A high-efficiency multifunctional water purifier and its preparation method and application

Abstract

The present invention belongs to the technical field of sewage treatment, and specifically relates to a high-efficiency multifunctional water purifier, a preparation method and application thereof. The preparation method is: CFN coexistence and blending degradation agent, FNX synergistic removal agent, modified alumina powder, modified activated carbon powder calcium salt, flocculant, and complex catalyst are mixed in steps. Among them, the flocculant is a carboxymethyl chitosan derivative, which is prepared by epoxy compound ring-opening reaction, quaternization reaction, and esterification reaction in sequence; the carboxymethyl chitosan derivative contains mercaptobenzothiazole and quaternary ammonium salt structure, and has excellent adsorption performance, corrosion inhibition performance and antibacterial performance. The high-efficiency multifunctional water purifier provided by the present invention realizes the effective removal of multiple pollution factors. After the agent is added, the pH fluctuation of the sewage is small, and no subsequent acid-base adjustment is required. It can reduce the cost of sewage treatment at multiple levels, while improving the treatment efficiency and effluent quality.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment, and specifically relates to a high-efficiency multifunctional water purifier and a preparation method and application thereof. Background Art

[0002] Water purifiers are an important part of sewage treatment technology. With the help of physical and chemical technologies, they filter out impurities in water and play an important role in improving water quality, protecting water resources and promoting environmental protection. In the sewage treatment process, when the water quality after being treated by the biochemical system cannot meet the discharge standard requirements due to certain pollutants, it is necessary to purify the pollutants such as COD, ammonia nitrogen, total phosphorus, and fluoride ions in the sewage. Through the action of water purifiers, the pollutants enter the sludge system in the form of sediments. The supernatant treated by the water purifier can meet the discharge standards for discharge.

[0003] The patent with publication number CN117088578B provides a method for removing high-concentration suspended matter in water. First, micro-nano aeration method is used in a flotation tank to generate bubbles to remove most of the organic oil pollutants, and then anionic polyacrylamide derivatives are used as flocculants to remove high-concentration suspended particles that are difficult to settle. Finally, an ozone reactor is used to degrade and remove soluble organic matter in the wastewater. The above method has good COD, suspended matter and heavy metal ion removal effects, but the invention needs to first enter the pH rough adjustment tank in the process of removing high-concentration suspended particles using anionic polyacrylamide derivative flocculants, and use acid or alkali to control the effluent pH value. After staying for a period of time, it enters the pH fine adjustment tank and uses acid or alkali to control the effluent pH value again. This method has high requirements for the effluent pH. Abnormal fluctuations in the pH value may affect the efficiency of sewage treatment and extend the treatment time, which will not only affect its treatment capacity, but may also result in additional labor and equipment operating costs. The patent with publication number CN109592769A provides a water purifier for rapid purification of water bodies, including a surfactant-modified acrylamide-4-chlorophthalic anhydride copolymer and an inorganic coating. The acrylamide copolymer is hydrophobically modified by a surfactant to exhibit the characteristics of a hydrophobic colloid. Through the microphase separation of the copolymer, the polyaluminium chloride in the water purifier plays a flocculation and sedimentation role, while the acrylamide plays a coagulant role. At the same time, due to the microphase separation, the water purifier is dispersed in a larger range in the water body, thereby increasing the treatment load of the water source and reducing the dosage of the water purifier. In addition, due to the characteristics of the copolymer high molecular weight material, flocculation occurs early, the flocs are tightly clustered, and the particles are large and difficult to break, which further improves the stability of the flocs. The surfactant-modified acrylamide-4-chlorophthalic anhydride copolymer and the inorganic coating act synergistically, so that after the water purifier is added to the water body, the flocs formed in the water body can be quickly settled, and the purification effect is good. However, the water purifier provided by the invention has poor corrosion inhibition and antibacterial properties. In the process of sewage treatment, it will not only reduce the treatment efficiency, increase energy consumption and operating costs, but also have a negative impact on water treatment equipment, the ecological environment and human health. Summary of the invention

[0004] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a high-efficiency multifunctional water purifier and a preparation method and application thereof. The agent obtained by the method is added to sewage to achieve the removal effect of various pollutants. The present invention prepares an agent with excellent comprehensive performance by reasonably proportioning the components of the water purifier. It has obvious removal effects on COD, total phosphorus and fluoride ions, and also has certain removal effects on ammonia nitrogen and total nitrogen. The agent is suitable for deep treatment of sewage and has a wide range of applications.

[0005] The technical solution adopted by the present invention to achieve the above-mentioned purpose is:

[0006] A method for preparing a high-efficiency multifunctional water purifier comprises the following steps:

[0007] a. At room temperature, add the CFN coexisting and degrading agent to the reactor I, stir for 5-15 minutes, then add the FNX synergistic removal agent, and continue stirring for 50-70 minutes; then add the modified alumina powder and the modified activated carbon powder in turn, and stir for 50-70 minutes;

[0008] b. adding the product obtained in step a to reactor Ⅱ, and keeping reactor Ⅱ in a stirring state;

[0009] c. At room temperature, add the CFN coexisting and degrading agent to the reactor I again, stir for 5-15 minutes, then add the FNX synergistic removal agent, and continue stirring for 50-70 minutes; finally, add the modified alumina powder and the modified activated carbon powder in sequence, and stir for 50-70 minutes;

[0010] d. The product obtained in step c is added to reactor II, stirred and mixed, and then calcium salt, flocculant, and complex catalyst are added in sequence, and stirring is continued for 100-140min to obtain;

[0011] The mass ratio of the CFN coexisting blending degradation agent, FNX synergistic removal agent, modified alumina powder, and modified activated carbon powder in step a is 22-26:11-13:2.5:1.5;

[0012] The mass ratio of the CFN coexisting blending degradation agent, FNX synergistic removal agent, modified alumina powder, and modified activated carbon powder in step c is 34-38:7-9:2.5:1.5;

[0013] The ratio of the mass of the CFN co-existing and harmonizing degradation agent added in the reactor I of step a to the mass of the CFN co-existing and harmonizing degradation agent added in the reactor I of step c is 24:35-37;

[0014] The mass ratio of the calcium salt, the flocculant and the complex catalyst in step d is 2:1.8-2.2:0.9-1.1, and the mass ratio of the calcium salt to the product obtained in step c is 2:45-50.

