JP2003245699A - Sludge dewatering agent and sludge dewatering method - Google Patents

Abstract

(57) [Summary] [PROBLEMS] When a crosslinkable water-soluble polymer is used as a sludge dewatering agent, excellent points such as a decrease in the water content of a dewatered cake are exhibited, but on the other hand, it is added until the effect is exhibited. Inevitably, the amount of addition increases, and as a result, there arises a problem that the cost increases. An object of the present invention is to develop a sludge dewatering agent that does not increase the amount of addition even when a crosslinkable water-soluble polymer is used and that reduces the water content of a dewatered cake. SOLUTION: This can be achieved by adding an ionic polymer having a crosslinked structural unit represented by the following general formula (1) to sludge and performing a dehydration treatment. Embedded image General formula (1)

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a sludge dewatering agent and a sludge dewatering method, and more particularly to a sludge dewatering agent comprising an ionic polymer having a specific structural unit, and a sludge dewatering method using the same.

[0002]

2. Description of the Related Art Conventionally, a cationic polymer dehydrating agent has been used alone for the sludge dehydration treatment, but in recent years, due to an increase in the amount of sludge generated and deterioration of sludge properties, conventional cationic polymer dehydration agents have been used. With the agent, the treatment condition is not always satisfactory in terms of the sludge treatment amount, the dehydrated cake water content, the SS recovery rate, and the releasability of the cake from the filter cloth. There is. Various ampholytic polymer dehydrating agents have been proposed in order to improve the drawbacks of these conventional cationic polymer dehydrating agents, but these amphoteric polymer dehydrating agents are not always sufficiently satisfactory. For example, (1) an amphoteric polymer dehydrating agent having a tertiary amino group (JP-A-62-205112) and (2) an amphoteric polymer dehydrating agent containing a quaternary ammonium group (JP-A-53-1492).
92), (3) amphoteric polymer dehydrating agents containing tertiary and quaternary compounds (JP-A-3-18900). However, the amphoteric polymer dehydrating agent of the above (1) has excellent cohesiveness as compared with the conventional cationic polymer dehydrating agent and forms large coagulated flocs, but has high pH such as digested sludge of sewage or night soil. For sludge, the performance is significantly reduced due to the problem of dissociation of tertiary amino groups, and it is susceptible to changes in sludge properties such as pH, including sludge concentration, and stable treatment is not possible. However, there is a drawback in that it is inferior to the conventional cationic polymer dehydrating agent in terms of stability of the product in a powder or solution state. In addition, (2)
In the amphoteric polymer dehydrating agent of, although the product stability is better than the amphoteric polymer dehydrating agent containing a tertiary amino group and the cohesive force is higher than that of the conventional cationic polymer dehydrating agent, it is necessary. There are many points to be improved, such as a large addition amount, a high water content of the cake, and poor peelability of the cake from the filter cloth. On the other hand, the amphoteric polymer dehydrating agent of (3) described above has improved the drawbacks of the dehydrating agents of (1) and (2),
The required addition amount and cake water content are not yet at a satisfactory level, and improvements are required for practical use.

Under these circumstances, improvements in amphoteric polymer dehydrating agents are being made. For example, an amphoteric polymer containing both a quaternary ammonium salt group of dialkylaminoethyl acrylate and dialkylaminoethyl methacrylate has been proposed, and JP-A-3-293100 discloses both. An amphoteric polymeric dehydrating agent containing 1 to 5 mol% of methacrylate is disclosed. In addition, JP-A-7
-256299 discloses an amphoteric polymer dehydrating agent having a high methacrylate content and a high cationic group content, and JP-A-7-256300 discloses a high acrylate content and an anionic group. An amphoteric polymer dehydrating agent having a high content is disclosed. However, the conventional method of cross-linking with methylenebisacrylamide or the like to modify the polymer has reached its limit, and no major progress can be expected.

[0004]

When a crosslinkable water-soluble polymer is used as a sludge dehydrating agent, excellent points such as a decrease in the water content of the dehydrated cake are exhibited, but on the other hand, it is added until the effect is exhibited. Inevitably, the amount of addition increases, and as a result, there arises a problem of increased cost. An object of the present invention is to develop a sludge dewatering agent that does not increase the amount added even when a crosslinkable water-soluble polymer is used and also lowers the water content of the dehydrated cake.

[0005]

Means for Solving the Problems The inventors of the present invention have made extensive studies in order to solve the above problems, and as a result, have reached the following inventions. That is, the invention of claim 1 of the present invention is a sludge dehydrating agent comprising an ionic polymer having a cross-linking structural unit represented by the following general formula (1).

[Chemical 1] General formula (1) However, n in Formula (1) is an integer greater than or equal to 0, R1-R
9 is hydrogen, or an alkyl group having 1 to 3 carbon atoms, hydroxyalkyl go or benzyl group, and X1 to X2 are anions.

