JP2012157816A - Polymer flocculant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polymer flocculant excellent in dehydrating effects, such as drastically improving efficiency in dehydrating sludge by forming strong and coarse flock, in treatment of sludge or waste water.SOLUTION: The polymer flocculant includes water-soluble polymer (A) containing vinyl group-containing monomer (a) represented by the following general formula (1) or containing (a) and (meth)acryloyl group-containing monomer (b) represented by the following general formula (2), as structural units, provided that the general formula (1) is CH=CH-(NRR) and the general formula (2) is CH=CR-CO-X-(Q-NRRR* Z)(H).

Description

  The present invention relates to a polymer flocculant used for treatment of organic or inorganic sludge or wastewater such as sewage or human waste (hereinafter abbreviated as sewage) or factory wastewater, and sludge or wastewater using the polymer flocculant. It relates to the processing method.

  Conventionally, as a polymer flocculant used for the treatment of organic sludge generated by the treatment of sewage or the like, or the inorganic sludge produced by the treatment of factory wastewater or the like, a tertiary salt or quaternary of dialkylaminoethyl (meth) acrylate is used. Polymers of chlorinated salts and copolymers with acrylamide are widely used. Also, diallylamine quaternized salts or quaternized salt polymers (see, for example, Patent Document 1), diallylamine quaternized salts or 4 A copolymer of a quaternized salt and a tertiary or quaternized salt of dialkylaminoethyl (meth) acrylate (for example, see Patent Documents 2 and 3), a polymer having an amidine structure (for example, see Patent Document 4) Etc. are also known.

JP-A-56-18611 JP-A 51-37986 Japanese Unexamined Patent Publication No. 63-242309 Japanese Patent Laid-Open No. 5-192513

However, a polymer of a tertiary or quaternized salt of dialkylaminoethyl (meth) acrylate and a copolymer of these monomers and acrylamide can be used alone for sludge treatment and have excellent handleability. Because the cation density cannot be increased, the strength of the floc formed is small with the usual addition amount, and when the excessive amount is added, the flocs once aggregated are redispersed, or the separated flocs are separated into the separated liquid. The dehydrating property of the cake separated into solid and liquid deteriorates, such as viscosity.
In addition, since it is difficult to increase the molecular weight of the polymer flocculants of Patent Documents 1 to 4, there is a problem that, when used alone, the floc particle size formed is small and the drainage is deteriorated. Although it is used in combination with a (co) polymer such as a tertiary salt of ethyl (meth) acrylate, there is a problem in treatment efficiency, such as treatment of sludge or wastewater in two stages.
That is, with the conventional polymer flocculant, it is difficult to obtain a sufficient dehydration effect with excellent treatment efficiency when treating sludge or wastewater.
An object of the present invention is to provide a polymer flocculant having an excellent dewatering effect, for example, by forming a strong coarse floc in the treatment of sludge or wastewater to greatly improve the dewatering efficiency of sludge.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have reached the present invention. That is, the present invention provides a vinyl group-containing monomer (a) represented by the following general formula (1), or (a) and a (meth) acryloyl group-containing monomer (b) represented by the following general formula (2). Polymer flocculant containing water-soluble polymer (A) as structural unit

^{_{CH 2 = CH- (NR 1 R}} 2) (1)
^{_{CH 2 = CR 3 -CO-X-}} (Q-N + R 4 R 5 R 6 · Z -) m (H) 1-m (2)

[In Formula (1), R ¹ and R ² each independently represent H or a C 1-6 hydrocarbon group that may contain a hetero atom, and R ¹ and R ² are bonded to each other; A ring may be formed, and (NR ¹ R ² ) represents a monovalent group bonded to a vinyl group at N or any of R ¹ and R ² .
In the formula (2), X is O or NH; Q is an alkylene group having 1 to 4 carbon atoms or a hydroxyalkylene group having 2 to 4 carbon atoms; R ³ is H or a methyl group; R ⁴ , R ⁵ , R ⁶ are Each independently H, an alkyl, aralkyl or alkylaryl group having 1 to 16 carbon atoms; Z ⁻ represents a counter anion; m represents a number of 0 or 1; ]
And a method for treating sludge or wastewater, characterized in that the polymer flocculant is added to and mixed with sludge or wastewater to form a floc for solid-liquid separation.

The polymer flocculant of the present invention has the following effects.
(1) Form strong coarse flocs in sludge and wastewater treatment.
(2) Since the formed floc is not easily broken or redispersed, the stability and processing speed of the aggregation treatment can be remarkably increased.
(3) The moisture content of the cake after the dehydration step is low, and the amount of waste and incineration costs can be reduced.
(4) Excellent dehydration effect without using a coagulant.

[Water-soluble polymer (A)]
The water-soluble polymer (A) in the present invention is a vinyl group-containing monomer (a) represented by the following general formula (1), or a (meth) acryloyl group represented by (a) and the following general formula (2). It is a water-soluble polymer comprising the containing monomer (b) as a structural unit.

^{_{CH 2 = CH- (NR 1 R}} 2) (1)
^{_{CH 2 = CR 3 -CO-X-}} (Q-N + R 4 R 5 R 6 · Z -) m (H) 1-m (2)

In general formula (1), R ¹ and R ² are each independently H or a hydrocarbon group having 1 to 6 (preferably 1 to 4) carbon atoms (hereinafter abbreviated as C) that may contain a hetero atom. Represents. R ¹ and R ² may be bonded to each other to form a ring, and (NR ¹ R ² ) is a monovalent group bonded to a vinyl group at either N or R ¹ or R ² .

The heteroatoms include N, O, and S. When C of R ¹ and R ² exceeds 6, the solubility of (A) in water becomes poor.
Examples of the hydrocarbon group include methyl, ethyl, n- and i-propyl, n-, i-, sec- and t-butyl, n-, i-, sec- and t-amyl, n-hexyl and ethenyl. Examples of the ring in which R ¹ and R ² are bonded to each other include piperidine, piperazine, pyridine, pyrrolidine, morpholine and thiomorpholine rings. Of these, piperidine, piperazine and pyridine ring are preferred from the viewpoint of aggregation performance.