[0015] Furthermore, the CFN coexistence and harmonizing degradation agent is prepared by mixing polyferric sulfate and anhydrous ferric chloride, and the mass ratio of polyferric sulfate to anhydrous ferric chloride is 30:5-10; the FNX synergistic removal agent is prepared by mixing equal masses of polyaluminum chloride and calcium aluminate; the calcium salt is calcium carbonate; and the complex catalyst is one or more of ethylenediaminetetraacetic acid, thiourea, citric acid, tartaric acid, and triethanolamine.

[0016] Furthermore, the preparation method of the modified alumina powder is as follows: disperse the alumina powder in a hydrochloric acid solution, stir and heat it to 60-70°C, reflux reaction for 10-30 minutes, separate the solid and liquid, take the solid, wash it to neutrality, place it in a muffle furnace and heat it to 500-600°C, keep it warm for 4-6 hours, cool it to room temperature, grind it, and obtain it; the mass volume ratio of alumina powder and hydrochloric acid solution is 0.08-0.14g / mL, and the mass fraction of hydrochloric acid in the hydrochloric acid solution is 15-20%. Due to its porosity, high specific surface area and high dispersibility, the modified alumina powder has a strong adsorption capacity, which enables it to effectively remove pollutants such as COD, suspended matter and heavy metal ions in wastewater.

[0017] Furthermore, the preparation method of the modified activated carbon powder is as follows: the activated carbon powder is dispersed in a nitric acid solution, the temperature is raised to 60-70°C with stirring, and the reaction is performed for 2-3 hours to obtain oxidized activated carbon; the oxidized activated carbon is then dispersed in deionized water, and 2-amino-4-hydroxythiazole and sulfuric acid are added in sequence, and the reaction is stirred at 70-80°C for 1-2 hours to obtain; the mass volume ratio of the activated carbon powder to the nitric acid solution is 0.07-0.12 g / mL, the amount of the oxidized activated carbon added in the deionized water is 0.015-0.025 g / mL, and the mass ratio of the oxidized activated carbon, 2-amino-4-hydroxythiazole, and sulfuric acid is 1:4-8:0.4-0.6.

[0018] 2-Amino-4-hydroxythiazole, as a nitrogen-containing organic compound, can introduce nitrogen-containing functional groups on the surface of activated carbon after esterification reaction with activated carbon. The nitrogen-containing functional groups can increase the surface polarity of activated carbon, thereby improving the adsorption capacity of polar pollutants in water such as COD; the modified activated carbon powder has a better flocculation effect due to the change in surface properties, which can promote the aggregation and sedimentation of suspended matter, thereby improving the removal efficiency of suspended matter.

[0019] Furthermore, the flocculant is a carboxymethyl chitosan derivative, and the preparation method of the carboxymethyl chitosan derivative is:

[0020] S1. Disperse 2-thio-2,3-dihydrobenzo[D]thiazole-5-carboxylic acid in toluene, stir and heat to 95-100° C., then add epichlorohydrin and chromium acetate in sequence, reflux for 5-7 hours, cool to room temperature, and purify to obtain intermediate 1;

[0021] S2. Under a nitrogen atmosphere, disperse the intermediate 1 and N,N-dimethylpropylamine in ethanol, stir and heat to 70-75°C, then add potassium iodide, reflux for 20-25h, cool to room temperature, and purify to obtain the intermediate 2;

[0022] S3, dispersing carboxymethyl chitosan and intermediate 2 in tetrahydrofuran, stirring and heating to 55-65°C, then adding p-toluenesulfonic acid, reflux reaction for 5-8h, cooling to room temperature, and dialyzing to obtain a carboxymethyl chitosan derivative;

[0023] Among them, the synthetic route of intermediate 2 is as follows: ; .

[0024] The invention uses 2-thio-2,3-dihydrobenzo[D]thiazole-5-carboxylic acid and epichlorohydrin as starting materials, and performs an epoxy compound ring-opening reaction under the catalysis of chromium acetate to obtain an intermediate 1; then uses the intermediate 1 and N,N-dimethylpropylamine as raw materials, and performs a quaternization reaction under the catalysis of potassium iodide to obtain an intermediate 2; finally, uses the intermediate 2 as a modifier to modify carboxymethyl chitosan to obtain a carboxymethyl chitosan derivative.

[0025] In order to functionalize carboxymethyl chitosan, the molar ratio of 2-thio-2,3-dihydrobenzo[D]thiazole-5-carboxylic acid, epichlorohydrin, and chromium acetate in step S1 is 1.2:1.0-1.2:0.018-0.023, and the mass volume ratio of 2-thio-2,3-dihydrobenzo[D]thiazole-5-carboxylic acid to toluene is 0.11-0.14 g / mL; the intermediate 1, N , the molar ratio of N,N-dimethylpropylamine and potassium iodide is 1:1.2-1.3:0.21-0.24, and the mass volume ratio of N,N-dimethylpropylamine and ethanol is 0.2-0.3 g / mL; the mass ratio of carboxymethyl chitosan, intermediate 2 and p-toluenesulfonic acid in step S3 is 90:10-14:1.0-1.3, and the mass volume ratio of carboxymethyl chitosan and tetrahydrofuran is 0.10-0.12 g / mL.

[0026] The high-efficiency multifunctional water purifier prepared by the method and its application in sewage treatment.

