WO1996002581A1

WO1996002581A1 - Process for producing aqueous gel, heavy-metal ion adsorbent, pigment adsorbent, microbe carrier, and carrier for enzyme immobilization

Info

Publication number: WO1996002581A1
Application number: PCT/JP1995/001424
Authority: WO
Inventors: Reizo Fukushima; Toshiaki Sugiyama; Akira Nakajima; Naomi Maeda
Original assignee: Hymo Corporation
Priority date: 1994-07-18
Filing date: 1995-07-18
Publication date: 1996-02-01
Also published as: CN1153519A; KR970704796A; AU2936895A; JPH0827214A; CN1063759C; KR100385848B1; TW324724B; JP3071364B2

Abstract

A process for producing an aqueous gel easily without the necessity for complicated operations and large-scale equipment, which comprises bringing an aqueous solution of a polymer having repeating units comprising cationic groups represented by general formulae (1) and/or (2) into contact with an aqueous alkali solution to cause deposition of an aqueous gel, (wherein R?1 and R2¿ represent each hydrogen or methyl; and X represents an anion). The obtained gel is formed into a heavy-metal ion adsorbent, pigment adsorbent, microbe carrier, and carrier for enzyme immobilization.

Description

Description Manufacturing method of hydrogel, heavy metal ion adsorbent, dye adsorbent, microbial carrier and enzyme immobilizing carrier Technical field

The present invention relates to a method for producing a hydrogel having an amidine structure, a heavy metal ion adsorbent, a dye adsorbent, a microorganism carrier and a carrier for immobilizing enzymes. Background art

Hydrous gels containing cationic dissociation groups have been used as adsorbents, adsorbents for anionic organic substances, adsorbents for bacteria, cells, and drugs, carriers for immobilized enzymes, fluidized bed ion exchange resins, It is used for various purposes such as fluid carriers in water treatment equipment and water-absorbing resins. Examples of the hydrogel used for this purpose include cationic resins having a structure in which polyvinylamines useful as a chelating resin or polyvinylamines such as polysobopenylamine are crosslinked (Japanese Patent Application Laid-Open No. 61-449 / 1986). No. 02), ^ basic anion exchange resin, polyvinylamines such as polyvinylamine or polyisobutenylamine useful as a chelating resin and the like, which are cross-linked and insolubilized in spherical form (Japanese Patent Laid-Open No. 61- No. 5106), a crosslinked polyvinylamine having a high amino group content (Japanese Patent Application Laid-Open No. 61-50707), a dialkylaminomethacrylate and a quaternary compound thereof. Polymer as a dimer (Japanese Patent Application Laid-Open (JP-A) No. Hei 1-269493) A polymer obtained by processing a cross-linkable polymer such as vinylaviridin and chitin present in the carapace such as radish shrimp. Is a basic polysaccharide The acidic aqueous solution of chitosan are known al force key Bok San solidified particles obtained was dropped into Li aqueous solution medium (JP 6 2 2 8 8 6 0 1 JP) soil strength.

The production of these hydrogels is carried out by using an organic solvent in a dispersing medium in the presence of a crosslinking agent. It is generally manufactured and has the drawback of requiring complicated operations and large-scale equipment.On the other hand, it is difficult to obtain a large amount of natural materials such as chitosan stably in large quantities. Is expensive.

An object of the present invention is to provide a method for easily and economically producing a hydrogel without requiring complicated operations and using a large-scale apparatus, and a heavy metal ion adsorbent comprising the hydrogel. A dye adsorbent, a microorganism carrier and a carrier for enzyme immobilization. Disclosure of the invention

In view of the above problems, the present inventors have conducted intensive studies, and as a result, easily contacting an aqueous solution of a specific cationic polymer compound having an amidine structure with an aqueous solution of an aqueous solution to easily produce a hydrogel. And found that the present invention was achieved. The present invention is characterized in that an aqueous solution of a polymer having a repeating unit composed of a cationic group represented by the following formula (1) and / or (2) is brought into contact with an alkaline aqueous solution to precipitate and form. This is a method for producing a hydrogel.

