Water treatment agent, water treatment agent kit, and water treatment method

Abstract

The present invention is a water treatment agent containing a cationic surfactant having at least one aliphatic hydrocarbon group and at least one quaternary nitrogen atom, the cationic surfactant having a chemical formula amount or a number average molecular weight of 500 or less, a cation charge density of 2.0-5.0 meq / g, and a carbon number of 6-18. According to the present invention, it is possible to provide a water treatment agent having an excellent effect of reducing a water-soluble COD component.

Description

Water treatment chemical, water treatment chemical kit and water treatment method

[0001] The present invention relates to a water treatment chemical, a water treatment chemical kit, and a water treatment method.

[0002] Wastewater generated after the cleaning process in factories that handle various products (chemical products, food, pharmaceuticals, electronic materials, and machinery) and dry cleaning factories contains soluble COD components such as surfactants. As a method for removing soluble COD components contained in industrial wastewater, a method has been proposed in which a cationic polymer flocculant is used as a water treatment chemical to reduce the water solubility of the soluble COD and coarsen precipitated fine particles by flocculation, thereby removing the soluble COD components (Patent Document 1).

[0003] However, the method described in Patent Document 1 was insufficient in reducing soluble COD components (also called water-soluble COD components).

[0004] Patent No. 5867125

[0005] The present invention has been made in consideration of the above-mentioned problems of the conventional technology, and an object of the present invention is to provide a water treatment chemical, a water treatment chemical kit, and a water treatment method that have a more effective effect of reducing water-soluble COD components than conventional methods.

[0006] The present inventors have conducted extensive research to solve the above problems and have arrived at the present invention, which is a water treatment agent containing a cationic surfactant having a chemical formula weight or number average molecular weight of 500 or less, a cationic charge density of 2.0 to 5.0 meq / g, and having at least one aliphatic hydrocarbon group having 6 to 18 carbon atoms and at least one quaternary nitrogen atom.

[0007] The present invention also provides a water treatment kit comprising: a first water treatment agent containing a cationic surfactant having a chemical formula weight or number average molecular weight of 500 or less, a cationic charge density of 2.0 to 5.0 meq / g, and having at least one aliphatic hydrocarbon group having 6 to 18 carbon atoms and at least one quaternary nitrogen atom; and a second water treatment agent containing a cationic polymer having a cationic monomer (m1) as a constituent monomer, a weight average molecular weight of 10,000 to 1,000,000, and a colloid equivalent value of 0.1 to 6.5 meq / g, wherein the cationic monomer (m1) comprises at least one monomer selected from the group consisting of cationic monomers (m11) represented by the following general formula (i) and cationic monomers (m12) represented by the following general formula (ii): CH ２ = C(R ｉ １ )-CO-X ｉ -Q-N ＋ (R ｉ ２ ) ３ ・Z － (i) [wherein, R ｉ １ is a hydrogen atom or a methyl group, and there are three R ｉ ２ are each independently a hydrogen atom, an alkyl group having 1 to 22 carbon atoms, or a benzyl group; ｉ is an oxygen atom or an imino group, Q is an alkylene group having 1 to 6 carbon atoms, and Z － represents a monovalent anion.] (CH ２ = C(R ｉ ３ )-CH ２ ) ２ -N ＋ (R ｉ ４ ) ２ ・Z － (ii) [wherein, R ｉ ３ is a hydrogen atom or a methyl group, and there are two R ｉ ４ are each independently a hydrogen atom, an alkyl group having 1 to 22 carbon atoms, or a benzyl group; Z － represents a monovalent anion.

[0008] The present invention also provides a water treatment method comprising: a step of adding an inorganic flocculant to water to be treated (first adding step); and a step of adding a cationic surfactant having a chemical formula weight or number average molecular weight of 500 or less, a cationic charge density of 2.0 to 5.0 meq / g, and having at least one aliphatic hydrocarbon group having 6 to 18 carbon atoms and at least one quaternary nitrogen atom to the water to be treated (second adding step).

[0009] The water treatment chemical, water treatment chemical kit, and water treatment method of the present invention have a more effective effect of reducing water-soluble COD components than conventional methods.

[0010] <Water Treatment Agent> The water treatment agent according to the present embodiment includes a cationic surfactant having a chemical formula weight or number average molecular weight of 500 or less, a cationic charge density of 2.0 to 5.0 meq / g, and having at least one aliphatic hydrocarbon group having 6 to 18 carbon atoms and at least one quaternary nitrogen atom.

[0011] [Cationic Surfactant] The cationic surfactant may be any surfactant having a chemical formula weight or number average molecular weight of 500 or less, a cationic charge density of 2.0 to 5.0 meq / g, and having at least one aliphatic hydrocarbon group having 6 to 18 carbon atoms and at least one quaternary nitrogen atom.

[0012] The cationic surfactant has a chemical formula weight or number average molecular weight of 500 or less. If the chemical formula weight or number average molecular weight is greater than 500, the cationic surfactant will have insufficient solubility in water, making it difficult to form a complex with water-soluble COD components, and the effect of reducing water-soluble COD components will be reduced. From the viewpoint of the effect of reducing water-soluble COD components, the chemical formula weight or number average molecular weight is preferably 150 or more and 500 or less.

[0013] The number average molecular weight of the cationic surfactant can be measured by high performance liquid chromatography under the following conditions: [Measurement conditions] Column: TSK-GEL LS410 [length 200 mm x inner diameter 6 mm (particle size: 5 μm), manufactured by Tosoh Corporation] Eluent: 1 M sodium perchlorate dissolved in a methanol / water (85 / 15) mixed solution, adjusted to pH 2.5 with phosphoric acid Flow rate: 15 ml / min Sample injection amount: 10 to 20 μl of 0.5 to 1.0% methanol solution Detector: RI

[0014] The cationic surfactant has a cationic charge density of 2.0 to 5.0 meq / g. If the cationic charge density is less than 2.0 meq / g, the cationic surfactant will have insufficient solubility in water, making it difficult to form a complex with water-soluble COD components, resulting in a reduced effect of reducing water-soluble COD components. If the cationic charge density is greater than 5.0 meq / g, the water solubility of the complex between the cationic surfactant and water-soluble COD components will be high, making it difficult for the complex to precipitate, resulting in a reduced effect of reducing water-soluble COD components.

[0015] The cationic charge density of the cationic surfactant is 2.0 to 5.0, preferably 2.0 to 4.5, and more preferably 2.0 to 4.0, from the viewpoint of the effect of reducing soluble COD components. In this specification, the term "cationic charge density" refers to the number of positive charges (N ＋ The cationic charge density of the cationic surfactant can be calculated, for example, according to the following formula (1): Cationic charge density (meq / g) = 1,000 × number of quaternary nitrogen atoms per mole of the cationic surfactant / (chemical formula weight or number average molecular weight of the cationic surfactant) (1)

[0016] The cationic surfactant has at least one aliphatic hydrocarbon group having 6 to 18 carbon atoms and at least one quaternary nitrogen atom.

[0017] From the viewpoint of the effect of reducing soluble COD components, the aliphatic hydrocarbon group having 6 to 18 carbon atoms contained in the cationic surfactant is preferably a branched or linear alkyl group having 6 to 18 carbon atoms, more preferably a linear alkyl group having 6 to 18 carbon atoms (such as an n-hexyl group, an n-octyl group, an n-decyl group, an n-dodecyl group, an n-tetradecyl group, an n-hexadecyl group, or an n-octadecyl group), and even more preferably an n-hexadecyl group or an n-octadecyl group. Furthermore, from the viewpoint of the effect of reducing soluble COD components, the number of aliphatic hydrocarbon groups having 6 to 18 carbon atoms contained in the cationic surfactant is preferably one.

[0018] It is presumed that linear alkyl groups have stronger intermolecular forces than branched alkyl groups with the same number of carbon atoms, and therefore tend to associate with each other, resulting in a larger particle size of the complex between the water-soluble COD components and the cationic surfactant, making the complex more likely to separate as a precipitate. Therefore, it is presumed that a linear alkyl group is more effective in reducing water-soluble COD components than a branched alkyl group when the aliphatic hydrocarbon group having 6 to 18 carbon atoms contained in the cationic surfactant is.

[0019] The number of quaternary nitrogen atoms contained in the cationic surfactant is preferably 1 to 2, more preferably 1, from the viewpoint of the effect of reducing soluble COD components.

[0020] Preferred examples of the cationic surfactant include quaternary ammonium salts represented by the following general formulas (1) to (5). [In formula (1), n １ is an integer from 5 to 17, and R １ ~R ３ each independently represents a methyl group, an ethyl group, a propyl group, or a butyl group; X １ － is a monovalent anion.

[0021] [In formula (2), n ２ and n ３ are each independently an integer of 5 to 17, and X ２ －is a monovalent anion.

[0022] [In formula (3), n ４ is an integer from 2 to 16, and R ４ ~R ９ are each independently an aliphatic hydrocarbon group having 1 to 18 carbon atoms, and R ４ ~R ９ At least one of X is an aliphatic hydrocarbon group having 6 to 18 carbon atoms; ３ － is a monovalent anion.

[0023] [In formula (4), n ５ is an integer from 5 to 17, and X ４ － is a monovalent anion.

[0024] [In formula (5), n ６ is an integer of 5 to 17, Y is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and X ５ － is a monovalent anion.

[0025] Hereinafter, the quaternary ammonium salt having the structure represented by the general formula (1) will be referred to as compound (A1), the quaternary ammonium salt having the structure represented by the general formula (2) will be referred to as compound (A2), the quaternary ammonium salt having the structure represented by the general formula (3) will be referred to as compound (A3), the quaternary ammonium salt having the structure represented by the general formula (4) will be referred to as compound (A4), and the quaternary ammonium salt having the structure represented by the general formula (5) will be referred to as compound (A5).

[0026] [Compound (A1)] The compound (A1) has a structure represented by the general formula (1).

[0027] In the general formula (1), n １ is an integer from 5 to 17. １If n is 4 or less, the water solubility of the complex of the cationic surfactant and the water-soluble COD components becomes high, the complex is difficult to precipitate, and the effect of reducing the water-soluble COD components decreases. On the other hand, if n is 18 or more, the solubility of the cationic surfactant in water is insufficient, making it difficult to form a complex with the water-soluble COD components, and the effect of reducing the water-soluble COD components decreases. １ is preferably 11 to 17 from the viewpoint of the effect of reducing water-soluble COD components.

[0028] In the general formula (1), CH ３ (CH ２ ) n １ Examples of the linear alkyl group having 6 to 18 carbon atoms represented by the formula (I) include an n-hexyl group, an n-octyl group, an n-decyl group, an n-dodecyl group, an n-tetradecyl group, an n-hexadecyl group, and an n-octadecyl group, with an n-hexadecyl group and an n-octadecyl group being preferred.

[0029] In the general formula (1), R １ ~R ３ are each independently a methyl group, an ethyl group, a propyl group, or a butyl group, and from the viewpoint of the effect of reducing soluble COD components, a methyl group is preferred.

[0030] In the general formula (1), X １ － is a monovalent anion. １ － Examples of monovalent anions represented by the formula (I) include conjugate bases of Bronsted acids. Bronsted acids include inorganic acids and organic acids. Inorganic acids include hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid, and nitric acid. Organic acids include sulfonic acids, carboxylic acids, and phosphonic acids. Examples of sulfonic acids include methylsulfonic acid, dodecylbenzenesulfonic acid, and naphthalenesulfonic acid. Examples of carboxylic acids include oxalic acid, acetic acid, and maleic acid. Examples of phosphonic acids include methylphosphonic acid and phenylphosphonic acid.

[0031] X １ －From the viewpoint of the effect of reducing water-soluble COD components, the monovalent anion represented by the formula (1) is preferably a conjugate base of hydrochloric acid (X １ － is Cl － ), a conjugate base of hydrobromic acid (X in general formula (1) １ － Br － ), or a conjugate base of sulfuric acid (X in the general formula (1) １ － HSO ４ － In addition, X in the general formula (1) is preferably １ － The anion represented by the formula (1) may be an anion introduced by a salt exchange reaction using a Bronsted acid, or may be an anion generated by elimination from a quaternizing agent (methyl chloride, dimethyl sulfate, benzyl chloride, etc.) used in synthesizing the cationic surfactant represented by the formula (1).

[0032] Examples of cations constituting the quaternary ammonium salt represented by the compound (A1) include a hexyltrimethylammonium ion, a heptyltrimethylammonium ion, an octyltrimethylammonium ion, a nonyltrimethylammonium ion, a decyltrimethylammonium ion, an undecyltrimethylammonium ion, a dodecyltrimethylammonium ion (also known as a lauryltrimethylammonium ion), a tridecyltrimethylammonium ion, a tetradecyltrimethylammonium ion (also known as a myristyltrimethylammonium ion), a pentadecyltrimethylammonium ion, a hexadecyltrimethylammonium ion, a heptadecyltrimethylammonium ion, and an octadecyltrimethylammonium ion (also known as a trimethylstearylammonium ion). From the viewpoint of the effect of reducing water-soluble COD components, the octyltrimethylammonium ion, a dodecyltrimethylammonium ion, a tetradecyltrimethylammonium ion, a hexadecyltrimethylammonium ion, a stearyltrimethylammonium ion, and an octadecyltrimethylammonium ion (also known as a trimethylstearylammonium ion) are preferred.