[0027] The present invention has the following beneficial effects:

[0028] The present invention uses a three-step method to prepare a carboxymethyl chitosan derivative, wherein the carboxymethyl chitosan derivative contains mercaptobenzothiazole and quaternary ammonium salt structures. Mercaptobenzothiazole can react with the metal surface to form a protective film on the metal surface, thereby increasing the transfer resistance and reducing the corrosion current, thereby effectively reducing the corrosion rate of the metal; the quaternary ammonium salt and carboxymethyl chitosan synergistically enhance the effect of inhibiting and killing bacteria by increasing the positive charge density, destroying the cell membrane, inhibiting the enzyme activity, and the like, thereby improving the antibacterial performance of the water purifier product. Carboxymethyl chitosan and its derivatives have strong flocculation properties. When used in combination with modified activated carbon powder, the flocculation effect can be further improved. The porous structure and adsorption properties of modified activated carbon combined with the flocculation effect of carboxymethyl chitosan can effectively remove suspended matter and pollutants in sewage. Carboxymethyl chitosan and its derivatives are a kind of amphoteric polyelectrolyte that can effectively complex with metal ions. Modified alumina powder also exhibits good adsorption properties due to its high specific surface area and porosity. When the two are used together, they can complement each other and significantly improve the adsorption efficiency of water purification products for pollutants.

[0029] The high-efficiency multifunctional water purifier provided by the present invention achieves effective removal of multiple pollution factors (COD, ammonia nitrogen, total phosphorus, fluoride ions, etc.), and also has excellent adsorption performance, corrosion inhibition performance and antibacterial performance. After the agent is added, the pH fluctuation of the sewage is small, and no subsequent acid-base adjustment is required. It can reduce the cost of sewage treatment at multiple levels, while improving the treatment efficiency and effluent quality. DETAILED DESCRIPTION

[0030] The following will be combined with the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0031] Activated carbon powder, mesh number 325, ash content ≤6%, purchased from Xinghua Carbon Technology Nanjing Co., Ltd.; alumina powder, mesh number 500, Al2O3 content ≥99.3-99.6%, Fe2O3 content ≤0.04-0.09%, Na2O content ≤0.2-0.30%, purchased from Zhengzhou Haixu Abrasive Co., Ltd.; polyaluminium chloride, effective ingredient content ≥99%, purchased from Zibo Yishengjia Aluminium Co., Ltd.; polyferric sulfate, mesh number 150, purchased from Jinan Duanxing Chemical Technology Co., Ltd.; carboxymethyl chitosan, effective ingredient content ≥99%, purchased from Shandong Xinxiong Biotechnology Co., Ltd. The raw materials used in the following examples are all common commercially available products. Example 1

[0032] A method for preparing a high-efficiency multifunctional water purifier comprises the following steps:

[0033] a. At room temperature, add the CFN co-existing harmonizing degradation agent into the reactor I, stir for 10 minutes, then add the FNX synergistic removal agent, and continue stirring for 60 minutes; then add the modified alumina powder and the modified activated carbon powder in sequence, and stir for 60 minutes; wherein the mass ratio of the CFN co-existing harmonizing degradation agent, the FNX synergistic removal agent, the modified alumina powder, and the modified activated carbon powder is 24:12:2.5:1.5;

[0034] b. adding the product obtained in step a to reactor Ⅱ, and keeping reactor Ⅱ in a stirring state;

[0035] c. At room temperature, the CFN co-existing harmonic degradation agent was added to the reactor I again, stirred for 10 minutes, and then the FNX synergistic removal agent was added, and the stirring was continued for 60 minutes; finally, the modified alumina powder and the modified activated carbon powder were added in sequence and stirred for 60 minutes; wherein, the mass ratio of the CFN co-existing harmonic degradation agent, the FNX synergistic removal agent, the modified alumina powder, and the modified activated carbon powder was 36:8:2.5:1.5, and the mass ratio of the CFN co-existing harmonic degradation agent added in the reactor I of step a to the mass ratio of the CFN co-existing harmonic degradation agent added in the reactor I of step c was 24:36;

[0036] d. Add the product obtained in step c to reactor II, stir and mix evenly, then add calcium salt, flocculant, and complex catalyst in sequence, and continue stirring for 120 min to obtain a high-efficiency multifunctional water purifier; wherein the mass ratio of calcium salt, flocculant, and complex catalyst is 2:2:1, the mass ratio of calcium salt to the product obtained in step c is 2:47, the calcium salt is calcium carbonate, and the complex catalyst is ethylenediaminetetraacetic acid;

[0037] The CFN coexistence and degradation agent is prepared by mixing polyferric sulfate and anhydrous ferric chloride, the mass ratio of polyferric sulfate to anhydrous ferric chloride is 30:8, and the FNX synergistic removal agent is prepared by mixing equal masses of polyaluminium chloride and calcium aluminate;

[0038] The preparation method of the modified activated carbon powder is as follows: dispersing the activated carbon powder in a nitric acid solution with a mass fraction of 40%, stirring and heating to 65° C., reacting for 2.5 hours, naturally cooling to room temperature, separating the solid and the liquid, taking the solid, washing it with deionized water until it is neutral, and vacuum drying it to constant weight to obtain oxidized activated carbon; then dispersing the oxidized activated carbon in deionized water, and then adding 2-amino-4-hydroxythiazole and sulfuric acid (mass fraction>98%) in sequence, stirring and reacting at 75° C. for 1.5 hours, naturally cooling to room temperature, separating the solid and the liquid, taking the solid, washing it with deionized water until it is neutral, vacuum drying it to constant weight, and grinding it to a particle size of ≤300 mesh, thereby obtaining the modified activated carbon powder; wherein the mass volume ratio of the activated carbon powder to the nitric acid solution is 0.09 g / mL, the amount of the oxidized activated carbon added in the deionized water is 0.02 g / mL, and the mass ratio of the oxidized activated carbon, 2-amino-4-hydroxythiazole, and sulfuric acid is 1:6:0.5;

[0039] The preparation method of the modified alumina powder is as follows: dispersing alumina powder in a hydrochloric acid solution, stirring and heating to 65°C, reflux reaction for 20 minutes, solid-liquid separation, taking solid, washing with deionized water until neutral, placing in a muffle furnace and heating to 550°C, keeping warm for 5 hours, cooling to room temperature with the furnace, and grinding to a particle size of ≤400 mesh, wherein the mass volume ratio of alumina powder to hydrochloric acid solution is 0.11 g / mL, and the mass fraction of hydrochloric acid in the hydrochloric acid solution is 18%.

