydiacryldimethylammonium halide, polydimethylaminoethyl methacrylate hydrochloride Cationic polymers such as polynucleotides and salts thereof may be used. Such polymers may be used alone or in combination of two or more.

Among these, a cationic polymer is preferable from the viewpoint of more efficiently adsorbing a biopolymer in combination with a hydrophilic matrix polymer, and particularly a polymer having a high cation density (for example, polyethyleneimine, polyallylamine, etc.). Is preferred.

The weight average molecular weight of the chemisorbable functional group-containing polymer (A) can be appropriately set within a preferable range depending on the type of the functional group. For example, the chemisorbable functional group-containing polymer (A ) Can be selected from a wide range of about 5000 to 100,000, preferably about 6000 to 90,000, more preferably about 7000 to 80,000. In addition, a weight average molecular weight can be calculated | required, for example using GPC.

[Hydrophilic matrix polymer (B)]
The hydrophilic matrix polymer (B) is non-ion exchangeable. Various hydrophilic polymers can be used as long as the chemisorbable functional group-containing polymer (A) can be dispersed within a predetermined range.
Here, that the matrix polymer (B) is non-ion exchange means that the ion exchange capacity (IEC) of the matrix polymer (B) is 0.01 mmol / g or less. In addition, ion exchange capacity shows the value measured by the method described in the Example mentioned later.

The hydrophilic matrix polymer (B) has a solubility parameter (δ) calculated by the following formula using the cohesive energy density (Ecoh) and molar molecular volume (V) calculated by the Fedor's estimation method. The polymer may be 22 or more. Preferably, the solubility parameter (δ) is 24 or more, and more preferably 25 or more. The upper limit of the solubility parameter is not particularly limited, but may be about 35, for example.
δ = [ΣEcoh / ΣV] ^1/2
Examples of the hydrophilic polymer include a polymer having a hydrophilic group such as a hydroxyl group, an ether group, a cationic group, an anionic group, and an amide group in a repeating unit.

Specifically, the hydrophilic matrix polymer (B) includes polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyvinyl acetal, polyvinyl alkyl alcohol, polyalkylene glycol, polyvinyl alkyl ether, polyalkylene oxide, poly (meth). Examples include acrylamide, polyamide, polyvinyl pyrrolidone, phenol resin, cellulose derivative, dextrin, chitin, and chitosan. These polymers may be used alone or in combination of two or more.

These polymers may have other comonomer units, and the content of the comonomer units is preferably 10 mol% or less, more preferably 5% mol or less in all monomer units. .

The weight average molecular weight of the hydrophilic matrix polymer (B) can be appropriately set in accordance with the type of the polymer. From the viewpoint of maintaining inside the molecule (B), for example, the weight average molecular weight of the hydrophilic matrix polymer (B) may be at least 5000 or more (eg, 5000 to 100,000), preferably 10,000 or more. May be. In addition, a weight average molecular weight can be calculated | required, for example using GPC.

Preferred hydrophilic matrix polymers (B) include polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyvinyl acetal (eg, polyvinyl formal, polyvinyl butyral), and polyamide (eg, polyamide 6, polyamide 10, polyamide 6,6). , Polyamide 11, polyamide 12, polyamide 6,12, polyamide 6,10, polyamide 6 / 6,6 copolymer, polyamide 6,6 / 6,10 copolymer, polyamide 6,11, polyamide 6,6 / 6 , 10/6 copolymer), and the like. Polyvinyl alcohol and ethylene-vinyl alcohol copolymer are more preferable. From the viewpoint of not only having high hydrophilicity but also excellent adsorption characteristics and durability, ethylene-vinyl. Alcohol copolymers are particularly preferred.

In the ethylene-vinyl alcohol copolymer, the content of ethylene units is preferably 20 to 60 mol%, more preferably 25 to 55 mol%, particularly preferably 35 to 48 mol% in the total monomer units. Also good. If the ethylene content is too small, the durability of the molded article may be deteriorated. On the other hand, when there is too much ethylene content, there exists a possibility that hydrophilicity may fall.

The saponification degree of the vinyl ester component of the ethylene-vinyl alcohol copolymer is preferably 90 mol% or more, more preferably 95 mol% or more, and particularly preferably 99.5 mol% or more. When the saponification degree is less than 90 mol%, the moldability as a matrix may be deteriorated.

Here, when the ethylene-vinyl alcohol copolymer is composed of two or more kinds of blends having different saponification degrees, the average value calculated from the blending weight ratio is defined as the saponification degree.

Further, the ethylene-vinyl alcohol copolymer may be evaluated by a melt flow rate (MFR) (210 ° C., load 2160 g). In this case, the melt flow rate (MFR) (210 ° C., load 2160 g) is 0.1 g / min or more is preferable, and 0.5 g / min or more is more preferable. If it is less than 0.1 g / min, the strength may decrease. In addition, the upper limit of a melt flow rate should just be the range normally used, for example, 25 g / min or less may be sufficient.

