JP4786569B2 - Organic coagulant - Google Patents

Description

  The present invention relates to an organic coagulant used for treating organic sludge and inorganic waste water, such as sewage or human waste (hereinafter abbreviated as sewage) and factory waste water, and a method for treating sludge or waste water using the organic coagulant. .

Conventionally, in the coagulation and decolorization treatment of organic sludge such as sewage, inorganic sludge such as mill wastewater, suspended water, colored water, paper mill wastewater and other aqueous solutions, inorganic coagulants (for example, sulfate bands, Aluminum chloride, ferric chloride, ferric sulfate, polyiron sulfate and slaked lime) and organic coagulant [for example, polycondensate of epihalohydrin and amine (see, for example, Patent Document 1), and diallyldimethylammonium halide polymer ( For example, see Patent Documents 2 and 3)].
In addition, for the dehydration treatment of these organic or inorganic sludges or wastewater, a method of using a condensed polyamine organic coagulant and an amphoteric polymer flocculant in combination (for example, see Patent Document 4) has been proposed. ing.

Japanese Examined Patent Publication No. 38-26794 (first page) JP 2001-38104 A JP 2001-270906 A JP 2000-225400 A

However, the currently used inorganic coagulant requires a huge amount of addition to the suspended water, etc., and the amount of sludge after solid-liquid separation increases, or the ash generated after drying and incineration of sludge increases. There was a problem to do. On the other hand, the above-mentioned organic coagulants can be added in a lower amount than inorganic coagulants, and the amount of sludge can be greatly reduced, but the effect of coagulation and decoloration is insufficient. Since it often does not improve, it is generally used in combination with an inorganic coagulant. Furthermore, with the recent tightening of drainage regulations, there is an increasing need to reduce COD components in effluent water, and further improvement in the performance of organic coagulants is particularly desired.
In addition, in the above-mentioned sludge or wastewater dewatering treatment, the ability to form stronger flocs is required from the viewpoint of improving the treatment speed associated with the recent increase in the amount of sludge and wastewater. From the viewpoint of increasing the cost of incineration or landfill disposal of dehydrated cake, there is an organic coagulant that has the ability to significantly reduce the water content in the dehydrated cake, and also has the ability to decolorize separation water and reduce COD after the dehydration process. It is desired. However, the proposed organic coagulant cannot satisfy these performances, and the method using the proposed organic coagulant and the polymer coagulant has not been sufficient.
The object of the present invention is to improve the clarity during the treatment of sludge or wastewater, an organic coagulant excellent in COD reduction effect, etc., as well as coarse floc, low water content of dehydrated cake, and COD reduction of filtrate, An object of the present invention is to provide a method for treating sludge or wastewater having excellent characteristics such as improved clarity.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have reached the present invention. That is, the present invention relates to a cationic monomer (a) represented by the following general formula (1), a monovalent (meth) acryloyl group-containing compound having a solubility in water at 20 ° C. of 1 g / 100 g or less of water and One or two or more kinds of hydrophobic monomers (b) selected from the group consisting of aromatic ring-containing monovalent vinyl compounds are used as a constituent unit, and the pH at which pH is dissolved in water at least at pH 3 and insolubilized in water is between pH 4 and 10. An organic coagulant characterized by comprising a copolymer (A) present in

^{_{CH 2 = CR 1 -CO-X}} -Q-N + R 2 R 3 R 4 · Z - (1)

[Wherein X is O or NH; Q is an alkylene group having 2 to 4 carbon atoms or a hydroxyalkylene group having 2 to 4 carbon atoms; R ¹ is H or a methyl group; R ² , R ³ and R ⁴ are each independently selected. And H, an alkyl, arylalkyl or alkylaryl group having 1 to 16 carbon atoms; Z ⁻ represents a counter anion. ]
And the organic coagulant was added to sludge or wastewater adjusted to a pH at which (A) dissolves, and the pH of sludge or wastewater was adjusted to a pH in the range of pH 4 to 10 at which (A) was insolubilized. Thereafter, a sludge or wastewater treatment method is characterized in that a polymer flocculant is added to form a floc for solid-liquid separation.

The organic coagulant of the present invention has the following effects.
(1) Addition and mixing to sludge or wastewater show excellent coagulation, COD reduction and decolorization.
(2) Even when the inorganic coagulant is not used in combination, the clarity of the filtrate is not deteriorated.
(3) Shows an excellent dewatering effect of sludge or wastewater by combining with a polymer flocculant.

The cationic monomer (a) in the present invention is represented by the following general formula (1).

^{_{CH 2 = CR 1 -CO-X}} -Q-N + R 2 R 3 R 4 · Z - (1)

In the formula, X represents O or NH, and Q represents an alkylene group having 2 to 4 (preferably 2 to 3) carbon atoms (hereinafter abbreviated as C) or a C2 to 4 (preferably 2 to 3) hydroxyalkylene group. To express. When C exceeds 4, the solubility of (A) in water becomes poor.

  C1-4 alkylene groups include methylene, ethylene, n- and i-propylene, 1,2-, 1,3- and 2,3-butylene and tetramethylene groups; C2-4 hydroxyalkylene groups Includes hydroxyethylene, 1- and 2-hydroxypropylene, 1-hydroxy-i-propylene, 2-hydroxymethylpropylene and 2-methyl-2-hydroxypropylene, and 1- and 2-hydroxytetramethylene groups .

In the formula, R ¹ represents H or a methyl group, and a methyl group is preferred from the viewpoint of the condensation performance of (A).
R ² , R ³ and R ⁴ each independently represent H, C 1-16 (preferably C 1-10) alkyl, arylalkyl or alkylaryl groups. When C exceeds 16, the solubility of (A) in water becomes poor. Examples of the alkyl group include methyl, ethyl, n- and i-propyl, n-, i-, sec- and t-butyl, n-, i-, sec- and t-amyl and lauryl groups; arylalkyl groups Examples include benzyl and phenylethyl groups; examples of alkylaryl groups include toluyl, ethylphenyl, and cumyl groups.
Of those exemplified as R ² , R ³ and R ⁴ , preferred are H, C1-2 methyl and ethyl groups.

Examples of Z ⁻ include the following anions.
(1) inorganic acids such as hydrogen halides (eg HF, HCl, HBr and HI), sulfuric acid, nitric acid and phosphoric acid (2) sulfate esters, eg C1-30 sulfate esters [eg alkyl or alkenyl sulfates (eg methyl sulfate) , Ethyl sulfate, lauryl sulfate, myristyl sulfate, palmityl sulfate, stearyl sulfate, oleyl sulfate, linole sulfate and cetyl sulfate) and higher alcohols (C10-20) ethylene oxide (hereinafter abbreviated as EO) 1-10 mol adduct Sulfate]

(3) Sulfonic acids such as C1-30 sulfonic acids [eg alkyl (C1-10) sulfonic acids (eg methylsulfonic acid and ethylsulfonic acid), alkylaryl (C7-30) sulfonic acids [alkylbenzenesulfonic acid, alkylphenolsulfone Acid and alkyl naphthalene sulfonic acid], higher alkyl (C10-30) sulfonic acid, higher fatty acid ester (C10-30) sulfonic acid, higher alcohol ether (C10-30) sulfonic acid, sulfosuccinic acid ester, higher fatty acid amide (C10 20) alkyl (C1-10) sulfonic acid, alkyl (C1-10) diphenyl ether sulfonic acid and alkyl (C1-10) benzimidazole sulfonic acid]

(4) Phosphate esters such as C1-30 phosphate esters [eg mono- and dialkyl (alkyl C1-30) phosphate esters, mono- and dialkenyl (alkenyl C1-30) phosphate esters, (poly) oxyalkylenes [EO 1-14 mol addition and / or propylene oxide (hereinafter abbreviated as PO) 1-9 mol addition] alkyl (C1-30) ether phosphate ester, sugar phosphate ester (eg glucose-phosphate ester, glucose amine phosphorus) Acid esters, maltose-1-phosphate and sucrose phosphate esters) and glycerin phosphate (eg phosphatidic acid)

(5) Phosphonic acids, such as C1-30 phosphonic acids [eg alkyl (C1-10) phosphonic acids (eg methylphosphonic acid and ethylphosphonic acid), alkylaryl (C7-30) phosphonic acids (eg alkylbenzene phosphonic acid and alkylphenol phosphones) Acid), higher alkyl (C10-30) phosphonic acid, phosphonic acid of higher fatty acid ester (C10-30), phosphonic acid of higher alcohol ether (C10-30), alkyl of higher fatty acid amide (C10-20) (C1 10) Phosphonic acid, alkyl (C1-10) diphenyl ether phosphonic acid and alkyl (C1-10) benzimidazolephosphonic acid]
(6) Carboxylic acids such as C1-30 carboxylic acids such as aliphatic [C1-30 mono- and dicarboxylic acids such as formic acid, oxalic acid, acetic acid, propionic acid, maleic acid, fumaric acid and adipic acid]; Cyclic [C4-30 mono- and dicarboxylic acids such as cyclopentane (di) carboxylic acid and cyclohexane (di) carboxylic acid]; and aromatic (aliphatic) [C7-30 mono- and dicarboxylic acids such as benzoic acid , Phthalic acid, xylylene dicarboxylic acid]

Of these Z ⁻ , the anion of sulfonic acid is preferable from the viewpoint of the coagulation performance of (A), and more preferable is sulfuric acid, halogen (for example, Cl ⁻ and Br ⁻ ) and sulfuric acid ester (for example, alkyl and alkenyl sulfuric acid esters). ), Particularly preferred are sulfuric acid, Cl ⁻ , methylsulfuric acid and ethylsulfuric acid anions, and most preferred is Cl ⁻ .

