KR100606434B1 - Manufacturing method of Waste water treatment water dispersant which containing branched acrylamide copolymer - Google Patents

Abstract

The present invention relates to a method for producing a branched acrylamide copolymer dispersion for wastewater treatment, and more particularly, to use a crosslinking monomer in a monomer mixture to make the molecular structure of the copolymer branched, and to use epichlorohesin as a dispersion stabilizer. By using the dimethylamine condensate, the cationic functional group is located at the main branch of the branched acrylamide copolymer, which exhibits stronger shearing properties than the existing linear copolymer, and improves dispersibility in water to improve product stability. When this is used as a flocculant in the wastewater treatment process, the epichlorohydrin dimethylamine condensate added as an organic coagulant also acts as an organic coagulant, reducing the cost of chemicals and improving the performance. Of a method for producing a topographic acrylamide copolymer dispersion to be.

Acrylamide, Copolymer, Branched, Epichlorohydrin Dimethylamine Condensate

Description

Manufacturing method of Waste water treatment water dispersant which containing branched acrylamide copolymer}

The present invention relates to a method for producing a branched acrylamide copolymer dispersion for wastewater treatment, and more particularly, to use a crosslinking monomer in a monomer mixture to make the molecular structure of the copolymer branched, and to use epichlorohesin as a dispersion stabilizer. By using the dimethylamine condensate, the cationic functional group is located at the main branch of the branched acrylamide copolymer, which exhibits stronger shearing properties than the existing linear copolymer, and improves dispersibility in water to improve product stability. When this is used as a flocculant in the wastewater treatment process, the epichlorohydrin dimethylamine condensate added as an organic coagulant also acts as an organic coagulant, reducing the cost of chemicals and improving the performance. Of a method for producing a topographic acrylamide copolymer dispersion The.

As a technique for manufacturing a polymer for use as a dewatering polymer and a flocculant for treating wastewater in the existing wastewater treatment, there is a powder phase production technology, water-in-oil emulsion phase production technology and water dispersion phase polymer production technology.

In the case of powder phase manufacturing technology, there is a high possibility that insoluble fraction is generated due to the essential drying process, it takes a long time to dissolve the product, and there are many difficulties in changing the molecular structure. In the case of water-in-oil emulsion phase manufacturing technology, in spite of many advantages such as easy change of molecular structure, since oil and surfactant are used a lot, contamination by products during water treatment is inevitable. However, the water-disperse phase polymer has an advantage of freeing the molecular structure without additional contamination of oil and surfactant.

As a technology for preparing a water-dispersed phase polymer for use as a flocculant for dewatering and wastewater treatment in conventional wastewater treatment, US Patent No. 5,938,937 discloses dimethylamino ethylacrylate methylchloride quaternary salt, acrylamide, diallyldimethyl ammonium chloride. A polymer obtained by copolymerizing or homopolymerizing monomers, etc., is used as a dispersion stabilizer, and a water dispersible polymer prepared by radical polymerization of acrylamide and a cationic monomer together with an anionic salt and a chaintransfer is used as a dehydration polymer in wastewater treatment. A method is disclosed.

In the above method, the dispersion stabilizer has a lower cationic density than the epichlorohydrindimethylamine condensate to be used in the present invention, and the repulsive force between the positive ions due to the presence of a cationic functional group on the side of the main branch of the polymer Weak and not good dispersion stability. In addition, since the water-dispersible polymer prepared by the above method has a linear form due to the use of a chaintransfer, the aggregates tend to be dismantled due to shear force applied to the aggregates during wastewater treatment.

Meanwhile, in the case of US Patent No. 6,531,531, a copolymer or homopolymer of dimethylamino ethylacrylate benzyl chloride quaternary salt and dimethylamino ethylacrylate methyl chloride quaternary salt as a dispersed polymer is used to obtain acrylamide, anionic monomer, and cationic monomer. Discloses a technique of applying a polymer prepared by radical copolymerization with an inorganic coagulant as a flocculant for wastewater treatment.

The above method also has a low cationic density of the dispersion stabilizer, the cationic functional group is present in the side branch of the main branch is low repulsive force between the cations, poor dispersion stability, the prepared polymer is weak in crosslinking force is applied to the aggregates during wastewater treatment There is a tendency for the aggregate to be easily disassembled by the shear force or the like.