Polyvinyl alcohol may be defined by the viscosity average degree of polymerization, and is not particularly limited as long as the chemically adsorbable functional group-containing polymer (A) can be dispersed with a predetermined dispersion diameter, and is determined from the viscosity of a 30 ° C. aqueous solution. The viscosity average degree of polymerization can be selected from a wide range of about 100 to 15000, for example. From the viewpoint of improving the durability of the matrix polymer, it is preferable to use those having a high degree of polymerization. In this case, for example, the viscosity average degree of polymerization is preferably about 800 to 13000, more preferably about 1000 to 10,000. May be.

Further, the degree of saponification of polyvinyl alcohol can be appropriately selected according to the purpose and is not particularly limited. For example, it may be 88 mol% or more, preferably 90 mol% or more, more preferably 95 mol% or more. Good. In particular, from the viewpoint of improving durability, those having a saponification degree of 98 mol% or more are preferred.

[Mass ratio between the chemisorbable functional group-containing polymer (A) and the hydrophilic matrix polymer (B)]
In the biopolymer adsorbing composition of the present invention, the ratio of the chemically adsorbing functional group-containing polymer (A) and the hydrophilic matrix polymer (B) is particularly limited as long as the polymer (A) is dispersed within a predetermined range. Although not limited, for example, the mass ratio may be about polymer (A) / polymer (B) = 1/99 to 70/30, preferably about 5/95 to 65/45, more preferably 8 It may be about / 92 to 60/40. If the amount of the polymer (A) is too much, there is a risk that the adsorption retention of the composition with time will be impaired. If the amount of the polymer (A) is small, the adsorption performance tends to be lowered.

[Other ingredients]
In the present invention, the biopolymer adsorbing composition is used as a resin component other than the chemically adsorbing functional group-containing polymer (A) and the hydrophilic matrix polymer (B) as long as the effects of the present invention are not impaired. The polymer polymer may be included. In addition, the biopolymer adsorbent composition may be added with various additives such as a cross-linking agent, an antioxidant, a stabilizer, a lubricant, a processing aid, an antistatic agent, a colorant, an antifoaming agent, and a dispersing agent as necessary. An agent may be included.

In particular, the biopolymer adsorbing composition may contain a crosslinking agent from the viewpoint of controlling durability and swelling property. A crosslinking agent can be suitably selected from a well-known crosslinking agent according to the kind of chemisorbable functional group containing polymer (A) and hydrophilic matrix polymer (B).

[Method for producing biopolymer adsorbing composition]
The biopolymer adsorbing composition according to the present invention includes a chemically adsorbing functional group-containing polymer (A) and a hydrophilic matrix polymer (B), and the polymer (A) is the polymer (B). As long as it exists in the range of a predetermined dispersion diameter, the manufacturing method is not specifically limited, It can manufacture by various methods according to the kind of polymer used.

As a suitable production method, a method of melt-kneading the chemisorbable functional group-containing polymer (A), the hydrophilic matrix polymer (B) and an optional component using a biaxial kneader (melt kneading method) Is mentioned. According to the melt kneading method, it is possible to obtain a composition in which the chemically adsorbing functional group-containing polymer (A) is dispersed with respect to the hydrophilic matrix polymer (B) with an average dispersion diameter in a predetermined range.

Specifically, as the melt kneading method, for example, the hydrophilic matrix polymer (B) is melt kneaded by a twin screw extruder, and the chemisorbable functional group-containing polymer (A) is placed from the side feeder. A fixed amount can be added and these can be mixed and implemented.

The kneading temperature after the addition of the polymer (A) can be appropriately set according to the desired dispersion diameter of the polymer (A). For example, the kneading temperature is the hydrophilic matrix polymer (B). If the melting point is Mp, it may be Mp−50 ° C. or higher, preferably Mp ° C. or higher, and more preferably Mp + 10 ° C. or higher. The upper limit of the kneading temperature is usually below the decomposition temperature of the hydrophilic matrix polymer.

The kneading time after the addition of the polymer (A) can be appropriately set according to the amount of the polymer (A) and the like. For example, the polymer (A) is charged into the kneader for 1 minute or more. It is preferable to knead, and it is more preferable to knead for 2 minutes or more. The kneading time may be 30 minutes or less from the viewpoint of preventing thermal deterioration of the resin.

Furthermore, the melt-kneaded product can be extruded to form molded bodies of various shapes, and further, can be immersed in a solution containing a crosslinking agent to be subjected to a crosslinking treatment, and a crosslinking agent is added during the kneading, The polymer can be melt-kneaded and a crosslink can be introduced. Furthermore, the molded body can be pulverized into a pulverized product (for example, in a particulate form).

