Efficient sewage treatment agent, preparation method thereof and application of efficient sewage treatment agent in steelmaking wastewater

Abstract

The invention discloses an efficient sewage treatment agent as well as a preparation method and application thereof in steelmaking wastewater, and relates to the technical field of water pollution treatment. The efficient sewage treatment agent comprises the following raw materials in parts by weight: 20-25 parts of diatomite, 18-22 parts of bentonite, 20-25 parts of cocoanut active charcoal, 10-13 parts of a flocculating agent and 7-8 parts of a coagulant aid. The high-efficiency sewage treatment agent prepared by the invention can effectively remove chemical oxygen demand, suspended matters and ammonia nitrogen in wastewater.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of water pollution treatment, in particular to a high-efficiency sewage treatment agent, a preparation method thereof and application thereof in steelmaking wastewater. BACKGROUND

[0002] The steelmaking wastewater is an industrial wastewater with complex composition and high pollution load, and its efficient treatment and reuse is a key difficulty for the green development of the steel industry. At present, the traditional process with "lime softening-coagulation sedimentation" as the core is generally used in the industry, and conventional reagents such as polyaluminum chloride and polyacrylamide are relied on. However, this process has limitations in treating the specific pollutants in steelmaking wastewater. First, in terms of chemical oxygen demand (COD) removal, the wastewater contains a large amount of emulsified oil from roll lubrication and corrosion-resistant coating and part of the dissolved organic matter, and the conventional coagulant is difficult to effectively demulsify and adsorb, resulting in incomplete COD removal and unstable effluent quality. Secondly, the ability to capture suspended solids such as fine iron oxide scale and colloidal substances is limited, and in order to ensure the effect, the reagent needs to be added in excess, which not only has high cost, but also produces chemical sludge with loose structure and high water content, greatly increasing the subsequent disposal burden. In addition, the traditional coagulation sedimentation method has limited effect on ammonia nitrogen removal, which poses a risk of eutrophication in the effluent and restricts the recycling of the wastewater.

[0003] The Chinese invention patent with the publication number CN106830120A discloses a sewage treatment agent with demulsification function and its preparation method and application. The sewage treatment agent is composed of the following raw materials in parts by weight: vermiculite 27-35 parts, propargyl chloride 11-19 parts, fumaric acid 4-8 parts, methyl tributyl ketoxime silane 1-5 parts, and chitin 19-27 parts. The sewage treatment agent prepared by the invention has fast settling speed, small dosage, strong impact resistance, and no corrosion to equipment, but its ability to reduce chemical oxygen demand and ammonia nitrogen content needs to be improved. SUMMARY

[0004] In view of the deficiencies of the prior art, the purpose of the present application is to provide a high-efficiency sewage treatment agent, a preparation method thereof and application thereof in steelmaking wastewater.

[0005] To achieve the above-mentioned purpose, the present application realizes the following technical solutions: A high-efficiency sewage treatment agent comprises the following raw materials in parts by weight: diatomite 20-25 parts, bentonite 18-22 parts, coconut shell activated carbon 20-25 parts, flocculant 10-13 parts, and coagulant aid 7-8 parts. The flocculant is prepared by the following method: S1: 6-chloro-6-oxohexanoic acid reacts with 6-hydroxyhexyl methacrylate to form 6-[(6-methacryloyloxyhexyl)oxy]-6-oxohexanoic acid, S2: 6-[(6-methacryloyloxyhexyl)oxy]-6-oxohexanoic acid is reacted with 1,2-bis(bromoacetyloxy)ethane in the presence of a catalyst and an organic ligand to form polymer 1, S3: Polymer 1 is reacted with 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt to form a flocculant.

[0006] The molar ratio of the 6-chloro-6-oxohexanoic acid to the 6-hydroxyhexyl methacrylate is (1.1-1.3):1.

[0007] The molar ratio of the 6-[(6-methacryloyloxyhexyl)oxy]-6-oxohexanoic acid to the 1,2-bis(bromoacetyloxy)ethane is (10-14):1.

[0008] The molar ratio of the polymer 1 to the 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt is 1:(2-6).

[0009] The coagulant aid is sodium polyacrylate.

[0010] In step S2, the catalyst is cuprous bromide.

[0011] In step S2, the organic ligand is pentamethyldiethylenetriamine.

