CN101402480A - Method for producing wastewater treatment agent with weathered coal graft organic macromolecule - Google Patents

Abstract

The invention relates to a method for preparing a waste water treatment agent by grafting weathered coal with an organic polymer. In an inorganic salt solution, using a cationic addition polymer soluble in the salt solution as a dispersant, through the graft polymerization reaction of weathered coal, methacrylamide or acrylamide and more than one water-soluble cationic monomer Prepare a cationic water-soluble polymer dispersion with a particle size of less than 100 microns. The water-soluble polymer dispersion liquid prepared by the invention can be used for white water treatment in papermaking, waste water treatment in food industry, iron and steel smelting plant, building material industry and petroleum industry, especially for sludge dehydration in urban sewage treatment plants or food factories The effect is particularly obvious. Various equipment used for sludge dewatering, such as belt dewatering machines, filter dewatering machines, centrifugal dewatering machines, etc., can use weathered coal grafted with organic polymers to prepare wastewater treatment agents.

Description

Method for preparing waste water treatment agent by grafting weathered coal with organic polymer

technical field

The invention relates to a method for preparing a waste water treatment agent by grafting weathered coal with an organic polymer.

Background technique

Due to its excellent viscosity-increasing, flocculating, drag-reducing and water-retaining properties, water-soluble polymers are widely used in many fields such as wastewater treatment and papermaking. The raw materials for the synthesis of water-soluble polymers come from petroleum products. With the shortage of petroleum resources, the use of other raw materials to replace petroleum products has become a research and development hotspot in the field of research and industrial production. Weathered coal is a natural product with low combustion value, which contains a large amount of humic acid and can be used in soil fertilizer, water treatment agent, fluid loss control agent and other fields. Chinese patents 200410058335.5, CN1244613C, CN1084781C, and 97105226 describe the process of extracting humic acid from weathered coal. This method can effectively extract humic acid to prepare fertilizers, water treatment agents, and fluid loss control agents. However, in the process of extraction, strong acid or strong base is needed, and the desired yield can be achieved only under high temperature conditions. The process itself has problems such as large energy consumption, high post-processing costs and environmental pollution.

Contents of the invention

To solve the above problems, the present invention provides a method for preparing a wastewater treatment agent by grafting weathered coal with an organic polymer. It involves adding a cationic addition polymer dispersant to an inorganic salt solution, and contacting weathered coal with a monomer mixture composed of methacrylamide or acrylamide and more than one water-soluble cationic monomer in the brine solution. Branch polymerization reaction, a method for preparing weathered coal grafted organic polymers to prepare wastewater treatment agents.

The steps and conditions of the preparation method of the waste water treatment agent prepared by grafting weathered coal with organic polymers are as follows:

The water-soluble monomer mixture is composed of 5-90 mole percent cationic monomers defined by chemical formula 1, and 10-95 mole percent methacrylamide or acrylamide monomers;

Chemical formula 1:

In the formula, R ₁ is H or CH ₃ ; R ₂ and R ₃ are both alkyl or alkoxy with 1-3 carbons; R ₄ is H, alkyl or alkoxy with 1-3 carbons; A Is O or NH; B is an alkylene or alkyleneoxy group with 1-3 carbons; _X is a halide ion;

Cationic monomers defined by chemical formula 1 are preferably: dimethylaminoethyl acrylate, dimethyl-propylacrylamide, chloride of methylaminoethyl acrylate, 3-acrylamido-methylpropylamine chloride or N, N-di-methyl-N-benzyl ethylamine chloride;

Dissolving the water-soluble monomer mixture in inorganic brine with a weight concentration of 7%-saturated range and making the weight concentration of the water-soluble monomer mixture 1-40%, adding cationic addition polymer dispersant and Weathering coal, adjusting the pH value of the system to 2-6, passing nitrogen gas under the condition of stirring to remove the oxygen in the system, adding an initiator to carry out polymerization, the reaction temperature is 5-90°C, the optimum temperature is 15-65°C, and the obtained Cationic water-soluble polymer dispersion;

Described cationic addition polymer dispersant is the cationic polymer of general chemical formula 2;

Chemical formula 2:

In the formula, R ₅ is H or CH ₃ ; R ₆ and R ₇ are both alkyl or alkoxy with 1-3 carbons; R ₈ is H, alkyl or alkoxy with 1-3 carbons; D Is O or NH; E is an alkylene or alkyleneoxy group with 1-3 carbons; _X2 is a halide ion;