In formula (2), X is O or NH, Q is an alkylene or hydroxyalkylene group of C2~4 of C1 -4, R ³ is H or ^{methyl; R 4, R 5, R} 6 are each independently H, a C1-16 alkyl, aralkyl or alkylaryl group; Z ⁻ represents a counter anion, and m represents a number of 0 or 1. When m is 0, the general formula (2) represents (meth) acrylic acid or (meth) acrylamide.
When C of Q exceeds 4, the solubility of (A) in water is deteriorated. Also, solubility in water of R ^4, R ^5, when C in R ⁶ is greater than 16 (A) is deteriorated.

The C1-4 alkylene group includes methylene, ethylene, and n- and i-propylene groups, and the C2-4 hydroxyalkylene group includes hydroxyethylene, 1- and 2-hydroxypropylene groups, and the like. .

As Z ⁻ in the general formula (2), halogen (Cl ⁻ , Br ⁻ etc.), inorganic acid (hydrohalic acid, sulfuric acid, nitric acid, phosphoric acid etc.), sulfuric ester (C1-30, for example, alkyl sulfate, Alkenyl sulfates), sulfonic acids (C1-30, such as alkane sulfonic acids), phosphate esters (C1-30, such as mono- and dialkyl phosphate esters), phosphonic acids (C1-30, such as alkyl sulfonic acids), organic Anions such as acids (C1-30, such as formic acid, acetic acid, maleic acid) can be mentioned.

Among these Z ⁻ , from the viewpoint of dehydrating performance of the polymer flocculant described later, preferred are anions of halogen, sulfuric acid, sulfate and sulfonic acid, and more preferred are anions of halogen, sulfuric acid and sulfate, particularly preferred. is Cl ^-, sulfates, anionic methyl sulfate and ethyl sulfate, most preferably Cl ^- it is.

Specific examples of the vinyl group-containing monomer (a) include N-vinylpiperidine, N-vinylpiperazine, 2- and 4-vinylpyridine, N-vinylamine, N-methylvinylamine, N, N-dimethylvinylamine, N -Ethyl vinylamine, N-vinyl pyrrolidine, N-vinyl morpholine, etc. are mentioned.
Among these, N-vinyl piperidine, N-vinyl piperazine, and vinyl pyridine are preferable from the viewpoint of aggregation performance.

Specific examples of the (meth) acryloyl group-containing monomer (b) include (meth) acrylamide, (meth) acrylic acid, (meth) acrylate [dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, these Hydrochloride or sulfate, ammonium salts obtained by quaternizing these amine salts with methyl chloride or benzyl chloride, and the like.
Among these, ammonium salt obtained by quaternizing acrylamide or dimethylaminoethyl (meth) acrylate hydrochloride with methyl chloride is preferable from the viewpoint of aggregation performance.

The molar ratio of (a) and (b) constituting (A) is preferably 5/95 to 100/0, more preferably 20/80 to 95/5, and 40/60 from the viewpoints of coagulation performance and aggregation performance. ~ 90/10.

In the present invention, the molecular weight of (A) is usually 0.1 when the intrinsic viscosity (dl / g) measured at 30 ° C. in a 1N—NaNO ₃ aqueous solution, and the lower limit of the aggregation performance (particularly floc coarsening). From the viewpoint, it is preferably 1, more preferably 2, most preferably 4, and the upper limit is preferably 20, more preferably 18, and most preferably 16 from the viewpoint of setting performance (particularly improvement of floc strength). Intrinsic viscosity in Examples described later is a value measured under the above conditions.

The production method of (A) is not particularly limited, and radical polymerization methods such as aqueous solution polymerization, reverse phase suspension polymerization, precipitation polymerization and reverse phase emulsion polymerization can be used. Among these, aqueous solution polymerization, reverse phase suspension polymerization and reverse phase emulsion polymerization are preferable from an industrial viewpoint, and aqueous solution polymerization and reverse phase suspension polymerization are more preferable.
As aqueous solution polymerization, for example, an aqueous monomer solution is placed in a heat-insulated container where heat does not enter and exit from the outside, and a method of performing adiabatic polymerization (eg, Japanese Patent Publication No. 59-40843) and a monomer aqueous solution in a container whose temperature can be adjusted from the outside A method of performing constant temperature polymerization (for example, JP-A-3-189000) can be used.

The reverse phase suspension polymerization is, for example, a method in which an aqueous solution of a water-soluble monomer is dispersed in a water-in-oil type and polymerized using an oil-soluble polymer substance or a nonionic surfactant as a dispersion stabilizer (for example, JP-A-56-56). 53111).

Examples of the oil-soluble polymer substance include cellulose ether [molecular weight of 100 or more and number average molecular weight [hereinafter abbreviated as Mn. The measurement is based on a gel permeation chromatography (GPC) method. 100,000 or less, such as ethyl cellulose, ethyl hydroxyethyl cellulose], a copolymer of an alkene and an α, β-unsaturated polycarboxylic acid (anhydride) or a derivative thereof [molecular weight of 100 or more and Mn of 100,000 or less, such as C20 Copolymers of 1 to 40 1-olefins and (anhydrous) maleic acid].

  Nonionic surfactants include, for example, sucrose fatty acid esters (C13-100, such as sucrose distearate, sucrose tristearate), sorbitan fatty acid esters (C7-100, such as sorbitan monostearate, sorbitan monooleate) and poly Glycerin fatty acid ester (C6-100, for example, glyceryl monostearate) is mentioned.