One (CH ₂ -CR ¹ -CH ₂ -CR ² )-

I _ C = N—— ¹ (1)

I

N ⁺ H ₃ X "

I (CH ₂ -CR ² -CH ₂ -CR ^I )-

¹ to N = C—— ¹ (2)

I

N + H ₃ X_

(Where RR ² represents a hydrogen atom or a methyl group, and X_ represents an anion.) The second invention of the present invention further comprises 10 to 80 mol% of a repeating unit comprising a cationic group represented by the above formula (1) and Z or (2), and further comprises a cyano group. This is a process for producing a hydrogel, which comprises contacting an aqueous solution of 1 to 50% by weight of a polymer containing 10 to 60 mol% with an aqueous solution of an alkali, precipitating and forming the gel. The third invention of the present invention is the invention according to the first invention, further characterized in that the polymer is capable of reacting with active hydrogen in the molecule of the polymer in an aqueous solution of the polymer and an aqueous solution of the polymer. A method for producing a hydrogel, which comprises coexisting a crosslinking agent. A fourth invention of the present invention is the method for producing a hydrogel according to the first invention, wherein the pH of the alkaline aqueous solution is 11 or more. A fifth invention of the present invention is the method for producing a hydrogel according to the first invention, wherein the pH of the alkaline aqueous solution is 12 or more. The sixth invention of the present invention is the method for producing a hydrogel according to the above-mentioned invention, further comprising immersing the hydrogel in an aqueous acid solution to control the swellability of the hydrogel.

A seventh invention of the present invention is the water-containing gel according to the sixth invention, wherein the aqueous acid solution is an aqueous solution of at least one polybasic acid selected from sulfuric acid, phosphoric acid, m, and carbonic acid. It is a manufacturing method of. According to an eighth aspect of the present invention, the acid aqueous solution according to the sixth aspect is selected from hydrochloric acid and acetic acid. A hydrogel, wherein the aqueous gel is an aqueous solution of at least one monobasic acid. A ninth invention of the present invention is a heavy metal ion adsorbent comprising the hydrogel according to any one of the first to eighth inventions. A tenth aspect of the present invention is a dye adsorbent comprising the hydrogel according to any one of the first to eighth aspects. An eleventh invention of the present invention is a microorganism carrier comprising the hydrogel according to any one of the first to eighth inventions. A twenty-second invention of the present invention is a carrier for immobilizing an enzyme, comprising the hydrogel according to any one of the first to eighth inventions. According to the method for producing a hydrogel of the present invention, it is possible to easily produce a hydrogel without the need for complicated operations and using a large-scale apparatus.

Hydrous gel has high industrial utility because it can be used as a heavy metal ion adsorbent, a dye adsorbent, a microbial carrier, and a carrier for enzyme immobilization. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view showing the structure of an aeration tank used in the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