The amount of the cationic addition polymer dispersant is 1-20% of the weight of the water-soluble monomer mixture, and the optimal amount is 2-15%;

The weathered coal: the weight ratio of inorganic salt brine is 5-30:100; the particle size range of the weathered coal is 20-60 microns, preferably 30-50 microns;

The initiator is an azo initiator: 2,2-azobis(2-amididazolinyl propane) dihydrochloride (VA-044), 2,2-azobis(2-amidinopropane) Dihydrochloride (V-50), 2,2-azobisisobutyronitrile (V-60) or 2,2-azobis(2,4-dimethylvaleronitrile) (V-65); azo Preferred initiators: 2,2-azobis(2-amidinopropane) dihydrochloride (V-50) or 2,2-azobis(2-amididazolinylpropane) dihydrochloride (VA-044) ;

Described inorganic salt is the salt that sodium ion, potassium ion or ammonium ion and halide ion radical, sulfate radical, nitrate radical or phosphate radical form; Preferred inorganic salt is ammonium sulfate, sodium sulfate, magnesium sulfate, sodium phosphate, ammonium phosphate, Monosodium Phosphate, Sodium Chloride, or Potassium Chloride.

The cationic addition polymer dispersant used in the present invention has a very obvious effect on the preparation of weathered coal grafted cationic water-soluble polymer dispersion, but there are still many problems to be discussed in terms of its mechanism. From the reaction phenomenon, the following speculation can be made: when the reaction proceeds to a certain extent in the salt solution, and the generated polymer exceeds the critical point, part of the polymer will be precipitated from the salt solution in the form of particles, that is, dissolved and dissolved in the system. Precipitated macromolecules exist at the same time, and the macromolecules dissolved in the brine solution increase the overall viscosity of the system. Thereafter, with the increase of the amount of precipitated polymer, the viscosity of the system decreased and a dispersed state was formed. At this time, in the state of two-phase coexistence, the smooth effect between the precipitated particles and the dissolved polymer makes the system transition from a high-viscosity state to a low-viscosity dispersed state softer, and the dispersant plays a role in this change process. special role. Compared with the cationic polymer of addition polymerization, the condensation polymer has a lower molecular weight and a larger ion equivalent degree, which is easy to adsorb and tightly cover the surface of the particles, and the dispersed particles are stabilized by the repulsion of its charge. A microphase separation state is formed between the precipitated particles and the dissolved polymer, which plays a role in stabilizing the dispersed system. However, due to the low molecular weight, the coating covering the surface of the particles is relatively thin, and is easily damaged by external forces such as stirring and shearing forces during the reaction. Therefore, the combination with higher molecular weight addition polymers can increase the strength of the coating covering the particle surface. From the comprehensive effects of the above aspects, the viscosity around the precipitated particles is reduced, so that the phase change is carried out in a stable process.

Beneficial effects: the present invention provides a waste water treatment agent prepared by grafting weathered coal with an organic polymer, which can be used for white water treatment in papermaking, waste water treatment in the food industry, iron and steel smelting plants, building materials industry and petroleum industry, especially for urban sewage treatment plants or The dewatering effect of sludge in food factories is particularly obvious. Various equipment for sludge dehydration, such as belt dehydrator, filter dehydrator, centrifugal dehydrator and other equipment can be used. The amount of addition varies according to the turbidity of wastewater or sludge, and the range is 0.1-1000ppm of wastewater or 0.1-3% of solid impurities in sludge.

Detailed ways

Synthesis examples of dispersants are described below.

Synthesis Example 1-3: Synthesis Example of Cationic Addition Polymer Dispersant

Add 240g of deionized water to a 500mL reaction bottle, then add 60g of trimethylaminoethyl acrylate (DAC) (see NO.1 in Table 1), or 40g of trimethylaminoethyl acrylate and 80g of acrylamide (AM) The mixed monomer (see NO.2 in Table 1), or the mixed monomer of 20g trimethylaminoethyl acrylate and 100g acrylamide (see NO.3 in Table 1), add sulfuric acid dropwise to adjust the pH of the solution to 3. After raising the temperature to 42 degrees, pass nitrogen gas for about 30 minutes, then add 3g of V-50 in 2% aqueous solution to initiate the polymerization system. Heating was stopped after 15 hours of reaction to obtain dispersant synthesis examples No.1, No.2 and No.3. (See Table 1) Measure its weight-average molecular weight and cationicity respectively with static light scattering and colloid titration analysis.