The lower limit of the amount of the oil-soluble polymer substance and / or nonionic surfactant used is usually 0.1%, preferably 0.2%, more preferably based on the weight of the dispersion medium (organic solvent) described later. 0.5%, the upper limit is usually 10%, preferably 5%, more preferably 3%.
Examples of the dispersion medium (organic solvent) used include aliphatic hydrocarbons (C6-30, such as hexane, heptane, n-decane), alicyclic hydrocarbons (C6-30, such as cyclohexane, decalin), aromatics, and the like. Group hydrocarbons (C6-12, such as benzene, toluene, xylene and the like).

Further, as the reverse phase emulsion polymerization, for example, a method of polymerizing an aqueous solution of a water-soluble monomer by using a surfactant to form a water-in-oil emulsion (for example, Japanese Patent No. 2676483, Japanese Patent Laid-Open No. 9-208802). Can be used.

Examples of the dispersion medium to be used include hydrocarbons [C6-30, such as paraffin (eg, n-paraffin, isoparaffin), mineral oil (eg, kerosene, light oil, medium oil), synthetic oil] and mixtures thereof.
As the surfactant used for emulsification, known ones described in, for example, Japanese Patent No. 2676483 and Japanese Patent Application Laid-Open No. 9-208802 can be used, and among these, preferred from the viewpoint of emulsion stability. Are nonionic surfactants and combinations of nonionic surfactants with other ionic surfactants.

Nonionic surfactants include, for example, higher fatty acid esters (for example, sorbitan monostearate, sorbitan distearate, sorbitan monooleate and oleic acid sorbitan ester EO adduct), polyoxyethylene long chain alkyl ether (for example, lauryl alcohol polyester). Oxyethylene ethers and polyoxyethylene nonylphenyl ethers) and long chain alkyl alkanolamides such as N, N-dihydroxyethyllaurylamide.

The amount of these surfactants used is usually 0.05%, preferably 0.1%, more preferably 0.12%, and the upper limit is usually 1%, preferably 0, based on the weight of the dispersion medium. 0.5%, more preferably 0.25%.
In addition, when the water-in-oil emulsion is diluted with water and used, a phase inversion agent may be added to the water-in-oil emulsion in advance so that the water-in-oil emulsion is poured into water and phase inversion is performed quickly. As the phase inversion agent, a highly hydrophilic surfactant [for example, HLB (Hydrophile-Lipophile Balance, an index indicating a balance between hydrophilicity and lipophilicity, based on the Griffin's HLB theory) of 9 to 20] For example, cationic surfactants and / or nonionic surfactants described in Japanese Patent No. 2676483 and JP-A-9-208802 can be used.

Various radical polymerization initiators in the radical polymerization method, such as water-soluble azo compounds [for example, azobisamidinopropane (salt) [for example, 2,2′-azobis (2-methylpropionamidine) dihydrochloride] Azobiscyanovaleric acid (salt) and 2,2′-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] (salt)], oil-soluble azo compounds (for example, azobiscyanovaleronitrile) Azobisisobutyronitrile and azobiscyclohexanecarbonitrile), water-soluble peroxides (eg hydrogen peroxide, peracetic acid and t-butyl peroxide), oil-soluble peroxides (eg benzoyl peroxide and cumene hydroxyperoxide) Oxides) and inorganic peroxides (eg ammonium persulfate and persulfate) Sodium), and the like.

The above peroxides may be used as a redox initiator in combination with a reducing agent, such as bisulfite (eg, sodium bisulfite, potassium bisulfite and ammonium bisulfite), reducing metal salts [eg, iron sulfate] (II)], tertiary amines [eg dimethylaminobenzoic acid (salt) and dimethylaminoethanol], amine complexes of transition metal salts [eg pentamethylenehexamine complex of cobalt (III) chloride and diethylenetriamine complex of copper (II) chloride And an organic reducing agent (for example, ascorbic acid). In addition, the azo compound, peroxide and redox initiator may be used alone or in combination of two or more initiators.

The use amount of the radical polymerization initiator is preferably 0.001% from the viewpoint of obtaining the optimum molecular weight as (A) based on the total weight of the monomers including (a) or (a) and (b). More preferably 0.005%, particularly preferably 0.01%, most preferably 0.02%, the preferred upper limit is 1%, more preferably 0.5%, particularly preferably 0.1%, most preferably 0. .05%.

Moreover, you may use the chain transfer agent for radical polymerization as needed. The chain transfer agent for radical polymerization is not particularly limited. For example, a compound having one or more hydroxyl groups in the molecule [molecular weight of 32 or more and Mn of 50,000 or less, such as methanol, ethanol, isopropyl alcohol, ethylene glycol, propylene Glycol, polyethylene glycol (molecular weight 100 or more and Mn 50,000 or less) and polyethylene polypropylene glycol (molecular weight 100 or more and Mn 50,000 or less)], compounds having one or more amino groups in the molecule [for example, ammonia and amines (C1-30, such as methylamine, dimethylamine, triethylamine and propanolamine)] and compounds having one or more thiol groups in the molecule (described later).
Among these, a compound having one or more thiol groups in the molecule is preferable from the viewpoint of molecular weight control.

Compounds having a thiol group in the molecule include the following, mixtures thereof and salts thereof [alkali metal (for example, lithium, sodium and potassium) salts, alkaline earth metal (for example, magnesium and calcium) salts, ammonium salts, Amine (C1-20) salts and inorganic acids (eg hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid) salts].

(1) Monovalent thiol aliphatic thiol [C1-20, such as methanethiol, ethanethiol, propanethiol, n-octanethiol, n-dodecanethiol, hexadecanethiol, n-octadecanethiol, 2-mercaptoethanol, mercaptoacetic acid, 3-mercaptopropionic acid, 1-thioglycerol, thioglycolic acid monoethanolamine), 1-thioglycerol, thioglycolic acid monoethanolamine, thiomaleic acid, cysteine and 2-mercaptoethylamine], alicyclic thiols (C5-20) For example, cyclopentanethiol and cyclohexanethiol) and aromatic (aliphatic) thiols (C6-12, such as benzenethiol and benzyl mercaptan and thiosalicylic acid).