As another method for producing a biopolymer adsorbing composition, for example, a mixed liquid of a chemically adsorbing functional group-containing polymer (A) and a hydrophilic matrix polymer (B) and an arbitrary component is prepared. As the solvent, water is usually used, but an organic solvent such as dimethyl sulfoxide may be used. A solution with good properties can be obtained by adding both polymers to a solvent and raising the temperature while stirring.

The mixing method and mixing time after the addition of the chemisorbable functional group-containing polymer (A) and the hydrophilic matrix polymer (B) can be appropriately set according to the desired dispersion diameter of the polymer (A). However, for example, the polymer (A) resin is charged into a mixer and mixed for 1 minute or more, and more preferably kneaded for 2 minutes or more. In the case of heating, the mixing time may be 30 minutes or less from the viewpoint of preventing thermal degradation of the resin.

The obtained solution can be molded by cast film formation or the like to obtain molded bodies of various shapes. Moreover, this molded body may be further dipped in a solution containing a crosslinking agent and subjected to a crosslinking treatment.

[Biopolymer adsorptive composition]
The biopolymer adsorptive composition thus obtained contains a chemisorbable functional group-containing polymer (A) and a hydrophilic matrix polymer (B), and the polymer (A) is the polymer. In (B), it is dispersed with an average dispersion diameter of 10000 nm or less (for example, 1 to 10000 nm), and the biopolymer existing in water can be adsorbed efficiently.

The average dispersion diameter of the chemisorbable functional group-containing polymer (A) and the hydrophilic matrix polymer (B) can be measured by the method described in the examples described later. Is preferably 8000 nm or less (eg 1 to 7000 nm), more preferably 6000 nm or less (eg 5 to 5000 nm), further preferably 4000 nm or less (eg 10 to 3000 nm), particularly preferably 2000 nm or less (eg 50 to 1000 nm). May be. In addition, an average dispersion diameter shows the value measured by the method described in the Example mentioned later.

The biopolymer adsorbing composition of the present invention can adsorb at least biopolymers among dissolved organic substances, and can adsorb not only biopolymers but also various dissolved organic substances present in the water to be treated. is there.
Although various dissolved organic substances exist in the water to be treated, the biopolymer adsorbing composition of the present invention is a dissolved organic substance that has been difficult to be adsorbed in the past, particularly an organic substance having a particle size of 0.45 μm or less (for example, humin). It is possible to efficiently adsorb aromatic organic substances such as acids and fulvic acids, synthetic chemical substances such as surfactants, biopolymers, and the like.

The biopolymer adsorptive composition of the present invention is particularly excellent in adsorbing biopolymers having high hydrophilicity among dissolved organic substances. Biopolymers are a kind of dissolved organic substances present in various raw waters. Generally, biopolymers are polysaccharides and proteins having an apparent molecular weight of 100,000 Da or more.

The reason why the biopolymer adsorbability is excellent is not clear, but in such a state having a specific dispersion diameter, the chemisorbable functional group-containing polymer (A) is a non-ion-exchangeable hydrophilic matrix polymer. Because of the presence in (B), the composition of the present invention can efficiently recover a biopolymer that was very difficult to adsorb with a commercially available ion exchange resin. This is very surprising in view of the fact that commercially available ion exchange resins hardly adsorb biopolymers even though there are adsorptive functional groups, as shown in Comparative Examples described later. It should be an effect.

Biopolymers are compounds (for example, polysaccharides and proteins) having hydrophilic high molecular weight (for example, 100,000 daltons or more).

More specifically, the biopolymer has an A fraction measured by the method described in Stefan A. Huber et al. Water Research 45 (2011) pp879-885, for example, a retention time by LC-OCD of 25 minutes to 38 minutes. The following components may be used. In the examples, a component having a holding time of 25 minutes or more and 38 minutes or less is measured as a biopolymer in the analysis of LC-OCD (manufactured by DOC-Labor) based on the above-described method.
Note that the humic substance may be a B fraction in the measurement under the same conditions, for example, a component exceeding the holding time of 38 minutes and not more than 50 minutes.

Since biopolymers have few unsaturated bonds such as benzene rings, biopolymers are mainly composed of highly hydrophilic organic substances. For example, the SUVA value is 1.0 [L / (m · mg)] or less. It may be composed of an organic material showing.
On the other hand, since the humic substance includes a UV-absorbing structure such as a benzene ring, the humic substance is mainly composed of an organic substance having high hydrophobicity. For example, the SUVA value is 2.0 [L / (M · mg)] It may be composed of an organic material showing the above.

The SUVA value is obtained by the following formula.
SUVA (L / mg-C · m) = UV (m ⁻¹ ) / DOC (mg-C / L)

Here, each parameter for calculating the SUVA value was measured by the method described in Stefan A. Huber et al. Water Research 45 (2011) pp879-885, and "area value" The area value obtained by LC-OCD is expressed, “UV” indicates the absorbance at a wavelength of 254 nm, and “DOC” indicates the DOC concentration (mg-C / L) in the test sample.