[0040] The flocculant is a carboxymethyl chitosan derivative, and the preparation method of the carboxymethyl chitosan derivative is as follows:

[0041] S1. Disperse 2-thio-2,3-dihydrobenzo[D]thiazole-5-carboxylic acid in toluene, stir and heat to 98°C, then add epichlorohydrin and chromium acetate in sequence, reflux for 6 hours, cool naturally to room temperature, remove most of the toluene by concentration, add deionized water and ethyl acetate for extraction, take the organic phase and distill under reduced pressure, and vacuum dry to obtain intermediate 1; wherein the molar ratio of 2-thio-2,3-dihydrobenzo[D]thiazole-5-carboxylic acid, epichlorohydrin, and chromium acetate is 1.2:1.1:0.021, the mass volume ratio of 2-thio-2,3-dihydrobenzo[D]thiazole-5-carboxylic acid to toluene is 0.13 g / mL, and the volume ratio of toluene, deionized water, and ethyl acetate is 1:1:2;

[0042] S2. Under a nitrogen atmosphere, disperse the intermediate 1 and N,N-dimethylpropylamine in ethanol, stir and heat to 72°C, then add potassium iodide, reflux for 23h, naturally cool to room temperature, remove ethanol by distillation under reduced pressure, add ethyl acetate and deionized water for extraction, take the organic phase by distillation under reduced pressure, and vacuum dry to obtain intermediate 2; wherein the molar ratio of intermediate 1, N,N-dimethylpropylamine, and potassium iodide is 1:1.25:0.22, the mass volume ratio of N,N-dimethylpropylamine to ethanol is 0.25g / mL, and the volume ratio of ethanol, ethyl acetate, and deionized water is 1:2:1;

[0043] The NMR results of intermediate 2 are: 1 H NMR (300MHz, DMSO-d6) δ 17.81 (s, 1H), 7.92 (s, 1H), 7.71 (d, 1H), 7.54 (d, 1H), 5.37 (d, 1H), 4.50 (d, 1H), 4.16-4. 20 (m, 2H), 2.62 (d, 1H), 2.34-2.37 (m, 3H), 2.27 (s, 6H), 1.42-1.45 (m, 2H), 0.87 (t, 3H);

[0044] S3. Disperse carboxymethyl chitosan and intermediate 2 in tetrahydrofuran, stir and heat to 60°C, then add p-toluenesulfonic acid, reflux for 7 hours, cool naturally to room temperature, pour the reaction mixture into a dialysis bag (molecular weight 8000D) for dialysis, the dialysis time is 96 hours, replace deionized water every 24 hours, collect the dialysate in the dialysis bag, freeze-dry, and obtain a carboxymethyl chitosan derivative; wherein the mass ratio of carboxymethyl chitosan, intermediate 2, and p-toluenesulfonic acid is 90:12:1.1, and the mass volume ratio of carboxymethyl chitosan to tetrahydrofuran is 0.11 g / mL. Example 2

[0045] A method for preparing a high-efficiency multifunctional water purifier comprises the following steps:

[0046] a. At room temperature, add the CFN co-existing harmonic degradation agent into the reactor I, stir for 5 minutes, then add the FNX synergistic removal agent, and continue stirring for 50 minutes; then add the modified alumina powder and the modified activated carbon powder in sequence, and stir for 50 minutes; wherein the mass ratio of the CFN co-existing harmonic degradation agent, the FNX synergistic removal agent, the modified alumina powder, and the modified activated carbon powder is 26:13:2.5:1.5;

[0047] b. adding the product obtained in step a to reactor Ⅱ, and keeping reactor Ⅱ in a stirring state;

[0048] c. At room temperature, the CFN co-existing harmonic degradation agent was added to the reactor I again, stirred for 5 minutes, and then the FNX synergistic removal agent was added, and the stirring was continued for 50 minutes; finally, the modified alumina powder and the modified activated carbon powder were added in sequence and stirred for 50 minutes; wherein, the mass ratio of the CFN co-existing harmonic degradation agent, the FNX synergistic removal agent, the modified alumina powder, and the modified activated carbon powder was 38:9:2.5:1.5, and the mass ratio of the CFN co-existing harmonic degradation agent added in the reactor I of step a to the mass ratio of the CFN co-existing harmonic degradation agent added in the reactor I of step c was 24:37;

[0049] d. The product obtained in step c is added to reactor II, stirred and mixed, and then calcium salt, flocculant, and complex catalyst are added in sequence, and stirring is continued for 100 min to obtain a high-efficiency multifunctional water purifier; wherein the mass ratio of calcium salt, flocculant, and complex catalyst is 2:2.2:1.1, the mass ratio of calcium salt to the product obtained in step c is 2:50, the calcium salt is calcium carbonate, and the complex catalyst is thiourea;

[0050] The CFN coexistence and degradation agent is prepared by mixing polyferric sulfate and anhydrous ferric chloride, the mass ratio of polyferric sulfate to anhydrous ferric chloride is 30:10, and the FNX synergistic removal agent is prepared by mixing equal masses of polyaluminium chloride and calcium aluminate;