[0033] The compound (A1) is preferably octyltrimethylammonium chloride, dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, stearyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, octadecyltrimethylammonium chloride, octadecyltrimethylammonium bromide, or hexadecyltrimethylammonium hydroxide.

[0034] [Compound (A2)] The compound (A2) has a structure represented by the general formula (2).

[0035] In the general formula (2), n ２ and n ３ is an integer from 5 to 17. ２ and n ３If n is 4 or less, the water solubility of the complex of the cationic surfactant and the water-soluble COD components becomes high, the complex is difficult to precipitate, and the effect of reducing the water-soluble COD components decreases. ２ and n ３ If n is 18 or more, the cationic surfactant will have insufficient solubility in water, making it difficult to form a complex with the water-soluble COD components, resulting in a decrease in the effect of reducing the water-soluble COD components. ２ and n ３ is preferably 11 to 17 from the viewpoint of the effect of reducing water-soluble COD components, ２ and n ３ are preferably the same.

[0036] In the general formula (2), CH ３ (CH ２ ) n ２ and CH ３ (CH ２ ) n ３ Examples of the linear alkyl group having 6 to 18 carbon atoms represented by the formula (I) include an n-hexyl group, an n-octyl group, an n-decyl group, an n-dodecyl group, an n-tetradecyl group, an n-hexadecyl group, and an n-octadecyl group, with an n-hexadecyl group and an n-octadecyl group being preferred.

[0037] In the general formula (2), X ２ － is a monovalent anion, and the monovalent anion is X in the general formula (1). １ － The same anions as those mentioned above can be mentioned, and the preferred anions are also the same as those mentioned above.

[0038] Examples of the cation constituting the quaternary ammonium salt represented by the compound (A2) include a hexyldimethyloctylammonium ion, a didecyldimethylammonium ion, a didodecyldimethylammonium ion, and a ditetradecyldimethylammonium ion. From the viewpoint of the effect of reducing water-soluble COD components, the didecyldimethylammonium ion is preferred.

[0039] As the compound (A2), hexyldimethyloctylammonium chloride, didecyldimethylammonium chloride, didecyldimethylammonium bromide, didodecyldimethylammonium chloride, ditetradecyldimethylammonium chloride and didodecyldimethylammonium bromide are preferred.

[0040] [Compound (A3)] The compound (A3) has a structure represented by the general formula (3).

[0041] In the general formula (3), n ４ is an integer from 2 to 16. ４ If n is 1 or less, the water solubility of the complex of the cationic surfactant and the water-soluble COD components becomes high, the complex is difficult to precipitate, and the effect of reducing the water-soluble COD components decreases. On the other hand, if n is 17 or more, the solubility of the cationic surfactant in water is insufficient, making it difficult to form a complex with the water-soluble COD components, and the effect of reducing the water-soluble COD components decreases. ４ is preferably 2 to 16 from the viewpoint of the effect of reducing water-soluble COD components.

[0042] In the general formula (3), (CH ２ ) n ４ Examples of the alkylene group having 2 to 16 carbon atoms represented by the formula (I) include an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, a nonylene group, a decylene group, an undecylene group, and a dodecylene group, and an ethylene group, a propylene group, a butylene group, a hexylene group, an octylene group, a decylene group, and a dodecylene group are preferred.

[0043] In the general formula (3), R ４ ~R ９ each independently represents an aliphatic hydrocarbon group having 1 to 18 carbon atoms; R ４ ~R ９At least one of the groups is an aliphatic hydrocarbon group having 6 to 18 carbon atoms. Examples of the aliphatic hydrocarbon group having 1 to 18 carbon atoms include a methyl group, an ethyl group, and a branched or linear alkyl group having 3 to 18 carbon atoms, and examples of the branched alkyl group having 3 to 18 carbon atoms include the following alkyl groups: Branched alkyl groups having 3 carbon atoms: isopropyl group Branched alkyl groups having 4 carbon atoms: 1-methylpropyl group (sec-butyl group), 2-methylpropyl group, and 1,1-dimethylethyl group (tert-butyl group) Branched alkyl groups having 5 carbon atoms: 1-methylbutyl group, 1,1-dimethylpropyl group, 1,2-dimethylpropyl group, and 2,2-dimethylpropyl group (neopentyl group) Branched alkyl groups having 6 carbon atoms: 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, 1,1-dimethylbutyl group, 1,2-dimethylbutyl group, 1,3-dimethylbutyl group, 2,2-dimethylbutyl group, 2,3-dimethylbutyl group, 1-ethylbutyl group, and 2-ethylbutyl group Branched alkyl groups having 7 carbon atoms: 1-methylhexyl group, 2-methylhexyl group, 3-methylhexyl group, 4-methylhexyl group, 5-methylhexyl group, 1-ethylpentyl group, 2-ethylpentyl group, 3-ethylpentyl group, 1,1-dimethylpentyl group, 1,2-dimethylpentyl group, 1,3-dimethylpentyl group, 2,2-dimethylpentyl group, and 2,3-dimethylpentyl group. Branched alkyl groups having 8 carbon atoms: 1-methylheptyl group, 2-methylheptyl group, 3-methylheptyl group, 4-methylheptyl group, 5-methylheptyl group, 6-methylheptyl group, 1,1-dimethylhexyl group, 1,2-dimethylhexyl group, 1,3-dimethylhexyl group, 1,4-dimethylhexyl group, 1,5-dimethylhexyl group, 1-ethylhexyl group, and 2-ethylhexyl group. Branched alkyl groups having 9 carbon atoms: 1-methyloctyl group, 2-methyloctyl group, 3-methyloctyl group, 4-methyloctyl group, 5-methyloctyl group, 6-methyloctyl group, 7-methyloctyl group, 1,1-dimethylheptyl group, 1,2-dimethylheptyl group, 1,3-dimethylheptyl group, 1,4-dimethylheptyl group, 1,5-dimethylheptyl group, 1,a 6-dimethylheptyl group, a 1-ethylheptyl group, a 2-ethylheptyl group, etc. Branched alkyl groups having 10 carbon atoms: a 1-methylnonyl group, a 2-methylnonyl group, a 3-methylnonyl group, a 4-methylnonyl group, a 5-methylnonyl group, a 6-methylnonyl group, a 7-methylnonyl group, a 8-methylnonyl group, a 1,1-dimethyloctyl group, a 1,2-dimethyloctyl group, a 1,3-dimethyloctyl group, a 1,4-dimethyloctyl group, a 1,5-dimethyloctyl group, a 1,6-dimethyloctyl group, a 1,7-dimethyloctyl group, a 1-ethyloctyl group, a 2-ethyloctyl group, etc. Branched alkyl groups having 11 carbon atoms: 1-methyldecyl group, 2-methyldecyl group, 3-methyldecyl group, 4-methyldecyl group, 5-methyldecyl group, 6-methyldecyl group, 7-methyldecyl group, 8-methyldecyl group, 9-methyldecyl group, 1,1-dimethylnonyl group, 1,2-dimethylnonyl group, 1,3-dimethylnonyl group, 1,4-dimethylnonyl group, 1,5-dimethylnonyl group, 1,6-dimethylnonyl group, 1,7-dimethylnonyl group, 1,8-dimethylnonyl group, 1-ethylnonyl group, 2-ethylnonyl group, etc. Branched alkyl groups having 12 carbon atoms: 1-methylundecyl group, 2-methylundecyl group, 3-methylundecyl group, 4-methylundecyl group, 5-methylundecyl group, 6-methylundecyl group, 7-methylundecyl group, 8-methylundecyl group, 9-methylundecyl group, 10-methylundecyl group, 1,1-dimethyldecyl group, 1,2-dimethyldecyl group, 1,3-dimethyldecyl group, 1,4-dimethyldecyl group, 1,5-dimethyldecyl group, 1,6-dimethyldecyl group, 1,7-dimethyldecyl group, 1,8-dimethyldecyl group, 1,9-dimethyldecyl group, 1-ethyldecyl group, 2-ethyldecyl group, etc. Branched alkyl groups having 13 carbon atoms: 1-methyldodecyl group, etc. Branched alkyl groups having 14 carbon atoms: 7-ethyl-2-methyl-4-undecyl group, etc. Branched alkyl groups having 15 carbon atoms: 14-methylpentadecyl group, etc. Branched alkyl groups having 16 carbon atoms: 2-hexyldecyl group, 10-ethyl-7-tetradecyl group, etc. Branched alkyl groups having 18 carbon atoms: 16-methylheptadecyl group, 7-methylheptadecyl group, etc.

[0044] Examples of the linear alkyl group having 3 to 18 carbon atoms include an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-decyl group, an n-dodecyl group, an n-tetradecyl group, an n-hexadecyl group, and an n-octadecyl group. From the viewpoint of the effect of reducing water-soluble COD, the alkyl group having 1 to 18 carbon atoms is preferably a linear alkyl group having 3 to 18 carbon atoms, and an n-decyl group, an n-dodecyl group, an n-tetradecyl group, an n-hexadecyl group, and an n-octadecyl group are more preferred.

[0045] In the general formula (3), X ３ － is a monovalent anion, and the monovalent anion is X in the general formula (1). １ The same anions as those mentioned above can be mentioned, and the preferred anions are also the same.

[0046] Examples of the cation constituting the quaternary ammonium salt represented by the compound (A3) include N,N'-dihexyl-N,N,N',N'-tetramethyl-ethylenediammonium ion, N,N'-dioctyl-N,N,N',N'-tetramethyl-ethylenediammonium ion, N,N'-didecyl-N,N,N',N'-tetramethyl-ethylenediammonium ion, N,N'-dioctadecyl-N,N,N',N'-tetramethyl-ethylenediammonium ion, N,N'-dihexyl-N,N,N',N'-tetramethyl-1,3-propane ... Ammonium ion, N,N'-dioctyl-N,N,N',N'-tetramethyl-1,3-propanediammonium ion, N,N'-didecyl-N,N,N',N'-tetramethyl-1,3-propanediammonium ion, N,N'-dioctadecyl-N,N,N',N'-tetramethyl-1,3-propanediammonium ion, N,N'-dihexyl-N,N,N',N'-tetramethyl-1,4-butanediammonium ion, N,N'-dioctyl-N,N,N',N'-tetramethyl-1,4-butanediammonium ion, N,N' -didecyl-N,N,N',N'-tetramethyl-1,4-butanediammonium ion, N,N'-dioctadecyl-N,N,N',N'-tetramethyl-1,4-butanediammonium ion, N,N'-dihexyl-N,N,N',N'-tetramethyl-1,8-octanediammonium ion, N,N'-dioctyl-N,N,N',N'-tetramethyl-1,8-octanediammonium ion, N,N'-didecyl-N,N,N',N'-tetramethyl-1,8-octanediammonium ion, N,N'-dioctadecyl-N,N,N' ,N'-tetramethyl-1,8-octanediammonium ion, N,N'-dihexyl-N,N,N',N'-tetramethyl-1,10-decanediammonium ion, N,N'-dioctyl-N,N,N',N'-tetramethyl-1,10-decanediammonium ion, N,N'-didecyl-N,N,N',N'-tetramethyl-1,10-decanediammonium ion, and N,N'-dioctadecyl-N,N,N',N'-tetramethyl-1,10-decanediammonium ion. From the viewpoint of the effect of reducing water-soluble COD components, N,N'-didecyl-N,N,N',N'-tetramethyl-1,3-propanediammonium ion is preferred.

[0047] The compound (A3) is preferably N,N'-didecyl-N,N,N',N'-tetramethyl-1,3-propanediammonium dichloride.

[0048] [Compound (A4)] The compound (A4) has a structure represented by the general formula (4).

[0049] In the general formula (4), n ５ is an integer from 5 to 17. ５ If n is 4 or less, the water solubility of the complex of the cationic surfactant and the water-soluble COD components becomes high, the complex is difficult to precipitate, and the effect of reducing the water-soluble COD components decreases. If n is 18 or more, the solubility of the cationic surfactant in water is insufficient, making it difficult to form a complex with the water-soluble COD components, and the effect of reducing the water-soluble COD components decreases. ５ is preferably 11 to 17 from the viewpoint of the effect of reducing water-soluble COD components.

[0050] In the general formula (4), CH ３ (CH ２ ) n ５ Examples of the linear alkyl group having 6 to 18 carbon atoms represented by the formula (I) include an n-hexyl group, an n-octyl group, an n-decyl group, an n-dodecyl group, an n-tetradecyl group, an n-hexadecyl group, and an n-octadecyl group, with an n-hexadecyl group and an n-octadecyl group being preferred.