(2) Polyvalent thiol dithiol [aliphatic (C2-40) dithiol (for example, ethanedithiol, diethylenedithiol, triethylenedithiol, propanedithiol, 1,3- and 1,4-butanedithiol, 1,6-hexanedithiol, Neopentanedithiol, etc.), alicyclic (C5-20) dithiols (eg cyclopentanedithiol and cyclohexanedithiol) and aromatic (C6-16) dithiols (eg benzenedithiol, biphenyldithiol), trithiols (C3-20, eg thio) Glycerin).

The amount used in the case of using the chain transfer agent for radical polymerization is preferably the lower limit from the viewpoint of obtaining the optimum molecular weight as (A) based on the total weight of the monomers including (a) or (a) and (b). Is 0.0001%, more preferably 0.0005%, particularly preferably 0.001%, most preferably 0.005%, the preferred upper limit is 10%, more preferably 5%, particularly preferably 3%, most preferably Is 1%.

The monomer concentration in the aqueous monomer solution in radical polymerization is usually 20% based on the total weight of the aqueous monomer solution in aqueous polymerization, preferably 25%, more preferably 30%, and particularly preferably 40% from the viewpoint of increasing the molecular weight. %, Most preferably 50%, the upper limit is usually 80%, preferably 75%, more preferably 70%, particularly preferably 65%, most preferably 60% from the viewpoint of polymerization temperature control;

In the reverse phase suspension polymerization, the lower limit is usually 30%, preferably 40%, more preferably 45%, particularly preferably 50%, most preferably 55%, and the upper limit is usually 90%. From the viewpoint of control, it is preferably 85%, more preferably 80%, particularly preferably 78%, most preferably 75%;

In the inverse emulsion polymerization, the lower limit is usually 10%, preferably 20%, more preferably 30%, particularly preferably 40%, most preferably 55%, and the upper limit is usually 90%. From this viewpoint, it is preferably 80%, more preferably 75%, particularly preferably 70%, and most preferably 65%.

The amount of the dispersion medium used in the reverse phase suspension polymerization is preferably 25%, more preferably 40%, particularly preferably 65%, and the raw material cost from the viewpoint of dispersion stability based on the total weight of the monomer aqueous solution. From the viewpoint of yield, the upper limit is preferably 1,000%, more preferably 400%, and particularly preferably 200%.

The amount of the dispersion medium used in the inverse emulsion polymerization is preferably 20%, more preferably 30%, particularly preferably 40% from the viewpoint of the viscosity of the emulsion, based on the total weight of the monomer aqueous solution, and the viewpoint of the active ingredient content. Therefore, the preferable upper limit is 80%, more preferably 70%, and particularly preferably 60%.

In aqueous solution polymerization, the lower limit is usually −10 ° C., and preferably 0 ° C., more preferably 5 ° C., particularly preferably 10 ° C., most preferably 15 ° C., and the upper limit is usually 50 ° C. From the viewpoint of preventing thermal degradation, the temperature is preferably 40 ° C, more preferably 30 ° C, particularly preferably 25 ° C, and most preferably 20 ° C. Further, during polymerization, the temperature may be adjusted by appropriately heating and cooling so as to keep a predetermined temperature constant (for example, a predetermined polymerization temperature ± 5 ° C.), or adiabatic polymerization may be performed in a glass heat insulating container or the like. . In the adiabatic polymerization, it is preferable to adjust the starting temperature so that the boiling point of water (100 ° C.) or higher is not exceeded due to the heat of polymerization.

The polymerization temperature in the reverse phase suspension polymerization is usually 10 ° C. at the lower limit, preferably 20 ° C. from the viewpoint of the polymerization rate, more preferably 30 ° C., particularly preferably 40 ° C., most preferably 50 ° C., and the upper limit is usually 95 ° C. From the viewpoint of preventing thermal degradation of the polymer, it is preferably 90 ° C., more preferably 80 ° C., particularly preferably 70 ° C., and most preferably 60 ° C.
Further, during polymerization, it is preferable to adjust by appropriately heating and cooling so that the predetermined polymerization temperature is kept constant (for example, predetermined polymerization temperature ± 5 ° C.). In order to keep the polymerization temperature constant, the monomer may be added dropwise to the dispersion medium that has been previously adjusted to a predetermined polymerization temperature under stirring. The dropping time at that time varies depending on the monomer concentration and the amount of heat generated by the polymerization reaction, but is usually 0.5 to 20 hours, and preferably 1 to 10 hours from the viewpoint of productivity and temperature control.

In the reverse emulsion polymerization, the lower limit of the polymerization temperature is usually 0 ° C., preferably 5 ° C. from the viewpoint of polymerization rate, more preferably 10 ° C., particularly preferably 15 ° C., most preferably 20 ° C., and the upper limit is usually 95 ° C. From the viewpoint of preventing thermal deterioration, the temperature is preferably 90 ° C, more preferably 80 ° C, particularly preferably 70 ° C, and most preferably 55 ° C.
Further, during the polymerization, the temperature may be adjusted by appropriately heating and cooling so as to keep the predetermined polymerization temperature constant (for example, the predetermined polymerization temperature ± 5 ° C), or the polymerization may be performed at a relatively low temperature (for example, 15 to 35 ° C). It may be started and heated (for example, 55 to 80 ° C.) after polymerization for a certain time (for example, 1 to 3 hours).

The polymerization time can be confirmed to end when the heat generation due to the polymerization disappears, but usually 1 to 24 hours from the time when the polymerization start is confirmed by the heat generation, preferably 2 from the viewpoint of completion of the polymerization, suppression of residual monomers, and industrial viewpoint. ~ 12 hours.
As in the case of reverse phase suspension polymerization, when the monomer is dropped at any time, it is preferable to carry out the polymerization for the above time after completion of the dropping.
The monomer concentration, polymerization temperature, and polymerization time can be appropriately adjusted depending on the monomer composition, polymerization method, initiator type, and the like.