As the water-soluble polymer compound that can be used to produce a hydrogel by the method of the present invention, the above-mentioned (1) And / or a water-soluble polymer compound having a repeating unit (amidine unit) represented by (2), preferably 10 to 90 mol% of the above unit (amidine unit), and more preferably 10 to 90 mol% of the above unit (amidine unit). It is possible to use one having about 80% mo and 1% and having 10 to 60% moyl cyano group. The cationic polymer having an amidine structure is sold in large quantities as a polymer flocculant, as a wastewater treatment or sludge dewatering agent, and the hydrogel of the present invention can be produced using the polymer itself. Is not particularly specified. However, generally, a copolymer of an ethylenically unsaturated monomer having a substituted amino group and a nitrile of acrylonitrile or methacrylonitrile with a primary amino group or a primary amino group capable of forming a primary amino group by a conversion reaction is produced. Further, it can be produced by a method of reacting a cyano group and a primary amino group in the copolymer to form an amidine. The ethylenically unsaturated monomer has a general formula CH ₂ = CR ² —NHCOR ³ (wherein R ² represents a hydrogen atom or a methyl group, and R ³ represents an alkynole group having 1 to 4 carbon atoms or a hydrogen atom. ) Compound power represented by In the copolymer, a substituted amino group derived from such a compound is easily converted to a primary amino group by hydrolysis or alcoholysis. Further, this primary amino group reacts with an adjacent cyano group to form an amidine group. As the compound, N- vinyl formamidinium de ^{(= R 2 = H, R} 3 H), N- Biniruasetoami de ^{^{(R 2 = H, R 3}} = Me) and the like are exemplified. The polymerization molar ratio of these ethylenically unsaturated monomers to nitriles is usually from 30:70 to 70:30, but if desired, the polymerization molar ratio outside this range, for example, ethylenic unsaturated monomer The ratio L of the saturated monomer and the polymerization molar ratio may be employed. As a method of copolymerizing an ethylenically unsaturated monomer with nitriles, a usual radical polymerization method is used, and any of aqueous solution polymerization, bulk polymerization, aqueous solution precipitation polymerization, suspension polymerization, emulsion polymerization, etc., is used. Can be. When the polymerization is carried out in a solvent, the raw material monomer concentration is generally 5 to 80% by weight, preferably 20 to 60% by weight. The polymerization initiator is preferably a azo compound in which a general radical polymerization initiator can be used, and examples thereof include 2,2′-azobis-1-amidinopropane hydrochloride. Further, the polymerization reaction is generally carried out at a temperature of 30 to L 00 under an inert gas stream. The obtained copolymer can be subjected to the amidination reaction as it is or diluted, that is, in the form of a solution or suspension. In addition, after the solvent is removed and dried by a known method, and the copolymer is separated as a solid, it can be subjected to an amidination reaction in a solid state. When the N-vinylamide compound represented by the above general formula is used as the ethylenically unsaturated monomer in the amidination reaction, the substituted amino group of the copolymer is converted into a primary amino group. The cationic polymer according to the present invention can be produced by a two-step reaction of reacting a group with an adjacent cyano group to form an amidine structure. Then, preferably, the copolymer is heated in a water or alcohol solution in the presence of a strong acid or strong base to generate an amidine structure in one step. In this case, too, it is considered that the primary amino group was formed as an intermediate structure. Specific conditions for the reaction include, for example, usually 0.9 to 5.0 times, preferably 1.0 to 3.0 times the equivalent of a strong acid to a substituted amino group of the copolymer. Or hydrochloric acid, and heated at a temperature of usually 80 to 150 ° C., preferably 90 to 120 ° C., usually for 0.5 to 20 hours to form a cationized polymer having amidine units. It can be a molecule. In general, the greater the equivalent ratio of the strong acid to the substituted amino group, the greater the force, the higher the reaction temperature, the more the amidine formation proceeds. In addition, at the time of amidine formation, usually 10% by weight or more, preferably 20% by weight or more of water is present in the reaction system with respect to the copolymer to be subjected to the reaction. Most typically, the cationic polymer according to the present invention is obtained by copolymerizing N-vinylformamide and acrylonitrile in accordance with the description above, and the resulting copolymer is usually suspended in water. It is produced by heating in the presence of hydrochloric acid as a liquid to form an amidine unit from a substituted amino group and a neighboring cyano group. Then, cationic polymers having various compositions can be produced by selecting the molar ratio of N-vinylformamide and acrylonitrile to be subjected to the copolymerization and the conditions for amidination of the copolymer.

An aqueous solution of 0.5% by weight or more and less than 50% by weight, preferably 1% by weight or more and less than 20% by weight of the water-soluble cationic polymer compound thus obtained is adjusted to have a pH of 11 or more, The dissociation of the cation group of the water-soluble cation polymer compound is suppressed by contacting the cation group with an aqueous solution of water having a pH of preferably not less than 12, more preferably not less than pH 2.5, and the polymer compound is preferably water. It becomes an insoluble resin and a hydrogel is formed. This phenomenon is because the dissociation of the amino group having an amidine structure is suppressed at pH HI 0.5 or more, and the amino group is made hydrophobic. The water-containing gel can be washed with water to remove the components in the gel, thereby preventing deterioration. By holding in the presence of an alkali component, the cyano group and amidine unit in the polymer are hydrolyzed and converted to a carboxyl group, and the aniline is contained in the resin. An amphoteric type hydrogel having an on-group and a cationic group is formed.

Depending on the application, this hydrolysis can be positively progressed by immersing in an alkaline solution for a long time or immersing in an alkaline solution and heating to form a hydrogel that has a large number of carboxylic acid groups in the molecule. Can be formed. Normally, to suppress this hydrolysis, neutralization with an acid or washing with an aqueous acid solution is performed.However, the obtained water-containing gel recovers its original water solubility at around neutrality due to the polymer compound of the gel constituent unit. Then, they absorb water and swell, and eventually dissolve and lose their shape.

As a method for solving such a problem, a covalent bond is formed by a reaction with an amino group or a cyano group of a polymer compound in a polymer aqueous solution prepared at the time of production of a hydrogel or in an aqueous solution of alcohol to be contacted. A method is used in which a cross-linking agent having two or more functional groups in one molecule is caused to coexist, and then an aqueous polymer solution is brought into contact with an aqueous solution of the polymer.