Examples of the cationic monomer (a) include the following, and mixtures thereof.
(A1) Amine salt of (meth) acrylate [when X in general formula (1) is O] Primary amino group-containing (meth) acrylate [C5-20, such as aminoethyl (meth) acrylate and aminopropyl (meth) Acrylate], secondary amino group-containing (meth) acrylate [C6-20, such as methylaminoethyl (meth) acrylate, methylaminopropyl (meth) acrylate and aminoethyl (meth) acrylate] and tertiary amino group-containing (meth) Acrylate [C7-20, such as dimethylaminoethyl (meth)
Acrylate and dimethylaminopropyl (meth) acrylate], inorganic acid (above) salts, organic acid (e.g., sulfate, sulfonic acid, phosphate, phosphonic acid, carboxylic acid, etc.) salts and amines thereof (salts) ) Is quaternized with a quaternizing agent [C1-6 alkyl, C7-16 arylalkyl or C7-16 alkylaryl halide such as methyl chloride, ethyl chloride, benzyl chloride, phenethyl chloride]. Grade ammonium salt

(A2) amine salt of (meth) acrylamide compound [when X in general formula (1) is N] primary amino group-containing (meth) acrylamide [for example, aminoethyl (meth) acrylamide and aminopropyl (meth) acrylamide], Secondary amino group-containing (meth) acrylamide [eg methylaminoethyl (meth) acrylamide and methylaminopropyl (meth) acrylamide] and tertiary amino group-containing (meth) acrylamide [eg dimethylaminoethyl (meth) acrylamide and dimethylaminopropyl (Meth) acrylamide] inorganic acid (above) salt, organic acid (above) salt and quaternary ammonium salt obtained by quaternizing the above amine with a quaternizing agent (above).

Among these, after the above (A) is dissolved in water at least at pH 3, it is preferable from the viewpoint that the pH at which (A) becomes a free amine and insolubilizes is between pH 4 and 10, the primary, Secondary and tertiary amino group salts. Further, from the industrial viewpoint, a (meth) acrylate amine salt in which X is O is more preferable, and R ² and R ³ are both CH ₃ , R ⁴ is H, Z is Cl or 1 / 2SO _4. And dimethylaminoethyl (meth) acrylate hydrochloride and dimethylaminoethyl (meth) acrylate sulfate.

The hydrophobic monomer (b) constituting (A) has a solubility in water at 20 ° C. of 1 g / 100 g or less of water and has a monovalent (meth) acryloyl group-containing compound (b1) and an aromatic ring-containing monovalent vinyl compound ( One or two or more monomers selected from the group consisting of b2). Hereinafter, the solubility in water at 20 ° C. of 1 g / 100 g or less of water may be referred to as water-insoluble.
When the solubility of (b) exceeds 1 g / 100 g of water, it is difficult to make the pH at which (A) becomes insoluble in the range of pH 4 to 10 when it is designed to dissolve (A) at least at pH 3. The coagulation effect becomes insufficient, the COD reduction, the filtrate clarifying improvement and the decolorization effect are deteriorated, and the water content reduction effect of the dehydrated cake by the combined use with the polymer flocculant described later is deteriorated.

Examples of the (meth) acryloyl group-containing compound (b1) include the following and mixtures thereof.
(B11) (Meth) acrylic acid ester C8 or more and number average molecular weight [hereinafter abbreviated as Mn, measurement is by gel permeation chromatography (GPC) method. ] 1,000 or less, for example, (meth) acrylic acid alkyl ester, (meth) acrylic acid alkenyl ester, and (meth) acrylic acid polyoxypropylene ester: for example, butyl methacrylate, (meth) acrylic acid 2-ethylhexyl, ( (Meth) acrylic acid octyl, (meth) acrylic acid dodecyl, (meth) acrylic acid lauryl, (meth) acrylic acid cetyl, (meth) acrylic acid stearyl, (meth) acrylic acid oleyl, polypropylene glycol (Mn100-800) (Meth) acrylic acid ester.

(B12) C8-24 N-substituted (meth) acrylamides N-alkyl substituted (meth) acrylamides, N-alkenyl substituted (meth) acrylamides, and N- (poly) oxypropyl substituted (meth) acrylamides; for example, N, N -Diethyl (meth) acrylamide, N-2 ethylhexyl (meth) acrylamide, N-octyl (meth) acrylamide, N-dodecyl (meth) acrylamide, N-lauryl (meth) acrylamide, N-cetyl (meth) acrylamide, N- Stearyl (meth) acrylamide, N-oleyl (meth) acrylamide, N, N-di (poly) oxypropyl [(poly) oxypropyl group added with 1 to 3 moles of PO] (meth) acrylamide and the like.

  Among these (b1), when (A) is designed to be dissolved at at least pH 3, it is preferable from the viewpoint that the pH at which (A) is insolubilized is in the range of pH 4 to 10 (b11 More preferred are C8-24 alkyl and alkenyl esters of (meth) acrylates, particularly preferred are lauryl (meth) acrylate, -cetyl, -stearyl and -oleyl.

Examples of the aromatic ring-containing vinyl compound (b2) include the following and mixtures thereof.
(B21) Monocyclic compounds C8 to C13, such as styrene, α-methylstyrene, β-methylstyrene, methylstyrene, dimethylstyrene, trimethylstyrene, hydroxystyrene, methoxystyrene, acetoxystyrene, allylbenzene, and allylphenol.
(B22) Polycyclic compounds C12 to C15, such as vinylnaphthalene, naphthylacrylic acid, and vinylnaphthol.
Of these (b2), styrene, α-methylstyrene, hydroxystyrene, and acetoxystyrene are preferable from the industrial viewpoint, and styrene, α-methylstyrene, and acetoxystyrene are more preferable, and styrene is particularly preferable.

The copolymer (A) can contain other unsaturated group-containing monomer (c) as a constituent unit other than (a) and (b) if necessary as long as the effects of the present invention are not impaired. . (C) includes the following monomers and mixtures thereof.
(C1) Water-soluble monovalent unsaturated group-containing compound Here, water-soluble means that the solubility in water at 20 ° C. exceeds 1 g / 100 g of water.
(C11) (Meth) acrylate C5 or more and Mn 3,000 or less, for example, hydroxyl group-containing (meth) acrylate [for example, hydroxyethyl (meth) acrylate, diethylene glycol mono (meth) acrylate, polyethylene glycol (degree of polymerization 3 to 50) mono (meta ) Acrylate and (poly) glycerol (degree of polymerization 1 to 10) mono (meth) acrylate], 2-cyanoethyl (meth) acrylate, methyl (meth) acrylate

(C12) Unsaturated carboxylic acids Monocarboxylic acids [C3-30, such as (meth) acrylic acid, vinylbenzoic acid and allylic acetic acid] and poly (divalent to tetravalent or higher) carboxylic acids [C4-30, such as ( Anhydrous) maleic acid, fumaric acid and (anhydrous) itaconic acid]
(C13) Unsaturated sulfonic acid Aliphatic sulfonic acid [C2-20, such as vinylsulfonic acid, (meth) allylsulfonic acid]; Aromatic sulfonic acid [C6-20, such as styrenesulfonic acid, α-methylstyrenesulfonic acid] Alkenyl and alkyl (C1-18) alkenyl esters of sulfocarboxylic acids (eg α-sulfoalkanoic acids and sulfosuccinic acids) [C7-30, eg methylvinyl, propyl (meth) allyl and stearyl (meth) allylsulfosuccinate, (Meth) allylsulfolaurate]; sulfo group-containing (meth) acrylate [C4-30, such as (meth) acryloyloxyalkane (C2 of alkane is 2 to 20) sulfonic acid [eg 2- (meth) acryloyloxyethanesulfone Acid, 2- and 3- (meth) acryl Yloxypropanesulfonic acid, 2- and 4- (meth) acryloyloxybutanesulfonic acid, 2- (meth) acryloyloxy-2,2-dimethylethanesulfonic acid], p- (meth) acryloyloxymethylbenzenesulfonic acid] Sulfo group-containing (meth) acrylamide [C5-30, such as 2- (meth) acryloylaminoethane-, propane- and butane-sulfonic acid, 3- (meth) acryloylaminopropanesulfonic acid, 4- (meth) acryloylamino Butanesulfonic acid, 2- (meth) acryloylamino-2,2-dimethylethanesulfonic acid, p- (meth) acryloylaminomethylbenzenesulfonic acid]; alkyl (C1-20) (meth) allylsulfosuccinic acid ester [C8- 28, for example methyl (meth) allyls Rufosuccinate] etc.