[0051] In the general formula (4), X ４ － is a monovalent anion, and the monovalent anion is X in the general formula (1). １ － The same anions as those mentioned above can be mentioned, and the preferred anions are also the same as those mentioned above.

[0052] Examples of cations constituting the quaternary ammonium salt represented by the compound (A4) include benzylhexyldimethylammonium ion, benzylheptyldimethylammonium ion, benzyloctyldimethylammonium ion, benzylnonyldimethylammonium ion, benzyldecyldimethylammonium ion, benzylundecyldimethylammonium ion, benzyldodecyldimethylammonium ion (benzyllauryldimethylammonium ion), benzyltridecyldimethylammonium ion, benzyltetradecyldimethylammonium ion (benzylmyristyldimethylammonium ion), benzylpentadecyldimethylammonium ion, benzylhexadecyldimethylammonium ion, benzylheptadecyldimethylammonium ion, and benzyloctadecyldimethylammonium ion (benzyldimethylstearylammonium ion). From the viewpoint of the effect of reducing water-soluble COD components, the benzylhexyldimethylammonium ion, benzyllauryldimethylammonium ion, benzylhexadecyldimethylammonium ion, and benzyldimethylstearylammonium ion are preferred.

[0053] As the compound (A4), benzyl lauryl dimethyl ammonium chloride, benzyl hexadecyl dimethyl ammonium chloride, benzyl dimethyl hexadecyl ammonium bromide, benzyl dimethyl stearyl ammonium chloride, and benzyl dimethyl stearyl ammonium bromide are preferred.

[0054] [Compound (A5)] The compound (A5) has a structure represented by the general formula (5).

[0055] In the general formula (5), n ６ is an integer from 5 to 17. ６If n is 4 or less, the water solubility of the complex of the cationic surfactant and the water-soluble COD components becomes high, the complex is difficult to precipitate, and the effect of reducing the water-soluble COD components decreases. If n is 18 or more, the solubility of the cationic surfactant in water is insufficient, making it difficult to form a complex with the water-soluble COD components, and the effect of reducing the water-soluble COD components decreases. ６ is preferably 11 to 17 from the viewpoint of the effect of reducing water-soluble COD components.

[0056] In the general formula (5), CH ３ (CH ２ ) n ６ Examples of the linear alkyl group having 6 to 18 carbon atoms represented by the formula (I) include an n-hexyl group, an n-octyl group, an n-decyl group, an n-dodecyl group, an n-tetradecyl group, an n-hexadecyl group, and an n-octadecyl group, with an n-hexadecyl group and an n-octadecyl group being preferred.

[0057] In the general formula (5), X ５ － is a monovalent anion, and the monovalent anion is X in the general formula (1). １ － The same anions as those mentioned above can be mentioned, and the preferred anions are also the same as those mentioned above.

[0058] In the general formula (5), Y is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and is preferably a hydrogen atom or a methyl group from the viewpoint of the effect of reducing water-soluble COD components.

[0059] Examples of the cation constituting the quaternary ammonium salt represented by the compound (A5) include a 1-hexylpyridinium ion, a 1-hexyl-4-methylpyridinium ion, a 1-heptylpyridinium ion, a 1-heptyl-4-methylpyridinium ion, a 1-octylpyridinium ion, a 1-octyl-4-methylpyridinium ion, a 1-nonylpyridinium ion, a 1-nonyl-4-methylpyridinium ion, a 1-decylpyridinium ion, and a 1-decyl-4-methylpyridinium ion. ion, 1-undecylpyridinium ion, 1-undecyl-4-methylpyridinium ion, 1-dodecylpyridinium ion (1-laurylpyridinium ion), 1-dodecyl-4-methylpyridinium ion (1-lauryl-4-methylpyridinium ion), 1-tridecylpyridinium ion, 1-tridecyl-4-methylpyridinium ion, 1-tetradecylpyridinium ion (1-myristylpyridinium ion), 1-tetradecyl-4-methylpyridinium ion 1-myristyl-4-methylpyridinium ion, 1-pentadecylpyridinium ion, 1-pentadecyl-4-methylpyridinium ion, 1-hexadecylpyridinium ion, 1-hexadecyl-4-methylpyridinium ion, 1-heptadecylpyridinium ion, 1-heptadecyl-4-methylpyridinium ion, 1-octadecylpyridinium ion (1-stearylpyridinium ion), and 1-octadecyl-4-methylpyridinium ion (1-stearylpyridinium ion). From the viewpoint of the effect of reducing water-soluble COD components, 1-n-hexylpyridinium ion, 1-laurylpyridinium ion, 1-n-hexadecylpyridinium ion, 1-n-hexadecyl-4-methylpyridinium ion, 1-octadecylpyridinium ion (1-stearyl-4-methylpyridinium ion), and 1-octadecyl-4-methylpyridinium ion (1-stearyl-4-methylpyridinium ion) are preferred.

[0060] As the compound (A5), 1-n-hexylpyridinium chloride, 1-laurylpyridinium chloride, 1-n-hexadecylpyridinium bromide, 1-n-hexadecylpyridinium chloride, 1-n-hexadecyl-4-methylpyridinium chloride, 1-stearylpyridinium bromide and 1-stearylpyridinium chloride are preferred.

[0061] The cationic surfactants may be used alone or in combination of two or more.

[0062] [Cationic Polymer] From the viewpoint of the effect of reducing water-soluble COD components, the water treatment agent according to this embodiment preferably contains a cationic polymer having a cationic monomer (m1) as a constituent monomer, a weight-average molecular weight of 10,000 to 1,000,000, and a colloid equivalent value of 0.1 to 6.5 meq / g. The cationic monomer (m1) includes one or more selected from the group consisting of cationic monomers (m11) represented by the following general formula (i) and cationic monomers (m12) represented by the following general formula (ii): CH ２ = C(R ｉ １ )-CO-X ｉ -Q-N ＋ (R ｉ ２ ) ３ ・Z － (i) (CH ２ = C(R ｉ ３ )-CH ２ ) ２ -N ＋ (R ｉ ４ ) ２ ・Z － (ii)

[0063] R in the general formula (i) ｉ １ represents a hydrogen atom or a methyl group, and is preferably a methyl group from the viewpoint of the effect of reducing water-soluble COD.

[0064] In the general formula (i), there are three R ｉ ２Each independently represents a hydrogen atom, an alkyl group having 1 to 22 carbon atoms, or a benzyl group. From the viewpoint of the effect of reducing water-soluble COD, there are three R ｉ ２ is preferably an alkyl group having 1 to 22 carbon atoms or a benzyl group.

[0065] Examples of the alkyl group having 1 to 22 carbon atoms include a methyl group, an ethyl group, and a branched or linear alkyl group having 3 to 22 carbon atoms. Examples of the branched alkyl group having 3 to 22 carbon atoms include the following alkyl groups: Branched alkyl groups having 3 carbon atoms: isopropyl group Branched alkyl groups having 4 carbon atoms: 1-methylpropyl group (sec-butyl group), 2-methylpropyl group, 1,1-dimethylethyl group (tert-butyl group) Branched alkyl groups having 5 carbon atoms: 1-methylbutyl group, 1,1-dimethylpropyl group, 1,2-dimethylpropyl group, and 2,2-dimethylpropyl group (neopentyl group) Branched alkyl groups having 6 carbon atoms: 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, 1,1-dimethylbutyl group, 1,2-dimethylbutyl group, 1,3-dimethylbutyl group, 2,2-dimethylbutyl group, 2,3-dimethylbutyl group, 1-ethylbutyl group, and 2-ethylbutyl group Branched alkyl groups having 7 carbon atoms: -C8 branched alkyl groups: 1-methylhexyl group, 2-methylhexyl group, 3-methylhexyl group, 4-methylhexyl group, 5-methylhexyl group, 1-ethylpentyl group, 2-ethylpentyl group, 3-ethylpentyl group, 1,1-dimethylpentyl group, 1,2-dimethylpentyl group, 1,3-dimethylpentyl group, 2,2-dimethylpentyl group, and 2,3-dimethylpentyl group; -C8 branched alkyl groups: 1-methylheptyl group, 2-methylheptyl group, 3-methylheptyl group, 4-methylheptyl group, 5-methylheptyl group, 6-methylheptyl group, 1,1-dimethylhexyl group, 1,2-dimethylhexyl group, 1,3-dimethylhexyl group, 1,4-dimethylhexyl group, 1,5-dimethylhexyl group, 1-ethylhexyl group, 2-ethylhexyl group; -C9 branched alkyl groups: 1-methyloctyl group, 2-methyloctyl group, 3-methyloctyl group, 4-methyloctyl group, 5-methyloctyl group, 6-methyloctyl group, 7-methyloctyl group, 1,1-dimethylheptyl group, 1,2-dimethylheptyl group, 1,3-dimethylheptyl group, 1,4-dimethylheptyl group, 1,5-dimethylheptyl group, 1,6-dimethylheptyl group, 1-ethylheptyl group, 2-ethylheptyl group, etc. Branched alkyl groups having 10 carbon atoms: 1-methylnonyl group, 2-methylnonyl group, 3-methylnonyl group, 4-methylnonyl group, 5-methylnonyl group, 6-methylnonyl group, 7-methylnonyl group, 8-methylnonyl group, 1,1-dimethyloctyl group, 1,2-dimethyloctyl group, 1,3-dimethyloctyl group, 1,4-dimethyloctyl group, 1,5-dimethyloctyl group, 1,6-dimethyloctyl group, 1,7-dimethyloctyl group, 1-ethyloctyl group, 2-ethyloctyl group, etc. Branched alkyl groups having 11 carbon atoms: 1-methyldecyl group, 2-methyldecyl group, 3-methyldecyl group, 4-methyldecyl group, 5-methyldecyl group, 6-methyldecyl group, 7-methyldecyl group, 8-methyldecyl group, 9-methyldecyl group, 1,1-dimethylnonyl group, 1,2-dimethylnonyl group, 1,3-dimethylnonyl group, 1,4-dimethylnonyl group, 1,5-dimethylnonyl group, 1,6-dimethylnonyl group, 1,7-dimethylnonyl group, 1,8-dimethylnonyl group, 1-ethylnonyl group, 2-ethylnonyl group, etc. Branched alkyl groups having 12 carbon atoms: 1-methylundecyl group, 2-methylundecyl group, 3-methylundecyl group, 4-methylundecyl group, 5-methylundecyl group, 6-methylundecyl group, 7-methylundecyl group, 8-methylundecyl group, 9-methylundecyl group, 10-methylundecyl group, 1,1-dimethyldecyl group, 1,2-dimethyldecyl group, 1,3-dimethyldecyl group, 1,4-dimethyldecyl group, 1,5-dimethyldecyl group, 1,6-dimethyldecyl group, 1,7-dimethyldecyl group, 1,8-dimethyldecyl group, 1,9-dimethyldecyl group, 1-ethyldecyl group, and 2-ethyldecyl group. Branched alkyl groups having 13 carbon atoms: 1-methyldodecyl group, etc. Branched alkyl groups having 14 carbon atoms: 7-ethyl-2-methyl-4-undecyl group, etc. Branched alkyl groups having 15 carbon atoms: 14-methylpentadecyl group, etc. Branched alkyl groups having 16 carbon atoms: 2-hexyldecyl group, 10-ethyl-7-tetradecyl group, etc. Branched alkyl groups having 18 carbon atoms: 16-methylheptadecyl group, 7-methylheptadecyl group, etc. Branched alkyl groups having 20 carbon atoms: 3, 7, 11,15-tetramethylhexadecyl group, 2-octyldodecyl group, etc. Branched alkyl groups having 22 carbon atoms: 2-decyltetradecyl group, etc.

[0066] Examples of the linear alkyl group having 3 to 22 carbon atoms include an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-decyl group, an n-dodecyl group, an n-tetradecyl group, an n-hexadecyl group, an n-octadecyl group, an n-eicosyl group, and an n-docosyl group.

[0067] As the alkyl group having 1 to 22 carbon atoms, from the viewpoint of the effect of reducing water-soluble COD, a linear alkyl group having 1 to 22 carbon atoms is preferred, and a methyl group is more preferred.

[0068] X in general formula (i) ｉ represents an oxygen atom or an imino group.

[0069] In the general formula (i), Q represents an alkylene group having 1 to 6 carbon atoms.

[0070] Examples of alkylene groups having 1 to 6 carbon atoms include methylene, ethylene, branched alkylene groups having 3 to 6 carbon atoms (e.g., 2-methylpropylene), and linear alkylene groups having 3 to 6 carbon atoms (n-propylene, n-butylene, n-pentylene, and n-hexylene). If the alkylene group has 6 or fewer carbon atoms, the solubility of the polymer in water decreases, making it easier for the water treatment agent to reduce water-soluble COD components.