The water-containing gel thus formed can form a stable water-insoluble gel without being redissolved even after neutralization with an acid.

When a polybasic acid such as sulfuric acid / phosphoric acid is used as the acid used for neutralization, amino groups in the molecule form sulfates and phosphates, and can form a hydrogel having a small swelling property. .

When a monobasic acid such as hydrochloric acid or acetic acid is used for neutralization, a hydrogel having a swelling ratio of 100 times or more can be obtained by adjusting the amount of the crosslinking agent used. Specific examples of the cross-linking agent used include the ability to use diformylalkanes such as formaldehyde, acetoaldehyde, glyoxal, malonaldehyde, glutaraldehyde, and the like. Two or more functional groups capable of forming a covalent bond in a molecule A hydrogel can also be formed by using the above crosslinking agent.

In addition, when the monomer power of N-vinylformamide and N-vinylacetamide is present in the synthesized polymer, if these monomers coexist, these monomers are hydrolyzed to form acetoaldehyde, which is used as a cross-linking agent. In some cases, the addition of a cross-linking agent is unnecessary because it functions. The hydrogel of the present invention can be obtained by contacting an aqueous solution of a polymer compound having an amidine structure with a basic aqueous medium. In this case, the concentration of the adjusted aqueous solution of the polymer compound is 0.5% by weight or more. The concentration is selected from a concentration of less than 50% by weight, preferably 1% by weight or more and less than 20% by weight, and the concentration is determined by the final water content of the hydrogel and the gel.

—Generally, the higher the aqueous solution concentration of the polymer compound to be brought into contact, the lower the water content ratio and the higher the gel strength. Conversely, the lower the concentration, the lower the viscosity of the polymer solution, and upon contact with the aqueous alkali solution, the polymer solution disperses in the alkaline solution due to impact on the liquid surface, making it difficult to form a hydrogel. Therefore, in general, the lower the molecular weight, the more difficult it is to produce a hydrogel at a low concentration.

If the molecular weight is too high, when the hydrogel is formed by dropping or extruding into an alkaline aqueous solution, the aqueous polymer solution has spinnability, and the shape of the obtained hydrogel is distorted, Thread-like projections are formed. If the viscosity of the aqueous polymer solution is too high, perform appropriate dilution, but add an oxidizing agent to cut the molecule to reduce the molecular weight, or add a salt such as salt, sodium acetate, or potassium chloride. It is also possible to reduce the apparent viscosity. The basic compound used for the basic medium used to form the hydrogel is, for example, hydroxylated sodium hydroxide, sodium hydroxide, ammonium hydroxide, sodium carbonate, and the like. However, sodium hydroxide is usually used because of the cost of the ring.

The coexistence of a salt such as ammonium sulfate, salt crystals, sodium chloride, or potassium chloride in the basic medium used facilitates the formation of a hydrogel and can reduce the water content of the hydrogel. The concentration of the basic compound used in the basic medium varies depending on the total amount of the polymer compound to be brought into contact with the basic medium, but is usually used in the range of 1 to 2% by weight. No problem. However, contacting the aqueous polymer solution consumes the alcohol in the basic medium, so it is necessary to replenish the basic compound when producing a hydrogel.

The specific gravity of the aqueous solution of the polymer compound to be contacted is preferably adjusted to be equal to or higher than the specific gravity of the basic dispersion medium when extruding or dripping into a basic dispersion medium to form a hydrogel. In order to adjust the specific gravity, a method of coexisting an inorganic water-soluble electrolyte such as sodium chloride and salt crystals and a water-insoluble powder such as calcium carbonate, talc, activated clay, powdered graphite, and powdered activated carbon in an aqueous solution of a dissolved polymer compound is used. Can be In producing a hydrogel by the method of the present invention, an enzyme, a bacterium, and the like may coexist in an aqueous solution of a polymer compound, and these may be inclusively fixed and used as a carrier for a bioreactor.

Alternatively, the hydrogel obtained by the method of the present invention is brought into contact with an enzyme solution, and the enzyme is adsorbed to produce an immobilized enzyme.

In addition, by dispersing an antibiotic, a bactericide, an antibacterial agent, and the like in a polymer solution and then producing a hydrogel by the method of the present invention, it is possible to impart sustained release of these agents.