(C14) C3-7 (meth) acrylamide compound (meth) acrylamide, N-alkyl (C1-3) (meth) acrylamide [N-methyl, -ethyl, -n- and -i-propyl (meth) acrylamide, etc. And N-methylol (meth) acrylamide etc. (c15) Compound having amine imide group 1,1,1-trimethylamine (meth) acrylimide, 1,1-dimethyl-1-ethylamine (meth) acrylimide, 1,1- Dimethyl-1- (2′-phenyl-2′-hydroxyethyl) amine (meth) acrylimide and 1,1,1-trimethylamine (meth) acrylimide, etc. (c16) Other nitrogen atom-containing unsaturated group-containing compounds C3-20, such as acrylonitrile, N-vinylformamide, N-vinyl-2- Loridone, vinylimidazole, N-vinylsuccinimide, N-vinylcarbazole, vinylaniline, (meth) allylamine, di (meth) allylamine, 2-vinylpyridine, 3-vinylpiperidine, vinylpyrazine and vinylmorpholine (c17) ) Free amines that do not form salts

(C2) Water-insoluble monovalent unsaturated group-containing compound C2-7, such as unsaturated hydrocarbon [ethylene, propylene and other α-olefins (1-butene, 1-hexene, 1-heptane, etc.), etc.] Is mentioned.

(C3) Divalent unsaturated group-containing compound C10-54, for example, unsaturated hydrocarbon (divinylbenzene, etc.), di (meth) acrylate [1,6-hexanediol di (meth) acrylate, (poly) ethylene glycol ( C2 or more and Mn 1,200 or less) di (meth) acrylate, (poly) propylene glycol (C3 or more and Mn 900 or less) di (meth) acrylate, etc.]

  Among these (c), (meth) acrylamide and polyethylene glycol (degree of polymerization 3 to 50) mono are preferable from the viewpoint of enhancing water solubility without affecting the ionicity of (A) and from an industrial viewpoint. (Meth) acrylate, free amine of (a), more preferably free amine of (a), and divalent unsaturated groups are preferred from the viewpoint of improving aggregation density by providing a crosslinked structure and a branched structure. Containing compounds.

The proportion of (a) in the total monomer constituting (A) is determined in view of the coagulation action of (A) by charge neutralization of the cationic group and imparting hydrophilicity to (A) at least at pH 3; From the standpoint that the pH at which A) is insolubilized is in the range of pH 4 to 10 (hereinafter sometimes referred to as “hydrophobicity imparting effect”), preferably 10 to 95 mol%, more preferably 20 to 90 mol%, particularly The proportion of (b) is preferably from 5 to 90 mol%, more preferably from 10 to 80 mol%, particularly preferably from 15 to 85% from the viewpoint of imparting hydrophobicity and water solubility of (A). 70 mol%: The proportions other than (a) and (b) are preferably 40 mol% or less, more preferably 30 mol% or less, from the viewpoint of not adversely affecting the coagulation effect of (A) by charge neutralization of the cationic group. Especially The Mashiku not more than 20 mol%.

The production method of (A) is not particularly limited, and radical polymerization methods such as solution dropping polymerization, reverse phase suspension polymerization, photopolymerization, precipitation polymerization, and reverse phase emulsion polymerization can be employed. Of these, solution dropping polymerization is preferred from the industrial viewpoint and molecular weight control viewpoint.
The solution dropping polymerization can be produced, for example, by using a method of dropping a monomer, a solvent and a radical polymerization initiator solution at the boiling point of the solvent (for example, JP-A-6-211942), and an organic solvent is used as the solvent. When used, it is usually produced by removing the solvent and adding water as necessary in view of handling risk and environmental protection.

Examples of the solvent used include polar solvents such as water, alcohols (methanol, ethanol, isopropyl alcohol, etc.), ketones (methyl ethyl ketone, acetone, etc.), tetrahydrofuran (THF), dimethylformamide (DMF), and mixtures thereof, or toluene, Non-polar solvents such as xylene.
Among these, a mixed solvent of water and alcohol is preferable from the viewpoints of solubility of the monomer and initiator and ease of solvent removal after polymerization. More preferred is a mixed solvent of water and isopropyl alcohol.

Examples of the radical polymerization initiator in the radical polymerization method include water-soluble azo initiators [for example, azobisamidinopropane (salt) [for example, 2,2′-azobis (2-methylpropionamidine) dihydrochloride], azobis Cyanovaleric acid (salt) and 2,2′-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] (salt)], oil-soluble azo initiators (eg azobiscyanovaleronitrile, azo Bisisobutyronitrile and azobiscyclohexanecarbonitrile), water-soluble peroxides [inorganic peroxides (ammonium persulfate, sodium persulfate, hydrogen peroxide, etc.) and organic peroxides (peracetic acid, t-butyl hydroper Oxides)], oil-soluble peroxides (eg benzoyl peroxide, cumene hydroxy peroxide) Di -t- butyl peroxide, di -t- butyl peroxy hexahydro terephthalate) and the like.
The above peroxides may be used as a redox initiator in combination with a reducing agent, such as bisulfite (eg, sodium bisulfite, potassium bisulfite and ammonium bisulfite), reducing metal salts [eg, iron sulfate] (II)], tertiary amines [eg dimethylaminobenzoic acid (salt) and dimethylaminoethanol], amine complexes of transition metal salts [eg pentamethylenehexamine complex of cobalt (III) chloride and diethylenetriamine complex of copper (II) chloride And an organic reducing agent (for example, ascorbic acid). Further, the azo initiator, peroxide initiator, and redox initiator may be used alone or in combination of two or more initiators.

  The use amount of the radical polymerization initiator is preferably 0.001%, more preferably 0.005%, particularly preferably from the viewpoint of obtaining the optimum molecular weight as (A) based on the total weight of the monomers. 0.01%, most preferably 0.05%, and a preferable upper limit is 20%, more preferably 10%, particularly preferably 5%, and most preferably 3%.

Moreover, you may use the chain transfer agent for radical polymerization as needed. The chain transfer agent for radical polymerization is not particularly limited. For example, a compound having one or more hydroxyl groups in the molecule [molecular weight of 32 or more and Mn of 50,000 or less, such as methanol, ethanol, isopropyl alcohol, ethylene glycol, propylene Glycol, polyethylene glycol (molecular weight 106 or more and Mn 50,000 or less) and (poly) ethylene (poly) propylene glycol (molecular weight 120 or more and Mn 50,000 or less)], having one or two or more amino groups in the molecule Examples include compounds [for example, ammonia and amines (C1-30, for example, methylamine, dimethylamine, triethylamine, and propanolamine)] and compounds having one or more thiol groups in the molecule (described later).
Among these, a compound having one or more thiol groups in the molecule is preferable from the viewpoint of molecular weight control.

Compounds having a thiol group in the molecule include the following, salts thereof [alkali metal (for example, lithium, sodium and potassium) salts, alkaline earth metal (for example, magnesium and calcium) salts, ammonium salts, amines (C1- 20) salts and inorganic acids (eg hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid) salts], and mixtures thereof.
(1) Monovalent thiol Aliphatic thiol [C1-20, such as methanethiol, ethanethiol, propanethiol, n-octanethiol, n-dodecanethiol, hexadecanethiol, n-octadecanethiol, 2-mercaptoethanol, mercaptoacetic acid, 3-mercaptopropionic acid, 1-thioglycerol, thioglycolic acid monoethanolamine), 1-thioglycerol, thioglycolic acid monoethanolamine, thiomaleic acid, cysteine and 2-mercaptoethylamine], alicyclic thiols (C5-20) For example, cyclopentanethiol and cyclohexanethiol) and aromatic (aliphatic) thiols (C6-12, such as benzenethiol and benzyl mercaptan and thiosalicylic acid).