[0051] The preparation method of the modified activated carbon powder is as follows: dispersing the activated carbon powder in a nitric acid solution with a mass fraction of 40%, stirring and heating to 60° C., reacting for 3 hours, naturally cooling to room temperature, separating the solid and the liquid, taking the solid, washing it with deionized water until it is neutral, and vacuum drying it to constant weight to obtain oxidized activated carbon; then dispersing the oxidized activated carbon in deionized water, and then adding 2-amino-4-hydroxythiazole and sulfuric acid (mass fraction>98%) in sequence, stirring and reacting at 70° C. for 2 hours, naturally cooling to room temperature, separating the solid and the liquid, taking the solid, washing it with deionized water until it is neutral, vacuum drying it to constant weight, and grinding it to a particle size of ≤300 mesh, thereby obtaining the modified activated carbon powder; wherein the mass volume ratio of the activated carbon powder to the nitric acid solution is 0.12 g / mL, the amount of the oxidized activated carbon added in the deionized water is 0.025 g / mL, and the mass ratio of the oxidized activated carbon, 2-amino-4-hydroxythiazole, and sulfuric acid is 1:8:0.6;

[0052] The preparation method of the modified alumina powder is as follows: dispersing alumina powder in a hydrochloric acid solution, stirring and heating to 60°C, reflux reaction for 30 minutes, solid-liquid separation, taking the solid, washing it with deionized water until it is neutral, placing it in a muffle furnace and heating it to 500°C, keeping it warm for 6 hours, cooling it to room temperature with the furnace, and grinding it to a particle size of ≤400 mesh, wherein the mass volume ratio of the alumina powder to the hydrochloric acid solution is 0.14 g / mL, and the mass fraction of hydrochloric acid in the hydrochloric acid solution is 20%.

[0053] The flocculant is a carboxymethyl chitosan derivative, and the preparation method of the carboxymethyl chitosan derivative is as follows:

[0054] S1. Disperse 2-thio-2,3-dihydrobenzo[D]thiazole-5-carboxylic acid in toluene, stir and heat to 95°C, then add epichlorohydrin and chromium acetate in sequence, reflux for 7h, cool naturally to room temperature, remove most of the toluene by concentration, then add deionized water and ethyl acetate for extraction, take the organic phase and distill under reduced pressure, and vacuum dry to obtain intermediate 1; wherein the molar ratio of 2-thio-2,3-dihydrobenzo[D]thiazole-5-carboxylic acid, epichlorohydrin, and chromium acetate is 1.2:1.2:0.023, the mass volume ratio of 2-thio-2,3-dihydrobenzo[D]thiazole-5-carboxylic acid to toluene is 0.14 g / mL, and the volume ratio of toluene, deionized water, and ethyl acetate is 1:1:2;

[0055] S2. Under a nitrogen atmosphere, disperse the intermediate 1 and N,N-dimethylpropylamine in ethanol, stir and heat to 70°C, then add potassium iodide, reflux for 25h, cool naturally to room temperature, remove ethanol by distillation under reduced pressure, add ethyl acetate and deionized water for extraction, take the organic phase by distillation under reduced pressure, and vacuum dry to obtain intermediate 2; wherein the molar ratio of intermediate 1, N,N-dimethylpropylamine, and potassium iodide is 1:1.3:0.24, the mass volume ratio of N,N-dimethylpropylamine to ethanol is 0.3g / mL, and the volume ratio of ethanol, ethyl acetate, and deionized water is 1:2:1;

[0056] S3. Disperse carboxymethyl chitosan and intermediate 2 in tetrahydrofuran, stir and heat to 55°C, then add p-toluenesulfonic acid, reflux for 8 hours, cool naturally to room temperature, pour the reaction mixture into a dialysis bag (molecular weight 8000D) for dialysis, the dialysis time is 96 hours, replace deionized water every 24 hours, collect the dialysate in the dialysis bag, freeze-dry, and obtain a carboxymethyl chitosan derivative; wherein the mass ratio of carboxymethyl chitosan, intermediate 2, and p-toluenesulfonic acid is 90:14:1.3, and the mass volume ratio of carboxymethyl chitosan to tetrahydrofuran is 0.12 g / mL. Example 3

[0057] A method for preparing a high-efficiency multifunctional water purifier comprises the following steps:

[0058] a. At room temperature, add the CFN co-existing and harmonizing degradation agent into the reactor I, stir for 15 minutes, then add the FNX synergistic removal agent, and continue stirring for 70 minutes; then add the modified alumina powder and the modified activated carbon powder in sequence, and stir for 70 minutes; wherein the mass ratio of the CFN co-existing and harmonizing degradation agent, the FNX synergistic removal agent, the modified alumina powder, and the modified activated carbon powder is 22:11:2.5:1.5;

[0059] b. adding the product obtained in step a to reactor Ⅱ, and keeping reactor Ⅱ in a stirring state;

[0060] c. At room temperature, the CFN co-existing harmonic degradation agent was added to the reactor I again, stirred for 15 minutes, and then the FNX synergistic removal agent was added, and the stirring was continued for 70 minutes; finally, the modified alumina powder and the modified activated carbon powder were added in sequence and stirred for 70 minutes; wherein, the mass ratio of the CFN co-existing harmonic degradation agent, the FNX synergistic removal agent, the modified alumina powder, and the modified activated carbon powder was 34:7:2.5:1.5, and the mass ratio of the CFN co-existing harmonic degradation agent added in the reactor I of step a to the mass ratio of the CFN co-existing harmonic degradation agent added in the reactor I of step c was 24:35;

[0061] d. The product obtained in step c is added to reactor II, stirred and mixed evenly, and then calcium salt, flocculant, and complex catalyst are added in sequence, and stirring is continued for 140 min to obtain a high-efficiency multifunctional water purifier; wherein the mass ratio of calcium salt, flocculant, and complex catalyst is 2:1.8:0.9, the mass ratio of calcium salt to the product obtained in step c is 2:45, the calcium salt is calcium carbonate, and the complex catalyst is prepared by mixing equal masses of tartaric acid and citric acid;

[0062] The CFN coexistence and degradation agent is prepared by mixing polyferric sulfate and anhydrous ferric chloride, the mass ratio of polyferric sulfate to anhydrous ferric chloride is 30:5, and the FNX synergistic removal agent is prepared by mixing equal masses of polyaluminium chloride and calcium aluminate;