UV value calculation method (i) UV of biopolymer = UV of entire test sample × area value of biopolymer in spectrum (holding time t _b : 25 minutes ≦ t _b ≦ 38 minutes) / area value of entire spectrum (ii ) humic humic substance of UV = test sample total UV × in the spectrum of (holding time _t h: 38 min <area value / spectrum total area values of _{t h} ≦ 50 minutes)

DOC value calculation method (i) DOC of biopolymer = DOC of the entire test sample x area value of biopolymer in the spectrum (holding time t _b : 25 minutes ≤ t _b ≤ 38 minutes) / area value of the entire spectrum (ii ) Humic DOC = DOC of the entire test sample x area value of humic substance in the spectrum (holding time t _h : 38 minutes <t _h ≤ 50 minutes) / area value of the entire spectrum

In the biopolymer adsorbing composition of the present invention, the adsorption rate of the biopolymer in the treated water (that is, the removal rate of the biopolymer from the treated water) is, for example, 15% or more, preferably 20% or more, more preferably 25. % Or more. In addition, an adsorption rate shows the value measured by the method described in the Example mentioned later.

The biopolymer adsorbing composition of the present invention may have, for example, an ion exchange capacity of 0.1 mmol / g or more (eg, 0.1 to 15 mmol / g), preferably 1 mmol / g or more (eg, 1 To 12 mmol / g), more preferably 1.5 mmol / g or more (for example, 1.5 to 11 mmol / g).
The ion exchange capacity can be applied to either the cation exchange capacity or the anion exchange capacity depending on the type of the adsorptive functional group.
The higher the ion exchange capacity, the better the adsorptivity. However, if the ion exchange capacity is too high, the adsorptive retention performance tends to decrease.

Further, the biopolymer adsorbing composition of the present invention may have an adsorption rate of, for example, 20% or more, preferably 30 when sodium alginate is used as a model substance as an index indicating the adsorption performance. % Or more, more preferably 40% or more, and particularly preferably 50% or more. In addition, this adsorption rate shows the value measured by the method described in the Example mentioned later.

Further, from the viewpoint of durability, the biopolymer adsorbent composition of the present invention may have a weight loss when a boiling test is performed, for example, 20% by mass or less, and preferably 10% by mass or less. It may be more preferably 7% by mass or less, particularly preferably 5% by mass or less. In addition, about the weight loss part at the time of performing a boiling test, the value measured by the method described in the Example mentioned later is shown.

Furthermore, from the viewpoint of maintaining the adsorptivity of the biopolymer adsorbent composition, for example, the biopolymer adsorbent composition of the present invention has an adsorbability retention rate of 45% when immersed in warm water at a temperature of 60 ° C. for 1 week. It may be above, preferably 55% or more, more preferably 65% or more, and particularly preferably 75% or more. In addition, an adsorptive retention rate shows the value measured by the method described in the Example mentioned later.

The shape of the biopolymer adsorbent composition of the present invention is not particularly limited as long as the biopolymer can be adsorbed, and is in the form of particles, flakes, fibers, hollow fibers, sheets, woven / knitted fabrics, nonwoven fabrics, etc. It is possible to select from various shapes such as processed products. From the viewpoint of improving the adsorption efficiency, the biopolymer adsorbent composition is preferably particulate [spherical or non-spherical (for example, irregularly shaped particles such as a pulverized product)] or fibrous.

When the biopolymer-adsorbing composition is in the form of particles, it may be adjusted to the desired particle size by appropriate pulverization, but the particle size is preferably 1 μm to 5000 μm, more preferably 10 μm to 4000 μm, and most preferably 20 μm to 3000 μm. When the particle size is too small, handling is difficult, for example, the fine powder tends to fly. If the particle size is too large, sufficient adsorption performance may not be obtained. In addition, a particle diameter shows the value classified by sieving.

When the biopolymer adsorbing composition is fibrous, the average fiber diameter is not particularly limited, but can be selected from a wide range of 0.1 to 1000 μm, and may be 1 to 500 μm, for example. May be 2 to 200 μm. The average fiber diameter can be calculated as an average fiber diameter by measuring the fiber diameter at 10 locations of fibers in a standard state defined by JIS L 0105 with a micrometer.
Moreover, as a fiber, a continuous fiber may be sufficient and a short fiber may be sufficient. In the case of short fibers, the fiber length may be, for example, about 0.1 to 100 mm (for example, 1 to 100 mm), preferably about 0.5 to 80 mm (for example, 5 to 80 mm), more preferably 10 It may be about 50 mm.