In addition, as the inorganic flocculant is added, the flocculation action of the sludge component may be slightly increased during wastewater treatment, but there is a problem in that the input amount is increased compared to the epichlorohydrin dimethylamine condensate.

Therefore, the inventors of the present invention are weak in shear force due to the linear molecular structure of the acrylamide copolymer as described above, homopolymers, copolymers or terpolymers used as dispersion stabilizers in the conventional acrylamide copolymer production Efforts have been made to solve the problems of lowering of dispersibility due to low cation density and other problems due to the formation of cationic functional groups on the side of the copolymer molecules of the acrylamide copolymer prepared using the dispersion stabilizer.                         

As a result, when the copolymerization is carried out by adding a crosslinking monomer to a mixture of acrylamide monomers, molecules of the obtained copolymer are formed in a branched form, and acrylamide air contained in the acrylamide copolymer underwater dispersion used for conventional wastewater treatment. It has been found that coalescing can solve the problems caused by having a linear structure.

In addition, it was found that by using epichlorohydrin dimethylamine condensate as a dispersion stabilizer, cationic functional groups of the acrylamide copolymer are formed on the main branches of the copolymer molecules, and dispersion stability can be improved by the repulsive force of the high cationic functional group. It became.

Therefore, the present invention makes the acrylamide copolymer branched by using a crosslinking monomer, and by using epichlorohydrin dimethylamine condensate as a dispersion stabilizer, it is stable against strong shear force when used as a flocculant in wastewater treatment process. Epichlorohydrin dimethylamine condensate, added as a dispersion stabilizer, also acts as an organic coagulant to improve various physical properties and to reduce the cost of chemicals. The purpose is to provide a manufacturing method.

The present invention mixes 150 to 250 parts by weight of anionic salts with 5 to 20 parts by weight of epichlorohydrin dimethylamine condensate in an aqueous monomer mixture solution having a monomer concentration of 8 to 20% by weight based on 100 parts by weight of the total monomers. Remove dissolved oxygen, add 0.01 to 1 part by weight of an azo polymerization initiator, and copolymerize at 20 to 45 ° C., after the completion of the copolymerization, increase the temperature to 55 to 65 ° C., and then add 20 to 50 parts by weight of anionic salt. A method for preparing a branched acrylamide copolymer dispersion for wastewater treatment by a method of producing a water dispersion polymer, including decreasing the viscosity of a solution, stirring the solution for 3 to 10 hours, and then lowering the temperature to room temperature.

The present invention will be described in detail as follows.

In the present invention, the crosslinking monomer is added to the monomer mixture so that the molecular structure of the copolymer is branched, and the cationic functional group is used as the main branch of the branched acrylamide copolymer using epichlorohydrin dimethylamine condensate as a dispersion stabilizer. Epichlorohydrin, which exhibits stronger shearing properties than conventional linear copolymers, improves dispersibility in water and increases product stability, and is added as a dispersion stabilizer when used as a flocculant in wastewater treatment. A dimethylamine condensate also acts as an organic coagulant and relates to a method for producing a branched acrylamide copolymer dispersion for wastewater treatment by a water-dispersible polymer production method which exhibits an effect of reducing chemical costs and improving performance.

Hereinafter, the present invention will be described in detail for each manufacturing process.

First, 150 to 250 parts by weight of anionic salts and 5 to 20 parts by weight of epichlorohydrin dimethylamine condensate are mixed with an aqueous monomer mixture solution having a monomer concentration of 8 to 20% by weight based on 100 parts by weight of the total monomers. Oxygen is removed, and 0.01 to 1 parts by weight of azo polymerization initiator is added thereto, followed by copolymerization at 20 to 45 ° C.

In the present invention, the monomer uses a neutral monomer, a cationic monomer and a monomer for crosslinking.

The (meth) acrylamide monomer may be used as the neutral monomer, and the following Chemical Formula 1 represents acrylamide among these neutral monomers. Such neutral monomers are used in an amount of 5 to 94.9999% by weight, and when the amount is less than 5% by weight, the size of the aggregates is reduced due to the repulsion of the cationic functional group of the copolymer. This deterioration problem may occur, so it is preferable to comply with the above range if possible.