[0071] In terms of the water solubility of the polymer, preferred examples of Q in the general formula (i) are a methylene group, an ethylene group, and a branched or linear alkylene group having 3 to 4 carbon atoms, and more preferred examples are an ethylene group and an n-propylene group from the viewpoint of the effect of reducing water-soluble COD.

[0072] Z in the general formula (i) － represents a monovalent anion.

[0073] Z in the general formula (i) － The monovalent anion represented by the formula (1) is X １ － Among them, Z－ From the viewpoint of the effect of reducing water-soluble COD components by water treatment chemicals, Cl is preferred. － , HSO ４ － and CH ３ SO ４ － is.

[0074] Preferred examples of the cationic monomer (m11) represented by the general formula (i) include salts of the amino group-containing (meth)acrylates described below with the Brønsted acids or quaternized products obtained with the quaternizing agents, and salts of the amino group-containing (meth)acrylamides described below with the Brønsted acids or quaternized products obtained with the quaternizing agents.

[0075] In this specification, (meth)acrylate means methacrylate and / or acrylate, and (meth)acrylamide means methacrylamide and / or acrylamide.

[0076] Among the amino group-containing (meth)acrylates constituting the cationic monomer (m11), preferred are amino group-containing (meth)acrylates having 4 to 10 carbon atoms, and more preferred are aminomethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, and dimethylaminobutyl (meth)acrylate.

[0077] Among the amino group-containing (meth)acrylamides constituting the cationic monomer (m11), preferred are amino group-containing (meth)acrylamides having 4 to 8 carbon atoms, and from the viewpoint of hydrophilicity, more preferred are aminomethyl(meth)acrylamide, dimethylaminoethyl(meth)acrylamide, aminopropyl(meth)acrylamide, and aminobutyl(meth)acrylamide.

[0078] The salt of the amino group-containing (meth)acrylate with the Brønsted acid, and the salt of the amino group-containing (meth)acrylamide with the Brønsted acid can be obtained by neutralizing the amino group-containing (meth)acrylate and the amino group-containing (meth)acrylamide with the Brønsted acid by a known method.

[0079] The quaternized product of the amino group-containing (meth)acrylate and the quaternized product of the amino group-containing (meth)acrylamide can be obtained by reacting the amino group-containing (meth)acrylate and the amino group-containing (meth)acrylamide with the quaternizing agent by a known method.

[0080] As the cationic monomer (m11), (meth)acryloyloxyethyl trimethyl ammonium chloride, (meth)acryloyloxyethyl benzyl dimethyl ammonium chloride, and (meth)acrylamidopropyl trimethyl ammonium chloride are preferred, and (meth)acryloyloxyethyl trimethyl ammonium chloride and (meth)acryloyloxyethyl benzyl dimethyl ammonium chloride are more preferred. As the cationic monomer (m11) represented by general formula (i), one type may be used alone, or two or more types may be used in combination.

[0081] R in the general formula (ii) ｉ ３ represents a hydrogen atom or a methyl group, and is preferably a methyl group from the viewpoint of the effect of reducing soluble COD components.

[0082] The two R in the general formula (ii) ｉ ４ R each independently represents a hydrogen atom, an alkyl group having 1 to 22 carbon atoms, or a benzyl group, and from the viewpoint of the effect of reducing water-soluble COD, a methyl group or a benzyl group is preferred. ４ The alkyl group having 1 to 22 carbon atoms in the formula (i) is ２ The same examples as those exemplified in the above are included, and the preferred examples are also the same.

[0083] Z in the general formula (ii) － represents a monovalent anion, and Z in the general formula (i)－ The same as those exemplified above can be mentioned, and the preferred examples are also the same.

[0084] Preferable examples of the cationic monomer (m12) represented by the general formula (ii) include salts of diallylamine or its N-monoalkyl-, N-dialkyl-, or N-benzyl-substituted compounds (diallylmonoalkylamine, diallylbenzylamine, etc.) with the Bronsted acid, or quaternized products with the quaternizing agent.

[0085] The salt of the diallylamine or the like and the Bronsted acid can be obtained by neutralizing the diallylamine or the like with the Bronsted acid by a known method.

[0086] The quaternized products of diallylamine etc. can be obtained by reacting diallylamine etc. with the quaternizing agent by a known method.

[0087] As the cationic monomer (m12), diallyldimethylammonium chloride is particularly preferable.

[0088] The cationic monomer (m12) may be used alone or in combination of two or more kinds.

[0089] The cationic monomer (m1) may contain a cationic monomer having a cationic group other than the cationic monomer (m11) and the cationic monomer (m12) as long as the effects of the present invention are not impaired.

[0090] From the viewpoint of the effect of reducing water-soluble COD, the ratio of the total number of moles of the cationic monomer (m11) and the cationic monomer (m12) in the cationic monomer (m1) is preferably 80 mol % or more, more preferably 90 mol % or more, and even more preferably 100 mol %.

[0091] The cationic polymer may contain a monomer (m2) having no cationic functional group as a constituent monomer. Examples of the monomer (m2) having no cationic functional group include a nonionic monomer (m21) and an anionic monomer (m22).

[0092] Examples of the nonionic monomer (m21) include (meth)acrylates (m211) having 4 to 30 carbon atoms, unsaturated hydrocarbons (m212) having 2 to 30 carbon atoms, (meth)acrylamide-based monomers (m213) having 3 to 30 carbon atoms, vinylamine-based monomers (m214), vinyl ether-based monomers (m215), (meth)allylamine-based monomers (m216), (meth)allyl ether-based monomers (m217), and monomers having an unsaturated group and an epoxy group (m218).

[0093] Examples of the (meth)acrylate (m211) having 4 to 30 carbon atoms include alkyl (meth)acrylates {methyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, isobornyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, dodecyl (meth)acrylate, decyl (meth)acrylate, tetradecyl (meth)acrylate, hexadecyl (meth)acrylate, octadecyl (meth)acrylate, isostearyl (meth)acrylate, ethylene glycol di(meth)acrylate, pentaerythritol poly(valent number 2 to 4) (meth)acrylate, dipentaerythritol hexa(meth)acrylate, etc.}, and aromatic (meth)acrylates {benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, etc.}.

[0094] Examples of the unsaturated hydrocarbons (m212) having 2 to 30 carbon atoms include aliphatic unsaturated hydrocarbons (ethylene, nonene, etc.) and aromatic unsaturated hydrocarbons (styrene, 1-methylstyrene, etc.).

[0095] Examples of the (meth)acrylamide-based monomer (m213) having 3 to 30 carbon atoms include (meth)acrylamide, N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N-butyl(meth)acrylamide, N,N'-dimethylacrylamide, N,N-diethylacrylamide, and N,N-methylenebis(meth)acrylamide.

[0096] Examples of the vinylamine-based monomer (m214) include vinylamine and divinylamine.

[0097] Examples of the vinyl ether monomer (m215) include vinyl ether and divinyl ether.

[0098] Examples of the (meth)allylamine monomer (m216) include (meth)allylamine, di(meth)allylamine, and N-alkyl (having 1 to 20 carbon atoms) di(meth)allylamine.

[0099] Examples of the (meth)allyl ether monomer (m217) include di(meth)allyl ether, poly(meth)allyl ether of polyhydric alcohols (as described above), and poly(meth)allyloxyalkanes (having 1 to 20 carbon atoms) (such as tetraallyloxyethane).

[0100] Examples of the monomer (m218) having an unsaturated group and an epoxy group include glycidyl (meth)acrylate, 3,4-epoxyhexahydrobenzyl (meth)acrylate, and polyethylene glycol monoglycidyl ether (meth)acrylate (Mn 6,000 or less).

[0101] Examples of the anionic monomer (m22) include unsaturated carboxylic acids (anhydrides) (m221) having 2 to 30 carbon atoms and unsaturated sulfonic acids (m222) having 2 to 24 carbon atoms.

[0102] Examples of the unsaturated carboxylic acid (anhydride) (m221) having 2 to 30 carbon atoms include (meth)acrylic acid, maleic acid (anhydride), fumaric acid, itaconic acid (anhydride), vinylbenzoic acid, allylacetic acid, and monoesters of maleic acid and polyether. In this specification, the term "acid (anhydride)" refers to an acid and / or an acid anhydride.

[0103] Examples of the unsaturated sulfonic acid (m222) having 2 to 24 carbon atoms include aliphatic unsaturated sulfonic acids having 2 to 20 carbon atoms (vinyl sulfonic acid), aromatic unsaturated sulfonic acids having 6 to 20 carbon atoms (styrene sulfonic acid, etc.), sulfo group-containing (meth)acrylates having 2 to 24 carbon atoms (sulfoalkyl (meth)acrylates in which the alkyl group has 2 to 20 carbon atoms [2-(meth)acryloyloxyethane-1-propanesulfonic acid, 2-(meth)acryloyloxyethane-1-butanesulfonic acid, 3-(meth)acryloyloxypropanesulfonic acid, 4-(meth)acryloyloxybutanesulfonic acid, 2-(meth)acryloyloxyethane-1-butanesulfonic acid, 3-(meth)acryloyloxypropanesulfonic acid, 4-(meth)acryloyloxybutanesulfonic acid, 2-(meth)acryloyloxyethane-1-propanesulfonic acid, 2-(meth)acryloyloxyethane-1-butanesulfonic acid, 3-(meth)acryloyloxypropanesulfonic acid, 4-(meth)acryloyloxybutanesulfonic acid, 2-(meth)acryloyloxyethane-1- ... 2-(meth)acryloylamino-2,2-dimethylethanesulfonic acid, p-(meth)acryloyloxymethylbenzenesulfonic acid, etc.], sulfo group-containing (meth)acrylamides [2-(meth)acryloylaminoethanesulfonic acid, 2- or 3-(meth)acryloylaminopropanesulfonic acid, 2- or 4-(meth)acryloylaminobutanesulfonic acid, 2-(meth)acryloylamino-2,2-dimethylethanesulfonic acid, p-(meth)acryloylaminomethylbenzenesulfonic acid, etc.], and alkyl (meth)allyl sulfosuccinates in which the alkyl group has 1 to 20 carbon atoms [methyl (meth)allyl sulfosuccinate, etc.].

[0104] Of the above-mentioned monomers (m2) not having a cationic functional group, from the viewpoint of the water-soluble COD reduction performance of water treatment chemicals, preferred are (meth)acrylates (m211) having 4 to 30 carbon atoms, unsaturated hydrocarbons (m212) having 2 to 30 carbon atoms, (meth)acrylamide-based monomers (m213) and vinylamine-based monomers (m221) having 3 to 30 carbon atoms, more preferred are (m211), (m212) and (m221), particularly preferred are (meth)acrylates having 4 to 30 carbon atoms, unsaturated hydrocarbons having 8 to 10 carbon atoms, (meth)acrylamide and (meth)acrylic acid, and most preferred are alkyl (meth)acrylates having 4 to 20 carbon atoms, aromatic (meth)acrylates having 4 to 20 carbon atoms, styrene and (meth)acrylic acid.

[0105] The monomer (m2) not having a cationic functional group is preferably a nonionic monomer (m21), more preferably (m211) or (m212). The monomer (m2) not having a cationic functional group may be used alone or in combination of two or more.

[0106] The molar ratio of the total number of moles of the cationic monomer (m1) to the total number of moles of the monomer (m2) not having a cationic functional group in the constituent monomers of the cationic polymer (total number of moles of the cationic monomer (m1):total number of moles of the monomer (m2) not having a cationic functional group) is preferably 0.1:99.1 to 100:0, more preferably 1:99 to 99:1, particularly preferably 5:95 to 95:5, and most preferably 10:90 to 90:10, from the viewpoint of the effect of reducing water-soluble COD components.

[0107] The cationic polymer preferably has a weight average molecular weight (hereinafter abbreviated as "Mw") of 10,000 to 1,000,000 from the viewpoint of the solubility of the cationic polymer in water, and more preferably 10,000 to 500,000 from the viewpoint of the performance of reducing water-soluble COD components.

[0108] The Mw of the cationic polymer can be measured by gel permeation chromatography under the following conditions. When the cationic polymer is dissolved in a water-methanol mixture (volume ratio of water to methanol is 8:2), the measurement is performed under the following conditions (condition 1). (Condition 1) Measuring instrument: HLC-8220GPC, manufactured by Tosoh Corporation Columns: TSKgel Guard column PWXL-CP, TSKgel 6000-PWXL-CP, TSKgel 5000-PWXL-CP Eluent: water / methanol=8 / 2 (volume ratio) (NaNO ３ 0.05M) Flow rate: 1 ml / min Sample concentration: 0.25 wt % Injection volume: 100 μl When the cationic polymer is not soluble in a water-methanol mixture (volume ratio of water to methanol is 8:2), measurement is performed under the following conditions (condition 2). (Condition 2) Measuring instrument: HLC-8320GPC, manufactured by Tosoh Corporation Column: Guard column α, TSKgel α-M Eluent: dimethylformamide (containing 0.01M LiBr) Flow rate: 1 ml / min Sample concentration: 0.125 wt % Injection volume: 100 μl

[0109] From the viewpoint of ease of formation of a complex between the cationic polymer, the cationic surfactant, and the water-soluble COD component, and the water solubility of the complex, the cationic polymer preferably has a colloid equivalent value of 0.1 to 6.5 meq / g, more preferably 1.0 to 5.0 meq / g. The colloid equivalent value of the cationic polymer can be adjusted to a predetermined range by adjusting the types of cationic monomer (m11) represented by general formula (i) and cationic monomer (m12) represented by general formula (ii) that constitute the cationic polymer, and the copolymerization ratio of cationic monomer (m11) represented by general formula (i), cationic monomer (m12) represented by general formula (ii), and optionally, monomer (m2) that does not have a cationic functional group.

