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CN-122010205-A - Composite treating agent for domestic sewage and preparation method thereof

CN122010205ACN 122010205 ACN122010205 ACN 122010205ACN-122010205-A

Abstract

The invention relates to the technical field of sewage treatment, and discloses a composite treating agent for domestic sewage and a preparation method thereof. The composite treating agent comprises, by weight, 15-25 parts of ferric trichloride, 3-8 parts of polyaluminium ferric silicate, 5-8 parts of polyacrylamide, 4-8 parts of magnesium sulfate, 1-3 parts of sodium hydroxide, 15-20 parts of a modified chelating agent, 20-30 parts of a modified flocculant, 2-6 parts of ferric hydroxide, 15-20 parts of bentonite and 10-15 parts of mesoporous silica. The modified chelating agent can efficiently chelate free lead, cadmium, copper and other heavy metal ions in sewage, avoid secondary pollution caused by the diffusion of the heavy metal ions along with the effluent, and can quickly adsorb suspended matters, colloid particles and soluble organic matters in the sewage to form compact and easily-settled flocs, thereby effectively reducing the COD, BOD, nitrogen and phosphorus and suspended matter contents of the sewage.

Inventors

  • Xu Hudong
  • ZHENG YILI
  • ZHANG XIUPING
  • GU LIHUA
  • WANG SICHAO
  • ZHU QI
  • HE YANA

Assignees

  • 浙江上鑫生态科技有限公司

Dates

Publication Date
20260512
Application Date
20260304

Claims (10)

  1. 1. The composite treating agent for domestic sewage is characterized by comprising, by weight, 15-25 parts of ferric trichloride, 3-8 parts of polyaluminosilicate, 5-8 parts of polyacrylamide, 4-8 parts of magnesium sulfate, 1-3 parts of sodium hydroxide, 15-20 parts of a modified chelating agent, 20-30 parts of a modified flocculant, 2-6 parts of ferric hydroxide, 15-20 parts of bentonite and 10-15 parts of mesoporous silica.
  2. 2. The composite treating agent for domestic sewage according to claim 1, wherein the modified chelating agent is prepared by the steps of: step A1, mixing phytic acid and glycidyl methacrylate, stirring at room temperature until the pH value is constant, and stopping the reaction to obtain an intermediate product 1; step A2, mixing the intermediate product 1, cysteine, triethylamine and tetrahydrofuran, heating to 60 ℃ under the protection of nitrogen, carrying out reflux reaction for 12 hours, cooling to room temperature, rotary steaming, washing, centrifuging and vacuum drying to obtain an intermediate product 2; Step A3, mixing an intermediate product 2, 3-hydroxy propane sulfonic acid, p-toluene sulfonic acid and toluene, stirring and heating to 140 ℃, carrying out reflux reaction until no water drops are generated, adding ethyl acetate, washing by using 10wt% sodium bicarbonate solution, washing by using deionized water and saturated sodium chloride solution in sequence, separating liquid, drying, filtering, distilling under reduced pressure, and drying to obtain an intermediate product 3; And A4, mixing sodium alginate and deionized water, stirring for 1h, adding EDC and NHS, adding an intermediate product 3, adjusting the pH to 4 by using a 3.6wt% hydrochloric acid aqueous solution, stirring for 2h at room temperature, adjusting the pH to 6 by using A4 wt% sodium hydroxide aqueous solution, continuing to react for 1h, and finally freeze-drying to obtain the modified chelating agent.
  3. 3. The composite treating agent for domestic sewage according to claim 2, wherein the amount ratio of phytic acid to glycidyl methacrylate in the step A1 is 0.1-0.2mol:0.4-0.8mol.
  4. 4. The compound treating agent for domestic sewage according to claim 2, wherein the dosage ratio of the intermediate 1, the cysteine, the triethylamine and the tetrahydrofuran in the step A2 is 0.06-0.08mol:0.12-0.16mol:0.024-0.04mol:300-400mL.
  5. 5. The compound treating agent for domestic sewage according to claim 2, wherein the dosage ratio of the intermediate 2, 3-hydroxy propane sulfonic acid, p-toluene sulfonic acid, toluene, ethyl acetate, sodium bicarbonate solution, deionized water and saturated sodium chloride solution in the step A3 is 0.033-0.053mol:0.06-0.1mol:0.006-0.01mol:100-140mL:120-180mL:100-160mL:300 mL.
  6. 6. The compound treating agent for domestic sewage according to claim 2, wherein the dosage ratio of sodium alginate, deionized water, EDC, NHS and intermediate 3 in the step A4 is 1g to 100mL to 1.4-1.5g to 0.8-0.9g to 0.01-0.02mol.
  7. 7. The composite treating agent for domestic sewage according to claim 1, wherein the modified flocculant is prepared by the steps of: Step B1, mixing 1-vinylimidazole, normal hexane and BHT, introducing nitrogen, dropwise adding bromohexadecane, heating to 40 ℃ for reaction for 24 hours, cooling to room temperature, washing, filtering, and drying in vacuum to obtain imidazole bromide; And B2, mixing starch and deionized water, gelatinizing for 30min at 80 ℃, cooling to 35 ℃, sequentially adding imidazole bromide, acrylamide and styrene, adding Fenton initiator solution, reacting for 1.5h at 35 ℃, adding hydrogen peroxide, continuing to react for 1.5h, washing with absolute ethyl alcohol after the reaction is finished, washing with 50wt% ethanol water solution, centrifuging for three times, and vacuum drying to obtain the modified flocculant.
  8. 8. The composite treating agent for domestic sewage according to claim 7, wherein the dosage ratio of 1-vinylimidazole, n-hexane, BHT and bromohexadecane in the step B1 is 0.1-0.2mol:40-50mL:0.01-0.02g:0.2-0.4mol.
  9. 9. The composite treating agent for domestic sewage according to claim 7, wherein in the step B2, the starch, deionized water, imidazole bromide, acrylamide, styrene, fenton initiator solution, hydrogen peroxide, absolute ethyl alcohol and aqueous ethanol solution are mixed according to the dosage ratio of 10g to 80mL to 10mmol to 5-10mmol to 11-22mL to 1-2mL to 200mL to 300mL, wherein the Fenton initiator solution is formed by mixing hydrogen peroxide, ferrous sulfate and deionized water according to the dosage ratio of 1-2mL to 0.335-0.67g to 10-20 mL.
  10. 10. A method for preparing the composite treatment agent for domestic sewage according to any one of claims 1 to 9, wherein the composite treatment agent is prepared by the steps of: step S1, weighing raw materials according to parts by weight, adding magnesium sulfate, bentonite, mesoporous silica and ferric hydroxide into a pulverizer, and pulverizing into 110-mesh powder to obtain a mixture; And S2, sequentially adding ferric trichloride, polyaluminum ferric silicate and sodium hydroxide into the mixture, adding each raw material for 3min at intervals, stirring while adding, sequentially adding a modified flocculant, polyacrylamide and a modified chelating agent, and performing ultrasonic vibration for 10min after the complete feeding, wherein the ultrasonic power is 1000W, so as to obtain the composite treating agent for domestic sewage.