Synthesis example 4-6:

Add 240g of deionized water to a 500mL reaction bottle, then add 60g of trimethylaminoethyl methacrylate (DMC) (see NO.4 in Table 1), or 40g of trimethylaminoethyl methacrylate and 80g of propylene A mixed monomer of amide (AM) (see NO.5 in Table 1), or a mixed monomer of 20g trimethylaminoethyl methacrylate and 100g acrylamide (see NO.6 in Table 1), add sulfuric acid dropwise Adjust the pH of the solution to 3, heat up to 42 degrees, and pass nitrogen gas for about 30 minutes, then add 3g of 2% aqueous solution of V-50 to initiate the polymerization system. Heating was stopped after 15 hours of reaction to obtain dispersant synthesis examples No.4, No.5 and No.3. (See Table 1) Measure its weight-average molecular weight and cationicity respectively with static light scattering and colloid titration analysis.

The preparation example of the waste water treatment agent prepared by grafting weathered coal with organic polymer is introduced below.

Example 1

In the 500 milliliters of 4 mouthfuls of round-bottomed flasks that are equipped with condenser tube, thermometer, nitrogen inlet and agitator, add polymer NO-1 (20%) 25g prepared in Synthetic Example 1, weathered coal 15g, 170.4g deionized Water, 115g of ammonium sulfate, 67.4g of 50% concentration of acrylamide, 115g of 80% trimethylethylamine acrylate chloride, heating up and keeping the temperature at 30-33°C to completely dissolve it. After 30 minutes of nitrogen gas, 1.9 g of 1% VA-044 aqueous solution was added to initiate the reaction. The viscosity of the reaction system began to increase 2.5 hours after the start of the reaction, and decreased after 25 minutes to form a dispersion. After reacting for 8 hours, 0.5 g of the above-mentioned initiator solution was added and the reaction was continued for 8 hours to obtain weathered coal grafted organic polymers to prepare wastewater treatment agents. The concentration, viscosity and particle size of the dispersion are 25%, 185 mPa.s and 50 microns, respectively. The data are shown in Example 1 of Table 2.

Example 2-6

The reaction device and operation mode were the same as those in Example 1, and the weathered coal was grafted with organic polymers to prepare waste water treatment agent according to the dosage of dispersant and monomer shown in Table 2. The results are shown in Table 2.

Comparative example 1

In a 500 ml 4-neck round bottom flask equipped with a condenser, a thermometer, a nitrogen inlet and a stirrer, add 15 g of weathered coal, 178.2 g of deionized water, 115 g of ammonium sulfate, 67.4 g of 50% concentration of acrylamide, and 115 g of 80% Acrylate trimethylethylamino ester chloride, heat up and keep the temperature at 30-33°C to completely dissolve it. After 30 minutes of nitrogen gas, 1.9 g of 1% VA-044 aqueous solution was added to initiate the reaction. One hour after the start of the reaction, the viscosity of the reaction system began to increase sharply and lasted for about one hour, after which the viscosity decreased and a dispersion liquid was formed. After reacting for 8 hours, 0.5 g of the above-mentioned initiator solution was added and the reaction was continued for 8 hours to obtain a sample of Comparative Example 1. The results are shown in Comparative Example 1 in Table 2.

Comparative example 2

The reaction device and operation mode are the same as in Example 1, and the comparative example 2 is synthesized according to the dispersant dosage and monomer dosage and conditions shown in Table 2, and the results are shown in Table 2.

Table 1. Synthesis example of dispersant

NO. The composition of the dispersant Cation molar weight/meq/g Molecular weight/10,000 1 DAC homopolymer 5.25 20 2 DAC/AM copolymer 4.52 50 3 DAC/AM copolymer 5.97 70 4 DMC homopolymer 7.33 20 5 DMC/AM copolymer 7.01 65 6 DMC/AM copolymer 6.45 90

Note: DAC: trimethylethylamine acrylate chloride;

DMC: trimethylethylamine methacrylate chloride;

AM: acrylamide.

Table 2. Formulations and results of dispersion synthesis examples

Reality Concentrated monomer dispersed Amount added weathered coal DAC DMA ABC AAm Dispersion sticky

Example Degree (WT%) agent (WT%) Concentration (WT%) Degree/mPa.s 1 25.0 No.1 4.0 5 50 50 180 2 25.0 No.2 5.0 10 50 20 30 150 3 25.0 No.3 5.0 30 40 20 40 250 4 23.0 No.4 4.0 5 10 50 40 200 5 22.3 No.5 4.0 10 40 60 190 6 25.0 No.6 5.0 30 40 20 40 220 comparative example 1 25.0 - 0 5 50 50 1350 2 21.0 - 0 10 50 20 30 2530

Note: DAC: trimethylethylamine acrylate chloride;

AAM: acrylamide;

DMC: trimethylethylamine methacrylate chloride;

ABC: ethyl acrylate-N,N-dimethyl-N-benzylamine chloride.