In addition, inorganic powders such as powdered activated carbon, zeolite and ferrite are After the dispersion, the hydrogel is produced by the method of the present invention, whereby the specific gravity of the hydrogel can be adjusted and, at the same time, the obtained hydrogel can have various functions. In producing a hydrogel by the method of the present invention, a spherical spherical hydrogel can be generally formed by dropping an aqueous solution of a polymer compound using a metering pump or the like. The particle size of the hydrogel can be changed by the viscosity of the polymer solution, the dropping speed, the diameter of the dropping port, and the like.

Further, by extruding the aqueous polymer solution into the alkaline aqueous solution, a rod-like or thread-like hydrogel can be formed. In addition, various water-containing gel composites can be formed by impregnating a porous body, a fiber assembly, or the like with the aqueous polymer solution used in the present invention and then bringing the resultant into contact with an alkali solution. The hydrogel obtained according to the present invention can be used in various industrial fields, but the following specific examples can be given.

1) Use as a fluidized carrier in a biological fluidized bed wastewater treatment method.

2) Application to wastewater treatment systems as adsorbents for anionic organic substances such as dyes, surfactants, lignin, and humic substances.

3) Application to bioreactors by entrapping or adsorbing bioactive substances such as microorganisms and enzymes.

4) Since the hydrogel having the structure of the present invention has an excellent effect as a chelating resin, water containing metal ions is passed through a column filled with the hydrogel of the present invention, or the solution of the present invention is placed in a metal ion-containing solution. By immersing the hydrogel, the metal ions in the solution can be removed and concentrated. If a crosslinked hydrogel is used, the adsorbed metal ions can be immersed in a mineral acid, recovered, and the regenerated gel can be used repeatedly. Example

Hereinafter, the present invention will be more specifically described with reference to examples. The present invention is not limited to the following examples unless it exceeds the gist of the present invention.

In Examples, “%” means “% by weight” unless otherwise specified.

[Method for producing cationic polymer]

A mixture of acrylonitrile and N-vinylformamide, containing the mole fraction of acrylonitrile shown in Table 1, in a 100 milliliter four-neck flask equipped with a stirrer, nitrogen inlet tube, and condenser tube And 34.0 g of demineralized water. After the temperature was raised to 60 ° C. with stirring in a nitrogen gas stream, 0.12 g of an aqueous solution of 10% 2,2′-azobis-2 monoamidinobutane pan • dihydrochloride was added. After stirring and maintaining at 45 C for 4 hours, the temperature was raised to 60 and further maintained for 3 hours to obtain a suspension in which a polymer was precipitated in water. 20 g of water was added to the suspension, then 2 equivalents of concentrated hydrochloric acid was added to the formyl groups in the polymer, and the mixture was kept at 100 ° C for 4 hours with stirring, and the polymer was added. Amidine. The obtained polymer solution was added to acetone to precipitate, and this was dried under vacuum to produce solid polymers A to E as prototypes.

The polymer E was obtained by polymerizing without using acrylonitrile and performing the same reaction.

The compositions and reduced viscosities of the polymers A to E were measured by the following methods. The results are summarized in Table 1.

[Composition analysis method]

The composition of each raw material polymer before amidination was calculated from the integrated value of the absorption peak corresponding to each monomer unit of the ¹³ C-NMR spectrum. The compositions of Polymers A to E after amidine formation were calculated from the integrated values of absorption peaks corresponding to each repeating unit of the ¹³ C-NMR spectrum. Note that the repeating units (1) and (2) should not be distinguished. The total amount was calculated. In addition, the absorption beaks of the repeating units (1), (2), and primary amines are recognized at very close positions around 170 to 185 ppm, so that each absorption beak is applied in the following manner. The corresponding structure was assigned. That is, the weight balance was confirmed by the elemental analysis of the polymer and the measurement of the water content. Further, in addition to the ¹³ C-NMR spectrum of the polymer, the IR spectrum was also measured, and the polymer spectrum and the amidine were measured. The method employs a method for comparing and examining in detail the spectrum of a known compound having a group, an amide group and a lactam group.