The pressure at the time of polymerization (unit: kPa, hereinafter indicates absolute pressure) is not particularly limited, but is usually carried out under normal pressure. In the case of reverse phase suspension polymerization, the pressure at which the dispersion medium boils or the pressure at which the hydrophobic dispersion medium and water azeotrope is preferably used at the polymerization temperature because the temperature can be easily adjusted during the polymerization. . Specifically, the preferred lower limit is 5 kPa, more preferably 12 kPa, particularly preferably 25 kPa, and the preferred upper limit is 95 kPa, more preferably 80 kPa, and particularly preferably 65 kPa.

The pH of the aqueous monomer solution during polymerization is not particularly limited, but is preferably 1 to 8, more preferably 2 to 7, particularly preferably 3 to 6. from the viewpoint of the polymerization rate and the solubility of the resulting water-soluble polymer. 5.
The pH adjuster used for adjusting the pH is not particularly limited. When the monomer aqueous solution is alkaline, an inorganic acid (for example, hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid), an inorganic solid acidic substance (for example, Acid sodium phosphate, acid sodium nitrate, ammonium chloride, ammonium sulfate, ammonium bisulfate and sulfamic acid) and organic acids (eg oxalic acid, succinic acid and malic acid), and inorganic alkaline substances (if the aqueous monomer solution is acidic) Examples include sodium hydroxide, potassium hydroxide and ammonia) and organic alkaline substances (eg guanidine). The pH is a value measured at room temperature (20 ° C.) for a stock solution of the monomer aqueous solution used in polymerization.

The lower limit of the cation colloid equivalent value (meq / g) in the polymer flocculant of the present invention is preferably 0.5 from the viewpoint of aggregation performance, more preferably 1.0, particularly preferably 2.0, and viewpoint of aggregation performance. Therefore, the preferable upper limit is 25, more preferably 20, and particularly preferably 15.

The colloid equivalent value can be determined by the colloid titration method shown below. The subsequent measurement is performed at room temperature (about 20 ° C.).
(1) Preparation of measurement sample (50 ppm aqueous solution of polymer flocculant) Weigh accurately 0.2 g (converted to solid content) of sample, put it in a 200 mL Erlenmeyer flask, and add the total weight (total of sample and ion-exchanged water) After adding ion-exchanged water so that the weight becomes 100 g, the mixture is stirred for 3 hours with a magnetic stirrer (a cylindrical magnet having a length of 40 mm and a diameter of 5 mm, a rotational speed of 1,000 rpm) to completely dissolve it. Prepare a 2% by weight polymer flocculant solution. Take 10 mL of the prepared solution in a 500 mL beaker, add ion-exchanged water so that the total weight (total 10 mL of the solution and ion-exchanged water) is 400 g, and again magnetic stirrer (1,000 to 1,200 rpm). Then, stir for 30 minutes to obtain a uniform measurement sample.
The solid content of the polymer flocculant was weighed (W1) in a petri dish (diameter: 100 mm, depth: 10 mm) and dried at 105 ± 5 ° C. for 90 minutes in a circulating drier. This is a value calculated from the following equation, assuming that the remaining weight after (W2).

Solid content (% by weight) = (W2) × 100 / (W1)

(2) Measurement of cation colloid equivalent value 100 g of a measurement sample is placed in a 200 mL conical beaker, and a 0.5 wt% aqueous sulfuric acid solution is gradually added while stirring with a magnetic stirrer (500 rpm) to adjust to pH 3. Next, add 2-3 drops of toluidine blue indicator (TB indicator) and titrate with N / 400 potassium potassium sulfate (N / 400 PVSK) reagent. The titration rate is 2 mL / min, and the end point is the time when the measurement sample changes from blue to reddish purple and the reddish purple color is maintained for 30 seconds.
(3) Blank test The same operation as (2) is performed except that 100 g of ion-exchanged water is used instead of the measurement sample.
(4) Calculation method Cationic colloid equivalent value (meq / g) = (1/2) ×
(Titration of sample-titration of blank test) x (N / 400 PVSK titer)

The polymer flocculant of the present invention is an antifoaming agent, a chelating agent, a pH adjuster, a surfactant, an antiblocking agent, an antioxidant, an ultraviolet absorber, and an antifoaming agent, as long as it does not inhibit the effects of the present invention. An additive (B) selected from the group consisting of preservatives can be used in combination.

The above (B) may be added in advance to the monomer aqueous solution before polymerization or may be added to the polymer after production. The total amount of (B) used is usually 30% or less based on the total weight of the monomer or polymer, and preferably 1 to 10% from the viewpoint of the effect of adding each additive and the aggregation performance.
The amount of each additive used is usually 5% or less, preferably 1 to 3%, and the chelating agent is usually 20% or less, preferably 2 to 10%, based on the same weight as above. The regulator is usually 10% or less, preferably 1 to 5%, the surfactant and the anti-blocking agent are each usually 5% or less, preferably 1 to 3%, and the antioxidant, the ultraviolet absorber and the preservative are each usually 5%. % Or less, preferably 0.1 to 2%.

The method for adding the polymer flocculant of the present invention to sludge, waste water or the like (hereinafter abbreviated as sludge etc.) is not particularly limited. For example, the method described in Japanese Patent No. 1311340 or Japanese Patent No. 2038341 is used. Can be mentioned.
The amount of the polymer flocculant used in the present invention varies depending on the type of sludge, the content of suspended particles, the molecular weight of the polymer flocculant, etc., but is not particularly limited, , Abbreviated as TS), usually 0.01 to 10%, preferably lower limit from the viewpoint of aggregation performance is 0.1%, more preferably 0.5%, particularly preferably 1%, preferable from the viewpoint of processing cost The upper limit is 5%, more preferably 3%, particularly preferably 2%.