[0110] The colloid equivalent value of the cationic polymer can be determined by the colloid titration method described below. All colloid equivalent value measurements are performed at room temperature (approximately 20°C). (1) Preparation of Measurement Sample Solution (50 ppm Aqueous Solution of Sample): 0.2 g of polymer is accurately weighed and placed in a 200 ml Erlenmeyer flask. Ion-exchanged water is added to a total weight (total weight of sample and ion-exchanged water) of 100 g. The mixture is then stirred for 3 hours with a magnetic stirrer (cylindrical magnet, 40 mm long, 5 mm diameter, 1,000 rpm) to completely dissolve the polymer, preparing a 0.2 wt. % solution. 10 ml of the prepared solution is placed in a 500 ml beaker, and ion-exchanged water is added to a total weight (total weight of 10 ml of solution and ion-exchanged water) of 400 g. The mixture is then stirred again with a magnetic stirrer (1,000-1,200 rpm) for 30 minutes to obtain a uniform measurement sample. (2) Measurement of the Colloid Equivalent Value of a Polymer: 100 g of the sample solution to be measured was placed in a 200 ml conical beaker. While stirring with a magnetic stirrer (rotation speed: 500 rpm), 0.5 wt % aqueous sulfuric acid solution was gradually added to adjust the pH of the sample solution to 3 to prepare the measurement sample. Next, 2-3 drops of toluidine blue indicator (TB indicator) were added to the measurement sample, and the solution was titrated with N / 400 polyvinyl potassium sulfate (N / 400 PVSK) reagent. The titration rate was 2 ml / min, and the endpoint was the point at which the sample changed color from blue to reddish purple and maintained the reddish purple color for 30 seconds. (3) Blank Test: The same procedure as in (2) above was performed, except that 100 g of ion-exchanged water was used as the measurement sample. (4) Calculation method: Colloid equivalent value of polymer (meq / g) = (1 / 2) × (titration amount in measurement sample - titration amount in blank test) × (titer of N / 400PVSK)

[0111] Among the cationic polymers, preferred homopolymers of the cationic monomer (m11) include poly[(meth)acryloyloxyethyltrimethylammonium chloride], poly[(meth)acryloyloxyethylbenzyldimethylammonium chloride], and poly[(meth)acrylamidopropyltrimethylammonium chloride], and preferred homopolymers of the cationic monomer (m12) include poly[diallyldimethylammonium chloride].

[0112] Preferred polymers containing the cationic monomer (m11) as a constituent monomer include copolymers of (meth)acryloyloxyethyltrimethylammonium chloride and / or (meth)acryloyloxyethylbenzyldimethylammonium chloride with acrylamide, styrene, benzyl (meth)acrylate, hexyl (meth)acrylate, dodecyl (meth)acrylate, or (meth)acrylic acid, and copolymers of (meth)acrylamidopropyltrimethylammonium chloride with styrene, benzyl (meth)acrylate, hexyl (meth)acrylate, dodecyl (meth)acrylate, or (meth)acrylic acid.

[0113] As the polymer having the cationic monomer (m12) as a constituent monomer, a copolymer of diallyldimethylammonium chloride with styrene, benzyl (meth)acrylate, hexyl (meth)acrylate, dodecyl (meth)acrylate or (meth)acrylic acid is preferred.

[0114] As the copolymer containing the cationic monomer (m11) and the cationic monomer (m12) as constituent monomers, a copolymer of (meth)acryloyloxyethyltrimethylammonium chloride and diallyldimethylammonium chloride with styrene, benzyl (meth)acrylate, hexyl (meth)acrylate, dodecyl (meth)acrylate, or (meth)acrylic acid is preferred. Among these, more preferred cationic polymers are poly[(meth)acryloyloxyethylbenzyldimethylammonium chloride], poly[diallyldimethylammonium chloride], a copolymer of (meth)acryloyloxyethyltrimethylammonium chloride with styrene benzyl (meth)acrylate, hexyl (meth)acrylate, or dodecyl (meth)acrylate, a copolymer of (meth)acryloyloxyethyltrimethylammonium chloride with acrylamide, and acrylic acid, a copolymer of (meth)acryloyloxyethylbenzyldimethylammonium chloride with styrene, benzyl (meth)acrylate, hexyl (meth)acrylate, or dodecyl (meth)acrylate, and a copolymer of (meth)acrylamidopropyltrimethylammonium chloride with styrene, benzyl (meth)acrylate, hexyl (meth)acrylate, or dodecyl (meth)acrylate.

[0115] The cationic polymer can be obtained by polymerizing the cationic monomer (m1) and the optional monomer (m2) by a known method. Known polymerization methods for polymerizing the cationic monomer (m1) and the optional monomer (m2) include known radical polymerization methods (solution dropping polymerization, reversed-phase suspension polymerization, photopolymerization, precipitation polymerization, and reversed-phase emulsion polymerization). Among these, solution dropping polymerization is preferred from the viewpoint of temperature control and molecular weight control during polymerization.

[0116] Examples of solution dropping polymerization include a method in which a solution of a monomer, a solvent, and a radical polymerization initiator is dropped below the boiling point of the solvent (e.g., JP-A-6-211942). When an organic solvent is used as the solvent, it is preferable to remove the solvent and add water as necessary to produce the polymer, from the viewpoints of handling hazards and environmental protection.

[0117] Alternatively, the cationic monomer (m11) can be polymerized, as essential monomers, by a known method using an amino group-containing (meth)acrylate and / or amino group-containing (meth)acrylamide constituting the cationic monomer (m11) and the monomer (m2), which is used as needed, and then the structural units derived from the amino group-containing (meth)acrylate and / or amino group-containing (meth)acrylamide constituting the cationic monomer (m11) contained in the resulting polymer are neutralized with the Brønsted acid, or by quaternization with the quaternizing agent.

[0118] Alternatively, the copolymer can also be obtained by polymerizing diallylamine or an N-monoalkyl-, N-dialkyl-, or N-benzyl-substituted compound thereof and the monomer (m2) used as needed as essential monomers by a known method, and then neutralizing a structural unit derived from diallylamine or an N-monoalkyl-, N-dialkyl-, or N-benzyl-substituted compound thereof contained in the obtained polymer with the Bronsted acid, or by quaternizing the structural unit with the quaternizing agent.

[0119] From the viewpoint of operability (handling properties) and the like, the water treatment agent may further contain water in addition to the cationic surfactant and cationic polymer.

[0120] The content of the cationic surfactant contained in the water treatment agent is preferably 1 to 99.0 wt %, more preferably 5.0 to 95.0 wt %, based on the total weight of the water treatment agent. Furthermore, when the water treatment agent contains a cationic polymer, the content of the cationic polymer contained in the water treatment agent is preferably 1 to 50 wt %, based on the total weight of the water treatment agent.

[0121] In order to further improve the performance of removing water-soluble COD components, the water treatment chemical may contain a known organic coagulant within a range that does not impair the effects of the present invention.

[0122] Examples of the organic coagulant include polycondensates of epihalohydrin and amine and their hydrochlorides, polycondensates of epihalohydrin and alkylenediamine and their hydrochlorides, polyethyleneimine and its hydrochlorides, alkylene dihalide-alkylene polyamine polycondensates and their hydrochlorides, aniline-formaldehyde polycondensates and their hydrochlorides, polyvinylbenzyltrimethylammonium chloride, polyvinylpyridine and its hydrochlorides, and polyvinylimidazoline and its hydrochlorides, etc. One type of organic coagulant may be used alone, or two or more types may be used in combination.

[0123] The water treatment agent can be produced by mixing the cationic surfactant, the cationic polymer (if necessary), and other additives (such as preservatives and antioxidants). The mixing method is not particularly limited, and for example, mixing may be performed using a known mixing container and a stirrer. The cationic surfactant and the cationic polymer (if necessary) may be diluted with water before mixing.

[0124] In the case where the cationic surfactant and the cationic polymer used as needed are diluted with water and then mixed in the production of the water treatment agent, a method can be used in which a predetermined amount of the cationic surfactant or the cationic polymer is added to water being stirred using a known stirring device (such as a jar tester), and the mixture is stirred for several hours (about 1 to 4 hours).

[0125] When the water treatment chemical is added to water to be treated that contains water-soluble COD components (such as various types of industrial wastewater, sewage, and sludge (organic sludge and inorganic sludge)), the water-soluble COD components are insolubilized and precipitated, and the precipitate can be separated and removed to reduce the water-soluble COD components contained in the water to be treated. The water to be treated to which the water treatment chemical is added is preferably one to which an inorganic coagulant has been added.

[0126] Furthermore, when the water treatment agent contains a cationic polymer, the precipitates become coarse and are easier to separate and remove, so that an even more excellent effect of reducing water-soluble COD components can be expected.

[0127] The water treatment chemicals are very useful because, when added to various industrial wastewaters (wastewater from factories in the paper pulp, dyeing, automobile, metal processing, steelmaking, food, gravel extraction, semiconductor-related and cleaning industries, etc.), sewage, and sludge (organic sludge and inorganic sludge) generated in the treatment of industrial wastewaters, etc., they can exert a stable effect of reducing water-soluble COD components even when the amount of water treatment chemical added is small.

[0128] <Water Treatment Chemical Kit> The water treatment chemical kit according to this embodiment is a water treatment chemical kit including a first water treatment chemical containing the cationic surfactant (hereinafter abbreviated as water treatment chemical (P1)) and a second water treatment chemical containing the cationic polymer (hereinafter abbreviated as water treatment chemical (P2)).

[0129] The cationic surfactant contained in the water treatment chemical (P1) constituting the water treatment chemical kit according to this embodiment is the same as the cationic surfactant contained in the water treatment chemical according to the previous embodiment, and therefore description thereof will be omitted.

[0130] The cationic polymer contained in the water treatment chemical (P2) constituting the water treatment chemical kit according to this embodiment is the same as the cationic polymer that can be contained in the water treatment chemical according to the previous embodiment, and therefore description thereof will be omitted.

[0131] The water treatment chemical (P1) may contain components other than the cationic surfactant, but preferably does not contain the cationic polymer.

[0132] The water treatment chemical (P1) may contain water in addition to the cationic surfactant. When the water treatment chemical (P1) contains water, the content of the cationic surfactant in the water treatment chemical (P1) is preferably 1 to 99 wt %, more preferably 5 to 95 wt %, based on the weight of the water treatment chemical (P1), from the viewpoints of operability and the effect of reducing water-soluble COD components.

[0133] The water treatment chemical (P2) may contain components other than the cationic polymer, but preferably does not contain the cationic surfactant.

[0134] The water treatment chemical (P2) may contain water in addition to the cationic polymer. When the water treatment chemical (P2) contains water, the content of the cationic polymer in the water treatment chemical (P2) is preferably 1 to 99 wt %, more preferably 5 to 95 wt %, based on the weight of the water treatment chemical (P2), from the viewpoints of operability and the effect of reducing water-soluble COD components.

[0135] The water treatment chemicals (P1) and (P2) may contain an organic coagulant to further improve the removal performance of water-soluble COD components, provided that the effects of the present invention are not impaired. Examples of such organic coagulants include polycondensates of epihalohydrin and amine and their hydrochlorides, polycondensates of epihalohydrin and alkylenediamine and their hydrochlorides, polyethyleneimine and its hydrochlorides, alkylenedihalide-alkylenepolyamine polycondensates and their hydrochlorides, aniline-formaldehyde polycondensates and their hydrochlorides, polyvinylbenzyltrimethylammonium chloride, polyvinylpyridine and its hydrochlorides, and polyvinylimidazoline and its hydrochlorides. These organic coagulants may be used alone or in combination.

[0136] The water treatment chemical kit may include an agent (P3) containing an organic coagulant in addition to the water treatment chemical (P1) and the water treatment chemical (P2).

[0137] The water treatment chemical (P1) constituting the water treatment chemical kit can be produced by mixing the cationic surfactant diluted with water as needed, and additives to be used as needed.

[0138] The water treatment chemical (P2) constituting the water treatment chemical kit can be produced by mixing the cationic polymer, which has been diluted with water as needed, with additives as needed.