According to a second aspect of the present invention, the ionic polymer is 5 to 100 mol% of a monomer represented by the following general formula (2) and / or (3), and is represented by the following general formula (4). 0-60 mol% and nonionic monomers 0-9
Copolymerization by adding 0.001 to 1 mol% of a monomer mixture consisting of 5 mol% and a polyfunctional water-soluble polycationic monomer represented by the following general formula (5) to the monomer mixture. The sludge dewatering agent according to claim 1, which is produced by

[Chemical 2] In the general formula (2), R5 is hydrogen or a methyl group, R6 and R7 are C1 to C3 alkyl or alkoxyl groups, R8 is hydrogen, a C1 to C3 alkyl group, an alkoxyl group or a benzyl group. May be different, A is oxygen or N
H and B represent an alkylene group having 2 to 4 carbon atoms or an alkoxylene group, and X3 represents an anion.

[Chemical 3] General formula (3) R9 is hydrogen or a methyl group, R10 and R11 are carbon numbers 1 to 1.
3 alkyl group, alkoxy group or benzyl group, X
4 represents anion respectively

[Chemical 4] Formula (4) R12 is hydrogen, methyl group or carboxymethyl group, Q
Is SO3, C6H4SO3, CONHC (CH3) 2C
H2SO3, C6H4COO or COO, R13 is hydrogen or COOY2, Y1 or Y2 is hydrogen or cation

[Chemical 5] In formula (5), R14 to R17 represent hydrogen or a methyl group, X5 and X6 represent anions, and p represents an integer of 0 to 20, provided that P is P.
Is represented by the following general formula (6).

[Chemical 6] General formula (6) R <_18> , R < ₁₉ > is hydrogen, a C1-C3 alkyl group or a benzyl group, G is a 2-4 alkylene group or an alkoxylene group, L is -O- or -NH-, and X <7> is The anion, R _20, is hydrogen or a methyl group. However, R ₁₄ ~
When R ₁₇ is hydrogen, it may be partially substituted with P.

According to a third aspect of the present invention, the polyfunctional water-soluble polycationic monomer is ammonia, an aliphatic primary amine,
A reaction product of a dialkylaminoalkyl (meth) acrylamide and a polycondensate formed from one or more amines selected from aliphatic secondary amines and aliphatic tertiary amines and epihalohydrin. The sludge dehydrating agent according to Item 2.

According to a fourth aspect of the present invention, the polyfunctional water-soluble polycationic monomer has epihalohydrin as A (mol) and is selected from ammonia, primary amines, secondary amines, and tertiary amines. B (mol)
Then, it is a reaction product of a polycondensate produced by the reaction in the range of A / B = 0.25 to 1.2 and a dialkylaminoalkyl (meth) acrylamide, and the method according to claim 2, It is a sludge dehydrating agent.

According to a fifth aspect of the invention, in the oil, the ionic polymer has an aqueous monomer mixture solution as a discontinuous phase and a water-immiscible liquid hydrocarbon containing an oil-soluble emulsifier as a continuous phase. The sludge dehydrating agent according to claim 1, which comprises a dispersion liquid produced by forming an aqueous emulsion and emulsion-polymerizing it with stirring.

A sixth aspect of the present invention is the sludge dewatering agent according to the first aspect, wherein the ionic polymer has a weight average molecular weight of 2,000,000 to 20,000,000.

A seventh aspect of the present invention is a sludge dewatering method, characterized in that the ionic polymer is added to an organic sludge, mixed and coagulated, and then dehydrated by a dehydrator.

The invention of claim 8 is characterized in that an inorganic coagulant and the ionic polymer are added to and mixed with the organic sludge and then dehydrated by a dehydrator.
The sludge dewatering method described in 1.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The water-soluble ionic polymer of the present invention contains the structural unit represented by the chemical formula (1) and / or (2). This ionic polymer can be synthesized by copolymerizing a polycation polyfunctional monomer having an acryloyl group at the terminal with a general monomer. First, the polycation polyfunctional monomer will be described. The component (A) of the present invention comprises (E) epihalohydrin, (F) ammonia, one or more amines selected from primary amines or secondary amines, and (G) a tertiary amino group-containing acrylic monomer. A polycationic polyfunctional monomer having a vinyl group in which at least two of the ends of the reaction product are reacted. That is, R1 to R4, R6, and R7 represent an epihalohydrin residue to which hydrogen or the same or different alkyl group selected from the alkyl groups having 1 to 3 carbon atoms is bonded. This epihalohydrin residue is a polymer of repeating units of the same type when one type of amine is used, while it is a polymer of different repeating units when two or more types of amine are used.