As a method of using the polymer flocculant of the present invention, it is preferable to add it to sludge after making it into an aqueous solution from the viewpoint of sufficient flocculation performance, but the polymer flocculant should be added directly to sludge etc. in a solid state. You can also. The concentration when the polymer flocculant is used as an aqueous solution is preferably 0.05 to 1% by weight from the viewpoint of handling and dissolution rate.
The method for dissolving the polymer flocculant is not particularly limited. For example, a predetermined amount of the polymer flocculant is gradually added while stirring the water weighed in advance using a stirring device such as a jar tester, A method of dissolving for several hours (about 2 to 4 hours) can be employed. When the powdery polymer flocculant is dissolved in water, a method of adding a predetermined amount of the polymer flocculant at a stretch is undesirably caused by the fact that it becomes difficult to completely dissolve in water.

When adding the polymer flocculant of the present invention, the pH of sludge or the like may be adjusted in advance. The pH adjustment range is usually from 3 to 8, the lower limit preferable from the viewpoint of hydrolysis prevention is 3.5, more preferably 4, particularly preferably 4.5, and the upper limit preferable from the viewpoint of solubility is 7, more preferably 6. Particularly preferred is 5.5.
The pH adjustment method is not particularly limited, and an acidic substance such as inorganic acid (sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, etc.) or an alkaline substance such as caustic alkali (sodium hydroxide, potassium hydroxide, etc.) is used. The method to use is mentioned.

  Further, as a dehydration method (solid-liquid separation method) for floc formed by adding the polymer flocculant of the present invention to sludge, centrifugal dehydration, filter press dehydration, belt press dehydration, screw press dehydration, capillary dehydration, etc. Various dehydration methods can be applied. Among these, screw press dewatering and belt press dewatering are preferable from the viewpoint of high floc strength, which is the specific aggregation performance of the polymer flocculant of the present invention.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In addition, the part in an Example represents a weight part and% represents weight%.
Example 1
In a beaker, 21.5 parts of N-vinylpiperidine (a-1), 7 parts of a 50% aqueous solution of acrylamide (b-1) and 21.5 parts of water were stirred to obtain a uniform aqueous solution. Thereafter, the pH of the aqueous solution was adjusted to 3.0 using a 10% aqueous solution of sulfamic acid. The whole amount of the aqueous solution was transferred to a reaction vessel, and after nitrogen substitution was performed by bubbling nitrogen through the solution for 5 minutes, 1 part of a 0.25% aqueous solution of 2,2′-azobis- (amidinopropane) dihydrochloride and thioglycerol 1 part of a 0.05% aqueous solution was added and polymerized at 50 ° C. for 20 hours in a sealed state. Thereafter, the gel in the reaction vessel is taken out and shredded, dried with a circulating dryer at 50 ° C. for 10 hours, and further pulverized with a juicer mixer to obtain a powder (volume average particle size of 0.1 to 1.7 mm, the same applies hereinafter). Water-soluble polymer (A1) was obtained. The intrinsic viscosity of (A1) was 10.1 dl / g (hereinafter represented only by numerical values), and the cation colloid equivalent value was 6.0 meq / g (hereinafter represented only by numerical values). In the following, (A1) was used as the polymer flocculant (X1).

Example 2
In Example 1, instead of 21.5 parts of (a-1), 7 parts of 50% aqueous solution of (b-1) and 21.5 parts of water, 8.5 parts of N-vinylpiperazine (a-2), N , N-dimethylaminoethyl acrylate methyl chloride quaternary ammonium salt (b-2) 80% aqueous solution 20.7 parts and water 20.8 parts, thioglycerol 0.05% aqueous solution instead of 1 part thio A water-soluble polymer (A2) was obtained in the same manner as in Example 1 except that 1 part of a 0.04% aqueous solution of glycerol was used. The intrinsic viscosity of (A2) was 10.5, and the cation colloid equivalent value was 7.8. In the following, (A2) was used as the polymer flocculant (X2).

Example 3
A water-soluble polymer (A3) was obtained in the same manner as in Example 1 except that 1 part of a thioglycerol 0.01% aqueous solution was used instead of 1 part of a 0.05% aqueous solution of thioglycerol in Example 1. The intrinsic viscosity of (A3) was 18.1, and the cation colloid equivalent value was 6.0. In the following, (A3) was used as the polymer flocculant (X3).

Example 4
A water-soluble polymer (A4) was obtained in the same manner as in Example 1 except that 21.5 parts of (a-2) was used instead of 21.5 parts of (a-1) in Example 1. The intrinsic viscosity of (A4) was 9.8, and the cation colloid equivalent value was 10.9. In the following, (A4) was used as the polymer flocculant (X4).

Example 5
In Example 1, in place of 21.5 parts of (a-1), 7 parts of 50% aqueous solution of (b-1) and 21.5 parts of water, 25 parts of (a-1) and 25 parts of water were used. A water-soluble polymer (A5) was obtained in the same manner as in Example 1 except that 1 part of a 0.1% aqueous solution of thioglycerol was used instead of 1 part of a 0.05% aqueous solution of glycerol. The intrinsic viscosity of (A5) was 5.6, and the cation colloid equivalent value was 6.7.
In the following, (A5) was used as the polymer flocculant (X5).

Example 6
In Example 1, instead of 21.5 parts of (a-1), 7 parts of 50% aqueous solution of (b-1) and 21.5 parts of water, 10.5 parts of 4-vinylpyridine (a-3), (b -2) A water-soluble polymer (A6) was obtained in the same manner as in Example 1 except that 18.1 parts of 80% aqueous solution and 21.4 parts of water were used. The intrinsic viscosity of (A6) was 7.8, and the cation colloid equivalent value was 5.9. In the following, (A6) was used as the polymer flocculant (X6).

Example 7
In Example 1, instead of 21.5 parts of (a-1), 7 parts of 50% aqueous solution of (b-1) and 21.5 parts of water, 22.3 parts of N-vinylmorpholine (a-4), (b A water-soluble polymer (A7) was obtained in the same manner as in Example 1 except that 5.3 parts of a 50% aqueous solution of -1) and 22.4 parts of water were used. The intrinsic viscosity of (A7) was 7.2, and the cation colloid equivalent value was 6.0. In the following, (A7) was used as the polymer flocculant (X7).