(2) polyvalent thiol dithiol [aliphatic (C2-40) dithiol (for example, ethanedithiol, diethylenedithiol, triethylenedithiol, propanedithiol, 1,3- and 1,4-butanedithiol, 1,6-hexanedithiol, Neopentanedithiol, etc.), alicyclic (C5-20) dithiols (eg cyclopentanedithiol and cyclohexanedithiol) and aromatic (C6-16) dithiols (eg benzenedithiol, biphenyldithiol).

  In the case of using the chain transfer agent for radical polymerization, the preferred lower limit is 0.001% based on the total weight of the monomers, more preferably 0.001%, from the viewpoint of obtaining the optimum molecular weight as (A). 005%, particularly preferably 0.01%, most preferably 0.05%, and a preferred upper limit is 10%, more preferably 5%, particularly preferably 3%, most preferably 1%.

The cationic monomer (a) may be polymerized as a cationic salt or may form a salt after polymerization, but after polymerization as a free amine from the viewpoint of polymer solubility during polymerization. It is preferable to form a salt by adding an acid (hydrochloric acid, sulfuric acid, etc.).
The monomer concentration in the monomer solution in the solution dropping polymerization is, based on the total weight of the monomer solution, the lower limit is usually 5%, preferably 10% from the viewpoint of reducing the residual monomer, more preferably 15%, particularly preferably 25%, Most preferably, it is 25%, the upper limit is usually 90%, preferably 85%, more preferably 80%, particularly preferably 75%, most preferably 70% from the viewpoint of temperature control during polymerization.

  The polymerization temperature in the solution dropping polymerization is preferably controlled from the viewpoint of molecular weight control so as to keep the predetermined temperature constant (for example, predetermined temperature ± 5 ° C.). Although the temperature can be controlled by appropriately heating and cooling the reaction vessel, it is preferable to perform drop polymerization at the boiling point of the solvent from the viewpoint that it is easy to keep the predetermined temperature constant. The boiling point of the solvent can be adjusted by the type and pressure of the solvent. The polymerization temperature is usually from 40 to 190 ° C., preferably from 50 to 180 ° C., more preferably from 60 to 170 ° C., particularly preferably from 70 to 160 ° C., and most preferably from 80 to 150 ° C. from the viewpoint of ease of temperature control and safety. It is.

The end point of the reaction can be confirmed when the heat generation due to the polymerization disappears, but the polymerization time is usually 1 to 24 hours from the time when the start of the polymerization is confirmed by the heat generation. From a specific viewpoint, it is preferably 2 to 12 hours.
The monomer concentration, polymerization temperature, and polymerization time can be appropriately adjusted depending on the monomer composition, polymerization method, initiator type, and the like.

  In the case of using an organic solvent as a solvent during polymerization, it is preferable to replace the organic solvent with water after removing the solvent from the viewpoints of the environment and the handling risk when using the product organic coagulant. Solvent removal may be performed by heating at normal pressure or may be performed under reduced pressure. As a method for replacing with water, water may be added at any stage before, during or after the solvent removal.

  The pH of the aqueous solution of the organic coagulant is preferably 1 to 7, more preferably 2 to 6, particularly preferably 3 to 5, from the viewpoint of the solubility of the organic coagulant. (A) is used as an amine salt, and after polymerization to adjust the pH, inorganic acids (for example, hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid), inorganic solid acidic substances (for example, acidic sodium phosphate, acidic sodium nitrate, ammonium chloride) , Ammonium sulfate, ammonium bisulfate and sulfamic acid) and organic acids such as oxalic acid, succinic acid and malic acid. In order to control the pH of the aqueous solution, an inorganic alkaline substance (for example, sodium hydroxide, potassium hydroxide and ammonia) and an organic alkaline substance (for example, guanidine) can be added to adjust the pH. In addition, the said pH is a measured value using the pH meter etc. at room temperature (20 degreeC) about the stock solution of organic coagulant aqueous solution.

  Mn of (A) is preferably 1,000, more preferably 3,000, particularly preferably 5,000 from the viewpoint of setting performance, and 1,000,000, more preferably, from the viewpoint of polymer solubility. 500,000, particularly preferably 200,000. The Mn is a value obtained by GPC measurement with the polymer in a free amine state. The GPC measurement conditions will be described later.

(A) is soluble in water at least at pH 3, preferably at pH 4 or less, more preferably at pH 5 or less, particularly preferably at pH 6 or less. When the pH at which (A) dissolves is limited to less than 3, a large amount of acid is required to lower the pH of sludge and wastewater, and then a large amount of alkali is also required for insolubilization. This is a problem from the viewpoint of reducing the amount of waste sludge.
Further, (A) is present when the insolubilizing pH is between 4 and 10 (preferably 5 to 9, more preferably 5 to 8, particularly preferably 6 to 7). If the pH to be insolubilized is less than 4, when the pH of waste water or sludge is relatively high, when (A) is added, it is insolubilized before uniform mixing and the coagulation action is not effectively exhibited. In addition, when the pH to be insolubilized exceeds 10, the amount of alkali added for insolubilization increases, and it is necessary to neutralize with a large amount of acidic substances when discarding the filtrate after sludge or wastewater treatment. This is a problem from the viewpoint of reducing the amount of waste sludge.

  The organic coagulant of the present invention is usually used in the form of an aqueous solution or dispersion of (A). The content (% by weight) of (A) in the aqueous solution or dispersion is preferably 5 to 80%, more preferably 10 to 75%, particularly preferably 15 to 70% from the viewpoints of industrial and handling properties. It is.

The organic coagulant of the present invention can be used in combination with other coagulants (organic and inorganic coagulants) as long as the effects of the present invention are not impaired in order to further improve the coagulation action.
Other organic coagulants include epichlorohydrin and dimethylamine polycondensate (hydrochloride), polyallylamine (hydrochloride), polyethyleneimine (hydrochloride), polyallylamine hydrochloride, polydiallyldimethylammonium chloride, polydiallylmethylamine hydrochloride Examples thereof include a salt, a copolymer of diallyldimethylammonium chloride and sulfur dioxide, a copolymer of diallyldimethylammonium chloride and acrylamide, and a copolymer of diallylamine hydrochloride and sulfur dioxide. Examples of other inorganic coagulants include aluminum sulfate, polyaluminum chloride, ferric chloride, polyferric sulfate, and slaked lime.

  Further, the organic coagulant of the present invention is selected from the group consisting of an antifoaming agent, a chelating agent, a pH adjusting agent, an antioxidant, an ultraviolet absorber and a preservative, as long as it does not inhibit the effects of the present invention. One or two or more additives can be used in combination.

Antifoaming agents include silicone oil (eg dimethylpolysiloxane with Mn 100-100,000), mineral oil (eg spindle oil, kerosene), C12-22 metal soap (eg calcium stearate);
Examples of chelating agents include C6-12 aminocarboxylic acids (for example, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, hydroxyethylethylenediaminetriacetic acid, nitrilotriacetic acid, triethylenetetraminehexaacetic acid), and polyvalent carboxylic acids [for example, maleic acid, polyacrylic acid. Acid (Mn 1,000-10,000) and isoamylene-maleic acid copolymer (Mn 1,000-10,000)], C3-10 hydroxycarboxylic acids (eg citric acid, gluconic acid, lactic acid, malic acid), Condensed phosphoric acid (for example, tripolyphosphoric acid, trimetaphosphoric acid) and salts thereof [for example, alkali metal (for example, sodium, potassium) salt, alkaline earth metal (for example, calcium, magnesium) salt, ammonium salt, C1-20 alkylamine ( Example, if methylamine, ethylamine, octylamine) salt and alkanolamine C2-12 (e.g. mono -, di- - and triethanolamine) salts];

Examples of pH adjusters include caustic (eg caustic soda), amines (eg mono-, di- and triethanolamine), inorganic acids (salts) [eg inorganic acids (eg hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, sulfamic acid, Carbonates), and their metals [eg alkali metals (same as above) and alkaline earth metals (same as above)] salts (eg sodium carbonate, potassium carbonate, sodium sulfate, sodium hydrogen sulfate, monosodium phosphate) and ammonium Salts (eg ammonium carbonate, ammonium sulfate)], organic acids (salts) [eg organic acids (eg carboxylic acids, sulfonic acids, phenols) and their metal (same as above) salts (eg sodium acetate, sodium lactate) and Ammonium salts (eg ammonium acetate, ammonium lactate)];