[0063] The preparation method of the modified activated carbon powder is as follows: dispersing the activated carbon powder in a nitric acid solution with a mass fraction of 40%, stirring and heating to 70°C, reacting for 2h, naturally cooling to room temperature, separating the solid and the liquid, taking the solid, washing it with deionized water until it is neutral, and vacuum drying it to constant weight to obtain oxidized activated carbon; then dispersing the oxidized activated carbon in deionized water, and then adding 2-amino-4-hydroxythiazole and sulfuric acid (mass fraction>98%) in sequence, stirring and reacting at 80°C for 1h, naturally cooling to room temperature, separating the solid and the liquid, taking the solid, washing it with deionized water until it is neutral, vacuum drying it to constant weight, and grinding it to a particle size of ≤300 mesh, thereby obtaining the modified activated carbon powder; wherein the mass volume ratio of the activated carbon powder to the nitric acid solution is 0.07g / mL, the amount of the oxidized activated carbon added in the deionized water is 0.015g / mL, and the mass ratio of the oxidized activated carbon, 2-amino-4-hydroxythiazole, and sulfuric acid is 1:4:0.4;

[0064] The preparation method of the modified alumina powder is as follows: dispersing alumina powder in a hydrochloric acid solution, stirring and heating to 70°C, reflux reaction for 10 minutes, solid-liquid separation, taking the solid, washing it with deionized water until it is neutral, placing it in a muffle furnace and heating it to 600°C, keeping it warm for 4 hours, cooling it to room temperature with the furnace, and grinding it to a particle size of ≤400 mesh, wherein the mass volume ratio of the alumina powder to the hydrochloric acid solution is 0.08 g / mL, and the mass fraction of hydrochloric acid in the hydrochloric acid solution is 15%.

[0065] The flocculant is a carboxymethyl chitosan derivative, and the preparation method of the carboxymethyl chitosan derivative is as follows:

[0066] S1. Disperse 2-thio-2,3-dihydrobenzo[D]thiazole-5-carboxylic acid in toluene, stir and heat to 100°C, then add epichlorohydrin and chromium acetate in sequence, reflux for 5 hours, cool naturally to room temperature, remove most of the toluene by concentration, add deionized water and ethyl acetate for extraction, take the organic phase and distill under reduced pressure, and vacuum dry to obtain intermediate 1; wherein the molar ratio of 2-thio-2,3-dihydrobenzo[D]thiazole-5-carboxylic acid, epichlorohydrin, and chromium acetate is 1.2:1.0:0.018, the mass volume ratio of 2-thio-2,3-dihydrobenzo[D]thiazole-5-carboxylic acid to toluene is 0.11 g / mL, and the volume ratio of toluene, deionized water, and ethyl acetate is 1:1:2;

[0067] S2. Under a nitrogen atmosphere, disperse the intermediate 1 and N,N-dimethylpropylamine in ethanol, stir and heat to 75°C, then add potassium iodide, reflux for 20 hours, cool naturally to room temperature, remove ethanol by vacuum distillation, add ethyl acetate and deionized water for extraction, take the organic phase by vacuum distillation and vacuum drying to obtain intermediate 2; wherein the molar ratio of intermediate 1, N,N-dimethylpropylamine and potassium iodide is 1:1.2:0.21, the mass volume ratio of N,N-dimethylpropylamine to ethanol is 0.2 g / mL, and the volume ratio of ethanol, ethyl acetate and deionized water is 1:2:1;

[0068] S3. Disperse carboxymethyl chitosan and intermediate 2 in tetrahydrofuran, stir and heat to 65°C, then add p-toluenesulfonic acid, reflux for 5 hours, cool naturally to room temperature, pour the reaction mixture into a dialysis bag (molecular weight 8000D) for dialysis, the dialysis time is 96 hours, replace deionized water every 24 hours, collect the dialysate in the dialysis bag, freeze-dry, and obtain a carboxymethyl chitosan derivative; wherein the mass ratio of carboxymethyl chitosan, intermediate 2, and p-toluenesulfonic acid is 90:10:1.0, and the mass volume ratio of carboxymethyl chitosan to tetrahydrofuran is 0.10 g / mL.

[0069] Comparative Example 1

[0070] A method for preparing a high-efficiency multifunctional water purifier comprises the following steps:

[0071] a. At room temperature, add the CFN co-existing harmonic degradation agent into the reactor I, stir for 5 minutes, then add the FNX synergistic removal agent, and continue stirring for 40 minutes; then add the modified alumina powder and the modified activated carbon powder in sequence, and stir for 40 minutes; wherein the mass ratio of the CFN co-existing harmonic degradation agent, the FNX synergistic removal agent, the modified alumina powder, and the modified activated carbon powder is 20:8:2:1;

[0072] b. adding the product obtained in step a to reactor Ⅱ, and keeping reactor Ⅱ in a stirring state;

[0073] c. At room temperature, the CFN co-existing harmonic degradation agent was added to the reactor I again, stirred for 5 minutes, and then the FNX synergistic removal agent was added, and the stirring was continued for 40 minutes; finally, the modified alumina powder and the modified activated carbon powder were added in sequence and stirred for 40 minutes; wherein, the mass ratio of the CFN co-existing harmonic degradation agent, the FNX synergistic removal agent, the modified alumina powder, and the modified activated carbon powder was 30:5:2:1, and the mass ratio of the CFN co-existing harmonic degradation agent added in the reactor I of step a to the mass ratio of the CFN co-existing harmonic degradation agent added in the reactor I of step c was 24:30;

[0074] d. The product obtained in step c is added to reactor II, and after stirring and mixing, calcium salt, flocculant, and complex catalyst are added in sequence, and stirring is continued for 100 minutes to obtain a high-efficiency multifunctional water purifier; wherein the mass ratio of calcium salt, flocculant, and complex catalyst is 2:1:1, the mass ratio of calcium salt to the product obtained in step c is 2:47, the calcium salt is calcium carbonate, and the complex catalyst is ethylenediaminetetraacetic acid;