Example 8
In Example 1, instead of 21.5 parts of (a-1), 7 parts of 50% aqueous solution of (b-1) and 21.5 parts of water, 4 parts of (a-2), 80 of (b-2) Example 1 except that 26.3 parts of a 1% aqueous solution and 19.7 parts of water were used and 1 part of a 0.04% aqueous solution of thioglycerol was used instead of 1 part of a 0.05% aqueous solution of thioglycerol. Thus, a water-soluble polymer (A8) was obtained. The intrinsic viscosity of (A8) was 10.8, and the cation colloid equivalent value was 6.5. In the following, (A8) was used as the polymer flocculant (X8).

Comparative Example 1
In Example 1, instead of 21.5 parts of (a-1), 7 parts of 50% aqueous solution of (b-1) and 21.5 parts of water, 4.2 parts of 50% aqueous solution of (b-1), ( A water-soluble polymer (ratio A1) was obtained in the same manner as in Example 1 except that 28.6 parts of an 80% aqueous solution of b-2) and 17.2 parts of water were used. The (ratio A1) had an intrinsic viscosity of 10.4 and a cation colloid equivalent value of 4.7. In the following, (Ratio A1) was defined as a polymer flocculant (Ratio X1).

Comparative Example 2
In Production Example 1, 21.5 parts of (a-1), 7 parts of 50% aqueous solution of (b-1) and 50 parts of 70% aqueous solution of diallyldimethylammonium chloride were used instead of 21.5 parts of water, and the pH was 6 , And in place of 1 part of a 0.25% aqueous solution of 2,2′-azobis- (amidinopropane) dihydrochloride and 1 part of a 0.05% aqueous solution of thioglycerol, A water-soluble polymer (ratio A2) was obtained in the same manner as in Example 1 except that 5 parts of a 2% aqueous solution of amidinopropane) dihydrochloride was used. (Ratio A2) had an intrinsic viscosity of 3.8 and a cation colloid equivalent value of 5.7. In the following, (Ratio A2) was defined as a polymer flocculant (Ratio X2).

Comparative Example 3
A reaction vessel was charged with 1.5 parts of acrylonitrile, 4.5 parts of N-vinylformamide, and 34 parts of water. In a nitrogen gas atmosphere, the temperature was raised to 60 ° C. with stirring, 1 part of a 1.2% aqueous solution of 2,2′-azobis- (amidinopropane) dihydrochloride was added, and the mixture was stirred at 60 ° C. for 5 hours. Continuing, a suspension with the polymer precipitated in water was obtained. The polymer was filtered off from the suspension, washed with acetone, and then vacuum dried to obtain a polymer. 20 parts of water was added to the polymer, and then 13.2 parts of hydrochloric acid (concentration 35%) was added and kept at 100 ° C. for 4 hours with stirring to amidine the polymer. An aqueous solution of the obtained polymer was added to acetone to cause precipitation, and this was vacuum dried to obtain a water-soluble polymer (ratio A3). (Ratio A3) had an intrinsic viscosity of 4.0 and a cation colloid equivalent value of 6.1. In the following, (Ratio A3) was defined as a polymer flocculant (Ratio X3).

Comparative Example 4
In Example 1, instead of 21.5 parts of (a-1), 7 parts of 50% aqueous solution of (b-1) and 21.5 parts of water, 13.9 parts of 50% aqueous solution of (b-1), ( 15.8 parts of an 80% aqueous solution of b-2), 5.6 parts of an 80% aqueous solution of methyl chloride quaternary ammonium salt (b-3) of N, N-dimethylaminoethyl methacrylate, acrylic acid (b-4) A water-soluble polymer (ratio A4) was obtained in the same manner as in Example 1 except that 2.9 parts of an 80% aqueous solution and 11.8 parts of water were used. (Ratio A4) had an intrinsic viscosity of 8.8 and a cation colloid equivalent value of 3.2. In the following, (Ratio A4) was used as the polymer flocculant (Ratio X4).

Comparative Example 5
Into a reaction vessel, 100 parts of water and 16.8 parts of 35% hydrochloric acid were charged. While cooling, 15 parts of benzyldiallylamine obtained by reacting benzyl chloride with diallylamine and 8.9 parts of methyldiallylamine obtained by reacting diallylamine with methyl chloride were gradually added. To obtain benzyl diallyl ammonium chloride and methyl diallyl ammonium chloride aqueous solution. Next, after sufficiently replacing the system with nitrogen (purity 99.999% or more), 14.5 parts of a 10% aqueous solution of 2,2′-azobis (2-methylpropionamidine) dihydrochloride as an initiator was stirred. Added while. The inside of the system was gradually heated from the outside, and after the polymerization reaction started at 50 ° C. and heat generation was observed, the system was cooled from the outside and polymerized at a system temperature of 50 to 60 ° C. for 10 hours. Thereafter, the mixture was heated from the outside and aged at 80 ° C. for 1 hour to complete the polymerization. Thereafter, the contents were taken out, 200 parts of acetone was added thereto, and the mixture was stirred for 30 minutes with a commercially available juicer mixer to obtain a precipitate. After the precipitate was taken out by vacuum filtration (using JIS standard 2 types of filter paper), the solvent was distilled off in a vacuum dryer (vacuum degree 1.3 kPa, 40 ° C. × 2 hours) to form a powder. Water-soluble copolymer (ratio A5) (organic coagulant) was obtained. (Ratio A5) had an intrinsic viscosity of 0.6 and a cation colloid equivalent value of 6.6.
80 parts of (Ratio A4) and 20 parts of (Ratio A5) were put in a glass bottle capable of being sealed and shaken and mixed until uniform to obtain a polymer flocculant (Ratio X5).