  Antioxidants include phenol compounds [eg hydroquinone, methoxyhydroquinone, catechol, 2,6-di-t-butyl-p-cresol (BHT), 2,2′-methylenebis (4-methyl-6-t-butylphenol). )], Sulfur-containing compounds [eg thiourea, tetramethylthiuram disulfide, dimethyldithiocarbamic acid and its salts [eg metal (same as above) salts, ammonium salts], sodium sulfite, sodium thiosulfate, 2-mercaptobenzothiazole and Salts thereof (same as above), dilauryl 3,3′-thiodipropionate (DLTDP), distearyl 3,3′-thiodipropionate (DSTDP)], phosphorus-containing compounds [eg triphenyl phosphite, triethylphos Fight, sodium phosphite, next Sodium phosphate, triphenyl phosphite (TPP), triisodecyl phosphite (TDP)] and nitrogenous compounds [amines (eg octylated diphenylamine, Nn-butyl-p-aminophenol, N, N-diisopropyl- p-phenylenediamine), urea, guanidine, guanidine above-mentioned inorganic acid salt];

Examples of the ultraviolet absorber include benzophenone compounds (for example, 2-hydroxybenzophenone, 2,4-dihydroxybenzophenone), salicylate compounds (for example, phenyl salicylate, 2,4-di-t-butylphenyl-3,5-di-t). -Butyl-4-hydroxybenzoate), benzotriazole compounds [eg (2′-hydroxyphenyl) benzotriazole, (2′-hydroxy-5′-methylphenyl) benzotriazole] and acrylic compounds [eg ethyl-2-cyano- 3,3-diphenyl acrylate, methyl-2-carbomethoxy-3- (paramethoxybenzyl) acrylate];
Examples of the preservative include benzoic acid, paraoxybenzoic acid ester, and sorbic acid.

  The total use amount of the above additives is usually 40% or less, preferably 20% or less, based on the weight of (A), and the use amount of each additive is based on the weight of (A). Is usually 5% or less, preferably 1 to 3%, chelating agent is usually 30% or less, preferably 2 to 10%, pH adjuster is usually 10% or less, preferably 1 to 5%, antioxidant, ultraviolet light Each of the absorbent and the preservative is usually 5% or less, preferably 0.1 to 2%.

  The organic coagulant of the present invention includes various factory wastewater (paper pulp, dyeing, automobile, metal processing, steelmaking, food, gravel collection, wastewater from factories such as semiconductor-related and cleaning industries), sewage, etc. Addition to organic sludge or inorganic sludge generated during treatment reduces specific coagulation, agglomeration effect and clarification of filtrate (COD reduction, decolorization), cake generation and cake moisture content. Show the effect.

Examples of the method for treating sludge or waste water described above using the organic coagulant of the present invention include the following methods.
(1) A method in which an organic coagulant is added to and stirred in sludge or wastewater adjusted to a pH at which (A) dissolves, and after adjusting the pH to be higher than the pH at which (A) is insolubilized, the coagulate is solid-liquid separated. ;
(2) Add organic aggregating agent and inorganic coagulant to sludge or wastewater adjusted to pH at which (A) dissolves, stir, adjust the pH to above the pH at which (A) insolubilizes, and then solidify the coagulated product. A method of liquid separation;
(3) An organic coagulant is added to and stirred in sludge or waste water adjusted to a pH at which (A) dissolves, and then the coagulant is adjusted by adjusting the pH to be higher than the pH at which (A) is insolubilized. A solid-liquid separation in which a coarse floc is formed by adding
(4) After adding and stirring an organic coagulant and an inorganic coagulant to sludge or wastewater adjusted to a pH at which (A) dissolves, adjusting the pH to above the pH at which (A) becomes insoluble, and coagulating , A method in which a polymer flocculant is added to form a coarse floc for solid-liquid separation;
(5) A mixture of an organic coagulant, a polymer coagulant, and, if necessary, an inorganic coagulant is added to sludge or waste water adjusted to a pH at which (A) dissolves, and stirred, and (A) becomes insoluble. A method of solid-liquid separation by adjusting pH above pH to form coarse floc.

Solid-liquid separation methods include, for example, gravity sedimentation, membrane filtration, column filtration, pressurized flotation, concentration devices (eg thickeners), dewatering devices (eg centrifuges, belt press dehydrators, filter press dehydrators, etc.) ) Etc. can be used. As will be described later, when the sludge or wastewater has a high pH and (A) does not dissolve, it is preferable to adjust the pH of the sludge or wastewater before adding the organic coagulant.
Among these processing methods (1) to (5), the processing methods (3) and (4) are preferable from the viewpoint that coarser flocs are formed and solid-liquid separation becomes easy.
When an inorganic coagulant is used in the treatment methods (2), (4) and (5), the inorganic coagulant may be the above-mentioned inorganic coagulant, and two or more kinds may be used in combination. Regarding the organic coagulant, the above-mentioned other organic coagulants can be used in combination with the organic coagulant of the present invention. In any of these combined use, the addition method is not particularly limited. In the combined use of an organic coagulant and an inorganic coagulant, either one of them is added sequentially, added simultaneously, or added in advance. Any of them may be used, and the same applies to the case of using the organic coagulant of the present invention and another organic coagulant.

The polymer flocculant used in the above treatment methods (3) to (5) is not particularly limited, and may be any of cationic, nonionic, anionic, and amphoteric, and these may be used in combination.
Examples of cationic polymer flocculants include polyethyleneimine, poly (meth) acrylamide Mannich modified products, homopolymers of dialkylaminoethyl (meth) acrylate quaternized products, and other monomers such as (meth) acrylamide. Examples thereof include a copolymer and a (co) polymer containing the cationic monomer (a) as a constituent unit.
Examples of nonionic polymer flocculants include polyacrylamide.
Examples of anionic polymer flocculants include sodium poly (meth) acrylate, hydrolyzate of poly (meth) acrylamide, (meth) acrylamide / sodium (meth) acrylate copolymer, (meth) acrylamide / (meth) Sodium acrylate / sodium 2-acrylamido-2-methylpropane-1-sulfonate, sodium (meth) acrylamide / sodium 2-acrylamido-2-methylpropane-1-sulfonate, and other anionic properties described above (Co) polymer containing monomer (c), etc. are mentioned.
Examples of amphoteric polymer flocculants include cationic monomers [dialkylaminoethyl (meth) acrylate quaternized products, other cationic monomers (a) and the like] and anionic monomers [(meth) acrylic acid (salts), 2- Acrylamido-2-methylpropane-1-sulfonic acid (salt), other anionic monomers (c) and the like] and, if necessary, copolymers with nonionic monomers (acrylamide and the like).

Of these, cationic polymer flocculants and amphoteric polymer flocculants are preferred from the viewpoint of having the ability to neutralize the anionic charge of suspended particles in organic sludge treatment.
In addition, anionic polymer flocculants are preferred from the standpoint that they easily react with cationic components such as organic coagulants and inorganic coagulants in the coagulation sedimentation treatment of various factory wastewaters to form coarse flocs and facilitate sedimentation. is there.

The molecular weight of the polymer flocculant is represented by an intrinsic viscosity measured at 30 ° C. in a 1N-NaNO ₃ aqueous solution, and the cationic polymer flocculant is usually 4 to 30 dl / g, and the aggregation performance (floc particle size and floc strength). 5 to 20 dl / g, preferably from 5 to 40 dl / g for nonionic polymer flocculants, and preferably from 8 to 30 dl / g from the same viewpoint; usually from 5 to 40 dl / g for anionic polymer flocculants. From the same viewpoint, it is preferably 8 to 30 dl / g.

  The pH when adding the organic coagulant to sludge or wastewater and the adjusted pH after the addition are adjusted to the pH at which (A) dissolves, and after the addition and stirring of the organic coagulant, the pH is adjusted above the pH at which (A) becomes insoluble Is done. As a result, the effects of the present invention such as coagulation, improved clarity of the filtrate, and reduction of COD can be exhibited more. That is, by adjusting the pH of dissolved (A), (A) is insolubilized, aggregation of the suspension in the wastewater is promoted, and the adsorbed COD component can also be insolubilized.

As a method of adding the organic coagulant to sludge or wastewater, it is preferable that (A) is made into an aqueous solution from the viewpoint of uniform mixing, and then added to sludge or wastewater and sufficiently stirred. It may be added to waste water and stirred and mixed. When (A) is used as an aqueous solution, the concentration of (A) is preferably 0.01 to 20% by weight, more preferably 0.1 to 5% by weight.
Although the dissolution method of (A) and the dilution method after dissolution are not particularly limited, for example, a predetermined amount of (A) is added while stirring water previously weighed using a stirring device such as a jar tester described later. A method of stirring and dissolving for several hours (about 1 to 4 hours) can be employed.