The (A) epihalohydrin that constitutes the polycation polyfunctional monomer (A) represented by the general formula (1) of the present invention is not particularly limited, and examples thereof include epichlorohydrin and epibromohydrin. Examples thereof include phosphorus and epiiodohydrin. These epihalohydrins can be used alone or in combination of two or more. Of these epihalohydrins, epichlorohydrin is preferable.

(A) Ammonia, primary amine and secondary amine, which constitute the polycation polyfunctional monomer represented by the above general formula (1) of the present invention, are each alone. It is possible to use, and it is also possible to use a combination of two components of ammonia and a primary amine, ammonia and a secondary amine, primary amine and a secondary amine, or
It is also possible to use a combination of three components of ammonia, a primary amine and a secondary amine. The primary amine is
There is no particular limitation, for example, methylamine, ethylamine,
Examples thereof include n-propylamine and isopropylamine. These primary amines can be used alone or in combination of two or more. Of these primary amines, methylamine and ethylamine are preferable. The secondary amine is not particularly limited, and examples thereof include dimethylamine, diethylamine, dipropylamine, methylethylamine, methylpropylamine and dibenzylamine. These secondary amines can be used alone or in combination of two or more. Among these secondary amines, dimethylamine, diethylamine and methylethylamine are preferable.

The (A) tertiary amino group-containing acrylic monomer (A) constituting the polycation polyfunctional monomer (A) represented by the general formula (1) of the present invention is not particularly limited, and may be N, for example. , N-dimethylaminopropyl (meth) acrylamide, N, N-diethylaminopropyl (meth) acrylamide, N, N-dimethylaminobutyl (meth) acrylamide, N, N-diethylaminopropyl (meth) acrylamide, N, N-dimethyl Aminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-methylethylaminopropyl (meth) acrylamide, N, N-methylethyl
(Meth) acrylate etc. can be mentioned. These tertiary amino group-containing acrylic monomers may be used alone or in combination of two or more. Of these tertiary amino group-containing acrylic monomers, N, N-dimethylaminopropylacrylamide is more resistant to alkali hydrolysis than the tertiary amino group-containing acrylic monomer having an ester bond in the molecule, so Preferred as a tertiary amino group-containing acrylic monomer used in the invention.

The polycation polyfunctional monomer (A) represented by the above general formula (1) of the present invention has at least two of its terminals having vinyl groups. The other terminal structure is not particularly limited and may be an amino group, a secondary amine structure, a tertiary amine structure, a halohydrin structure, a glycidyl group, a hydroxypropyl group, or the like. The polycationic cross-linking agent represented by the general formula (1) (A) of the present invention is (E) epihalohydrin and (F) ammonia, primary amine or secondary amine, and (G) tertiary. It can be produced by reacting an amino group-containing acrylic monomer. The method for producing the water-soluble polycation polyfunctional monomer of the present invention is not particularly limited. For example, (E) epihalohydrin is charged into a reactor, and (F) ammonia, primary amine, or secondary amine is added dropwise. Then
After reacting (E) epihalohydrin with (F) ammonia, primary amine, or secondary amine, (G) tertiary amino group-containing acrylic monomer can be added and reacted. Alternatively, (E) epihalohydrin may be charged into a reactor and a mixture of (F) ammonia, a primary amine or a secondary amine and (G) a tertiary amino group-containing acrylic monomer may be added dropwise for the reaction. Furthermore, for example, (F) ammonia, a primary amine, or a secondary amine and (G) a tertiary amino group-containing acrylic monomer may be charged into a reactor at the same time, and (E) epihalohydrin may be added dropwise to react. it can.

The polycationic polyfunctional monomer represented by the general formula (1) (A) of the present invention is prepared by charging (E) epihalohydrin into a reactor, and (F) ammonia, primary amine, or A method in which a secondary amine is dropped, (E) epihalohydrin and (F) ammonia, a primary amine, or a secondary amine are reacted, and then (G) a tertiary amino group-containing acrylic monomer is added and reacted. Is preferred. (F) Ammonia, primary amine, or secondary amine and (G)
Mixing an acrylic monomer containing a tertiary amino group is inconvenient because it reacts by a Michael addition reaction. Also, (E)
By charging epihalohydrin into the reactor first, (E)
Epihalohydrin and (F) ammonia, primary amine,
Alternatively, the terminal of the cation resin obtained by reacting the secondary amine is likely to have a halohydrin structure, which is convenient for reacting the (G) tertiary amino group-containing acrylic monomer.