[0139] As additives that are used as needed in the water treatment chemicals (P1) and (P2), the same additives as those that are used as needed in the water treatment chemicals according to the above-described embodiments can be used.

[0140] In the water treatment chemical (P1) and the water treatment chemical (P2), the dilution method for diluting the cationic surfactant and / or the cationic polymer with water can be the same as the dilution method for the water treatment chemical according to the embodiment.

[0141] By adding each of the water treatment chemicals (P1) and (P2) to water to be treated that contains water-soluble COD components, the water-soluble COD components are insolubilized, coarse precipitates are precipitated, and the precipitates can be easily separated and removed, and an excellent effect of reducing the water-soluble COD components can be expected. The water to be treated to which each of the water treatment chemicals (P1) and (P2) is added is preferably water to which an inorganic coagulant has been added.

[0142] The water treatment chemical (P1) and the water treatment chemical (P2) may be added to the water to be treated simultaneously, or the water treatment chemical (P1) and the water treatment chemical (P2) may be added in that order, but it is preferable to add the water treatment chemical (P1) and then the water treatment chemical (P2).

[0143] The water treatment chemical kit is very useful because, by adding it to various industrial wastewater (wastewater from factories in the paper pulp, dyeing, automobile, metal processing, steelmaking, food, gravel extraction, semiconductor-related and cleaning industries, etc.), sewage, sludge (organic sludge and inorganic sludge) generated in the treatment of industrial wastewater, etc., even if the amount of the water treatment chemical (P1) and the water treatment chemical (P2) added is small, a stable effect of reducing water-soluble COD components can be exhibited.

[0144] <Water Treatment Method> The water treatment method according to this embodiment includes a step of adding an inorganic flocculant to water to be treated (first adding step) and a step of adding the cationic surfactant to water to be treated (second adding step).

[0145] [First Addition Step] The first addition step is a step of adding an inorganic flocculant to water to be treated.

[0146] Examples of the inorganic flocculant used in the first addition step include aluminum sulfate, polyaluminum chloride, ferric chloride, polyferric sulfate, ferrous sulfate, and hydrated lime. Each of the inorganic flocculants may be used alone or in combination. Among these, aluminum sulfate, polyaluminum chloride, ferric chloride, polyferric sulfate, and ferrous sulfate are preferred from the viewpoint of COD reduction effect.

[0147] In the first addition step, the amount of the inorganic flocculant added to the water to be treated can be adjusted depending on the type of water to be treated, the content of particulate matter to be removed that is suspended in the water to be treated, and the amount of water-soluble COD components to be removed, etc., but from the viewpoint of the performance of reducing water-soluble COD components, the amount is preferably 1 mg to 10,000 mg, more preferably 10 mg to 5,000 mg, even more preferably 50 mg to 2,500 mg, and even more preferably 100 mg to 1,000 mg per 1 L of water to be treated.

[0148] The inorganic flocculant can be added to the water to be treated in the first addition step by a known method.

[0149] [Second Addition Step] The second addition step is a step of adding the cationic surfactant to the water to be treated.

[0150] The cationic surfactant added to the water to be treated in the second addition step is the same as the cationic surfactant contained in the water treatment agent according to the embodiment, and therefore a description thereof will be omitted.

[0151] In the second addition step, the amount of the cationic surfactant added to the water to be treated is preferably an amount such that the weight ratio of the cationic surfactant to the weight of the inorganic flocculant added in the first addition step is 0.01 to 100, more preferably an amount such that the weight ratio is 0.1 to 50, and even more preferably an amount such that the weight ratio is 0.5 to 10.

[0152] The cationic surfactant can be added to the water to be treated in the second addition step by a known method.

[0153] [Third Addition Step] In addition to the first addition step and the second addition step, the water treatment method according to this embodiment preferably further includes a third addition step of adding the cationic polymer to the water to be treated.

[0154] The cationic polymer added to the water to be treated in the third addition step is the same as the cationic polymer that can be contained in the water treatment agent according to the embodiment, and therefore a description thereof will be omitted.

[0155] In the third addition step, the amount of the cationic polymer added to the water to be treated is preferably an amount such that the weight ratio of the cationic polymer to the weight of the inorganic flocculant added in the first addition step is 0.01 to 100, more preferably 0.1 to 50, and even more preferably 0.5 to 10.

[0156] The cationic polymer can be added to the water to be treated in the third addition step by a known method.

[0157] In the water treatment method, the second addition step may be carried out after the first addition step, the first addition step may be carried out after the second addition step, or the first addition step and the second addition step may be carried out simultaneously. Among these, it is preferable to carry out the second addition step after the first addition step.

[0158] When the water treatment method includes the third addition step, it is preferable that the second addition step and the third addition step are carried out separately or simultaneously after the first addition step. When the second addition step and the third addition step are carried out simultaneously, the water treatment chemical according to the embodiment containing the cationic surfactant and the cationic polymer may be added to the water to be treated, or the cationic surfactant and the cationic polymer may be added simultaneously to the water to be treated. When the cationic surfactant and the cationic polymer are added simultaneously to the water to be treated, the cationic surfactant may be added as the water treatment chemical (P1) constituting the water treatment chemical kit, and the cationic polymer may be added as the water treatment chemical (P2) constituting the water treatment chemical kit.

[0159] In the water treatment method, when the second addition step and the third addition step are performed separately, the cationic surfactant added to the water to be treated in the second addition step may be added as the water treatment chemical (P1) constituting the water treatment chemical kit. Also, the cationic polymer added to the water to be treated in the third addition step may be added as the water treatment chemical (P2) constituting the water treatment chemical kit. When the second addition step and the third addition step are performed separately, the first addition step and the second addition step may be performed simultaneously followed by the third addition step, or the first addition step, the second addition step, and the third addition step may be performed in this order, and preferably the first addition step, the second addition step, and the third addition step may be performed in this order.

[0160] [pH Adjustment Step] From the viewpoint of reducing water-soluble COD components, the water treatment method preferably includes a pH adjustment step of adjusting the pH of the water to be treated after the second addition step. The pH adjustment step may be performed after the second addition step, but if the water treatment method includes the third addition step, it is preferable to perform the pH adjustment step after the third addition step.

[0161] The pH of the water to be treated after being adjusted in the pH adjustment step is preferably 2.0 to 10.0, more preferably 3.0 to 9.0, and even more preferably 3.5 to 8.0.

[0162] The pH can be adjusted by adding a pH adjuster [inorganic acids (hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, etc.), inorganic solid acidic substances (acidic sodium phosphate, acidic sulfuric acid, ammonium chloride, ammonium sulfate, ammonium bicarbonate, sulfamic acid, etc.), organic acids (oxalic acid, succinic acid, malic acid, etc.), inorganic alkaline substances (e.g., sodium hydroxide, potassium hydroxide, ammonia, etc.), organic alkaline substances (e.g., guanidine, etc.)] to the water to be treated after the second addition step using a known method. Note that the pH is measured by using the water to be treated as a measurement sample directly at 25±1°C.

[0163] [Polymer flocculant addition step] From the viewpoint of facilitating solid-liquid separation, the water treatment method preferably includes a polymer flocculant addition step of further adding a polymer flocculant after the second addition step. The polymer flocculant addition step may be carried out after the second addition step, but if the water treatment method includes the third addition step, it is preferably carried out after the third addition step. By carrying out the polymer flocculant addition step, the precipitate can be converted into coarse flocs that are easier to process, which is preferable.

[0164] As the polymer flocculant, known polymer flocculants available on the market can be used alone or in combination. Note that a polymer flocculant is a polymer having a weight-average molecular weight of more than 1,000,000, and is distinguished from the cationic polymer that can be contained in the water treatment agent according to the embodiment.

[0165] Among the polymer flocculants, cationic polymer flocculants include polyethyleneimine having a weight-average molecular weight of more than 1,000,000, Mannich-modified poly(meth)acrylamide having a weight-average molecular weight of more than 1,000,000, homopolymers of quaternized dialkylaminoethyl (meth)acrylate having a weight-average molecular weight of more than 1,000,000, and polymers containing (meth)acrylamide as a constituent unit and having a weight-average molecular weight of more than 1,000,000, and polymers containing the cationic monomer (m11) as a constituent unit and having a weight-average molecular weight of more than 1,000,000. Commercially available products include Sanfloc C-009P (manufactured by Sanyo Chemical Industries, Ltd.).

[0166] Among the polymer flocculants, examples of nonionic polymer flocculants include polyacrylamides having a weight-average molecular weight of more than 1,000,000. Commercially available products include the Sanfloc NOP and Sanfloc N series (both manufactured by Sanyo Chemical Industries, Ltd.).

[0167] Among the polymer flocculants, examples of anionic polymer flocculants include sodium poly(meth)acrylate, hydrolyzed poly(meth)acrylamide, (meth)acrylamide-sodium (meth)acrylate copolymer, (meth)acrylamide-sodium (meth)acrylate-2-acrylamido-2-methylpropane-1-sodium sulfonate copolymer, and (meth)acrylamide-2-acrylamido-2-methylpropane-1-sodium sulfonate copolymer, each having a weight average molecular weight of more than 1,000,000. Commercially available products include the Sunfloc AH series and the Sunfloc AS series (both manufactured by Sanyo Chemical Industries, Ltd.).

[0168] Among the polymer flocculants, the amphoteric polymer flocculant may be a polymer having a weight average molecular weight of more than 1,000,000, which contains, as constituent monomers, the cationic monomer (m11) and / or the cationic monomer (m12), which are constituent monomers of the cationic polymer, and the anionic monomer (m22), which may be contained as a constituent monomer in the cationic polymer. Commercially available products include the Sanfloc C series (manufactured by Sanyo Chemical Industries, Ltd.).

[0169] In the polymer flocculant addition step, the polymer flocculant may be added as is, but from the viewpoint of uniform mixing, it is preferable to add the polymer flocculant to the water to be treated after preparing it as an aqueous solution. When the polymer flocculant is used as an aqueous solution, the concentration of the polymer flocculant in the aqueous solution to be added is preferably 0.05 to 1 wt %, more preferably 0.1 to 0.5 wt %, based on the total weight of the aqueous solution. When dissolving the polymer flocculant in water to prepare an aqueous solution, it is preferable to add it gradually, because adding the polymer flocculant all at once will cause clumps of the polymer flocculant to form and make it difficult to dissolve in water.

[0170] [Solid-Liquid Separation Step] The water treatment method may include a solid-liquid separation step of removing precipitates formed in the second adding step, the third adding step, or the like from the water to be treated.

[0171] In the solid-liquid separation step, examples of a method for separating the solid and the liquid that can be used include gravity settling, membrane filtration, column filtration, pressure flotation, concentrators (e.g., thickeners), and dehydrators (e.g., centrifuges, belt press dehydrators, and filter press dehydrators).

[0172] Examples of the water treatment method include the methods described below in [Water Treatment Method 1] to [Water Treatment Method 4]. From the viewpoints of reducing water-soluble COD components and solid-liquid separation, [Water Treatment Method 2] and [Water Treatment Method 4] are preferred. [Water Treatment Method 1]: A method in which the first and second addition steps are performed, the pH adjustment step is performed if necessary, and then a solid-liquid separation step is performed. [Water Treatment Method 2]: A method in which the first and second addition steps are performed, the pH adjustment step is performed if necessary, then a polymer flocculant addition step is performed, and then a solid-liquid separation step is performed. [Water Treatment Method 3]: A method in which the first, second, and third addition steps are performed, the pH adjustment step is performed if necessary, and then a solid-liquid separation step is performed. [Water Treatment Method 4]: A method in which the first, second, and third addition steps are performed, the pH adjustment step is performed if necessary, then a polymer flocculant addition step is performed, and then a solid-liquid separation step is performed.

[0173] The effect of the water treatment method in reducing water-soluble COD components can be confirmed by measuring the COD of the water to be treated after the water treatment, and by measuring TOC (total organic carbon), which can be measured more easily than COD.

[0174] The water treatment method is very useful because, by adding the water treatment chemical to various industrial wastewater (wastewater from factories in the paper pulp, dyeing, automobile, metal processing, steelmaking, food, gravel extraction, semiconductor-related, and cleaning industries, etc.), sewage, and sludge (organic sludge and inorganic sludge) generated in the treatment of industrial wastewater, etc., even if the amount of water treatment chemical added is small, it is possible to achieve a stable effect of reducing water-soluble COD components.

[0175] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. In the examples, "parts" means "parts by weight."