  The amount of organic coagulant used [(A)] varies depending on the type of sludge or wastewater, the content of suspended particles, etc., and is not particularly limited, but the weight of evaporation residue in wastewater and sludge. (Hereinafter abbreviated as TS), from the viewpoint of the effect of improving the clarity of the filtrate, the preferred lower limit is 0.005%, more preferably 0.01%, particularly preferably 0.05%, most preferably 0. The upper limit is preferably 10%, more preferably 8%, particularly preferably 5%, and most preferably 2% from the viewpoint of aggregation performance.

  When inorganic and / or other organic coagulants are added to the wastewater separately from the organic coagulant of the present invention, the amount used is the type of sludge or wastewater, the size of suspended particles, the TS in the wastewater, etc. Depending on the TS in the wastewater, the inorganic coagulant has a preferable lower limit of 0.5%, more preferably 1%, particularly preferably 2%, and sludge generation amount from the viewpoint of improving the clarity of the filtrate. From the viewpoint of reduction, the preferable upper limit is 10%, more preferably 8%, particularly preferably 5%. For other organic coagulants, the preferable lower limit is 0.005% from the viewpoint of improving the clarity of the filtrate, The upper limit is preferably 0.01%, particularly preferably 0.05%, and from the viewpoint of cohesiveness, the upper limit is preferably 5%, more preferably 3%, and particularly preferably 1%.

In the above processing methods (3) to (5), the method for adding the polymer flocculant to the sludge or wastewater treated with the organic coagulant of the present invention is not particularly limited, and the polymer flocculant is added as it is. However, from the viewpoint of uniform mixing, a method in which the polymer flocculant is made into an aqueous solution and then added to the sludge or waste water is preferable. When the polymer flocculant is used as an aqueous solution, the concentration of the polymer flocculant is preferably 0.05 to 1% by weight, more preferably 0.1 to 0.5% by weight.
The dissolution method and the dilution method after dissolution are not particularly limited, and are the same as in the case of the organic coagulant. In particular, when a powdery polymer flocculant is dissolved in water, adding the polymer flocculant all at once is not preferable because it will leave a residue and hardly dissolve in water.

  In the treatment methods (3) to (5) above, the amount of the polymer flocculant used when added to the sludge or wastewater is the kind of sludge or wastewater, the content of suspended particles, and the amount of the polymer flocculant. Depending on the molecular weight and the like, there is no particular limitation, but from the viewpoint of coagulation performance based on TS in the sludge or wastewater, the preferred lower limit is 0.01%, more preferably 0.05%, particularly preferably 0.1%, Most preferably, it is 0.5%. From the same viewpoint, the upper limit is preferably 10%, more preferably 8%, particularly preferably 5%, and most preferably 3%.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In addition, the part in an Example represents a weight part and% represents weight%.
About Mn, solid content of copolymer aqueous solution or dispersion, determination of solubility of copolymer in water at pH 3 and measurement of insolubilization pH, and measurement or determination method for TS in wastewater, etc. This will be described below.
<1> Mn measurement It measured on the following GPC conditions.
(GPC measurement conditions)
Measuring machine: HLC-8220GPC, manufactured by Tosoh Corporation Column: Guardcolumn α, TSKgel α-M
Eluent: DMF LiBr 0.01M
Flow rate: 1 ml / min
Sample concentration: 0.125%
Injection volume: 100 μl
Column temperature: 40 ° C
Calibration curve reference material: polystyrene

<2> Measurement of solid content of aqueous solution or dispersion of copolymer 2 g of an aqueous solution or dispersion of a copolymer was placed in a glass petri dish having a diameter of 80 mm and a depth of 15 mm, and was circulated and dried at 130 ° C. × It is expressed as an evaporation residue (% by weight) after drying for 90 minutes.
<3> Determination of solubility of copolymer in water at pH 3 and measurement of insolubilization pH Add to ion exchange water adjusted to pH 3 with hydrochloric acid so that the solid content of the copolymer is 0.1% and stir. After re-adjusting to pH 3 with hydrochloric acid or sodium hydroxide, the solubility of the copolymer was visually determined. The case where the liquid was colorless and transparent was regarded as dissolved, and the case where precipitation and cloudiness or haze of the liquid were observed was determined to be insoluble, and in Table 1 of Examples described later, it was expressed as follows.

○: Dissolved ×: Insoluble

While stirring the solution, an aqueous sodium hydroxide solution was added to gradually raise the pH, and the pH at which the solution became cloudy was confirmed, and the pH was defined as the insolubilized pH.
<4> TS measurement in wastewater It was performed according to the analysis method described in the sewer test method (Japan Sewerage Association, 1984 version).

  Evaluation of wastewater treatment using the organic coagulant and polymer flocculant of the present invention [1] (floc particle size, sludge volume%, COD, filtrate clarity and cake moisture content), and Evaluation [2] (filtrate clarity, coagulability, decolorization and COD) when the wastewater treatment was performed using only the organic coagulant was according to the following method.

Evaluation [1]
(1) Flock particle size Jar tester [Miyamoto Riken Kogyo Co., Ltd., model JMD-6HS-A, and so on. ] Two plate-shaped PVC stirring blades (horizontal 5 cm, vertical 2 cm, thickness 0.2 cm) are attached to the stirring bar continuously in a vertical shape so as to form a cross, and 500 ml of waste water is taken into a 500 ml beaker. Set on a tester. The rotation number of the jar tester is set to 150 rpm, and while stirring the wastewater slowly, the following predetermined amount of the coagulant aqueous solution is added and further stirred for 1 minute. After adjusting the pH to 7.0 with a 1% sodium hydroxide aqueous solution, a predetermined amount of the polymer flocculant aqueous solution (0.2%) was added (the amount added was the solid content with respect to the wastewater: mg / L), and 2 minutes After stirring, stirring is stopped and the size of the aggregate is visually observed and evaluated (the floc particle size at a rotation speed of 150 rpm is shown in the table).
The addition amount of the coagulant is 8 points of 5, 10, 20, 40, 80, 160, 320 or 640 mg / L, and the following evaluation is made with respect to the addition amount with the largest floc diameter by visual observation.

(2) Sludge volume ratio T-1189 nylon filter cloth [Shikishima Canvas Co., Ltd., circular shape, diameter 9 cm], Nutsche funnel, 500 ml graduated cylinder set, and the total amount of treated water after the above flock particle size test Are filtered at once. The amount of sludge obtained by filtration is measured, and the volume ratio (%) with respect to the total wastewater volume is calculated as sludge volume%.

(3) COD
About the filtrate after filtration by said (2), COD _Mn is measured according to the COD _Mn analysis method described in JIS K-0102 (1998 version).
(4) Filtrate Clarity Absorbance meter [UV-1200, manufactured by Shimadzu Corporation, the same applies to the filtrate after filtration in (2) above. ], The absorbance at wavelengths of 590 nm and 700 nm is measured, and the filtrate clarity is evaluated. The numerical value (%) of absorbance indicates a value when the absorbance of ion-exchanged water is 100%.
(5) Cake moisture content Part of the sludge obtained by filtration in (2) above is taken out with a spatula and dehydrated using a press filter tester. (Pressurizing condition 2 kg / cm ² , 60 seconds) About 3 g of dehydrated cake was weighed (W1) in a petri dish and completely evaporated in a circulating dryer (for example, 8 at 105 ± 5 ° C.) Time) After drying, the cake moisture content is calculated from the following equation, where (W2) is the weight of the dried cake remaining on the petri dish.