(A) Ammonia, primary amine to (E) epihalohydrin in the polycation polyfunctional monomer represented by the above general formula (1) of the present invention,
Alternatively, the molar ratio of the secondary amine is appropriately selected depending on the desired properties, structure, molecular weight and the like of the crosslinking agent, but is generally in the range of 0.25 to 1.20. When the molar ratio of (F) ammonia, primary amine, or secondary amine to (E) epihalohydrin is 0.25 or less,
(E) Epihalohydrin remains. (E) When the molar ratio of (F) ammonia, primary amine, or secondary amine to epihalohydrin is 1.20 or more, (E)
Epihalohydrin and (F) ammonia, primary amine,
Alternatively, the cationic resin obtained by the reaction of the secondary amine does not have a halohydrin structure at the terminal and does not react with the (G) tertiary amino group-containing acrylic monomer. The molar ratio of (G) the tertiary amino group-containing acrylic monomer to (E) epihalohydrin in the (A) polycation polyfunctional monomer represented by the general formula (1) of the present invention is not particularly limited. However, the range is preferably 0.24 or less. If the molar ratio of the (G) tertiary amino group-containing acrylic monomer to the (E) epihalohydrin is greater than 0.24, the (G) tertiary amino group-containing acrylic monomer remains in the polycation crosslinking agent.

Regarding (A) the polycation polyfunctional monomer represented by the above general formula (1), (E) epihalohydrin and (F) ammonia, a primary amine, or a secondary amine are A cationic resin can be obtained by reacting easily. The reaction can also be carried out by adding an alkali catalyst such as sodium hydroxide in a molar ratio of 1.0 or less with respect to epihalohydrin. The temperature range in which the reaction is carried out is appropriately selected depending on the desired properties, structure, molecular weight and the like of the crosslinking agent, but is generally 10 to 90 ° C, preferably 20 to 60 ° C. The reaction temperature is 2
Below 0 ℃, the reaction rate is slow and not practical, and 60 ℃
Above, (E) epihalohydrin and (F) ammonia,
The halohydrin structure at the terminal of the cationic resin obtained by the reaction of the primary amine or the secondary amine is hydrolyzed and cannot react with the (G) tertiary amino group-containing acrylic monomer. The reaction time depends on the reaction temperature and the like, but usually 24 hours or less is sufficient.

The cationic resin obtained by reacting (E) epihalohydrin with (F) ammonia, primary amine, or secondary amine contains a resin having two or more halohydrin structures at its terminals. This is (G) Third
It can be easily reacted with an acrylic monomer containing a primary amino group. The temperature range for carrying out the reaction is generally from 10
The temperature is 90 ° C, preferably 20 to 60 ° C. If the reaction temperature is 20 ° C or lower, the reaction rate is slow and not practical, and if it is 60 ° C or higher, (E) epihalohydrin and (F)
The terminal halohydrin structure of the cationic resin obtained by the reaction of ammonia, primary amine, or secondary amine is hydrolyzed, and it becomes impossible to react with (G) the tertiary amino group-containing acrylic monomer. The reaction time depends on the reaction temperature and the like, but usually 24 hours or less is sufficient.

The ionic polymer of the present invention is prepared by copolymerizing the polycation polyfunctional monomer with a vinyl cationic monomer, an anionic monomer and a nonionic monomer. You can Polymerization methods include aqueous solution polymerization, water-in-oil emulsion polymerization, water-in-oil dispersion polymerization, and salt-water dispersion polymerization, and can be made into any product form such as aqueous solution, dispersion, emulsion or powder. . The most preferable form is a water-in-oil emulsion polymerized product which does not require a drying step, can be concentrated, and has a short dissolution time.

As a method for producing a water-in-oil type polymer emulsion, a cationic monomer or a monomer mixture comprising a monomer copolymerizable with the cationic monomer is mixed with water or at least immiscible with water. After mixing an oily substance consisting of a water-soluble hydrocarbon, an amount effective to form a water-in-oil emulsion and at least one surfactant having HLB, and stirring vigorously to form a water-in-oil emulsion, It is synthesized by polymerizing.

Examples of the oily substance composed of hydrocarbons used as the dispersion medium include paraffins or mineral oils such as kerosene, light oil and middle oil, or hydrocarbons having properties such as boiling point and viscosity in the substantially same range as these. Synthetic oil,
Alternatively, a mixture of these may be used.

An example of at least one surfactant having an HLB and an amount effective to form a water-in-oil emulsion is a nonionic surfactant of HLB 3 to 11, and a specific example thereof is sorbitan. Monooleate, sorbitan monostearate, sorbitan monopalmite
And so on. The amount of these surfactants added is 0.5 to 10% by weight, preferably 1 to 5% by weight, based on the total amount of the water-in-oil emulsion.

After the polymerization, a hydrophilic interfacial forming agent called a phase inversion agent is added to the emulsion particles covered with the oil film so that the emulsion particles are easily made compatible with water and the water-soluble polymer therein is easily dissolved. Perform, dilute with water and use for each purpose. Examples of hydrophilic interfacial chemicals include cationic interfacial chemicals and H
LB9 to 15 are nonionic interfacial chemicals, such as polyoxyethylene alkyl ether type and polyoxyethylene alcohol ether type.