Among the monomers of the present invention, as the cationic monomer, quaternary amine salts are used. Specifically, for example, dimethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl acrylate benzyl chloride quaternary salt, and dimethylaminoethyl methacrylate. Methyl chloride quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt and diallyl methylammonium chloride quaternary salt and the like can be selected and used. Among these cationic monomers, the following formula (2) shows dimethylaminoethyl acrylate methyl chloride quaternary salt. Formula 3 shows the dimethylaminoethyl acrylate benzyl chloride quaternary salt. Such cationic monomers are used in the range of 5 to 94.9999% by weight. If the amount is less than 5% by weight, the agglomeration performance is reduced due to the decrease in cationicity, and when the amount exceeds 94.9999% by weight, the cationic functional groups of the copolymer are repelled. Since the size of the aggregates is reduced, it is better to comply with the above range if possible.

Among the monomers of the present invention, monomers for crosslinking may be selected from N, N'methylenebisacrylamide or trimethylolpropane triacrylate, and the following Chemical Formulas 4 and 5 are respectively represented by N, N'methylenebisacrylamide and Trimethylolpropane triacrylate is shown. Unlike conventional acrylamide copolymers for wastewater treatment, the acrylamide copolymer of the present invention is formed in a branched shape, which is due to the addition of a crosslinking monomer in the monomer mixture. Such a crosslinking monomer is used in 0.0001 ~ 0.01% by weight, if the amount is less than 0.0001% by weight cross-linking does not occur sufficiently in the main branch of the polymer, the resistance to shear force is not well expressed, the amount used exceeds 0.01% by weight If the use of the flocculant as a flocculant due to the excessive cross-linking to form a polymer may occur.

Conventional dispersions for wastewater treatment in water are in the form of linear polymers, which is advantageous for initial flocculation when introduced into the wastewater flocculant of the polymer, but agglomerations are destroyed by strong stirring and shearing force. Therefore, the present invention is to prepare a branched acrylamide copolymer dispersion by introducing a cross-linking monomer to be able to withstand strong shear force.

The total concentration of the monomers contained in the aqueous monomer solution as described above is 8 to 20% by weight. If the concentration is less than 8% by weight, the concentration of the copolymer in the dispersion in water is low, so that the aggregation performance is lowered and exceeds 20% by weight. When the copolymerization is difficult to control the reaction, and the prepared copolymer dispersion can be easily precipitated, so as to maintain the above range.

The epichlorohydrin dimethylamine condensate used as a dispersion stabilizer in the present invention may be represented by the following formula (6), wherein the epichlorohydrin dimethylamine condensate is more preferred when using a molecular weight range of 100,000 ~ 1,000,000, wherein If the molecular weight of the epichlorohydrin dimethylamine condensate is less than 100,000, the dispersibility in water decreases, and if it exceeds 1,000,000, the prepared dispersion in water precipitates. Such epichlorohydrin dimethylamine condensate is used in an amount of 5 to 20 parts by weight based on 100 parts by weight of the total monomer, but when the amount is less than 5 parts by weight, sufficient dispersion effect cannot be obtained. There may be a problem that the molecular weight of the coalescence is low.

The epichlorohydrin dimethylamine condensate is such that the cationic functional group is located at the main branch of the copolymer, and the cationic functional group is densely formed to improve the stability of the product by improving the dispersion stability due to excellent repulsion between the cations. In addition, since epichlorohydrin dimethylamine condensate has been used as an organic coagulant in the wastewater treatment process, when the branched acrylamide copolymer prepared according to the present invention is applied to the wastewater treatment process, significant chemical cost reduction and performance improvement are achieved. Can be achieved.

In the present invention, an azo initiator is used as the radical initiator, and the amount of the azo initiator used is 0.01 to 1 part by weight, and when the amount is less than 0.01 part by weight, the polymerization initiation reaction tends to be slow, and exceeds 1 part by weight. There is a problem that the molecular weight is lowered. The following Chemical Formulas 7 and 8 represent V-50 (Japanese Wako Corp.) and VA-044 (Japanese Wako Corp.) used in the examples of the present invention, respectively.