Cake moisture content (% by weight) = {(W1) − (W2)} × 100 / (W1)

Evaluation [2]
(1) Supernatant liquid clarity 500 ml of waste water is taken in a 500 ml beaker and set in a jar tester in the same manner as in the evaluation method of [1] (1) above. While rotating the jar tester at 120 rpm and slowly stirring the wastewater, the following predetermined amount of 2% coagulant aqueous solution is added at once and stirred for 30 seconds, and then the pH is adjusted to 7.0 with an aqueous sodium hydroxide solution. Three minutes after adjusting the pH, the clarity of the supernatant is evaluated using an absorptiometer in the same manner as in [1] and (4) above. The addition amount of coagulant (solid content / waste water: unit mg / L) is 8 points of 5, 10, 20, 40, 80, 160, 320 or 640 mg / L. The following evaluations such as evaluation of the supernatant liquid are performed for good addition amounts.
(2) Congeability After the evaluation of (1) above, the measurement liquid is returned to the beaker, and the treated wastewater is then centrifuged (model LC06, TOMY SEIKO CO. LTD. The product is centrifuged at 2,000 rpm for 10 minutes, and the sedimentation sludge (lower layer) volume% with respect to the total wastewater volume is measured to evaluate the setting property. It shows that it is excellent in setting property, so that this volume% is small.
(3) Decolorization of supernatant after centrifugation The supernatant after the centrifugation is measured for absorbance at wavelengths of 430 nm and 700 nm with an absorptiometer to evaluate decolorization. In addition, the numerical value (%) of the absorbance indicates a value when the absorbance of the ion exchange water is 100%.
(4) COD of supernatant after centrifugation
The supernatant after the centrifugation is evaluated in the same manner as in the methods [1] and (3).

Production Example 1
Into a four-necked flask equipped with a stirrer, a temperature sensor, a cooling tube, a dropping funnel and a mantle heater, 112 parts of isopropyl alcohol (hereinafter abbreviated as IPA) and 28 parts of water were added, and heated and refluxed with stirring. From the dropping funnel, 179 parts of IPA as a reaction solvent, 45 parts of water, 2.2 parts of azobisisobutyronitrile (hereinafter abbreviated as AIBN) as a polymerization initiator, N, N-dimethylaminoethyl methacrylate (hereinafter abbreviated as DAM) as a monomer component ) 132 parts and a uniform mixture of 148 parts of styrene were added dropwise to the flask over 4 hours with stirring in the flask at 80 to 85 ° C. After the dropwise addition, the mixture was aged at the same temperature for 2 hours to complete the polymerization, and a homogeneous mixed solution of 76 parts of IPA and 3.6 parts of AIBN was dropped into the flask at 80 to 85 ° C. over 1 hour and aged at the same temperature for 180 minutes. . Thereafter, 87 parts of hydrochloric acid (containing 35% hydrogen chloride) was added dropwise over 1 hour, and the temperature was raised to 100 ° C. to remove IPA. Since the viscosity increases during the removal, 1,185 parts of water is added, and finally 95 parts of a 5% aqueous solution of sodium hydroxide is added and uniformly stirred to adjust the pH to 3.5. 1,720 parts of an aqueous solution of (A1) was obtained. The aqueous solution had a solid content of 19% and Mn of the copolymer before introduction of hydrochloric acid was 9,000. The solubility of (A1) in water at pH 3 was good, and the insolubilized pH was 6.2. The evaluation of the solubility and insolubilization pH of (A1) and (A2), (A3), (Ratio A1), and (Ratio A2), which will be described later, was carried out by determining the solubility at pH 3 of the copolymer in <3> water. And the measurement method of insolubilized pH was followed.

Production Example 2
In Production Example 1, DAM 146 parts, styrene 108 parts, lauryl methacrylate 26 parts were used instead of DAM 132 parts and styrene 148 parts, 87 parts of hydrochloric acid after polymerization and aging, 5% sodium hydroxide for pH adjustment Instead of 95 parts of the aqueous solution, 1,740 parts of an aqueous solution of the copolymer (A2) was obtained in the same manner as in Production Example 1, except that 97 parts of hydrochloric acid and 106 parts of a 5% sodium hydroxide aqueous solution were used. The aqueous solution had a solid content of 19% and Mn of the copolymer before addition of hydrochloric acid was 10,000. The solubility of (A2) in water at pH 3 was good, and the insolubilized pH was 6.8.

Production Example 3
In Production Example 1, in place of 132 parts of DAM and 148 parts of styrene, 135 parts of DAM and 145 parts of lauryl methacrylate were used, 87 parts of hydrochloric acid after polymerization and aging, and 95 parts of 5% aqueous sodium hydroxide solution for pH adjustment. Instead, 1,800 parts of an aqueous solution of the copolymer (A3) was obtained in the same manner as in Production Example 1 except that 89 parts of hydrochloric acid and 97 parts of a 5% aqueous solution of sodium hydroxide were used. The aqueous solution had a solid content of 19% and Mn of the copolymer before addition of hydrochloric acid was 13,000. The solubility of (A3) in water at pH 3 was good, and the insolubilized pH was 6.8.

Production Example 4
In Production Example 1, instead of 132 parts of DAM and 148 parts of styrene, 85 parts of DAM, 166 parts of butyl methacrylate and 29 parts of stearyl acrylate were used, 87 parts of hydrochloric acid after polymerization and aging, sodium hydroxide for pH adjustment Instead of 95 parts of 5% aqueous solution, 1,660 parts of aqueous solution of copolymer (A4) was obtained in the same manner as in Production Example 1, except that 57 parts of hydrochloric acid and 62 parts of sodium hydroxide 5% aqueous solution were used. The aqueous solution had a solid content of 18% and Mn of the copolymer before addition of hydrochloric acid was 13,000. The solubility of (A4) in water at pH 3 was good, and the insolubilized pH was 4.6.

Production Example 5
In Production Example 1, 6.6 parts of AIBN were used instead of 2.2 parts of AIBN, 28 parts of N, N-dimethylaminoethyl acrylate (hereinafter abbreviated as DAA) instead of 132 parts of DAM and 148 parts of styrene, methacrylic acid Except for using 252 parts of butyl, 87 parts of hydrochloric acid after polymerization and aging, and 95 parts of 5% aqueous solution of sodium hydroxide for pH adjustment, except that 20 parts of hydrochloric acid and 22 parts of 5% aqueous solution of sodium hydroxide were used. In the same manner as in Production Example 1, 1,580 parts of an aqueous solution of copolymer (A5) was obtained. The aqueous solution had a solid content of 18% and Mn of the copolymer before addition of hydrochloric acid was 4,000. The solubility of (A5) in water at pH 3 was good, and the insolubilized pH was 4.3.

Production Example 6
In Production Example 1, instead of 132 parts of DAM and 148 parts of styrene, 128 parts of DAA and 152 parts of lauryl methacrylate were used, 87 parts of hydrochloric acid after polymerization and aging, and 95 parts of 5% aqueous sodium hydroxide solution for pH adjustment. Instead, 1,730 parts of an aqueous solution of the copolymer (A6) was obtained in the same manner as in Production Example 1, except that 93 parts of hydrochloric acid and 102 parts of a 5% aqueous solution of sodium hydroxide were used. The aqueous solution had a solid content of 18% and Mn of the copolymer before addition of hydrochloric acid was 15,000. The solubility of (A6) in water at pH 3 was good, and the insolubilized pH was 8.5.

Production Example 7
In Production Example 1, in place of 132 parts of DAM and 148 parts of styrene, 250 parts of DAA and 30 parts of stearyl acrylate were used and replaced with 87 parts of hydrochloric acid after polymerization and aging, and 95 parts of 5% aqueous sodium hydroxide solution for pH adjustment. Then, 1,920 parts of an aqueous solution of the copolymer (A7) was obtained in the same manner as in Production Example 1, except that 182 parts of hydrochloric acid and 199 parts of a 5% aqueous solution of sodium hydroxide were used. The aqueous solution had a solid content of 18% and Mn of the copolymer before addition of hydrochloric acid was 15,000. The solubility of (A7) in water at pH 3 was good, and the insolubilized pH was 9.8.

Production Example 8
In Production Example 1, 118 parts of N, N-diethylaminoethyl methacrylate and 162 parts of lauryl methacrylate were used instead of 132 parts of DAM and 148 parts of styrene, 87 parts of hydrochloric acid after polymerization and aging, and hydroxylation for pH adjustment Instead of 95 parts of 5% aqueous sodium solution, 1,730 parts of aqueous solution of copolymer (A8) were obtained in the same manner as in Production Example 1 except that 67 parts of hydrochloric acid and 73 parts of 5% aqueous sodium hydroxide solution were used. . The aqueous solution had a solid content of 18% and Mn of the copolymer before addition of hydrochloric acid was 10,000. The solubility of (A8) in water at pH 3 was good, and the insolubilized pH was 5.3.

Comparative production example 1
In Production Example 1, instead of 132 parts of DAM and 148 parts of styrene, 280 parts of DAM were used, 87 parts of hydrochloric acid after polymerization and aging, 185 parts of hydrochloric acid instead of 95 parts of 5% aqueous sodium hydroxide solution for pH adjustment, Except for using 202 parts of a 5% aqueous solution of sodium hydroxide, 1,930 parts of an aqueous solution of a copolymer (ratio A1) was obtained in the same manner as in Production Example 1. The aqueous solution had a solid content of 18% and Mn of the copolymer before addition of hydrochloric acid was 15,000. Although the solubility of (Ratio A1) in water at pH 3 was good, the insolubilized pH did not exist between pH 4 and 10, and dissolved even when it was raised to pH 14.