[0012] The bentonite is of the type Bentone® 38.

[0013] A preparation method of a high-efficiency sewage treatment agent, comprising the following steps: (1) Pretreatment: diatomite, bentonite and coconut activated carbon are respectively crushed by a crusher and sieved through a 200-mesh sieve; (2) Weighing: diatomite 20-25 parts, bentonite 18-22 parts, coconut activated carbon 20-25 parts, flocculant 10-13 parts and coagulant aid 7-8 parts are weighed according to weight parts; (3) The diatomite, bentonite and coconut activated carbon are stirred and uniformly mixed to obtain a mixture, the flocculant and the coagulant aid are slowly added into the mixture, and the mixture is stirred and uniformly mixed, thereby obtaining the high-efficiency sewage treatment agent.

[0014] Application of a high-efficiency sewage treatment agent in steelmaking wastewater.

[0015] By adopting the above technical solutions, the application has the following beneficial effects: The high-efficiency sewage treatment agent prepared by the application can effectively reduce the content of COD, suspended solids and ammonia nitrogen in wastewater. DETAILED DESCRIPTION

[0016] The application will be further described in connection with the following examples, but the application is not limited to these examples.

[0017] Example 1 Preparation of flocculant: S1: Under nitrogen protection, 200 ml of dichloromethane, 0.1 mol of 6-hydroxyhexyl methacrylate, 2 g of 4-dimethylaminopyridine (DMAP), 0.12 mol of triethylamine were added into a reactor under ice bath, 0.11 mol of 6-chloro-6-oxohexanoic acid was slowly added dropwise for 20 min, and then the temperature was raised to room temperature after dropping, and the reaction was carried out for 4 h. Then the reaction solution was poured into 200 ml of 0.5M dilute hydrochloric acid solution, and the organic phase was washed with 100 ml of deionized water and 100 ml of saturated brine in sequence, and then dried with 20 g of anhydrous sodium sulfate for 2 h, filtered, distilled at 30°C under reduced pressure for 3 h, and dried at 40°C under vacuum for 10 h to obtain 6-[(6-methacryloyloxyhexyl)oxy]-6-oxohexanoic acid. The reaction equation is shown as follows: .

[0018] The nuclear magnetic resonance hydrogen spectrum data are as follows: 1 H NMR (400 MHz, Chloroform- d ) δ 10.38 (s, 1H), 5.91 – 5.42 (m, 2H),4.12 (q, J = 6.3 Hz, 4H), 2.52 – 2.25 (m, 2H), 2.19 – 2.02 (m, 2H), 1.93 (dd,J = 1.4, 0.9 Hz, 3H), 1.76 – 1.54 (m, 8H), 1.34 – 1.09 (m, 4H).

[0019] S2: Under nitrogen protection, 200 ml of toluene, 0.1 mol of 6-[(6-methacryloyloxyhexyl)oxy]-6-oxohexanoic acid, 0.01 mol of 1,2-bis(bromoacetyloxy)ethane, and 0.6 g of pentamethyldiethylenetriamine were added into a reactor, stirred and mixed uniformly, 1.8 g of cuprous bromide was added, and the temperature was raised to 80°C, and the reaction was carried out for 3 h. Then the temperature was lowered to room temperature, and the copper catalyst was removed by passing through a neutral alumina column to obtain a crude product. The crude product was dissolved in 1000 ml of tetrahydrofuran, and rotary evaporation was carried out at 60°C for 30 min to form a concentrated solution. Under the condition of magnetic stirring, the concentrated solution was slowly added dropwise into 600 ml of cold acetone, and the dropping was carried out for 30 min. The precipitate was separated by stirring and filtering, and vacuum dried at 70°C for 6 h to obtain polymer 1. The number average molecular weight was 3440. The reaction equation is shown as follows: .

[0020] Its 1H NMR data are as follows: 1 H NMR (400 MHz, Chloroform- d ) δ 10.33 (s, 10H), 4.31 (s, 4H), 4.23 –4.03 (m, 40H), 2.73 – 2.52 (m, 20H), 2.45 (ddd, J = 14.9, 8.7, 8.3 Hz, 2H), 2.29 (dt, J = 10.8, 8.6 Hz, 40H), 2.19 (dt, J = 14.9, 8.4 Hz, 2H), 1.86 (s,30H), 1.74 – 1.67 (m, 40H), 1.65 – 1.55 (m, 40H), 1.51 – 1.38 (m, 40H).