The polymerization concentration is from 8 to 8 for aqueous solution polymerization.
15% by weight, preferably 10 to 12% by weight, and 20 to 50% by weight, preferably 25 to 40% in the case of water-in-oil emulsion polymerization or water-in-oil dispersion polymerization.
% By weight, and 15 to 35% by weight for dispersion polymerization in salt water,
It is preferably 20 to 30% by weight. The polymerization temperature is 0 to 80 ° C., preferably 20 to 50 ° C., and most preferably 20 to 40 ° C. The polymerization temperature is appropriately set depending on the composition of the monomer, the polymerization method and the selection of the initiator.

Examples of the cationic monomer include (meth)
Polymers and copolymers such as dimethylaminoethyl acrylate, dimethylaminopropyl (meth) acrylamide, and methyldiallylamine are listed. Examples of the quaternary ammonium group-containing polymer are methyl chloride of the above-mentioned tertiary amino-containing monomer. (Meth) acryloyloxyethyltrimethylammonium chloride, which is a quaternary compound with benzyl chloride,
(Meth) acryloyloxy 2-hydroxypropyltrimethylammonium chloride, (meth) acryloylaminopropyltrimethylammonium chloride, (meth)
And acryloyloxyethyldimethylbenzylammonium chloride, (meth) acryloyloxy 2-hydroxypropyldimethylbenzylammonium chloride, (meth) acryloylaminopropyldimethylbenzylammonium chloride and the like. In addition, a dimethyldiallylammonium-based monomer can also be used, and examples thereof include dimethyldiallylammonium chloride and diallylmethylbenzylammonium chloride.

Further, as an example of the anionic monomer represented by the general formula (5), a sulfone group or a carboxyl group may be used, and both may be used in combination. Examples of the sulfonic group-containing monomer are vinyl sulfonic acid, vinyl benzene sulfonic acid, 2-acrylamido 2-methylpropane sulfonic acid, and the like. Examples of the carboxyl group-containing monomer are methacrylic acid, acrylic acid, itaconic acid, maleic acid, p-carboxystyrene and the like.

Examples of nonionic monomers include (meth)
Acrylamide, N, N-dimethylacrylamide, vinyl acetate, acrylonitrile, methyl acrylate, 2-hydroxyethyl (meth) acrylate, diacetone acrylamide, N-vinylpyrrolidone, N-vinylformamide, N-vinylacetamide acryloylmorpholine, acryl Examples include kuriloyl piperazine.

The polymerization conditions are usually determined appropriately depending on the monomers used and the mole% of the copolymerization, and the temperature is 0-10.
Perform in the range of 0 ° C. Particularly when the water-in-oil emulsion polymerization method is applied, the temperature is 20 to 80 ° C., preferably 20 to 60.
Perform at ℃. A radical polymerization initiator is used to initiate the polymerization. These initiators may be either oil-soluble or water-soluble, and can be polymerized by any of azo type, peroxide type and redox type. Examples of the oil-soluble azo initiator include 2,2′-azobisisobutyronitrile, 1,
1'-azobis (cyclohexanecarbonitrile),
2,2'-azobis (2-methylbutyronitrile),
2,2'-azobis (2-methylpropionate),
4,4-Azobis (4-methoxy-2,4dimethyl) valeronitrile and the like are mentioned, which are dissolved in a water-miscible solvent and added.

Examples of water-soluble azo initiators are:
2'-azobis (amidinopropane) dihydrochloride,
2,2'-Azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 4,4 '
-Azobis (4-cyanovaleric acid) and the like. Further, examples of the redox system include a combination of ammonium peroxodisulfate and sodium sulfite, sodium hydrogen sulfite, trimethylamine, tetramethylethylenediamine and the like. Further examples of peroxides include ammonium or potassium peroxodisulfate,
Examples thereof include hydrogen peroxide, benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, succinic peroxide, t-butylperoxy 2-ethylhexanoate and the like.

The molecular weight of the ionic polymer obtained by copolymerizing the above-mentioned monomers is 3 to 20 million, preferably 5 to 15 million, and more preferably 50.
It is from 0 to 10 million.