[0176] Production Example 1: Production of a water treatment agent (P2-1) containing cationic polymer 1 A four-necked flask equipped with a stirrer, a temperature sensor, a cooling tube, a dropping funnel, and a mantle heater was charged with 190 parts of isopropyl alcohol (hereinafter abbreviated as "IPA") and 69 parts of ion-exchanged water, and the mixture was heated to reflux under stirring. A mixed solution of 80 parts of IPA, 20 parts of ion-exchanged water, and 0.7 parts of azobisisobutyronitrile (hereinafter abbreviated as "AIBN") was added dropwise from the dropping port as an initiator solution, and a mixed solution of 352 parts of methacryloyloxyethyltrimethylammonium chloride (m11-1), 48 parts of styrene (m2-2), 180 parts of IPA, and 60 parts of ion-exchanged water was added dropwise from the other dropping port as a monomer solution. The mixture was stirred at 80 to 85°C, and each solution was added dropwise into the flask over 4 hours. After the dropwise addition, the same temperature was maintained for 2 hours, and then a homogeneous mixture of 80 parts IPA, 20 parts ion-exchanged water, and 2.0 parts AIBN was added dropwise over 1 hour to a flask at 80-85°C, and the reaction was carried out at the same temperature for 180 minutes. Subsequently, 465 parts of ion-exchanged water was added to the flask to replace the IPA that was distilled off, and the temperature was raised to 100°C to remove the IPA, yielding 1,000 parts of an aqueous solution containing 40% by weight of cationic polymer 1 in ion-exchanged water. The resulting aqueous solution was used as water treatment agent (P2-1) as is. The pH of the water treatment agent (P2-1) was 4.5, the Mw of the cationic polymer 1 contained in the water treatment agent (P2-1) was 180,000, and the colloid equivalent value of the cationic polymer 1 was 4.1.

[0177] <Production Examples 2 to 12 and Comparative Production Examples 1 to 4> Water treatment agents (P2-1) to (P2-12) containing cationic polymers 1 to 12 and cationic polymers C1 to C4, respectively, and comparative water treatment agents (CP2-1) to (CP2-4) were obtained in the same manner as in Production Example 1, except that the types and amounts of raw materials used were changed to those shown in Table 1.

[0178] The molar ratio of the total number of moles of cationic monomer (m1) to the total number of moles of monomer (m2) not having a cationic functional group in cationic polymers 1 to 12 and cationic polymers C1 to C4 contained in the water treatment agents (P2-1) to (P2-12) obtained in Production Examples 1 to 12 and the comparative water treatment agents (CP2-1) to (CP2-4) is shown in the column "Molar ratio [(m1):(m2)]" in Table 1, and the colloid equivalent value and Mw of the cationic polymer are also shown in Table 1.

[0179]

[0180] The raw materials and symbols listed in Table 1 are as follows: (1) Cationic monomer (m1) (i) Cationic monomer (m11) represented by general formula (i) (m11-1): methacryloyloxyethyl trimethyl ammonium chloride (m11-2): acryloyloxyethyl trimethyl ammonium chloride (m11-3): acryloyloxyethyl benzyl dimethyl ammonium chloride (m11-4): acrylamidopropyl trimethyl ammonium chloride (ii) Cationic monomer (m12) represented by general formula (ii) (m12-1): diallyl dimethyl ammonium chloride (2) Monomer (m2) not having a cationic functional group (m2) (m2-1): acrylamide (m2-2): styrene (m2-3): dodecyl methacrylate (m2-4): acrylic acid (m2-5): benzyl methacrylate

[0181] Example 1: A simulated wastewater (CODMn = 500 mg / L) containing sodium lauryl sulfonate, sodium lauryl benzene sulfonate, and sodium dodecyl diphenyl ether disulfonate was prepared as the water to be treated. 10 parts of the cationic surfactant octyltrimethylammonium chloride (A1-1) was dissolved in 90 parts of ion-exchanged water to prepare a water treatment agent (P1-1) containing a 10 wt% concentration of cationic surfactant. 1 L of simulated wastewater was collected in a beaker, and while stirring the simulated wastewater, 3,000 mg of a 10 wt% aqueous solution of aluminum sulfate (inorganic flocculant: 300 mg) was added to the simulated wastewater to perform a first addition step. After the addition of the inorganic flocculant, the mixture was stirred for a further 5 minutes, and then 2,000 mg of the prepared water treatment agent (P1-1) (cationic surfactant: 200 mg) was added to perform a second addition step. After stirring for another 5 minutes, a 10 wt% aqueous sodium hydroxide solution was added dropwise under stirring until the pH of the water to be treated reached 7.0, performing a pH adjustment step. The mixture was then stirred for another 5 minutes and then allowed to stand for 5 minutes. The supernatant separated by standing was filtered using filter paper (No. 5C), and the COD of the resulting filtrate was measured in accordance with the CODMn analysis method described in JIS K0102:2016. In this example, the weight ratio of the cationic surfactant added in the second addition step to the weight of the inorganic flocculant added in the first addition step was 0.7, and the COD of the filtrate was 150 mg / L. The ratio of the COD value reduced by the water treatment to the CODMn before water treatment (hereinafter referred to as the COD reduction rate) was calculated to be 0.81.

[0182] Examples 2 to 24 and Comparative Examples 1 to 9 The simulated wastewater was treated in the same manner as in Example 1, except that the type of inorganic flocculant used in the first addition step of Example 1 and the type of cationic surfactant contained in the water treatment chemical used in the second addition step of Example 1 were changed to the surfactants listed in Table 2, and water treatments according to Examples 2 to 24 and Comparative Examples 1 to 9 were carried out. In Examples 2 to 24 and Comparative Examples 1 to 9, the weight ratio of the cationic surfactant added in the second addition step to the weight of the inorganic flocculant added in the first addition step was 0.7. For each of Examples 2 to 24 and Comparative Examples 1 to 9, the COD of the obtained filtrate was measured, and the COD of the filtrate and the COD reduction rate are shown in Table 2.

[0183] Examples 25 to 27 Water treatment according to Examples 25 to 27 was carried out by treating simulated wastewater in the same manner as in Example 1, except that an aqueous solution containing two types of cationic surfactants listed in Table 2 at a concentration of 5% by weight was used as the water treatment chemical containing a cationic surfactant used in the second addition step. In Examples 25 to 27, the total weight ratio of the cationic surfactant added in the second addition step to the weight of the inorganic flocculant added in the first addition step was 0.7. For each of Examples 25 to 27, the COD of the obtained filtrate was measured, and the COD of the filtrate and the COD reduction rate are shown in Table 2.

[0184]

[0185] The cationic surfactants represented by symbols in Table 2 are as follows: (A1-1): Octyltrimethylammonium chloride [manufactured by Tokyo Chemical Industry Co., Ltd., chemical formula weight: 208, cation charge density: 4.8 meq / g] (A1-2): Dodecyltrimethylammonium chloride [manufactured by Tokyo Chemical Industry Co., Ltd., chemical formula weight: 264, cation charge density: 3.8 meq / g] (A1-3): Tetradecyltrimethylammonium chloride [manufactured by Tokyo Chemical Industry Co., Ltd., chemical formula weight: 292, cation charge density: 3.4 meq / g] (A1-4): Hexadecyltrimethylammonium chloride [manufactured by Tokyo Chemical Industry Co., Ltd., chemical formula weight: 320, cation charge density: 3.1 meq / g] (A1-5): Hexadecyltrimethylammonium bromide [manufactured by Tokyo Chemical Industry Co., Ltd., chemical formula weight: 364, cation charge density: 2.7 meq / g] (A1-6): Hexadecyltrimethylammonium hydroxide [manufactured by Tokyo Chemical Industry Co., Ltd., chemical formula weight: 302, cation charge density: 3.3 meq / g] (A1-7): Stearyltrimethylammonium chloride [manufactured by Tokyo Chemical Industry Co., Ltd., chemical formula weight: 348, cation charge density: 2.9 meq / g] (A2-1): Hexyldimethyloctylammonium chloride [manufactured by Tokyo Chemical Industry Co., Ltd., chemical formula weight: 278, cation charge density: 3.6 meq / g] (A2-2): Didecyldimethylammonium chloride [manufactured by Tokyo Chemical Industry Co., Ltd., chemical formula weight: 362, cation charge density: 2.8 meq / g] (A2-3): Didodecyldimethylammonium chloride [manufactured by Tokyo Chemical Industry Co., Ltd., chemical formula weight: 418, cation charge density: 2.4 meq / g] (A2-4): Ditetradecyldimethylammonium chloride [manufactured by Tokyo Chemical Industry Co., Ltd., chemical formula weight: 474, cation charge density: 2.1 meq / g] (A3-1): N,N'-didecyl-N,N,N',N'-tetramethyl-1,3-propanediammonium dichloride [manufactured by GuideChem, chemical formula weight: 484, cation charge density: 4.1 meq / g] (A4-1): benzylhexyldimethylammonium chloride [manufactured by Tokyo Chemical Industry Co., Ltd., chemical formula weight: 256, cation charge density: 3.9 meq / g] (A4-2): benzyllauryldimethylammonium chloride [manufactured by Tokyo Chemical Industry Co., Ltd., chemical formula weight: 340, cation charge density: 2.9 meq / g] (A4-3): benzylhexadecyldimethylammonium chloride [manufactured by Tokyo Chemical Industry Co., Ltd., chemical formula weight: 396, cation charge density: 2.5 meq / g] (A4-4): benzyldimethylstearylammonium chloride [manufactured by Tokyo Chemical Industry Co., Ltd., chemical formula weight: 424, cation charge density: 2.4 meq / g] (A5-1): 1-n-hexylpyridinium chloride [manufactured by Tokyo Chemical Industry Co., Ltd., chemical formula weight: 200, cation charge density: 5.0 meq / g] (A5-2): 1-laurylpyridinium chloride [manufactured by Tokyo Chemical Industry Co., Ltd., chemical formula weight: 284, cation charge density: 3.5 meq / g] (A5-3): 1-n-hexadecylpyridinium chloride [manufactured by Tokyo Chemical Industry Co., Ltd., chemical formula weight: 340, cation charge density: 2.9 meq / g] (A5-4): 1-stearylpyridinium chloride [manufactured by Tokyo Chemical Industry Co., Ltd., chemical formula weight: 368, cation charge density: 2.7 meq / g] (A5-5): 1-n-hexadecyl-4-methylpyridinium chloride [manufactured by Tokyo Chemical Industry Co., Ltd., chemical formula weight: 354, cation charge density: 2.8 meq / g] <Comparative Cationic Surfactants> (CA1-1): Tetramethylammonium chloride [manufactured by Tokyo Chemical Industry Co., Ltd., chemical formula weight: 110, cation charge density: 9.1 meq / g] (CA1-2): Docosyltrimethylaminium chloride [manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., chemical formula weight: 404, cation charge density: 2.5 meq / g] (CA2-1): Dihexadecyldimethylammonium chloride [manufactured by Tokyo Chemical Industry Co., Ltd., chemical formula weight: 530, cation charge density: 1.9 meq / g] (CA2-2): Didocosyldimethylaminium chloride [manufactured by Career Henan Chemical Co., chemical formula weight: 695, cation charge density: 1.4 meq / g] (CA3-1): Hexane-1,6-bis(trimethylammonium bromide) chloride [manufactured by Tokyo Chemical Industry Co., Ltd., chemical formula weight: 362, cation charge density: 5.5 meq / g] (CA4-1): benzyltrimethylammonium chloride [manufactured by Tokyo Chemical Industry Co., Ltd., chemical formula weight: 186, cation charge density: 5.4 meq / g] (CA4-2): benzyldocosyldimethylammonium chloride [manufactured by Career Henan Chemical Co., chemical formula weight: 478, cation charge density: 2.1 meq / g] (CA5-1): 1-methylpyridinium chloride [manufactured by Tokyo Chemical Industry Co., Ltd., chemical formula weight: 130, cation charge density: 7.7 meq / g] (CA5-2): 1-docosylpyridinium chloride [manufactured by Career Henan Chemical Co., Ltd. Chemical formula weight: 422, cation charge density: 2.4 meq / g],

[0186] Example 28 One liter of the same simulated wastewater as used in Example 1 was collected in a beaker, and while stirring the simulated wastewater, 3,000 mg of a 10 wt% aqueous solution of aluminum sulfate (inorganic flocculant: 300 mg) was added to perform the first addition step. After adding the inorganic flocculant, the mixture was further stirred for 5 minutes, and then 1,000 mg of the water treatment agent (P1-4) containing hexadecyltrimethylammonium chloride prepared in Example 4 (cationic surfactant: 100 mg) was added to perform the second addition step. After stirring for 5 minutes, 1,000 mg of a 10 wt% aqueous solution of cationic polymer (cationic polymer: 100 mg) prepared by diluting the water treatment agent (P2-1) prepared in Production Example 1 with 4 times the amount of ion-exchanged water was added to perform the third addition step. After stirring for 5 minutes, a 10 wt% aqueous solution of sodium hydroxide was added dropwise under stirring until the pH of the water to be treated reached 7.0, and the mixture was then stirred for another 5 minutes and allowed to stand for 5 minutes. The supernatant separated by standing was filtered using filter paper (No. 5C), and the COD of the resulting filtrate was measured in accordance with the CODMn analysis method described in JIS K0102: 2016. In this example, the weight ratio of the cationic surfactant added in the second addition step to the weight of the inorganic flocculant added in the first addition step was 0.3, the weight ratio of the cationic polymer added in the third addition step to the weight of the inorganic flocculant added in the first addition step was 0.3, the COD was 70 mg / L, and the calculated COD reduction rate was 0.86.