The anionic salt may be used ammonium sulfate salt or sodium sulfate salt, etc., the amount is 150 to 250 parts by weight based on 100 parts by weight of the total amount of monomers. At this time, when the amount of use is less than 150 parts by weight, the copolymer is precipitated during the reaction, and if it exceeds 250 parts by weight, anionic salts may be precipitated and molecular weight may be lowered. When the anionic salt is separated and added twice, more preferable results can be obtained. First, 120 to 200 parts by weight are added during the reaction to copolymerize, and the remaining anionic salt is more stable copolymer when added after the completion of the copolymerization. Dispersions can be prepared.

Nitrogen is purged in a mixed aqueous solution of the monomer, anionic salt, and epichlorohydrin dimethylamine condensate, which is configured as described above, to remove dissolved oxygen, to which an azo polymerization initiator is added, followed by copolymerization at 20 to 45 ° C. In this case, when the copolymerization temperature is less than 20 ℃, there is a difficulty in controlling the polymerization due to the viscosity increase during the reaction, and when it exceeds 45 ℃ there is a problem that the molecular weight of the copolymer is lowered.

After completion of the copolymerization, the temperature of the mixed aqueous solution was raised to 55-65 ° C. and then the remaining anionic salt was added to reduce the viscosity of the solution, at which time the viscosity was reduced to 10-200 cps (60 ° C.). If the temperature rises outside the above range, the stability of the dispersion may be lowered. Therefore, the above range should be maintained if possible, and if the viscosity of the solution is outside the above range, the storage stability is lowered.

After stirring the mixed solution for 3 to 10 hours, the temperature is lowered to room temperature to obtain the branched acrylamide copolymer dispersion desired in the present invention. The branched acrylamide copolymer prepared as described above exhibits a desirable effect having a molecular weight in the range of 1,000,000 to 10,000,000.

The branched acrylamide copolymer dispersion of the present invention can be applied as a flocculant by adding about 5 to 1,000 ppm of acrylamide copolymer concentration into the wastewater when applied to various industrial wastewater.

Hereinafter, the present invention will be described in detail with reference to Examples. The present invention is not limited by the following examples.

Examples 1-5 and Comparative Examples 1-3: Preparation of Copolymer Dispersion

Mix epichlorohydrin dimethylamine condensate, neutral monomer, cationic monomer, crosslinking monomer and anionic salt (160 g) in a 1000 ml 5-neck round bottom flask with stirrer, thermometer and countercurrent condenser Distilled water was added thereto so that the total amount of the mixed solution was 850 g. Types and amounts used of the components used in the mixed solution are shown in Table 1 below.

The temperature of the mixed solution was raised to 40 ° C., nitrogen was purged for 30 minutes to remove dissolved oxygen, and then an azo initiator was added, and the temperature was raised to 45 ° C. for radical copolymerization for 5 to 10 hours.

After completion of the copolymerization, the temperature of the reactant was increased to 55 to 65 ° C., and a portion of the anionic salt (40 g) was further added to lower the viscosity of the reactant to 10 to 200 (60 ° C.), followed by stirring for 3 hours or more. It was then cooled to room temperature to obtain the desired product.

Remarks Example (g) Comparative Example (g) One 2 3 4 5 One 2 3 Monomer Neutral ¹⁾ 53.999 73.999 47.999 32 24 54 74 48 Cationic A ²⁾ 19 11 18 25 24.1 19 11 18 B ³⁾ 27 15 34 40 33.3 27 15 34 For crosslinking A ⁴⁾ 0.001 - - 0.001 0.001 - - - B ⁵⁾ - 0.001 0.001 - - - - - Dispersion Stabilizer A ⁶⁾ 8 8 16 24 24 - - - B ⁷⁾ - - - - - 8 16 24 Anionic salt A ⁸⁾ - - 75 75 35 - - 75 B ⁹⁾ 200 200 125 125 165 200 200 125 Azo initiator A ¹⁰⁾ 0.1 0.1 - - - 0.1 0.1 - B ¹¹⁾ - - 0.1 0.1 0.1 - - 0.1 Distilled water ¹²⁾ Remaining amount Remaining amount Remaining amount Remaining amount Remaining amount Remaining amount Remaining amount Remaining amount 1) Acrylamide 2) Dimethylamino ethylacrylate methyl chloride quaternary salt 3) Dimethylamino ethylacrylate benzyl chloride quaternary salt 4) N, N'methylenebisacrylamide 5) Trimethylolpropane triacrylate 6) Epichlorohydrin Dimethylamine condensate, (50%, viscosity 1,540 CPS) 7) Dimethylamino ethylacrylate methylchloride quaternary homopolymer (50%, viscosity 1,580 CPS) 8) Sodium sulfate 9) Ammonium sulfate 10) Waco-V-50, Japan Wacosa 11) Waco-VA-044, Wakosa, Japan 12) Distilled water was added so that the total aqueous solution might be 850g.