Comparative production example 2
In Production Example 1, instead of 132 parts of DAM and 148 parts of styrene, 32 parts of DAM and 248 parts of styrene were used, and instead of 87 parts of hydrochloric acid after polymerization and aging, 95 parts of 5% aqueous sodium hydroxide solution for pH adjustment, A copolymer (ratio A2) dispersion 1,580 parts was obtained in the same manner as in Production Example 1, except that 21 parts of hydrochloric acid and 23 parts of a 5% aqueous solution of sodium hydroxide were used. In the dispersion, an insoluble precipitate of the copolymer was observed. The dispersion had a solid content of 18% and Mn of the copolymer before addition of hydrochloric acid was 8,000. (Ratio A2) was not dissolved in water at pH 3, and a white precipitate was formed. Even when the pH was increased from 3 to 14, the white precipitate did not dissolve.

Comparative production example 3
In Production Example 1, instead of 132 parts of DAM and 148 parts of styrene, 262 parts of DAA and 18 parts of stearyl acrylate were used, and 87 parts of hydrochloric acid after polymerization and aging, and 95 parts of 5% aqueous sodium hydroxide solution for pH adjustment were used. In the same manner as in Production Example 1 except that 191 parts of hydrochloric acid and 209 parts of a 5% sodium hydroxide aqueous solution were used, 1,940 parts of an aqueous solution of the copolymer (ratio A3) were obtained. The aqueous solution had a solid content of 18% and Mn of the copolymer before addition of hydrochloric acid was 15,000. The solubility of (Ratio A3) in water at pH 3 was good, and the insolubilized pH was 10.3.

Comparative production example 4
In Production Example 1, 6.6 parts of AIBN was used instead of 2.2 parts of AIBN, and 20 parts of DAA and butyl methacrylate were used instead of 132 parts of DAM and 148 parts of styrene, and 87 parts of hydrochloric acid after polymerization and aging. A copolymer (ratio A4) was prepared in the same manner as in Production Example 1 except that 15 parts of hydrochloric acid and 16 parts of 5% aqueous sodium hydroxide solution were used instead of 95 parts of 5% aqueous sodium hydroxide solution for pH adjustment. An aqueous solution of 1,570 parts was obtained. The aqueous solution had a solid content of 18% and Mn of the copolymer before addition of hydrochloric acid was 4,000. The solubility of (Ratio A4) in water at pH 3 was good, and the insolubilized pH was 3.7.

  Table 1 shows the compositions of (A1) to (A8) and (Ratio A1) to (Ratio A4), solubility at pH 3, insolubilized pH, solid content, and Mn. The aqueous solutions or dispersions of (A1) to (A8), (Ratio A1), (Ratio A3), and (Ratio A4) were each used as an organic coagulant in the following Examples and Comparative Examples for evaluation. (Ratio A2) cannot be used as an organic coagulant because it does not dissolve in water having a pH of 3 or more and does not form a uniform liquid.

DAM: N, N-dimethylaminoethyl methacrylate DAA: N, N-dimethylaminoethyl acrylate DEAM: N, N-diethylaminoethyl methacrylate St: styrene C4MA: butyl methacrylate C12MA: lauryl methacrylate C18A: stearyl acrylate ( * 1) Dissolved at pH 3-14.
(* 2) Not dissolved at pH 3-14.

Example 1
500 ml of waste water collected from H dyeing factory [pH 5.0, TS 0.8%, COD _Mn 1,000 mg / L] is put into a 500 ml beaker, set in a jar tester, organic coagulant (A1) and polymer flocculant Waste water treatment was performed using the above and evaluated by the method of the evaluation [1]. In the wastewater treatment, (A1) is used as an aqueous solution having a solid content of 2%, and an anionic polymer flocculant [trade name “Sunfloc AH2025P”, manufactured by Sanyo Chemical Industries, Ltd.] is used as the polymer flocculant. It was dissolved in ion exchange water and used as an aqueous solution having a solid content of 0.2%. The results are shown in Table 2.
Examples 2-8
In Example 1, it evaluated similarly to Example 1 except having used each of (A2)-(A8) instead of (A1). The results are shown in Table 2.
Comparative Examples 1-6
In Example 1, instead of (A1), (ratio A1), polydiallyldimethylammonium chloride [trade name “SWIFLOK SR-2000”, manufactured by Suirei Co., Ltd., and so on. ], Polyaluminum chloride (aluminum oxide 10-11% product) [trade name “polyaluminum chloride”, manufactured by Kayaku Kagaku Co., Ltd. ] Or sulfuric acid band (8% alumina product) [trade name “Liquid Aluminum Sulfate”, manufactured by Asahi Chemical Industry Co., Ltd., the same shall apply hereinafter. ], (Ratio A3), and (ratio A4), and polyaluminum chloride or sulfuric acid band was evaluated in the same manner as in Example 1 except that each was used as a 2% aqueous solution with a solid content. The results are shown in Table 2.

(* 1) SWIFLOCK SR-2000
(* 2) The amount added is the solid content of the organic coagulant, polyaluminum chloride or wastewater.
The sulfate band represents the amount of solid, and the unit is mg / L.

  From Table 2, in Examples 1-8, compared to Comparative Examples 1-6, the floc particle size, the COD and clarity of the filtrate are excellent, the amount of sludge is small, and the moisture content of the cake is low. It turns out that it can reduce more.

Example 9
Waste water collected from the M dyeing factory [pH 5.2, TS 0.06% COD _Mn 930 mg / L] was treated with the organic coagulant (A1) and evaluated by the method of the evaluation [2]. In the wastewater treatment, (A1) was used as an aqueous solution having a solid content of 2%. The results are shown in Table 3.
Examples 10-16
In Example 9, evaluation was performed in the same manner as in Example 9 except that (A2) to (A8) were used instead of (A1). The results are shown in Table 3.
Comparative Examples 7-13
In Example 9, in place of (A1), (ratio A1), polydiallyldimethylammonium chloride, polyaluminum chloride or sulfate band, (ratio A3), (ratio A4) were used. Each was evaluated in the same manner as in Example 1 except that each was used as an aqueous solution having a solid content of 2%. The results are shown in Table 3.

(* 1) SWIFLOCK SR-2000
(* 2) The amount added is the solid content of the organic coagulant, polyaluminum chloride or wastewater.
The sulfate band represents the amount of solid, and the unit is mg / L.

  It can be seen from Table 3 that all of the organic coagulants of Examples 9 to 16 are superior in terms of supernatant liquid clarity, coagulability, decoloring property, and COD as compared with the comparative examples.

  The organic coagulant of the present invention is used for COD reduction treatment of paper mill wastewater and the like, and for decolorization of coloring components, as well as dye fixing agents, paper making agents (for example, paper industry industrial formation forming aid, drainage yield) Improvers, drainage improvers and paper strength enhancers), sludge dehydration treatment agents, dispersants, scale inhibitors, antistatic agents and fiber treatment agents.

Claims (3)

A cationic monomer (a) represented by the following general formula (1), a monovalent (meth) acryloyl group-containing compound and an aromatic ring-containing monovalent vinyl having a solubility in water at 20 ° C. of 1 g / 100 g or less of water A copolymer having one or two or more hydrophobic monomers (b) selected from the group consisting of compounds as constituent units, dissolved in water at least at pH 3, and insoluble in water between pH 4 and 10 An organic coagulant comprising (A).

^{_{CH 2 = CR 1 -CO-X}} -Q-N + R 2 R 3 R 4 · Z - (1)

[Wherein X is O or NH; Q is an alkylene group having 2 to 4 carbon atoms or a hydroxyalkylene group having 2 to 4 carbon atoms; R ¹ is H or a methyl group; R ² , R ³ and R ⁴ are each independently selected. And H, an alkyl, arylalkyl or alkylaryl group having 1 to 16 carbon atoms; Z ⁻ represents a counter anion. ] The organic coagulant according to claim 1, wherein the proportion of (a) in (A) is 10 to 95 mol% and the proportion of (b) is 90 to 5 mol%. The organic coagulant according to claim 1 or 2 is added to sludge or wastewater adjusted to a pH at which (A) dissolves, and the pH of sludge or wastewater exceeds the pH in the range of 4 to 10 at which (A) becomes insoluble. After the adjustment, a polymer flocculant is added to form flocs, and solid-liquid separation is performed. A method for treating sludge or wastewater.