The ionic polymer of the present invention can be produced by copolymerizing the polyfunctional water-soluble polycationic monomer represented by the general formula (6) with the monomer mixture. When a cross-linkable water-soluble polymer is synthesized using a conventional cross-linking agent having a relatively short cross-linking point such as N, N-methylene bisacrylamide or ethylene glycol di (meth) acrylate, the molecule shrinks too much. Take a roll in the water. As a result, the contact with sludge particles becomes inefficient and the treatable addition amount increases. Conventionally, the cross-linking polymer has an excellent effect by reducing the water content of the dehydrated cake as has been said, but there is a disadvantage in that the cost is increased due to an increase in the amount added. However, the above polyfunctional water-soluble polycationic monomer has a long distance between crosslinking points, and moreover, a cationic group exists between the crosslinking points.
Therefore, the molecule does not shrink too much, and the morphology in water can exist in an appropriate state. As a result, the characteristics of the crosslinkable polymer are retained, and the contact with sludge particles is efficiently performed.

The amount of the polyfunctional water-soluble polycationic monomer added to the monomer mixture is 0.01 to 10%, preferably 0.05 to 5%, based on the amount of the monomer mixture substance. More preferably, it is 0.1 to 3%. The polymerization temperature can be the usual polymerization conditions as described above. Further, in order to adjust the degree of polymerization, it is effective to use isopropyl alcohol in combination with 0.1 to 5% by weight of the monomer.

Applicable sludge includes surplus sludge generated when biological treatment such as papermaking wastewater, chemical industry wastewater, food industry wastewater, organic wastewater sludge, mixed raw sludge, surplus sludge, digested sludge and the like. Although it is sludge, the most suitable sludge is digested sludge of municipal sewage. Further, the addition amount of the ionic polymer of the present invention is 0.1 by weight based on the sludge solid content.
Is 1.0%, preferably 0.2% to 0.5%.

The ionic polymer of the present invention can be subjected to sludge dewatering treatment alone, but when an inorganic coagulant is used in combination, the effect is further exhibited and efficient sludge dewatering can be carried out. Examples of the inorganic coagulant include aluminum sulfate, ferric chloride, polyaluminum chloride, polyiron chloride, etc., these inorganic coagulants are first added to sludge, after mixing, the amphoteric polymer of the present invention is added. Mix and send to dehydrator. The addition amount of the inorganic coagulant is 500 ppm to 1 by weight based on the sludge solid content.
It is about 0000 ppm, preferably 1000 to 50
It is 00 ppm.

[0037]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples unless it exceeds the gist.

[0038]

Example 1 Isoparaffin 1 having a boiling point of 190 ° C. to 230 ° C. was placed in a reaction vessel equipped with a stirrer and a temperature controller.
To 26.0 g, 6.0 g of sorbitan monooleate and 0.6 g of polyricinoic acid / polyoxyethylene block copolymer were charged and dissolved. Separately deionized water 113.
1 g and a 60% aqueous solution of acrylic acid (abbreviated as AAC) 23.
6 g were mixed, and this was mixed with 35% aqueous sodium hydroxide solution 2
Equivalent neutralization with 2.4 g. After neutralization, 126.7 g of an 80% aqueous solution of acryloyloxyethyl trimethyl ammonium chloride (hereinafter abbreviated as DMQ), 34.0 g of an 80% aqueous solution of methacryloyloxyethyl trimethyl ammonium chloride (hereinafter abbreviated as DMC), acrylamide (AAM
65.1 g of 50% aqueous solution and 0.8% of 60% aqueous solution of polyfunctional water-soluble polycationic monomer prepared in Synthesis Example.
g (0.3% by weight of monomer) was collected and added to the acrylic acid solution to completely dissolve it. In addition, the pH is 4.0
The oil was adjusted to 1, the oil and the aqueous solution were mixed, and the mixture was emulsified by stirring with a homogenizer at 1000 rpm for 15 minutes. The monomer composition at this time is DMQ / DMC / AAC / AAM = 40/1.
It is 0/15/35 (mol%).

2.0 g of 40% aqueous isopropyl alcohol solution (0.5% by weight of monomer) was added to the obtained emulsion.
Was added, the temperature of the monomer solution was maintained at 30 to 33 ° C., and nitrogen substitution was performed for 30 minutes, and then 2,2′-azobis [2- (5
-Methyl-2-imidazolin-2-yl) propane] 0.35 g of 10% aqueous solution of dihydrochloride (relative to monomer
(02 wt%) was added to initiate the polymerization reaction. The reaction was completed at a reaction temperature of 32 ± 2 ° C. for 12 hours to complete the reaction. After polymerization, 10.0 g of polyoxyethylene tridecyl ether (2.0% by weight of liquid) was added and mixed as a phase inversion agent to the produced water-in-oil emulsion to prepare a sample (Sample-1) to be used in the test. . Moreover, the weight average molecular weight was measured by a molecular weight measuring device (DLS-7000 manufactured by Otsuka Electronics) by the static light scattering method. The results are shown in Table 1.