[0021] S3: Under nitrogen protection, 200 ml of tetrahydrofuran and 0.01 mol of polymer 1 were added to the reactor and stirred until homogeneous. Then, 50 ml of a deionized aqueous solution containing 0.02 mol of 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, 2.5 g of pentamethyldiethylenetriamine, and 2 g of cuprous bromide were added and stirred until homogeneous. After reflux for 4 h, the mixture was cooled to room temperature, and the copper catalyst was removed by passing it through a neutral alumina column to obtain a crude product. The crude product was dissolved in 1000 ml of tetrahydrofuran, and 0.105 mol of NaHCO3 was added in 5 equal batches (5 min apart) under ice bath stirring, followed by stirring for 30 min. The mixture was then rotary evaporated at 60 °C for 30 min, washed with cold deionized water (5 °C) (3 × 50 ml), and vacuum dried at 60 °C for 8 h to obtain a flocculant with a number-average molecular weight of 4220. The reaction equation is shown below. .

[0022] Its 1H NMR data are as follows: 1 H NMR (400 MHz, Chloroform- d) δ 4.54 - 4.42 (m, 4H), 4.31 (s, 4H), 4.23 - 4.07 (m, 40H), 3.96 - 3.82 (m, 6H), 3.66 (d, J = 11.5 Hz, 2H), 3.53 (t, J = 9.5 Hz, 4H), 3.22 (d, J = 0.8 Hz, 12H), 2.87 (td, J = 11.4, 0.6 Hz, 4H), 2.51 (dt, J = 16.1, 8.1 Hz, 2H), 2.41 - 2.33 (m, 2H), 2.31 - 2.21 (m, 44H), 2.02 (dt, J = 14.3, 8.1 Hz, 20H), 1.77 - 1.66 (m, 40H), 1.65 - 1.55 (m, 40H), 1.51 - 1.40 (m, 40H), 1.33 (d, J = 14.9 Hz, 36H).

[0023] Example 2 Preparation of flocculant S1: Under nitrogen protection, 200 ml of dichloromethane, 0.1 mol of 6-hydroxyhexyl methacrylate, 2 g of 4-dimethylaminopyridine (DMAP), 0.12 mol of triethylamine were added to the reactor under ice bath, 0.12 mol of 6-chloro-6-oxohexanoic acid was slowly added dropwise, dropwise for 20 min, and then the temperature was raised to room temperature, and the reaction was carried out for 3 h. After the reaction, the reaction solution was poured into 200 ml of 0.5M dilute hydrochloric acid solution, and the organic phase was separated and washed with 100 ml of deionized water and 100 ml of saturated brine in turn, and then dried with 20 g of anhydrous sodium sulfate for 2 h, filtered, and distilled at 30°C under reduced pressure for 3 h, and then vacuum dried at 40°C for 10 h to obtain 6-[(6-methacryloyloxyhexyl)oxy]-6-oxohexanoic acid.

[0024] S2: Under nitrogen protection, 200 ml of toluene, 0.12 mol of 6-[(6-methacryloyloxyhexyl)oxy]-6-oxohexanoic acid, 0.01 mol of 1,2-bis(bromoacetyloxy)ethane, and 0.6 g of pentamethyldiethylenetriamine were added to the reactor, stirred and mixed, 1.8 g of cuprous bromide was added, the temperature was raised to 75°C, and the reaction was carried out for 3.5 h. After the reaction, the temperature was lowered to room temperature, and the copper catalyst was removed by passing through a neutral alumina column to obtain a crude product. The crude product was dissolved in 1000 ml of tetrahydrofuran, and rotary evaporation was carried out at 60°C for 30 min to form a concentrated solution. Under the condition of magnetic stirring, the concentrated solution was slowly added dropwise into 600 ml of cold acetone, and stirring was carried out for 30 min. The precipitate was filtered and vacuum dried at 70°C for 6 h to obtain polymer 1. The number average molecular weight was 4070.