[Measurement of reduced viscosity]

Polymers A to E were measured as solutions of 0.1 gZl00 milliliter in 1N saline at 25 ° C. using an Ostfield viscometer. Polymer type A B C D E Monomer composition N-vinylform

Acrylonitrile 30 50 80 50 0 Amidine conditions Temperature (.C) 100 100 100 50 100 hours (Hr) 5 5 5 20 5 Polymer composition (mol%) 31 56 55 15 0

Formyl group 2 0 0 6 19

7 22 34 42 0

59 22 8 37 81

0 0 1 0 0 or repho "xyl group 1 0 2 3 0 Reduced viscosity (dl / g) 2.8 3.5 3.3.3 3.14.0 (Example 1)

5 g of the polymers A to D of the prototype example were added to 85 g of distilled water, mixed and stirred to dissolve the polymer, and then 10 g of sodium chloride and 0.1 g of a 25% aqueous solution of glutaraldehyde were obtained. And mix well. This polymer solution is dropped into 500 ml of a 2% caustic soda solution at a rate of 10 milliliters per minute using a tubing pump made by Attoichi. In this case, the 2% caustic soda solution was stirred at 300 rpm with a stirrer, and the height of the dripping portion and the caustic soda liquid level was maintained at about 2 cm.

After the addition, this stirring is continued for another 30 minutes, and the pH of the caustic soda solution is adjusted to 7.5 with sulfuric acid. The hydrogel (samples 1 to 14) obtained by filtering this with a screen was washed with pure water, and the average particle size and the water content were measured. The results are shown in Table 2. The water content was calculated by the following equation.

Hydrous gel weight

Moisture content (%) = X100

Dry gel weight

(Comparative Example 1)

For comparison, an attempt was made to produce a hydrogel by operating in the same manner as in Example 1 except that the polymer E of the prototype example having no amidinated structure was used. << The hydrogel was not formed, and the caustic soda was not formed. The polymer dissolved in the solution. Table 2 shows the results.

Table 2

Hydrous gel Polymer particle size used (mm) Water content (%)

Example 1 Sample 1 A 2.3.5 5 0

Specimen-2 B 2. 1 4 8 0

Specimen-3 C 1.8 3 10

Sample-4D 2.0.30

Comparative Example 1

Do not form (Example 2)

Add 5 g of the polymer B of the prototype to 85 g of distilled water and mix and stir. After dissolving the polymer, add 10 g of common salt and mix and stir until complete dissolution.

To this solution, glutaraldehyde at a concentration of 1% is added and mixed at the ratio shown in Table 3, and then dropped and granulated in the same manner as in Example 1 in a caustic soda solution. After keeping the granules in an alkaline atmosphere at 3 O ^e C for 1 hour, neutralize half the volume with hydrochloric acid and neutralize the other half with sulfuric acid to adjust the pH to 7. Filter this, immerse each in pure water for 2 hours, filter again, and measure the weight of the hydrogel (Sample 15 to Sample 18). Then, the hydrogel is dried at 105 ° C for 20 hours, weighed, and the swelling ratio is determined by the following equation. The results obtained are summarized in Table 3.

Hydrous gel weight (g)

Swelling ratio (times) =

Dry gel weight (g)

(Comparative Example 2)

A sample operated in the same manner as in Example 1 except that 1% concentration of glutaraldehyde was not added to the above solution was dissolved at the time of neutralization, and did not form a hydrogel. Table 3 shows the results.

Table 3

Water-containing gel W 夕夕-了ル ί 'human' swelling magnification (times)

Addition amount (g) Neutralized hydrochloric acid Neutralized sulfuric acid

Example 2 Sample-5 1 145 7.1

Sample 1 6 2 106 6.8

Sample-7 5 44 5.1

Sample—8 10 11 5.0

Comparative Example 2 Measurement of hydrogel was impossible 0 Measurement was impossible

Do not form (Example 3)

Prototype polymer C 10 g, distilled water 90 g, triiron tetroxide powder (particle size 100 or less) 3 Og were mixed and stirred to make a uniform slurry, and then 2 g of 10% acetoaldehyde solution was added. After that, in the same operation as in Example 1, the solution is dropped into a 2% sodium hydroxide solution. After the completion of the dropwise addition, the pH of the caustic soda solution was adjusted to 7.5 with sulfuric acid, and then the mixture was filtered to obtain a hydrogel containing iron tetroxide. The apparent specific gravity of the obtained hydrogel in water was 1.54, and the average particle size was 2.3 mm. The water content of this hydrogel was 215%. This hydrogel can be separated from the liquid by a magnet.

(Example 4)

250 g of the water-containing gel of Sample 1 produced in Example 1 was packed in a column having a diameter of 4 Omm and a height of 30 Omm, and a solution having a concentration of 2 OmgZ liter of copper was applied from the lower end of the column at a rate of 10 ml / min. The copper ion concentration of the treated water flowing out from the upper end was measured using an atomic absorption spectrophotometer (manufactured by Shimadzu Corporation). The copper ion concentration of the treated water after passing through 200 liters was 0.08 mg / liter.