[Water treatment method]
The present invention includes a water treatment method as another embodiment. The water treatment method includes at least an adsorption step in which water to be treated containing a biopolymer is brought into contact with the biopolymer adsorbing composition to adsorb the biopolymer.
The water to be treated is not particularly limited as long as various kinds of water obtained in a natural environment or an artificial environment can be used as the water to be treated and contains a biopolymer. For example, seawater, general river water, lake water Soil elution water, irrigation water, biologically treated water, biologically treated water in sewage treatment and human waste treatment facilities, highly treated water such as tertiary treatment, and various factory effluents.

The adsorption process is not particularly limited as long as the water to be treated and the biopolymer adsorbent composition can be brought into contact with each other. For example, the adsorption treatment is performed by adding an adsorbent to the water to be treated and stirring the solution using a known method. The adsorption treatment may be carried out by passing water to be treated through a column filled with a hydrophilic polymer adsorbent. Further, the adsorption step may be a single step or a multi-step.
In the adsorption step, after the adsorption treatment, the solid-liquid separation step may be performed by a known method as necessary, and the adsorbent after the adsorption treatment may be removed from the adsorption treatment liquid by the solid-liquid separation step. .

In the adsorption step, dissolved organic substances in the water to be treated can be adsorbed efficiently, and in particular, the biopolymer can be adsorbed efficiently as described above.

Further, the water treatment method may further include a filtration step of membrane-filtering the adsorption treated water obtained by the adsorption step.

These filtration membranes may be modularized. For example, in the case of a flat membrane, a spiral type, a pleat type, a plate-and-frame type, or a disc type in which discs are stacked may be used. It may be a hollow fiber membrane type bundled in an I shape and stored in a container.

The water treatment method of the present invention may be combined with an existing water treatment method as necessary within a range not impairing the effects of the invention. Examples of the existing water treatment method include sand filtration treatment, coagulation sedimentation treatment, ozone treatment, adsorption treatment using an existing adsorbent or activated carbon, biological treatment, and the like. These treatments may be performed singly or in combination of two or more.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Each numerical value was measured by the following method.

(Ion exchange capacity: IEC measurement)
Regarding the anion exchange capacity, 0.1 g of the obtained resin composition sample was immersed in a 0.5 M NaNO ₃ aqueous solution for 1 hour and washed with ion exchange water. Thereafter, the sample was immersed in a 0.1 M NaCl aqueous solution to be substituted with chloride ions again, and the liberated nitrate ion A (mol) was quantified by ion chromatography ICS-1600 (manufactured by Nippon Dionex Co., Ltd.). Next, after thoroughly washing the resin composition sample used with ion-exchanged water, it was vacuum-dried at a temperature of 50 ° C. for 60 hours in a vacuum dryer “DP32” (manufactured by Yamato Scientific Co., Ltd.), and a dry weight Wa ( g) was measured. The anion exchange capacity was calculated using the following formula.
Ion exchange capacity = A × 1000 / Wa [mmol / g]

On the other hand, the cation exchange capacity was measured by the following method. It was immersed in a 0.5 M KCl aqueous solution for 1 hour and washed with ion exchange water. Thereafter, the sample was immersed in a 0.1 M NaCl aqueous solution to replace with sodium ions, and the liberated potassium ions B (mol) were quantified by ion chromatography ICS-1600 (manufactured by Nippon Dionex Co., Ltd.). Next, after thoroughly washing the resin composition sample used with ion-exchanged water, it was vacuum-dried at a temperature of 50 ° C. for 60 hours in a vacuum dryer “DP32” (manufactured by Yamato Scientific Co., Ltd.), and the dry weight Wb (g ) Was measured. The anion exchange capacity was calculated using the following formula.
Ion exchange capacity = B × 1000 / Wb [mmol / g]

(Average dispersion diameter of the chemisorbable functional group-containing polymer (A): nm)
Thin sections of the resin compositions obtained in the following examples were prepared with a cryomicrotome to a thickness of 65 to 80 nm. Further, an observation section was obtained by performing gas phase dyeing with RuO ₄ to give contrast in the observation image. The apparatus used for the analysis was JEOL JEM-2100F, and after taking a TEM image at an acceleration voltage of 200 kV, a setting magnification of 2000 times and 5000 times, the average dispersion diameter of the polymer (A) was estimated. .

(Weight loss in boiling test)
The obtained resin composition sample was dried at 105 ° C. for 4 hours, weighed the mass of the sample before the boiling test (mass Ag), boiled in water at 100 ° C. for 30 minutes, and dried under the same conditions. The mass of the sample after the boiling test was weighed (mass Bg).
Boiling loss = (A−B) / A × 100 (mass%)

(Adsorption rate of sodium alginate)
Adsorption evaluation of sodium alginate (Wako Pure Chemical Industries, Ltd., sodium alginate) considered as a biopolymer model substance was carried out. 5.0 g of resins prepared in the following examples and comparative examples were added to 1000 g (4.3 mg-C / L) of an aqueous sodium alginate solution, and the mixture was stirred with a six-unit magnetic hot stirrer (180 rpm, 25 ° C.). After stirring for 240 minutes, 25 ml of the supernatant was evaluated with a total organic carbon meter, and the adsorption rate of alginic acid by the resin was evaluated as follows.
Adsorption rate of alginic acid = (alginic acid concentration before adsorption evaluation−alginic acid concentration after adsorption evaluation) / alginic acid concentration before adsorption evaluation × 100 (%)