[0075] The CFN coexistence and degradation agent is prepared by mixing polyferric sulfate and anhydrous ferric chloride, the mass ratio of polyferric sulfate to anhydrous ferric chloride is 30:3, and the FNX synergistic removal agent is prepared by mixing equal masses of polyaluminium chloride and calcium aluminate;

[0076] The preparation method of the modified activated carbon powder is as follows: dispersing the activated carbon powder in a nitric acid solution with a mass fraction of 40%, stirring and heating to 50° C., reacting for 4 hours, naturally cooling to room temperature, separating the solid and the liquid, taking the solid, washing it with deionized water until it is neutral, and vacuum drying it to constant weight to obtain oxidized activated carbon; then dispersing the oxidized activated carbon in deionized water, and then adding 2-amino-4-hydroxythiazole and sulfuric acid (mass fraction>98%) in sequence, stirring and reacting at 60° C. for 2 hours, naturally cooling to room temperature, separating the solid and the liquid, taking the solid, washing it with deionized water until it is neutral, vacuum drying it to constant weight, and grinding it to a particle size of ≤300 mesh, thereby obtaining the modified activated carbon powder; wherein the mass volume ratio of the activated carbon powder to the nitric acid solution is 0.09 g / mL, the amount of the oxidized activated carbon added in the deionized water is 0.02 g / mL, and the mass ratio of the oxidized activated carbon, 2-amino-4-hydroxythiazole, and sulfuric acid is 1:4:0.4;

[0077] The preparation method of the modified alumina powder is as follows: dispersing alumina powder in a hydrochloric acid solution, stirring and heating to 50°C, reflux reaction for 40 minutes, solid-liquid separation, taking the solid, washing it with deionized water until it is neutral, placing it in a muffle furnace and heating it to 600°C, keeping it warm for 4 hours, cooling it to room temperature with the furnace, and grinding it to a particle size of ≤400 mesh, wherein the mass volume ratio of the alumina powder to the hydrochloric acid solution is 0.07 g / mL, and the mass fraction of hydrochloric acid in the hydrochloric acid solution is 18%.

[0078] The flocculant is the carboxymethyl chitosan derivative prepared in Example 1.

[0079] Comparative Example 2

[0080] A method for preparing a high-efficiency multifunctional water purifier is prepared according to the method described in Example 1, except that the flocculant is carboxymethyl chitosan, and the mass ratio of calcium salt, flocculant and complex catalyst is 2:1.9:1.

[0081] Comparative Example 3

[0082] A method for preparing a high-efficiency multifunctional water purifier is prepared according to the method described in Example 1, except that no flocculant is added.

[0083] The high-efficiency multifunctional water purifier prepared in Examples 1-3 and Comparative Example 1 was tested for sewage treatment. 1000 mL of industrial sewage was weighed, and the high-efficiency multifunctional water purifier was added at an amount of 1.5 g / L. The water quality was tested 48 hours after the water purifier was added. The total nitrogen concentration was tested by alkaline potassium persulfate ultraviolet spectrophotometry, the fluoride ion concentration was tested by ion selective electrode method, the COD concentration was tested by potassium dichromate method, the ammonia nitrogen concentration was determined by Nessler colorimetry, the total phosphorus concentration was tested by orthophosphate colorimetry, and the pH value of the mixed solution was tested by Bangyi PHB-1 portable pH meter; the above tests were repeated three times and the average values ​​were taken. The test results are shown in Table 1. It can be seen from Table 1 that compared with Comparative Example 1, the high-efficiency multifunctional water purifier prepared in Examples 1-3 exhibited a more excellent sewage treatment effect; it can be seen from the effect data of Examples 1-3 that the high-efficiency multifunctional water purifier provided by the present invention has a significant removal effect on COD, total phosphorus, and fluoride ions, and also has a certain removal effect on ammonia nitrogen and total nitrogen.

[0084] Table 1 Sewage treatment effect of high-efficiency multifunctional water purifier

[0085]

[0086] In the sewage treatment process, it is usually necessary to add a variety of agents for removing pollutants to achieve the effect of removing various pollutants. For example, common COD and total phosphorus pollutants need to first add a small amount of acid to maintain a weakly acidic environment, and then add iron-containing or aluminum-containing agents. After the precipitate is formed, an alkaline regulating liquid such as liquid caustic soda is used to adjust the pH to a neutral range, and then a small amount of flocculant is added to quickly flocculate and precipitate the precipitate. If the sewage also contains fluoride ions, the effect of removing fluoride ions is poor after using iron-containing or aluminum-containing agents alone, and it is necessary to add a defluorinating agent. After the fluoride precipitate is formed, a flocculant is added again to form a new precipitate to ensure the fluoride ion removal effect. The present invention prepares an agent with excellent pollution factor removal effect by reasonably proportioning the components of the water purifier.

[0087] The high-efficiency multifunctional water purifiers prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to relevant performance tests. The adsorption performance test was conducted using a methylene blue solution with an initial concentration of 500 mg / L, a water purifier dosage of 1.5 g / L, a test temperature of 50°C, and an adsorption time of 2 hours to test the adsorption capacity; the corrosion inhibition performance test was conducted using a static hanging plate method, the material was Q235 carbon steel, the size was 70 mm × 15 mm × 1.5 mm, the carbon steel was degreased with acetone and absorbent cotton in turn, and dried to a constant weight after alcohol dehydration treatment, the test temperature was 50°C, the time was 48 hours, and the corrosion rate was calculated; the antibacterial performance test was conducted using a plate count method; the above tests were repeated three times to take the average value, and the test results are shown in Table 2. As can be seen from the data in Table 2, compared with Comparative Examples 1-3, the high-efficiency multifunctional water purifiers prepared in Examples 1-3 exhibit excellent adsorption performance, corrosion inhibition performance, and antibacterial performance. The various components of the high-efficiency multifunctional water purifier provided by the present invention are synergistically effective, the adsorption capacity is all above 145.4 mg / g, the corrosion rate is all below 0.070 mm / a, the antibacterial rate is all above 99.5%, the comprehensive performance is excellent, and the use requirements of various environments can be met.