Claims (7)

1, the method for producing wastewater treatment agent with weathered coal graft organic macromolecule is characterized in that, step and condition are:

The water-soluble monomer mixture is by the cationic monomer of the 5-90 mole % of Chemical formula 1 definition, and the Methacrylamide of 10-95 mole % or acrylamide monomer constitute;

Chemical formula 1:

In the formula, R ₁Be H or CH ₃R ₂, R ₃Be alkyl or the alkoxyl group of carbon number 1-3; R ₄Alkyl or alkoxyl group for H, carbon number 1-3; A is O or NH; B is alkylidene group or the alkylene oxide group of carbon number 1-3; X ₁Be halide-ions;

Is dissolving and to make the weight concentration of water-soluble monomer mixture be 1-40% in the inorganic salt solution of 7%-saturation range with the water-soluble monomer mixture in weight concentration, in reaction system, add cationic addition polymer dispersion agent and weathered coal, the regulation system pH value is 2-6, logical nitrogen is with the oxygen in the system of removing under stirring condition, add initiator and carry out polymerization, temperature of reaction is 5-90 ℃, obtains producing wastewater treatment agent with weathered coal graft organic macromolecule;

The cation type polymer that described cationic addition polymer dispersion agent is a chemical general formula 2;

Chemical formula 2:

In the formula, R ₅Be H or CH ₃R ₆, R ₇Be alkyl or the alkoxyl group of carbon number 1-3; R ₈Alkyl or alkoxyl group for H, carbon number 1-3; D is O or NH; E is alkylidene group or the alkylene oxide group of carbon number 1-3; X ₂Be halide-ions;

The consumption of described positively charged ion addition polymer dispersion agent is the 1-20% of water-soluble monomer mixture weight;

Described weathered coal: inorganic salt brinish weight ratio is 5-30: 100; The particle size range of weathered coal is the 20-60 micron;

Described initiator is an azo-initiator: 2, and 2-azo two (2-amidine azoles quinoline base propane) two hydrochloric acid, 2,2-azo two (2-amidine propane) two hydrochloric acid, 2,2-Diisopropyl azodicarboxylate or 2,2-azo two (2, the 4-methyl pentane nitrile);

Described inorganic salt are the salt that sodium ion, potassium ion or ammonium ion and halogen ion root, sulfate radical, nitrate radical or phosphate radical form.

2, the method for producing wastewater treatment agent with weathered coal graft organic macromolecule as claimed in claim 1, it is characterized in that described cationic monomer by the Chemical formula 1 definition is: vinylformic acid dimethylin second fat ester, dimethyl-propyl group acrylamide, the muriate of vinylformic acid methylamino ethyl ester, 3-acrylamido-methyl chlorination propylamine or N, N-two-methyl-N-benzyl vinylformic acid ethamine ester muriate.

3, the method for producing wastewater treatment agent with weathered coal graft organic macromolecule as claimed in claim 1, the consumption that it is characterized in that described positively charged ion addition polymer dispersion agent is the 2-15% of water-soluble monomer mixture weight.

4, the method for producing wastewater treatment agent with weathered coal graft organic macromolecule as claimed in claim 1, the particle size range that it is characterized in that described weathered coal is the 30-50 micron.

5, the method for producing wastewater treatment agent with weathered coal graft organic macromolecule as claimed in claim 1 is characterized in that described azo-initiator is: 2, and 2-azo two (2-amidine propane) two hydrochloric acid or 2,2-azo two (2-amidine azoles quinoline base propane) two hydrochloric acid.

6, the method for producing wastewater treatment agent with weathered coal graft organic macromolecule as claimed in claim 1 is characterized in that described inorganic salt are ammonium sulfate, sodium sulfate, sal epsom, sodium phosphate, ammonium phosphate, SODIUM PHOSPHATE, MONOBASIC, sodium chloride or Repone K.

7, the method for producing wastewater treatment agent with weathered coal graft organic macromolecule as claimed in claim 1 is characterized in that described adding initiator carries out polymerization, and temperature of reaction is 15-65 ℃.