(Adsorption retention rate)
The obtained resin composition sample was first immersed in warm water at 60 ° C. for 1 week, and then the adsorption evaluation of sodium alginate as described above was performed. The amount of adsorption (A) of the resin composition sample immersed as described above is compared with the amount of adsorption (B) of the hot water resin composition sample not immersed. The retention rate, which is a parameter indicating a good adsorption performance, was calculated.
Retention rate = A / B x 100 (%)

(Adsorption evaluation in river water)
An adsorption experiment similar to the above was conducted with surface water collected from Inba Marsh (Chiba Prefecture) (surface water, dissolved organic matter concentration = 3.6 mg-C / L, biopolymer SUVA value: 0.21 (L / mg) -C · m), the humic substance SUVA value: 3.3 (L / mg-C · m), pH = 8.7), water to be treated was first filtered with a stainless mesh cartridge filter with an exclusion diameter of 2 μm ( The insoluble matter was removed by filtration with TMP-2 (manufactured by Advantech), and 5 g of the obtained resin composition sample was added to 1 L of the filtered water and stirred at 25 ° C. for 2 hours. The supernatant liquid after stirring is taken out, and the post-adsorption evaluation is performed using HPLC (DOC-Labor, Hubers), and the biopolymer concentration (mg-C / L) contained in the supernatant liquid is analyzed. The biopolymer adsorption rate was evaluated from the existing peak area. The following formula was used for calculating the adsorption rate.
(A) Biopolymer adsorption rate = (Biopolymer concentration before adsorption evaluation−Biopolymer concentration after adsorption evaluation) / Biopolymer concentration before adsorption evaluation × 100 (%)

The biopolymer concentration was measured by the following method.
The biopolymer concentration is measured by LC-OCD (manufactured by DOC-Labor) in which a wet total organic carbon meter (OCD meter) is connected to high performance liquid chromatography (HPLC). Stefan A. Huber et al. “Characterisation of aquatic humic and non-humic matter with size-exclusion chromatography -organic carbon detection -organic nitrogen detection (LC-OCD-OND)” Water Research 45 (2011) pp879-885 In accordance with the method described in 1), it was carried out under the following conditions, and a component having a holding time of 25 minutes or more and 38 minutes or less was measured as a biopolymer.
Flow rate: 1.1 mL / min
Sample injection volume: 1 mL
Column: 250 mm x 20 mm, TSK HW50S
UV wavelength: 254 nm
OCD meter: Acid injection rate 0.2mL / min
Eluent: pH 6.85 Phosphate buffer acidified solution: Add 4 mL O-phosphoric acid (85%) and 0.5 g potassium peroxodisulfate to 1 L ultrapure water

[Example 1]
An ethylene-vinyl alcohol copolymer having an ethylene content of 27 mol% (“Eval L-104” manufactured by Kuraray Co., Ltd.) and polyethyleneimine having a weight average molecular weight of 10,000 (manufactured by Nippon Shokubai Co., Ltd., “Epomin SP- 200 ").

First, the above-mentioned ethylene-vinyl alcohol copolymer is melt-kneaded at 210 ° C. with a lab plast mill, so that the polyethyleneimine content is 3 parts by mass and the ethylene-vinyl alcohol copolymer is 97 parts by mass. Thus, polyethyleneimine was added, and the two polymers were mixed and kneaded for 5 minutes. The obtained kneaded product was cooled and then pulverized by a pulverizer to obtain a particulate material having a particle size of 200 to 500 μm by sieving. Subsequently, the particulate material was subjected to a crosslinking treatment in an aqueous solution of 25% by weight of an epoxy compound (manufactured by Nagase ChemteX Corporation, “Denacol EX-810”) at a concentration of 2% by mass to obtain a biopolymer adsorbing composition. It was. Table 1 shows the results of evaluation of adsorption characteristics and the like using the obtained biopolymer adsorbent composition.

[Examples 2 to 8]
As described in Table 1, biopolymer adsorptivity under the same conditions as in Example 1 except that the blending ratio was changed in Example 2, and the types and blends of ethylene-vinyl alcohol copolymers were changed in Examples 3 to 8. A composition was obtained. Table 1 shows the results of evaluation of adsorption characteristics and the like using the obtained biopolymer adsorbent composition.