[0025] S3: Under nitrogen protection, 200 ml of tetrahydrofuran, 0.01 mol of polymer 1 were added into a reactor, stirred and mixed, then 50 ml of a deionized water solution containing 0.04 mol of 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, 2.5 g of pentamethyldiethylenetriamine and 2 g of cuprous bromide were added, stirred and mixed, after refluxing for 3 h, it was cooled to room temperature, the copper catalyst was removed by a neutral alumina column to obtain a crude product, the crude product was dissolved in 1000 ml of tetrahydrofuran, under ice bath stirring, 0.125 mol of NaHCO3 was added in 5 batches (5 min interval between batches), then stirred for 30 min; 60°C rotary evaporation for 30 min, washed with cold deionized water (5°C) (3x50 ml), 60°C vacuum drying for 8 h to obtain a flocculant; the number average molecular weight is 5460.

[0026] Example 3 Preparation of flocculant: S1: Under nitrogen protection, 200 ml of dichloromethane, 0.1 mol of 6-hydroxyhexyl methacrylate, 2 g of 4-dimethylaminopyridine (DMAP), 0.12 mol of triethylamine were added into a reactor under ice bath, 0.13 mol of 6-chloro-6-oxohexanoic acid was slowly added dropwise, the dropwise addition was completed in 20 min, the temperature was raised to room temperature, and the reaction was carried out for 2 h. After the reaction, the reaction solution was poured into 200 ml of 0.5M dilute hydrochloric acid solution, the organic phase was separated, washed with 100 ml of deionized water and 100 ml of saturated brine in turn, then dried with 20 g of anhydrous sodium sulfate for 2 h, filtered, 30°C reduced pressure distillation for 3 h, 40°C vacuum drying for 10 h to obtain 6-[(6-methacryloyloxyhexyl)oxy]-6-oxohexanoic acid.

[0027] S2: Under nitrogen protection, 200 ml of toluene, 0.14 mol of 6-[(6-methacryloyloxyhexyl)oxy]-6-oxohexanoic acid, 0.01 mol of 1,2-bis(bromoacetyloxy)ethane, 0.6 g of pentamethyldiethylenetriamine were added into a reactor, stirred and mixed, 1.8 g of cuprous bromide was added, the temperature was raised to 70°C, and the reaction was carried out for 4 h. After the reaction, the temperature was cooled to room temperature, the copper catalyst was removed by a neutral alumina column to obtain a crude product, the crude product was dissolved in 1000 ml of tetrahydrofuran, 60°C rotary evaporation for 30 min to form a concentrated solution, under magnetic stirring, the concentrated solution was slowly added dropwise into 600 ml of cold acetone, the dropwise addition was completed in 30 min, the precipitate was separated by stirring and filtration, and 70°C vacuum drying for 6 h to obtain polymer 1; the number average molecular weight is 4700.

[0028] S3: Under nitrogen protection, 200 ml of tetrahydrofuran, 0.01 mol of polymer 1 were added into a reactor, stirred and mixed, then 50 ml of a deionized water solution containing 0.06 mol of 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, 2.5 g of pentamethyldiethylenetriamine and 2 g of cuprous bromide were added, stirred and mixed, refluxed for 2 h, then reduced to room temperature, the copper catalyst was removed by a neutral alumina column to obtain a crude product, the crude product was dissolved in 1000 ml of tetrahydrofuran, 0.145 mol of NaHCO3 was added in 5 batches under ice bath stirring (5 min interval between batches), then stirred for 30 min; 60°C rotary evaporation for 30 min, washed with cold deionized water (5°C) (3x50 ml), 60°C vacuum drying for 8 h to obtain a flocculant; the number average molecular weight is 6690.

[0029] Example 4: Preparation of high-efficiency sewage treatment agent: (1) Pretreatment: diatomite, bentonite and coconut activated carbon were respectively crushed by a crusher and sieved through a 200 mesh sieve; (2) Weighing: diatomite 200 g, bentonite (Bentone® 38) 180 g, coconut activated carbon 200 g, flocculant (prepared in Example 1) 100 g, coagulant aid (sodium polyacrylate) 70 g; (3) The diatomite, bentonite and coconut activated carbon were stirred and mixed to obtain a mixture, and the flocculant and coagulant aid were slowly added into the mixture, and stirred and mixed to obtain a high-efficiency sewage treatment agent.