[0040]

Example 2 Isoparaffin 1 having a boiling point of 190 ° C. to 230 ° C. was placed in a reaction vessel equipped with a stirrer and a temperature controller.
To 20.0 g, 6.0 g of sorbitan monooleate and 0.6 g of polyricinoic acid / polyoxyethylene block copolymer were charged and dissolved. Separately deionized water 32.0
g, acryloyloxyethyltrimethylammonium chloride (hereinafter abbreviated as DMQ) 80% aqueous solution 184.4
g, 50% aqueous solution of acrylamide (abbreviated as AAM) 2
7.0 g and 1.1 g of 60% aqueous solution of polyfunctional water-soluble polycationic monomer prepared in Synthesis Example (0.4% by weight relative to monomer) were collected and added to the acrylic acid solution to be completely dissolved. Let The pH was adjusted to 4.35, the oil and the aqueous solution were mixed, and the mixture was emulsified by stirring with a homogenizer at 1000 rpm for 15 minutes. The monomer composition at this time is DMQ / AA.
M = 80/20 (mol%).

2.4 g of 40% aqueous solution of isopropyl alcohol (0.6% by weight of monomer) was added to the obtained emulsion.
Was added, the temperature of the monomer solution was maintained at 30 to 33 ° C., and nitrogen substitution was performed for 30 minutes, and then 2,2′-azobis [2- (5
-Methyl-2-imidazolin-2-yl) propane] 0.35 g of 10% aqueous solution of dihydrochloride (relative to monomer
(02 wt%) was added to initiate the polymerization reaction. The reaction was completed at a reaction temperature of 32 ± 2 ° C. for 12 hours to complete the reaction. After the polymerization, 10.0 g of polyoxyethylene tridecyl ether (2.0 wt% with respect to the liquid) was added and mixed as a phase inversion agent to the produced water-in-oil emulsion to prepare a sample (sample-2) to be tested. . The results are shown in Table 1.

[0041]

[Third Embodiment] DMQ / AAC / AAM = 60/20 / by the same operation as in the first or second embodiment.
20 (Sample-3), DMQ / AAC / acrylamide 2
-Methyl propane sulfonic acid / AAM = 60/15 /
5/20 (Sample-4), DMQ / AAC / itaconic acid /
AAM = 60/15/5/20 (Sample-5), DMC /
A water-in-oil amphoteric polymer emulsion having a composition of AAM = 60/40 (Sample-6) and DMC = 100 (Sample-7) (both mol%) was synthesized. The results are shown in Table 1.

(Comparative Synthesis Example) N-1, N-methylenebisacrylamide was added as a cross-linking agent and polymerized to synthesize ionic polymers Comparative-1 to Comparative-3. The results are shown in Tables 1 and 2.

[0043]

[Table 1] DMC: Methacryloxyethyltrimethylammonium chloride DMQ: Acryloxyethyltrimethylammonium chloride, AAC: Acrylic acid, IA: Itaconic acid, A
MP: Acrylamide 2-methylpropanesulfonic acid,
AAM: acrylamide, cross-linking agent:% by weight of monomer

[0044]

[Table 2] Emulsion viscosity: mPa · s, molecular weight: 10,000

[0045]

[Examples 8 to 14] 200 mL of urban digested sludge (pH 8.15, total ss content 38,500 mg / L) was sampled in a poly-beaker, and the amphoteric polymer or cationic polymer in the present invention shown in Table 2 was used. Sample-1 to sample-7 were added to the sludge solid content of 2500 ppm, and after changing the beaker and stirring 10 times, the mixture was filtered through a T-1179L filter cloth (made of nylon), and the filtrate amount after 30 seconds was changed. It was measured. The filtered sludge is dehydrated for 1 minute at a pressing pressure of 2 Kg / m 2. Then, the filter cloth releasability and the cake self-supporting property (related to the hardness of the dehydrated cake and the water content) were visually checked, and the water content of the cake (1
Drying was performed at 05 ° C. for 20 hours). The results are shown in Table 3.

[0046]

Comparative Examples 4 to 6 Using the samples of Comparative Examples in Table 2 and the amphoteric or cationic polymers of Comparative-1 to Comparative-3, Example 8
It carried out by the same test operation as -14. The results are shown in Table 3.

[0047]

[Examples 15 to 21] Excess sludge (pH
6.33, total ss 21,000 mg / mL) 200 mL
Was collected into a poly beaker, ferric chloride polychloride was added to the sludge solid content of 1600 ppm, the beaker was transferred, and the mixture was stirred 5 times. The sludge pH at this time was 4.22. Next, the amphoteric or cationic polymer of the present invention shown in Table 1, Sample-1 to Sample-7, was added to the sludge solid content of 2000 ppm, the beaker was transferred and stirred 10 times, and then T-117.
After filtering with a 9 L filter cloth (made of nylon), the amount of filtrate after 30 seconds was measured. In addition, the sludge filtered is pressed at a pressure of 2 kg /
Dehydrate at m2 for 1 minute. Thereafter, the cake self-supporting property (related to the hardness of the dehydrated cake and the water content) was visually checked, and the water content of the cake (dried at 105 ° C. for 20 hours) was measured. The results are shown in Table 4.