[Example 9]
70 g of polyvinyl alcohol having a viscosity average polymerization degree of 1700 and a saponification degree of 98.5 mol% is dissolved in 630 g of ion-exchanged water, and 30 g of the above-mentioned polyethyleneimine (manufactured by Nippon Shokubai Co., Ltd., “Epomin SP-200”) is uniformly dispersed. Then, a 1200 μm cast film was formed on a PET film in a wet state and dried to obtain a desired film. Next, the film was immersed in an aqueous solution of 2 mol / L sodium sulfate for 24 hours, concentrated sulfuric acid was added to the aqueous solution so that the pH was 1.0, and then the film was crosslinked with an aqueous 0.5 volume% glutaraldehyde solution. It was carried out at 50 ° C. for 2 hours. Here, as the glutaraldehyde aqueous solution, a product obtained by diluting “glutaraldehyde” (25% by volume) manufactured by Ishizu Pharmaceutical Co., Ltd. with water was used. The obtained film was taken out, pulverized by a pulverizer, and sieved to obtain a small-piece biopolymer adsorbing composition (diameter: 100 to 500 μm). Table 1 shows the results of evaluation of adsorption characteristics and the like using the obtained biopolymer adsorbent composition.

[Examples 10 and 11]
Biopolymer adsorptive compositions prepared under the same conditions were obtained except that the crosslinking treatment of Example 9 was changed from 2 hours to 1 hour in Example 10 and 30 minutes in Example 11. Table 1 shows the results of evaluation of adsorption characteristics and the like using the obtained biopolymer adsorbent composition.

[Examples 12 and 13]
The component A under the conditions of Example 5 was changed to polyallylamine having a weight average molecular weight of 15000 in Example 12 (“PAA-15C” manufactured by Nittobo Medical Co., Ltd.). In Example 13, diallyldimethylammonium having a weight average molecular weight of 30000 was used. Biopolymer adsorptive compositions prepared under the same conditions were obtained except that the polymer was changed to a chloride polymer (“PAS-H-5L” manufactured by Nitto Bo Medical Co., Ltd.). Table 1 shows the results of the adsorption property evaluation using the obtained biopolymer adsorbent composition.

[Example 14]
The biopolymer adsorptive composition was obtained by changing the ethylene-vinyl alcohol copolymer from Example 1 to the conditions described in Table 1. Table 1 shows the results of evaluation of adsorption characteristics and the like using the obtained biopolymer adsorbent composition.

[Example 15]
A biopolymer adsorbing composition was obtained by producing under the same conditions as in Example 1 except that the kneading temperature of Laboplast Mill was set to 160 ° C. in Example 1 and melt kneading was performed for 1 minute. Table 1 shows the results of evaluation of adsorption characteristics and the like using the obtained biopolymer adsorbent composition.

[Comparative Example 1]
A resin composition was obtained under the same conditions as in Example 4 except that the polyethyleneimine component was not added in Example 4. Table 1 shows the results of the adsorption characteristics evaluation and the like of the obtained resin composition.

[Comparative Example 2]
A resin composition was obtained under the same conditions as in Example 5 except that the polyethyleneimine component was not added in Example 5. Table 1 shows the results of the adsorption characteristics evaluation and the like of the obtained resin composition.

[Comparative Example 3]
A resin composition was obtained under the same conditions as in Example 9 except that the polyethyleneimine component was not added in Example 9. Table 1 shows the results of the adsorption characteristics evaluation and the like of the obtained resin composition.

[Comparative Examples 4 and 5]
In Comparative Example 4, a commercially available ion exchange resin ("Diaion SA-10A" manufactured by Mitsubishi Chemical Corporation) that is a styrene quaternary ammonium type, and in Comparative Example 5, a commercially available ion exchange resin that is a styrene polyamine type (( Evaluation of adsorption properties of the adsorbent was evaluated using “Diaion WA-20” manufactured by Mitsubishi Chemical Corporation. The results are shown in Table 1.

[Comparative Example 6]
A kneaded material was obtained under the same conditions as in Example 2 except that the kneading temperature of Laboplast Mill was set to 160 ° C. in Example 2 and melt kneading was performed for 1 minute. The average dispersion diameter of PEI was 20000 nm. After the obtained kneaded product was cooled, a pulverization treatment with a pulverizer was attempted, but the adhesion of the resin was so great that almost no pulverized product could be obtained. Although a small amount of the particles obtained were used for the adsorption property evaluation, the elution of the PEI component was remarkable and could not be evaluated.

As shown in Examples 1 to 15, a composition obtained by combining a polymer having a chemical adsorption functional group with a hydrophilic matrix polymer in a state having a predetermined average dispersion diameter is a commercially available ion exchange resin. Compared with certain Comparative Examples 4 and 5, it is possible to adsorb the biopolymer with a high adsorption rate.
For example, as shown in FIG. 1, in the biopolymer adsorbing composition obtained in Example 2, the chemically adsorbing functional group-containing polymer (A) is uniformly dispersed in the matrix polymer (B). Dispersed by diameter.