Experimental Example 1: Physical property analysis of copolymer dispersion

The physical properties of the copolymer dispersions prepared according to Examples 1 to 5 and Comparative Examples 1 to 3 were analyzed by the following method, and the results are shown in Table 2 below.

1) solids

The residual amount was measured after drying for 2 hours by blowing air dryer temperature 105 degreeC.

2) viscosity

Spindle rotor No. using a Brookfield viscometer. 62 and the rotation speed were measured at 25 ° C.

3) Number average molecular weight (MWv)

Guidance Manual for Polymer Selection in Waste water Treatment Plants (1993, published by Water Environment Research Foundation, Module N: Item Viscosity and Molecular weight by rotational viscometer) was analyzed by the method described above.

4) Charge density CD, IR (Ionic regain)

Guidance Manual for Polymer Selection in Waste water Treatment Plants (1993, Water Environment Research Foundation, Module M: Item Charge density and ionic regain for cationic organic polyelectrolytes by titration) was analyzed by the assay described above. Here, the CD represents a measure of ionicity, IR represents a measure of the degree of crosslinking, generally near linear when the IR is less than 15%, branched when 15 to 30%, and the form of the net when 30 to 60% Indicates.

5) Centrifugation test

50 g of the sample was collected and centrifuged at a rotational speed of 3,000 RPM for 5 minutes, and then dispersibility and storage stability were determined as mm height of the thickness of the precipitated solid. In general, the higher the dispersibility, the better the storage stability and the smaller the amount of solid precipitated. Therefore, a low value indicates excellent storage stability.

Remarks Solid content (%) Viscosity (cps, 60 ℃) MWv (g / Mole) CD. (Meq / g) I.R. (%) pH Centrifugation (mm) Example 1 44.5 20 5,720,000 3.5 25 3.8 ~ 4.2 2.4 Example 2 44.2 16 3,900,000 2.45 22 3.8 ~ 4.2 2.4 Example 3 44.7 23 4,680,000 4.2 23 3.8 ~ 4.2 2.2 Example 4 44.4 15 5,200,000 5.1 26 3.8 ~ 4.2 1.9 Example 5 44.5 25 4,940,000 5.4 24 3.8 ~ 4.2 2.0 Comparative Example 1 44.2 31 6,240,000 3.6 3 3.8 ~ 4.2 4.1 Comparative Example 2 44.7 41 7,020,000 2.5 4 3.8 ~ 4.2 3.8 Comparative Example 3 44.7 109 5,980,000 4.2 6 3.8 ~ 4.2 3.2

Experimental Example 2: Application to Wastewater

After applying the copolymer dispersions prepared according to Examples 1 to 5 and Comparative Examples 1 to 3 to the wastewater, physical properties were analyzed by the following method, and the results are shown in Table 3 below.

1) Initial CST, Reaggregated CST:

Guidance Manual for Polymer Selection in Waste water Treatment Plants (1993, published by Water environment research foundation, Module G: Item The capillary suction time test) was analyzed by the method described above. In the case of reagglomeration CST, the agitation was disintegrated by vigorously stirring the wastewater for 10 seconds, and then the coagulation agent was added to test reaggregation by the above procedure. Reaggregation CST used the cohesion behavior at the strong shear force as the test scale. The lower the value, the better the cohesive performance.

2) Filtrate Turbidity Measurement

10 minutes after flocculation using a turbidimeter (2020 Turbidimeter, manufactured by LaMotte, Instrument type: Nephelometic turbidity, calibrated in NTU, Measure range: 0.00 ~ 1000 NTU, Accuracy: <100 NTU: ± 2%> 100 NTU: ± 3%) It was measured after standing. The lower the measured value, the better the suspended particle removal efficiency.