[0030] Example 5: Preparation of high-efficiency sewage treatment agent: (1) Pretreatment: diatomite, bentonite and coconut activated carbon were respectively crushed by a crusher and sieved through a 200 mesh sieve; (2) Weighing: diatomite 220 g, bentonite (Bentone® 38) 200 g, coconut activated carbon 230 g, flocculant (prepared in Example 2) 120 g, coagulant aid (sodium polyacrylate) 75 g; (3) The diatomite, bentonite and coconut activated carbon were stirred and mixed to obtain a mixture, and the flocculant and coagulant aid were slowly added into the mixture, and stirred and mixed to obtain a high-efficiency sewage treatment agent.

[0031] Example 6: Preparation of high-efficiency sewage treatment agent: (1) Pretreatment: diatomite, bentonite and coconut activated carbon were respectively crushed by a crusher and sieved through a 200 mesh sieve; (2) Weighing: diatomite 250 g, bentonite (Bentone® 38) 220 g, coconut activated carbon 250 g, flocculant (prepared in Example 3) 130 g, coagulant aid (sodium polyacrylate) 80 g; (3) The diatomite, bentonite and activated carbon of coconut shell are stirred and mixed uniformly to obtain a mixture, the flocculant and the coagulant aid are slowly added into the mixture, and then stirred and mixed uniformly, thereby obtaining the high-efficiency sewage treatment agent.

[0032] Comparative Example 1 The raw material ratio and preparation method of the high-efficiency sewage treatment agent are basically the same as those in Example 5, except that the flocculant is replaced by an equal weight of a flocculant prepared by the following method: The preparation method of the flocculant is basically the same as that in Example 2, except that the 6-[(6-methacryloyloxyhexyl)oxy]-6-oxohexanoic acid in step S2 is replaced by an equal molar amount of succinic acid mono[2-[(2-methyl-acryloyl)oxy]ethyl] ester.

[0033] Comparative Example 2 The raw material ratio and preparation method of the high-efficiency sewage treatment agent are basically the same as those in Example 5, except that the flocculant is replaced by an equal weight of a flocculant prepared by the following method: The preparation method of the flocculant is basically the same as that in Example 2, except that the feeding amount of 6-[(6-methacryloyloxyhexyl)oxy]-6-oxohexanoic acid in step S2 is increased to 0.2 mol.

[0034] Comparative Example 3 The raw material ratio and preparation method of the high-efficiency sewage treatment agent are basically the same as those in Example 5, except that the flocculant is replaced by an equal weight of the polymer 1 prepared by step S2 of Example 2.

[0035] Comparative Example 4 The raw material ratio and preparation method of the high-efficiency sewage treatment agent are basically the same as those in Example 5, except that the flocculant is replaced by an equal weight of a flocculant prepared by the following method: The preparation method of the flocculant is basically the same as that in Example 2, except that the 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt in step S3 is replaced by an equal molar amount of methacryloyloxyethyl trimethyl ammonium chloride.

[0036] Comparative Example 5 The raw material ratio and preparation method of the high-efficiency sewage treatment agent are basically the same as those in Example 5, except that the flocculant is replaced by an equal weight of a flocculant prepared by the following method: Into a reactor was added 250 ml of toluene, 0.12 mol of 6-[(6-methylacryloyloxyhexyl)oxy]-6-oxohexanoic acid (prepared in Example 2, Step S1), 0.04 mol of 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, stirred and mixed, heated to 70°C, then 2 g of AIBN was added, after 8 h of reaction, slowly reduced to room temperature, stirred in an ice bath, 0.125 mol of NaHCO3 was added in 5 batches (5 min interval between batches), then stirred for 30 min; 60°C rotary evaporation for 30 min, washed with cold deionized water (5°C) (3 x 50 ml), 60°C vacuum drying for 8 h to obtain the flocculant.

[0037] The diatomaceous earth SiO2 content used in the examples and comparative examples of the present application was 91.4 wt%, D50 = 150 μm, produced by Baishan Xingtai Diatomite New Material Co., Ltd.; the coconut shell activated carbon was coconut shell granular activated carbon, with a particle size of 10-20 mesh, produced by Anguo Chengze Activated Carbon Manufacturing Co., Ltd.; the number average molecular weight of the sodium polyacrylate was 3500 Da.

[0038] The high-efficiency sewage treatment agent prepared in the examples and comparative examples was subjected to chemical oxygen demand, suspended solids, and ammonia nitrogen content tests, and the test results are shown in Table 1.