In particular, Examples 1 to 13 having an average dispersion diameter of 10000 nm or less (particularly 7500 nm or less) and an ion exchange capacity of 0.3 mmol / g or more are compared with Comparative Examples 4 and 5 in that sodium alginate is a model substance. In this case, the adsorption rate is 7 times or more, and the adsorption rate in river water is also 6 times or more.
Further, in Examples 1 to 9 and 12 to 15 in which the weight loss in the boiling test is 10% by mass or less, the adsorptive retention rate tends to be good. Among these examples, those having an ion exchange capacity in the range of 0.5 to 10 mmol / g have particularly good adsorption retention.

On the other hand, Comparative Examples 4 and 5, which are commercially available ion exchange resins, have a poor biopolymer adsorption rate compared to the Examples, and the adsorption rate does not include the chemically adsorbing functional group-containing polymer (A). It is almost the same as 1-3.

According to the present invention, it is possible to provide a composition capable of adsorbing dissolved organic matter, and in particular, capable of efficiently adsorbing biopolymers that have been difficult to adsorb. Such a composition can be effectively used as a biopolymer adsorbent when various raw waters are treated with water.

As described above, the preferred embodiments of the present invention have been described. However, various additions, modifications, or deletions are possible without departing from the spirit of the present invention, and such modifications are also included in the scope of the present invention. It is.

Claims (14)

1. A composition comprising a chemisorbable functional group-containing polymer (A) and a hydrophilic matrix polymer (B),
   The hydrophilic matrix polymer (B) is non-ion exchangeable,
   The polymer (A) is dispersed in the polymer (B) with an average dispersion diameter of 10000 nm or less, and is a biopolymer adsorbent composition excellent in the adsorptivity of a biopolymer present in water to be treated.
2. The biopolymer adsorbent composition according to claim 1, wherein the ion exchange capacity is 0.1 mmol / g or more.
3. 3. The biopolymer adsorbing composition according to claim 1, wherein the chemisorbable functional group has an ability to form at least one type of bond selected from the group consisting of a hydrogen bond, an ionic bond, and a chelate bond to the biopolymer. object.
4. The biopolymer adsorbent composition according to any one of claims 1 to 3, wherein the chemisorbable functional group in the chemisorbable functional group-containing polymer (A) is selected from the group consisting of N, S, P and O. A biopolymer adsorbing composition, which is a chemisorbing functional group containing at least one selected element.
5. The biopolymer adsorbent composition according to any one of claims 1 to 4, wherein the biopolymer was measured by the method described in Stefan A. Huber et al. Water Research 45 (2011) pp879-885. A biopolymer adsorbent composition comprising a component having a retention time by OCD of 25 to 38 minutes.
6. 6. The hydrophilic matrix polymer (B) according to claim 1, wherein the hydrophilic matrix polymer (B) is polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyvinyl acetal, polyvinyl alkyl alcohol, polyalkylene glycol, polyvinyl alkyl ether, polyalkylene. A biopolymer adsorbing composition, which is at least one selected from oxides, poly (meth) acrylamides, polyamides, polyvinylpyrrolidone, cellulose derivatives, dextrin, chitin, and chitosan.
7. The biopolymer adsorbing composition according to any one of claims 1 to 6, wherein the hydrophilic matrix polymer (B) is at least one selected from polyvinyl alcohol and an ethylene-vinyl alcohol copolymer. Biopolymer adsorptive composition.
8. The biopolymer adsorbing composition according to any one of claims 1 to 7, wherein the chemically adsorbing functional group-containing polymer (A) is a cationic polymer.
9. 9. The cationic polymer according to claim 8, wherein the cationic polymer is polyethyleneimine, polyallylamine, polyvinylamine, polypyridine, polyvinylpyridine, polyamino acid, polydiallyldimethylammonium halide, polyvinylbenzyltrimethylammonium halide, polydiacryldimethylammonium halide, polydimethylaminoethyl. A biopolymer adsorbing composition which is at least one selected from the group consisting of methacrylate hydrochloride, polynucleotide, and salts thereof.
10. In any 1 item | term of Claim 1-9, the ratio (mass ratio) of a chemisorbable functional group containing polymer (A) and a matrix polymer (B) is polymer (A) / polymer (B ) = 1/99 to 70/30, the biopolymer adsorbing composition.
11. The biopolymer adsorptive composition according to any one of claims 1 to 10, wherein a weight loss when a boiling test is performed is 20% by mass or less.
12. The biopolymer adsorbent composition according to any one of claims 1 to 11, wherein the adsorbability retention rate when immersed in warm water at a temperature of 60 ° C for 1 week is 50% or more.
13. A water treatment method comprising at least an adsorption step of bringing a water to be treated containing a biopolymer into contact with the biopolymer adsorbing composition according to any one of claims 1 to 12 and adsorbing at least the biopolymer.
14. The water treatment method according to claim 13, further comprising a filtration step of membrane-filtering the adsorption treated water obtained by the adsorption step.

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