3) Filtrate COD

After the flocculation reaction was completed, the mixture was allowed to stand for 10 minutes and measured by potassium permanganate at 100 ° C according to the method for measuring the chemical oxygen demand in Chapter 4, Section 6 of the Water Pollution Process Test. It is a measure of the efficiency of organic pollutant removal by flocculant. The lower the value, the better.

division Initial input of flocculant (ppm) Initial CST (sec.) Additional Coagulant Input (ppm) Reaggregation CST (sec.) Filtration Turbidity NTU ¹⁾ Filtrate COD (ppm) Example 1 20 31.3 10 35.2 5.5 42 Example 2 20 29.7 10 32.1 4.6 34 Example 3 20 35.1 10 41.2 6.2 65 Example 4 20 37.8 10 43.6 7.5 92 Example 5 20 42.1 10 48.1 8.2 98 Comparative Example 1 20 55.8 10 63.9 9.6 118 Comparative Example 2 20 48.2 10 57.6 9.1 102 Comparative Example 3 20 62.3 10 69.1 12.0 125 1) NTU (Nephelometry Turbidity Unit)

According to Table 3 above, C.D. The cohesiveness was the best under the 2.45 meq / g ionic polymer condition (Example 2), and the polymer crosslinked with the crosslinking monomer was treated with the re-cohesiveness and wastewater treatment at the same ionicity as compared with the polymer of the comparative example without crosslinking. It was confirmed that the ability is excellent.

As described above, by using epichlorohydrin dimethylamine condensate as a dispersion stabilizer, cationic functional groups can be formed on the main branch of the copolymer molecule, and the dispersion stability can be improved by the repulsive force of the high cationic functional group, thereby It can increase the storage stability.

In addition, when used as a flocculant in wastewater treatment, the strong cationicity of the epichlorohydrin dimethylamine condensate added as a dispersion stabilizer makes the sludge agglomerate better than the inorganic flocculant, so that the desired sludge agglomerates without adding the inorganic flocculant. It can be carried out, due to the crosslinking of the copolymer is stable to the shear force, such as various mechanical properties are improved, there is a chemical cost reduction effect.

Claims (6)

Into the aqueous monomer mixture solution having a monomer concentration of 8 to 20% by weight, 150 to 250 parts by weight of the anionic salt and 5 to 20 parts by weight of the epichlorohydrin dimethylamine condensate are mixed with 100 parts by weight of the total monomer, followed by dissolved oxygen. Remove, add 0.01 to 1 part by weight of an azo polymerization initiator, and copolymerize at 20 to 45 ° C., After the copolymerization is completed, the temperature is increased to 55 to 65 ° C., and then 50 to 150 parts by weight of anionic salt is added to decrease the viscosity of the solution. Method for producing a branched acrylamide copolymer dispersion for wastewater treatment by a water-dispersible polymer production method comprising a. The method of claim 1, wherein the monomer mixture is selected from 5 to 94.9999 wt% of (meth) acrylamide monomer, 5 to 94.9999 wt% of quaternary amine salt monomer and N, N-methylenebisacrylamide or trimethylolpropane triacrylate. A method for producing a branched acrylamide copolymer dispersion for wastewater treatment, comprising 0.0001 to 0.01% by weight of a monomer for crosslinking. The quaternary amine salt according to claim 2, wherein the quaternary amine salt is dimethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl acrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate benzyl A process for producing a branched acrylamide copolymer dispersion for wastewater treatment, characterized in that selected from chloride quaternary salts and diallylmethyl ammonium chloride quaternary salts. The method of claim 1, wherein the anionic salt is ammonium sulfate or sodium sulfate salt, the method for producing a branched acrylamide copolymer dispersion for wastewater treatment. The method of claim 1, wherein the epichlorohydrin dimethylamine condensate has a molecular weight ranging from 100,000 to 1,000,000. The method of claim 1, wherein the acrylamide copolymer has a molecular weight of 1,000,000 ~ 10,000,000 method for producing a branched acrylamide copolymer dispersion for wastewater treatment.