[0048]

[Comparative Examples 7 to 9] Using the samples of Comparative Examples in Table 2 and the amphoteric or cationic polymers of Comparative-1 to Comparative-3, Example 15
It carried out by the same test procedure as -21. The results are shown in Table 4.

[0049]

[Table 3] After 30 seconds, the amount of filtrate: ml, the water content of cake: mass%, the hardness of dehydrated cake: good in order of ◯>Δ> x.

[0050]

[Table 4] After 30 seconds, filtrate amount: ml, cake water content: mass% Dehydrated cake hardness: Good in order of ○>△> ×

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Claims (8)

[Claims] 1. A sludge dehydrating agent comprising an ionic polymer having a cross-linking structural unit represented by the following general formula (1). [Chemical 1] General formula (1) However, n in Formula (1) is an integer of 0-20, R1-
R4 is hydrogen or an alkyl group having 1 to 3 carbon atoms, hydroxyalkyl go or benzyl groups X1 and X2 are anions. 2. The ionic polymer contains 5 to 10 monomers represented by the following general formulas (2) and / or (3).
0 mol%, a monomer represented by the following general formula (4)
A monomer mixture consisting of 60 mol% and a nonionic monomer of 0 to 95 mol% and a polyfunctional water-soluble polycationic monomer represented by the following general formula (5) are added to the monomer mixture. The sludge dewatering agent according to claim 1, which is produced by adding 0.01 to 2% by mass and copolymerizing. [Chemical 2] In the general formula (2), R5 is hydrogen or a methyl group, R6 and R7 are C1 to C3 alkyl or alkoxyl groups, R8 is hydrogen, a C1 to C3 alkyl group, an alkoxyl group or a benzyl group. May be different, A is oxygen or N
H and B represent an alkylene group having 2 to 4 carbon atoms or an alkoxylene group, and X3 represents an anion. [Chemical 3] General formula (3) R9 is hydrogen or a methyl group, R10 and R11 are carbon numbers 1 to 1.
3 alkyl group, alkoxy group or benzyl group, X
4 is an anion, respectively. Formula (4) R12 is hydrogen, methyl group or carboxymethyl group, Q
Is SO3, C6H4SO3, CONHC (CH3) 2C
H2SO3, C6H4COO or COO, R13 is hydrogen or COOY2, Y1 or Y2 is hydrogen or cation R14 to R17 are hydrogen or a methyl group, X5 and X6 are anions, and p is an integer of 0 to 20, provided that P is P.
Is represented by the following general formula (6). General formula (5) General formula (6) R <_18> , R < ₁₉ > is hydrogen, a C1-C3 alkyl group or a benzyl group, a C2-C4 alkylene group or an alkoxylene group, R < ₂₀ > is hydrogen or a methyl group, L is -O. −
Or -NH-, X7 ^- anion, provided that _R 14 to R
_{When 17} is hydrogen, it may be partially substituted with P. 3. The polyfunctional water-soluble polycationic monomer is one or more amines selected from ammonia, an aliphatic primary amine, an aliphatic secondary amine, and an aliphatic tertiary amine, and epihalohydrin. The organic sludge dehydrating agent according to claim 2, which is a reaction product of a polycondensate produced from the above and a dialkylaminoalkyl (meth) acrylamide. 4. The polyfunctional water-soluble polycationic monomer comprises epihalohydrin as A (mol), ammonia,
When B (mol) is one or more amines selected from primary amine, secondary amine, and tertiary amine, A / B
The organic sludge dewatering agent according to claim 2, which is a reaction product of a polycondensate produced by reaction in the range of 0.25 to 1.2 and a dialkylaminoalkyl (meth) acrylamide. 5. The ionic polymer forms a water-in-oil emulsion in which an aqueous solution of a monomer mixture serves as a discontinuous phase and a liquid hydrocarbon immiscible in water containing an oil-soluble emulsifier serves as a continuous phase. The organic sludge dehydrating agent according to claim 1, which comprises a dispersion liquid produced by emulsion polymerization under stirring. 6. The weight-average molecular weight of the ionic polymer is 2 to 20 million.
The sludge dehydrating agent described in. 7. The ionic polymer is added to organic sludge,
A sludge dewatering method comprising: mixing and aggregating and then dehydrating with a dehydrator. 8. The sludge dewatering method according to claim 7, wherein an inorganic coagulant and the ionic polymer are added to and mixed with the organic sludge and then dehydrated by a dehydrator.