[0088] Table 2 Related performance test results of high-efficiency multifunctional water purifier

[0089]

[0090] Although the embodiments of the present application have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a highly efficient and multifunctional water purifier, characterized in that: The following steps are involved: a. At room temperature, add the CFN coexisting and degrading agent to the reactor I, stir for 5-15 minutes, then add the FNX synergistic removal agent, and continue stirring for 50-70 minutes; then add the modified alumina powder and the modified activated carbon powder in turn, and stir for 50-70 minutes; b. adding the product obtained in step a to reactor Ⅱ, and keeping reactor Ⅱ in a stirring state; c. At room temperature, add the CFN coexisting and degrading agent to the reactor I again, stir for 5-15 minutes, then add the FNX synergistic removal agent, and continue stirring for 50-70 minutes; finally, add the modified alumina powder and the modified activated carbon powder in sequence, and stir for 50-70 minutes; d. The product obtained in step c is added to reactor II, stirred and mixed, and then calcium salt, flocculant, and complex catalyst are added in sequence, and stirring is continued for 100-140min to obtain; The mass ratio of the CFN coexisting blending degradation agent, FNX synergistic removal agent, modified alumina powder, and modified activated carbon powder in step a is 22-26:11-13:2.5:1.5; The mass ratio of the CFN coexisting blending degradation agent, FNX synergistic removal agent, modified alumina powder, and modified activated carbon powder in step c is 34-38:7-9:2.5:1.5; The ratio of the mass of the CFN co-existing and harmonizing degradation agent added in the reactor I of step a to the mass of the CFN co-existing and harmonizing degradation agent added in the reactor I of step c is 24:35-37; The mass ratio of the calcium salt, flocculant and complex catalyst in step d is 2:1.8-2.2:0.9-1.1, and the mass ratio of the calcium salt to the product obtained in step c is 2:45-50; The CFN coexistence and coordination degradation agent is prepared by mixing polyferric sulfate and anhydrous ferric chloride, and the mass ratio of polyferric sulfate to anhydrous ferric chloride is 30:5-10; the FNX synergistic removal agent is prepared by mixing equal masses of polyaluminium chloride and calcium aluminate; the calcium salt is calcium carbonate; the complex catalyst is one or more of ethylenediaminetetraacetic acid, thiourea, citric acid, tartaric acid, and triethanolamine; The preparation method of the modified alumina powder is as follows: dispersing the alumina powder in a hydrochloric acid solution, stirring and heating to 60-70°C, reflux reaction for 10-30 minutes, solid-liquid separation, taking the solid, washing it to neutrality, placing it in a muffle furnace and heating it to 500-600°C, keeping it warm for 4-6 hours, cooling it to room temperature, and grinding it to obtain the modified alumina powder; the mass volume ratio of the alumina powder to the hydrochloric acid solution is 0.08-0.14 g / mL, and the mass fraction of hydrochloric acid in the hydrochloric acid solution is 15-20%; The preparation method of the modified activated carbon powder is as follows: dispersing the activated carbon powder in a nitric acid solution, stirring and heating to 60-70° C., reacting for 2-3 hours to obtain oxidized activated carbon; then dispersing the oxidized activated carbon in deionized water, and then adding 2-amino-4-hydroxythiazole and sulfuric acid in sequence, stirring and reacting at 70-80° C. for 1-2 hours to obtain the modified activated carbon powder; the mass volume ratio of the activated carbon powder to the nitric acid solution is 0.07-0.12 g / mL, the amount of the oxidized activated carbon added in the deionized water is 0.015-0.025 g / mL, and the mass ratio of the oxidized activated carbon, 2-amino-4-hydroxythiazole, and sulfuric acid is 1:4-8:0.4-0.6; The flocculant is a carboxymethyl chitosan derivative, and the preparation method of the carboxymethyl chitosan derivative is as follows: S1. Disperse 2-thio-2,3-dihydrobenzo[D]thiazole-5-carboxylic acid in toluene, stir and heat to 95-100° C., then add epichlorohydrin and chromium acetate in sequence, reflux for 5-7 hours, cool to room temperature, and purify to obtain intermediate 1; S2. Under a nitrogen atmosphere, disperse the intermediate 1 and N,N-dimethylpropylamine in ethanol, stir and heat to 70-75°C, then add potassium iodide, reflux for 20-25h, cool to room temperature, and purify to obtain the intermediate 2; S3, dispersing carboxymethyl chitosan and intermediate 2 in tetrahydrofuran, stirring and heating to 55-65°C, then adding p-toluenesulfonic acid, reflux reaction for 5-8h, cooling to room temperature, and dialyzing to obtain a carboxymethyl chitosan derivative; In step S1, the molar ratio of 2-thio-2,3-dihydrobenzo[D]thiazole-5-carboxylic acid, epichlorohydrin, and chromium acetate is 1.2:1.0-1.2:0.018-0.023, and the mass volume ratio of 2-thio-2,3-dihydrobenzo[D]thiazole-5-carboxylic acid to toluene is 0.11-0.14 g / mL; The molar ratio of the intermediate 1, N,N-dimethylpropylamine and potassium iodide in step S2 is 1:1.2-1.3:0.21-0.24, and the mass volume ratio of N,N-dimethylpropylamine to ethanol is 0.2-0.3 g / mL; The mass ratio of carboxymethyl chitosan, intermediate 2 and p-toluenesulfonic acid in step S3 is 90:10-14:1.0-1.3, and the mass volume ratio of carboxymethyl chitosan to tetrahydrofuran is 0.10-0.12 g / mL; The synthetic route of intermediate 2 is as follows: ; .

2. A high-efficiency and multifunctional water purifier prepared by the method of claim 1.

3. Use of the high-efficiency and multifunctional water purifier according to claim 2 in sewage treatment.

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