[0039] A certain steel plant steelmaking wastewater (COD of 223 mg / L, suspended solids of 168 mg / L, and ammonia nitrogen content of 24.1 mg / L) was taken, divided into 8 portions, each 1000 ml, placed in a beaker, and 0.1 g of the high-efficiency sewage treatment agent prepared in Examples 4-6 and Comparative Examples 1-5 was added, respectively, stirred at a speed of 350 r / min for 1 min, then stirred at a speed of 200 r / min for 2 min, and then stirred at a speed of 50 r / min for 2 min, and then left to stand for 20 min, 800 ml of supernatant was taken, stirred and mixed, and used as a test liquid for chemical oxygen demand, suspended solids, and ammonia nitrogen content tests.

[0040] Chemical oxygen demand test: 10 ml of the test liquid was taken, and the chemical oxygen demand in the wastewater was determined according to the “GB / T 11914-1989 Water Quality-Determination of Chemical Oxygen Demand-Method of Dichromate”.

[0041] Suspended solids test: the suspended solids in the wastewater were determined according to the “GB / T 11901-1989 Water Quality-Determination of Suspended Solids-Gravimetric Method”.

[0042] Ammonia nitrogen content test: the ammonia nitrogen content in the wastewater was determined by spectrophotometry according to the “GB / T 7479-1987 Water Quality-Determination of Ammonium-Nessler’s Reagent Colorimetric Method”.

[0043] COD removal rate / suspended solids removal rate / ammonia nitrogen removal rate formula as follows: Removal rate = ((C0-C) / C0) x 100%; C0 represents the concentration of COD / suspended solids / ammonia nitrogen in wastewater before treatment; C represents the concentration of COD / suspended solids / ammonia nitrogen in wastewater after treatment.

[0044] Table 1 Performance indicators of high-efficiency sewage treatment agent

[0045] As can be seen from Table 1, the sewage treatment agent prepared in the present application can effectively reduce the COD, suspended solids and ammonia nitrogen content in wastewater.

[0046] The flocculant provided by the present application is a functional polymer based on a di-ester-ethyl backbone, which contains a plurality of 6-[(6-methacryloyloxyhexyl)oxy]-6-oxohexanoate sodium (anionic side chain) and a plurality of amphoteric 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonate inner salt (amphoteric side chain). The anionic side chain in the flocculant combines with the dissolved organic pollutants (such as organic acids, dyes or oils) in the wastewater through electrostatic attraction and hydrophobic interaction to form a macromolecular complex; at the same time, the sulfonic acid group and the quaternary ammonium group of the amphoteric side chain can further adsorb cationic, neutral or polar organic matter, and the hydrogen bond and van der Waals force are strengthened to form a dense floc, which significantly reduces the COD value. The di-ester-ethyl backbone of the flocculant provides a flexible skeleton, which makes the side chain stretch and play a bridging role, the anionic group neutralizes the positively charged suspended particles (such as clay or microorganisms), and the amphoteric group reduces the electrostatic repulsion between particles under charge balance, promotes the "bridging effect", and pulls the fine particles into larger flocs to accelerate gravity settling; in addition, the hydrophobic microzone of the di-ester group enhances the wrapping of colloidal particles, thereby realizing efficient settling and solid-liquid separation of suspended solids. For the removal of ammonia nitrogen, the sulfonate group of the amphoteric side chain and the carboxylate of the anionic side chain specifically capture ammonium ions through electrostatic attraction and ion exchange with quaternary ammonium cations, and NH4 + The flocculant provided by the present application is a functional polymer based on a di-ester-ethyl backbone, which contains a plurality of 6-[(6-methacryloyloxyhexyl)oxy]-6-oxohexanoate sodium (anionic side chain) and a plurality of amphoteric 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonate inner salt (amphoteric side chain). The anionic side chain in the flocculant combines with the dissolved organic pollutants (such as organic acids, dyes or oils) in the wastewater through electrostatic attraction and hydrophobic interaction to form a macromolecular complex; at the same time, the sulfonic acid group and the quaternary ammonium group of the amphoteric side chain can further adsorb cationic, neutral or polar organic matter, and the hydrogen bond and van der Waals force are strengthened to form a dense floc, which significantly reduces the COD value. The di-ester-ethyl backbone of the flocculant provides a flexible skeleton, which makes the side chain stretch and play a bridging role, the anionic group neutralizes the positively charged suspended particles (such as clay or microorganisms), and the amphoteric group reduces the electrostatic repulsion between particles under charge balance, promotes the "bridging effect", and pulls the fine particles into larger flocs to accelerate gravity settling; in addition, the hydrophobic microzone of the di-ester group enhances the wrapping of colloidal particles, thereby realizing efficient settling and solid-liquid separation of suspended solids. For the removal of ammonia nitrogen, the sulfonate group of the amphoteric side chain and the carboxylate of the anionic side chain specifically capture ammonium ions through electrostatic attraction and ion exchange with quaternary ammonium cations, and NH4