(Example 5)

250 g of the water-containing gel of sample 13 prepared in Example 1 was packed in a column having a diameter of 4 Omm and a height of 300 mm, and the alminol first force was applied from the lower end of the column—400 mg Z-liter of Letto BL (manufactured by Hoechst). The concentrated solution was passed through a tubing pump (manufactured by AT Corporation) at a flow rate of 2 milliliters per minute, and the residual dye concentration in the effluent from the upper end was measured using an absorptiometer. Calculate the total amount of dye adsorbed on the hydrogel when the water content is 20% or less of raw water.

Table 4 shows the water flow rate, the residual dye concentration and the accumulated amount of dye adsorption. From the results in Table 4, the dye adsorption capacity of this gel is 59.3 mgZg. Table 4

(Example 6)

The hydrogel (sample 14) obtained in Example 1 was used as a carrier in an aerobic fluidized-bed biological treatment device equipped with a diffuser tube and an air lift tube for flowing the carrier into the aeration tank. .

This will be described with reference to the drawings.

200 g of the hydrogel was put into a 1-liter aeration tank with the structure shown in Fig. 1. ミリ 900 ml of aeration tank sludge (sludge concentration 4000 mg liter) obtained from the activated sludge treatment site at the water treatment plant to, after 24 hours aeration, human E drainage (oxidized starch 25 OmgZ liters, peptone 25 OmgZ rate torr, potassium phosphate 15mg Bruno liter ferrous lmg Bruno liter sulfuric, Maguneshiu arm lmg _/ / liter Calcium chloride (lmgZ liter) was supplied quantitatively into the aeration tank at a rate of 3 liters Z days using a Verista pump (manufactured by Ato Corporation). The temperature inside the aeration tank during water flow is 25. C maintained. The BOD of this artificial drainage is 390mgZ liter. The supernatant water quality of the treated water was analyzed at 1 week, 2 weeks and 4 weeks after the start of water flow.

Table 5 summarizes the obtained results.

(Comparative Example 3)

For comparison, the same test as in Example 6 was performed without adding the carrier.

Table 5 summarizes the obtained results.

(Comparative Example 4)

For comparison, the same test as in Example 6 was performed using 200 g of polystyrene beads having an average particle size of about 1 mm as a carrier. _C shown in Table 5 summarizes the results obtained

Table 5

As is evident from the results in Table 5, without the addition of the carrier (Comparative Example 3), the activated sludge could not stay in the aeration tank and could not be treated, but the hydrogel of Example 6 (Sample 14) was not used. In the added aeration tank, activated sludge was fixed on the surface of the hydrogel, and two weeks later, the ability to form a microbial membrane on the surface of the hydrogel was confirmed, and the quality of the treated water was good. Even with the polystyrene beads (Comparative Example 4) used for comparison as a carrier, the formation of a microbial membrane was slightly observed after 4 weeks, and the quality of the treated water was also improved. The film formation rate is poor, and the processing is slow to start.

(Example 7)

10 g of each of the water-containing gels of Samples 12 and 13 produced in Example 1 were collected and placed in 200 milliliters of 0.05 mol of Tris-HCl buffer (pH 8.0). After suspension and dispersion, the mixture is filtered. Then, this was immersed in 100 milliliters of a 0.05 mol phosphate-monocitrate buffer solution, and 20 milliliters of an invertase solution (manufactured by Sankyo Co., Ltd.) was added. A dagger was performed.

The thus obtained enzyme-immobilized hydrogel was immersed in a 0.05 mol sodium borate-hydrochloric acid buffer solution containing 0.6% glutaraldehyde for 1.5 hours, and then separated by filtration and again subjected to 0.02 g. It is suspended and dispersed in 1 liter of 5 mol of Tris-HCl buffer, filtered and the weight of the obtained enzyme-fixed hydrogel is measured. The saccharose obtained by dissolving the immobilized enzyme in a 0.05 molar citrate monophosphate buffer (pH 4.2). The reaction mixture was added to 1 liter of a 10% solution and reacted at 40 ° C for 60 minutes.The total amount of reducing sugars formed was determined by the methylene blue method, and the amount of sucrose degradation per hour by 1 g of the enzyme-fixed hydrogel was shown in Table 6. Show.