Examples 1 to 8, Comparative Examples 1 to 5 [Aggregation performance evaluation]
Polymer flocculants (X1 to X8, ratio X1 to ratio X5) were each dissolved in ion-exchanged water to obtain an aqueous solution having a solid content of 0.2%. Digested sludge collected from digested A City treatment plant [pH 7.4, TS 2.9%, SS (floating matter content) 2.7%, organic content 65%, alkalinity 4,543 mg-CaCO ₃ / L] 200 Part was taken in a 500 mL beaker, and 16, 19 and 22 parts of each aqueous solution of the polymer flocculant was added (the amount of solid content added was 0.6, 0.7 and 0.8% / TS, respectively). The performance was evaluated. The results are shown in Table 1.

Comparative Example 6 [Aggregation Performance Evaluation]
The water-soluble polymer (ratio A4) and the organic coagulant (ratio A5) were each dissolved in ion exchange water to obtain an aqueous solution having a solid content of 0.2%. After taking 200 parts of the digested sludge into a 500 mL beaker, adding 3.2 parts, 3.8, and 4.4 parts of the aqueous solution of (Ratio A5), and stirring for 30 seconds at 2 rpm using a glass rod, (Ratio A4 12.8, 15.7, and 17.6 parts of the aqueous solution (the amount of solid added at this time is the sum of (Ratio A5) and (Ratio A4) is 0.6, 0.7, 0) .8% / TS], the aggregation performance was evaluated. The results are shown in Table 1.

<Performance evaluation method>
(1) Flock particle size (mm)
Jar tester [Miyamoto Riken Kogyo Co., Ltd., Model JMD-6HS-A] with two plate-shaped PVC stirring blades (diameter 5 cm, height 2 cm, thickness 0.2 cm) up and down to form a cross It was continuously attached to a stirring bar, and 200 mL of sludge or waste water was taken in a 500 mL beaker and set in a jar tester. Rotating the jar tester at 120 rpm, slowly stirring the sludge or waste water, adding a predetermined amount of 0.2% polymer flocculant aqueous solution at a time, stirring for 30 seconds, and then stopping the stirring, floc formed The particle size (mm) of was observed visually. Subsequently, the number of revolutions was set at 300 rpm, and after stirring for 30 seconds, stirring was stopped and the size of the floc was again visually observed.

(2) Filtrate volume (mL)
Set T-1189 nylon filter cloth [Shikishima Kanbusu Co., Ltd., circular shape, diameter 9 cm], Nutsche funnel, graduated cylinder measuring 300 mL, and put sludge after evaluation of the above floc particle size at once. Filtration was performed, and the processing rate was evaluated by measuring the amount of filtrate from immediately after charging to 60 seconds after using a stopwatch.

(3) Moisture content of cake (%)
A part of the filtered sludge is taken out with a spatula, subjected to a dehydration test (2 kg / cm ² , 60 seconds) using a press filter tester, and about 3.0 g of the dehydrated cake after the test is weighed (W1) in a petri dish. After drying in a circulating drier until water completely evaporates (105 ± 5 ° C x 8 hours), the weight of the cake left on the petri dish is (W2), and the moisture content of the cake is calculated from the following equation: Calculated.

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

  From Table 1, in the polymer flocculant of the present invention of Examples 1 to 8, compared with Comparative Examples 1 to 4, a coarse and strong floc is formed, and the amount of filtrate is large, so the processing speed is large. And the low moisture content of the cake, etc. show that the dehydration effect is extremely excellent. In addition, the polymer flocculant of the present invention is a one-step treatment that does not use a coagulant, and exhibits a dehydration effect superior to a one-step treatment (Comparative Example 5) and a two-step treatment (Comparative Example 6) that use a coagulant. I understand.

  The polymer flocculant of the present invention forms a strong coarse floc in the treatment of sludge and wastewater, and since the formed floc is not easily broken or redispersed, the stability and processing speed of the flocculant can be remarkably increased. Since the moisture content of the cake after the dehydration process is low, the amount of waste and incineration costs can be reduced, and the dehydration effect is excellent even without the use of a coagulant. It can be suitably used for the dehydration treatment of and is extremely useful.

Claims (5)

A water-soluble monomer comprising a vinyl group-containing monomer (a) represented by the following general formula (1) or (a) and a (meth) acryloyl group-containing monomer (b) represented by the following general formula (2). A polymer flocculant comprising the polymer (A).

^{_{CH 2 = CH- (NR 1 R}} 2) (1)
^{_{CH 2 = CR 3 -CO-X-}} (Q-N + R 4 R 5 R 6 · Z -) m (H) 1-m (2)

[In Formula (1), R ¹ and R ² each independently represent H or a C 1-6 hydrocarbon group that may contain a hetero atom, and R ¹ and R ² are bonded to each other; A ring may be formed, and (NR ¹ R ² ) represents a monovalent group bonded to a vinyl group at N or any of R ¹ and R ² .
In the formula (2), X is O or NH; Q is an alkylene group having 1 to 4 carbon atoms or a hydroxyalkylene group having 2 to 4 carbon atoms; R ³ is H or a methyl group; R ⁴ , R ⁵ , R ⁶ are Each independently H, an alkyl, aralkyl or alkylaryl group having 1 to 16 carbon atoms; Z ⁻ represents a counter anion; m represents a number of 0 or 1; ] The polymer flocculant according to claim 1, wherein (a) is at least one selected from the group consisting of N-vinylpiperidine, N-vinylpiperazine and vinylpyridine. The polymer flocculant according to claim 1 or 2, wherein the molar ratio of (a) to (b) is 100/0 to 5/95. The polymer flocculant according to any one of claims 1 to 3, which has an intrinsic viscosity of 0.1 to 20 dl / g measured at 30 ° C in 1N-NaNO ₃ . A method for treating sludge or wastewater, comprising adding and mixing the polymer flocculant according to any one of claims 1 to 4 to sludge or wastewater to form a floc for solid-liquid separation.