[0047] When 6-[(6-methylacryloyloxyhexyl)oxy]-6-oxohexanoic acid and 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt are directly polymerized for flocculation, the double ester group ethane flexible skeleton function is lost, the bridging function is lost, and it cannot achieve uniform distribution of the side chain, thereby resulting in a reduction in COD, suspended solids, and ammonia nitrogen removal rates.

[0048] The above is only the preferred embodiments of the present application, and is not intended to limit the present application; but for those of ordinary skill in the art, without departing from the scope of the technical solutions of the present application, some minor changes, modifications and equivalent changes of the above disclosed technical content can be made, which are equivalent embodiments of the present application; at the same time, any equivalent changes, modifications and evolution of the above embodiments according to the essential technology of the present application are still within the protection scope of the technical solutions of the present application.

Claims

1. A high-efficiency wastewater treatment agent, characterized in that, The ingredients include the following parts by weight: Diatomaceous earth 20-25 parts, bentonite 18-22 parts, coconut shell activated carbon 20-25 parts, flocculant 10-13 parts, coagulant aid 7-8 parts; The flocculant is prepared by the following method: S1: 6-Chloro-6-oxohexanoic acid reacts with 6-hydroxyhexyl methacrylate to produce 6-[(6-methacryloyloxyhexyl)oxy]-6-oxohexanoic acid. S2: 6-[(6-methacryloyloxyhexyl)oxy]-6-oxohexanoic acid reacts with 1,2-bis(bromoacetoxy)ethane in the presence of a catalyst and organic ligand to form polymer 1. S3: Polymer 1 reacts with 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt to generate a flocculant.

2. The high-efficiency wastewater treatment agent according to claim 1, characterized in that, In step S1, the molar ratio of 6-chloro-6-oxohexanoic acid to 6-hydroxyhexyl methacrylate is (1.1-1.3):

1.

3. The high-efficiency wastewater treatment agent according to claim 1, characterized in that, In step S2, the molar ratio of 6-[(6-methacryloyloxyhexyl)oxy]-6-oxohexanoic acid to 1,2-bis(bromoacetoxy)ethane is (10-14):

1.

4. The high-efficiency wastewater treatment agent according to claim 1, characterized in that, In step S3, the molar ratio of polymer 1 to 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt is 1:(2-6).

5. The high-efficiency wastewater treatment agent according to claim 1, characterized in that, The coagulant is sodium polyacrylate.

6. The high-efficiency wastewater treatment agent according to claim 1, characterized in that, In step S2, the catalyst is cuprous bromide.

7. The high-efficiency wastewater treatment agent according to claim 1, characterized in that, In step S2, the organic ligand is pentamethyldiethylenetriamine.

8. The high-efficiency wastewater treatment agent according to claim 1, characterized in that, The bentonite is designated as Bentone® 38.

9. A method for preparing the high-efficiency wastewater treatment agent according to any one of claims 1-8, characterized in that, Includes the following steps: (1) Pretreatment: Diatomaceous earth, bentonite and coconut shell activated carbon are crushed by a pulverizer and passed through a 200-mesh sieve; (2) Weigh out the following by weight: 20-25 parts diatomaceous earth, 18-22 parts bentonite, 20-25 parts coconut shell activated carbon, 10-13 parts flocculant, and 7-8 parts coagulant aid; (3) Mix diatomaceous earth, bentonite and coconut shell activated carbon to obtain a mixture. Slowly add flocculant and coagulant aid to the mixture and stir until well mixed to obtain a high-efficiency wastewater treatment agent.

10. The application of the high-efficiency wastewater treatment agent according to any one of claims 1-8 in steelmaking wastewater.

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