[0187] Examples 29 to 42 and Comparative Examples 10 to 13 In Example 28, simulated wastewater was treated in the same manner as in Example 28, except that the inorganic flocculant used in the first addition step and the water treatment chemical (P2) containing a cationic polymer used in the third addition step were changed to those shown in Table 3, and water treatment according to Examples 29 to 42 and Comparative Examples 10 to 13 was carried out. In Examples 29 to 42 and Comparative Examples 10 to 13, the weight ratio of the cationic surfactant added in the second addition step to the weight of the inorganic flocculant added in the first addition step was 0.3, and the weight ratio of the cationic polymer added in the third addition step to the weight of the inorganic flocculant added in the first addition step was 0.3. The COD of the filtrate for each of Examples 29 to 42 and Comparative Examples 10 to 13 was measured, and the COD of the filtrate and the COD reduction rate are shown in Table 3.

[0188] Examples 43 to 45 Water treatment according to Examples 43 to 45 was carried out by treating simulated wastewater in the same manner as in Example 28, except that an aqueous solution containing two types of cationic surfactants listed in Table 3 at a concentration of 5% by weight was used as the water treatment chemical containing the cationic surfactant used in the second addition step. In Examples 43 to 45, the total weight ratio of the cationic surfactant added in the second addition step to the weight of the inorganic flocculant added in the first addition step was 0.7. For each of Examples 43 to 45, the COD of the obtained filtrate was measured, and the COD of the filtrate and the COD reduction rate are shown in Table 3.

[0189]

[0190] The symbols representing the cationic surfactants listed in Table 3 are the same as those in Table 2, and the symbols representing the water treatment chemicals and cationic polymers used in the third addition step represent the water treatment chemicals and cationic polymers prepared in Production Examples 1 to 12 and Comparative Production Examples 1 to 4 and listed in Table 1.

[0191] Example 46 1 L of the same simulated wastewater as used in Example 1 was collected in a beaker, and while stirring the simulated wastewater, 3,000 mg of a 10 wt% aqueous solution of aluminum sulfate (inorganic flocculant: 300 mg) was added to perform the first addition step. After adding the inorganic flocculant, the mixture was stirred for another 5 minutes, and then 1,000 mg of the water treatment agent (P1-4) containing hexadecyltrimethylammonium chloride (A1-4) prepared in Example 4 (cationic surfactant: 100 mg) was added to perform the second addition step. After stirring for 5 minutes, a pH adjustment step was performed by adding a 10 wt% aqueous sodium hydroxide solution dropwise under stirring until the pH of the water to be treated reached 7.0. After that, the mixture was stirred for an additional 5 minutes, and 1,000 mg of a 0.1 wt% aqueous solution of a polymer flocculant (product name: Sunfloc AH-400P (manufactured by Sanyo Chemical Industries, Ltd.)) prepared by dissolving it in ion-exchanged water at a concentration of 0.1 wt% under stirring was added (polymer flocculant: 1 mg) to carry out the polymer flocculant addition step. After the polymer flocculant addition step, the mixture was stirred for 1 minute and then allowed to stand for 5 minutes. The supernatant separated by standing was filtered with filter paper (No. 5C), and the COD of the obtained filtrate was measured in accordance with the CODMn analysis method described in JIS K0102:2016. In this example, the weight ratio of the cationic surfactant added in the second addition step to the weight of the inorganic flocculant added in the first addition step was 0.7, the COD was 80 mg / L, and the calculated COD reduction rate was 0.84.

[0192] Examples 47 and 48 Water treatment according to Examples 47 and 48 was carried out by treating simulated wastewater in the same manner as in Example 46, except that the polymer flocculant was changed to one shown in Table 4. In Examples 47 and 48, the weight ratio of the cationic surfactant added in the second addition step to the weight of the inorganic flocculant added in the first addition step was 0.7. For each of Examples 47 and 48, the COD of the filtrate was measured, and the COD of the filtrate and the COD reduction rate are shown in Table 4.

[0193]

[0194] The symbols representing the cationic surfactants shown in Table 4 are the same as those in Table 2.

[0195] The polymer flocculants used in Table 4 were as follows: Sanfloc AH-400P: an anionic polymer flocculant manufactured by Sanyo Chemical Industries, Ltd. Sanfloc N-500P: a nonionic polymer flocculant manufactured by Sanyo Chemical Industries, Ltd. Sanfloc C-009P: a cationic polymer flocculant manufactured by Sanyo Chemical Industries, Ltd.

[0196] Example 49 1 L of the same simulated wastewater as used in Example 1 was collected in a beaker, and while stirring the simulated wastewater, 3,000 mg of a 10 wt% aqueous solution of aluminum sulfate (inorganic flocculation: 300 mg) was added to perform the first addition step. After adding the inorganic flocculant, the mixture was stirred for a further 5 minutes, and then 1,000 mg of the water treatment agent (P1-4) containing hexadecyltrimethylammonium chloride (A1-4) prepared in Example 4 (cationic surfactant: 100 mg) was added to perform the second addition step. After stirring for 5 minutes, the water treatment agent (P2-1) prepared in Production Example 1 was diluted with 4 times the amount of ion-exchanged water to prepare a 10 wt% aqueous solution of cationic polymer (cationic polymer: 100 mg) was added to perform the third addition step. Then, after stirring for 5 minutes again, a 10 wt% aqueous solution of sodium hydroxide was added dropwise under stirring until the pH of the water to be treated reached 7.0. After that, the mixture was stirred for an additional 5 minutes, and 1,000 mg of a 0.1 wt% aqueous solution of a polymer flocculant (product name: Sunfloc AH-400P (manufactured by Sanyo Chemical Industries, Ltd.), an anionic polymer flocculant) prepared by dissolving it in ion-exchanged water at a concentration of 0.1 wt% under stirring (polymer flocculant: 1 mg) was added to perform the polymer flocculant addition process. After the polymer flocculant addition process, the mixture was stirred for 1 minute and then allowed to stand for 5 minutes. The supernatant liquid separated by standing was filtered with filter paper (No. 5C), and the COD of the obtained filtrate was measured in accordance with the CODMn analysis method described in JIS K0102:2016. In this example, the weight ratio of the cationic surfactant added in the second addition step to the weight of the inorganic flocculant added in the first addition step was 0.3, the weight ratio of the cationic polymer added in the third addition step to the weight of the inorganic flocculant added in the first addition step was 0.3, the COD was 70 mg / L, and the calculated COD reduction rate was 0.86.

[0197] Examples 50 and 51: Water treatment was performed in the same manner as in Example 49, except that the polymer flocculant was changed to one listed in Table 5. In Examples 50 and 51, the weight ratio of the cationic surfactant added in the second addition step to the inorganic flocculant added in the first addition step was 0.3, and the weight ratio of the cationic polymer added in the third addition step to the inorganic flocculant added in the first addition step was 0.3. For each of Examples 50 and 51, the COD of the filtrate was measured, and the COD of the filtrate and the COD reduction rate are shown in Table 5.

[0198]

[0199] The symbols representing the cationic surfactants listed in Table 5 are the same as those in Table 2, and the polymer flocculants are the same as those listed in Table 4. The symbols representing the water treatment chemicals and cationic polymers used in the third addition step represent the water treatment chemicals and cationic polymers listed in Table 1.

[0200] The water treatment agent and water treatment method of the present invention have a higher COD reduction effect than the water treatment method of the comparative example.

[0201] The water treatment chemical, water treatment chemical kit, and water treatment method of the present invention are more effective in removing water-soluble COD components than conventional methods, and therefore can be used as a method for treating wastewater containing organic components, such as sewage or industrial wastewater. They are also suitable for use in treating muddy water at civil engineering sites, promoting sedimentation and separation of muddy water during dredging and landfilling, and treating wastewater in papermaking processes.

Claims

1. A water treatment agent containing a cationic surfactant having a chemical formula weight or number average molecular weight of 500 or less, a cationic charge density of 2.0 to 5.0 meq / g, and at least one aliphatic hydrocarbon group having 6 to 18 carbon atoms and at least one quaternary nitrogen atom.

2. Further, it contains a cationic polymer having a cationic monomer (m1) as a constituent monomer, a weight average molecular weight of 10,000 to 1,000,000, and a colloid equivalent value of 0.1 to 6.5 meq / g, and the cationic monomer (m1) contains one or more selected from the group consisting of a cationic monomer (m11) represented by the following general formula (i) and a cationic monomer (m12) represented by the following general formula (ii). The water treatment agent according to claim 1. CH ２ =C(R ｉ １ )-CO-X ｉ -Q-N ＋ (R ｉ ２ ) ３ ·Z － (i) [In the formula, R ｉ １ is a hydrogen atom or a methyl group, and three Rs ｉ ２ are each independently a hydrogen atom, an alkyl group having 1 to 22 carbon atoms, or a benzyl group, X ｉ is an oxygen atom or an imino group, Q is an alkylene group having 1 to 6 carbon atoms, and Z － represents a monovalent anion. ] (CH ２ =C(R ｉ ３ )-CH ２ ) ２ -N ＋ (R ｉ ４ ) ２ ·Z － (ii) [In the formula, R ｉ ３ is a hydrogen atom or a methyl group, and two Rs ｉ ４ are each independently a hydrogen atom, an alkyl group having 1 to 22 carbon atoms, or a benzyl group, and Z － represents a monovalent anion. ] 3. A first water treatment chemical containing a cationic surfactant having a chemical formula weight or number average molecular weight of 500 or less, a cationic charge density of 2.0 to 5.0 meq / g, and 6 to 18 carbon atoms, and having at least one aliphatic hydrocarbon group and at least one quaternary nitrogen atom; A water treatment kit having a second water treatment chemical containing a cationic polymer having a cationic monomer (m1) as a constituent monomer, a weight average molecular weight of 10,000 to 1,000,000, and a colloid equivalent value of 0.1 to 6.5 meq / g, wherein the cationic monomer (m1) is selected from the group consisting of a cationic monomer (m11) represented by the following general formula (i) and a cationic monomer (m12) represented by the following general formula (ii). One or more kinds are included, a water treatment kit. CH ２ =C(R ｉ １ )-CO-X ｉ -Q-N ＋ (R ｉ ２ ) ３ ·Z － (i) [In the formula, R ｉ １ is a hydrogen atom or a methyl group, and three Rs ｉ ２ are each independently a hydrogen atom, an alkyl group having 1 to 22 carbon atoms, or a benzyl group, X ｉ is an oxygen atom or an imino group, Q is an alkylene group having 1 to 6 carbon atoms, and Z － represents a monovalent anion. ] (CH ２ =C(R ｉ ３ )-CH ２ ) ２ -N ＋ (R ｉ ４ ) ２ ·Z － (ii) [In the formula, R ｉ ３ is a hydrogen atom or a methyl group, and two Rs ｉ ４ are each independently a hydrogen atom, an alkyl group having 1 to 22 carbon atoms, or a benzyl group, and Z － represents a monovalent anion. ] 4. A water treatment method having a step of adding an inorganic flocculant to the water to be treated (first addition step) and a step of adding a cationic surfactant having a chemical formula weight or number average molecular weight of 500 or less, a cationic charge density of 2.0 to 5.0 meq / g, and at least one aliphatic hydrocarbon group having 6 to 18 carbon atoms and at least one quaternary nitrogen atom to the water to be treated (second addition step).

5. A step of adding a cationic polymer having a cationic monomer (m1) as a constituent monomer, having a weight average molecular weight of 10,000 to 1,000,000, and having a colloid equivalent value of 0.1 to 6.5 meq / g to the water to be treated (third addition step), wherein the cationic monomer (m1) contains one or more selected from the group consisting of a cationic monomer (m11) represented by the following general formula (i) and a cationic monomer (m12) represented by the following general formula (ii). The water treatment method according to claim 4. CH ２ =C(R ｉ １ )-CO-X ｉ -Q-N ＋ (R ｉ ２ ) ３ ·Z － (i) [In the formula, R ｉ １ is a hydrogen atom or a methyl group, and three R ｉ ２ are each independently a hydrogen atom, an alkyl group having 1 to 22 carbon atoms or a benzyl group, X ｉ is an oxygen atom or an imino group, Q is an alkylene group having 1 to 6 carbon atoms, and Z － represents a monovalent anion. ] (CH ２ =C(R ｉ ３ )-CH ２ ) ２ -N ＋ (R ｉ ４ ) ２ ·Z － (ii) [In the formula, R ｉ ３ is a hydrogen atom or a methyl group, and two R ｉ ４ are each independently a hydrogen atom, an alkyl group having 1 to 22 carbon atoms or a benzyl group, and Z － represents a monovalent anion. ]

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