(Comparative 5)

For a comparative example, the same operation as in Example 7 was performed using a commercially available strong basic ion exchange resin Amberlite IRA-9OX (manufactured by Organo Corporation), and the amount of decomposition of Sacrose by resin lg was determined. Table 6 shows.

Table 6

(Example 8)

10 g of a water-containing gel using the polymer B produced in Example 1 (Sample 1) was washed with 10 g of water, filtered, and placed in 0.05 ml of sodium borate-monohydrochloride buffer (pH 6.0) for 10 minutes. After immersion, filter again. This is poured into 100 ml of a three-fold diluted dialcosyl isomerase (manufactured by Nagase) which has been dialyzed, gently stirred at room temperature, and filtered. The enzyme-immobilized hydrogel thus obtained was immersed in a 0.05 mol sodium borate / hydrochloric acid buffer solution containing 0.6% glutaraldehyde for 1.5 hours.

This hydrogel and the hydrogel not treated with daltaraldehyde were each immersed in 1 liter of 10% saline, stirred for 1 hour, filtered, washed, and then converted to glucose. Compared their ability to do so. Dalco-converting ability is determined by the following method.

The enzyme-immobilized hydrated gel obtained in 1 liter of a 40% glucose solution dissolved in a 0.1 M phosphate buffer was added, and the mixture was reacted at 60 ^{eC for} 1 hour. The amount of fructose formed as a result was determined by the HPLC method, and the amount of glucose converted to fructose per 1 g of the hydrogel (glucose conversion amount) was determined. Table 7 shows the results.

Table 7

From the results shown in Table 7, it can be seen that an enzyme-fixed hydrous gel from which the enzyme cannot be removed can be formed by adsorbing the enzyme to the hydrogel of the present invention and then treating it with glutaraldehyde. Industrial applicability

As described above, according to the present invention, a method capable of easily producing a hydrogel without using complicated equipment and without using a large-scale apparatus, a heavy metal ion adsorbent comprising the hydrogel, and a dye An adsorbent, a microbial carrier and a carrier for immobilizing enzymes can be provided.

Claims

1. An aqueous solution of a polymer having a repeating unit comprising a cationic group represented by the following formula (1) and _/ or (2) is brought into contact with an alkaline aqueous solution to precipitate and form. Manufacturing method for hydrogel.

One (CH ₂ -CR ¹ -CH ₂ -CR ² ) One

■ C = N-- ¹ of (1) enclosed

N + H ₃ X- (CH ₂ -CR ² -CH ₂ -CR ¹ )

1 to N = C ¹ (2)

N ⁺ HsX ~

(Where RR ² represents a hydrogen atom or a methyl group, and X— represents an anion.)

2. A polymer containing 10 to 80 mol% of a repeating unit composed of a cationic group represented by the above formula (1) and Z or (2), and containing 10 to 6 Omo 1% of a cyano group 2. The method for producing a hydrogel according to claim 1, wherein the aqueous solution of 1 to 50% by weight is brought into contact with an aqueous solution of aluminum hydroxide to form a precipitate by precipitation.

3. The method according to claim 1, wherein a crosslinker capable of reacting with active hydrogen in the molecule of the polymer coexists in the aqueous solution of the polymer and the Z or alkaline aqueous solution. A method for producing a hydrogel.

4. The method for producing a hydrogel according to any one of claims 1 to 3, wherein the pH of the alkaline aqueous solution is 11 or more.

5. The method for producing a hydrogel according to any one of claims 1 to 3, wherein the pH of the alkaline aqueous solution is 12 or more.

6. The swellability of the hydrogel is controlled by immersing the hydrogel in an aqueous acid solution. 4. The method for producing a hydrogel according to claim 3, wherein:

7. The method for producing a hydrogel according to claim 6, wherein the acid aqueous solution is an aqueous solution of at least one polybasic acid selected from sulfuric acid, phosphoric acid, boric acid, and carbonic acid.

8. The method for producing a hydrogel according to claim 6, wherein the aqueous acid solution is an aqueous solution of at least one monobasic acid selected from hydrochloric acid and acetic acid.

9. A heavy metal ion adsorbent comprising the hydrogel according to claims 1 to 8.

10. A dye adsorbent comprising the hydrogel according to claims 1 to 8.

11. A microbial carrier comprising the hydrogel according to claims 1 to 8.

1 2. A carrier for immobilizing an enzyme, comprising the hydrogel according to any one of claims 1 to 8.