Description

Composite treating agent for domestic sewage and preparation method thereof Technical Field The invention relates to the technical field of sewage treatment, in particular to a composite treating agent for domestic sewage and a preparation method thereof. Background Domestic sewage is waste water discharged from daily life and public buildings of residents, is mainly derived from houses, schools, hospitals and other places, comprises various waste water such as kitchen washing, bathing, laundry washing, toilet flushing and the like, has complex pollutant components and large fluctuation, and mainly contains organic matters, pathogenic microorganisms, nitrogen and phosphorus nutrients, suspended matters, trace heavy metal ions and other harmful substances. The water treatment agent is a core material for domestic sewage treatment, can rapidly remove various pollutants in sewage, and ensures that effluent reaches the standard. The traditional single water treatment agent has functional limitations, and the composite treatment agent gradually rises, realizes advantage complementation by compounding various functional components such as a heavy metal chelating agent, a flocculating agent, an adsorbent and the like, can synchronously remove various pollutants such as suspended matters, organic matters, heavy metals and the like in sewage, and meets the current strict sewage discharge standard requirements. At present, in the aspect of heavy metal chelating agents, the existing products have the problems of poor selectivity, insufficient chelating stability and the like, coexisting ions such as calcium, magnesium and the like in domestic sewage are easy to interfere with the chelating effect, part of the chelating agents are high in cost and difficult to recycle, secondary pollution is easy to cause, and meanwhile, the existing products are weak in environmental adaptability in complex water quality and easy to lose the chelating activity under the extreme pH condition. In the aspect of flocculant, the traditional inorganic flocculant has slow floc sedimentation, large dosage and high efficiency, but the organic flocculant has residual risk, and the problems of poor cooperativity and difficult regulation and control of the proportion are easy to occur when the traditional inorganic flocculant is compounded with the chelating agent. Patent application number 201310731583.0 discloses a domestic sewage treatment agent and a preparation method thereof, starch xanthate is used as a heavy metal chelating agent to realize sewage purification, but a small amount of carbon disulfide and sulfide can be released in the degradation process, and if the treated sludge is buried, the sulfide can permeate into underground water, so that secondary pollution is easily caused. The patent with the application number 201410156144.6 discloses a composite sewage treatment agent, which uses ferric polychloride and polyaluminium polychloride as flocculating agents, but the inorganic polymeric flocculating agent has single function, only focuses on flocculation and lacks multifunctional synergistic capability. Disclosure of Invention In order to solve the technical problems, the invention provides a composite treating agent for domestic sewage and a preparation method thereof. The aim of the invention can be achieved by the following technical scheme: 15-25 parts of ferric trichloride, 3-8 parts of polyaluminosilicate iron, 5-8 parts of polyacrylamide, 4-8 parts of magnesium sulfate, 1-3 parts of sodium hydroxide, 15-20 parts of modified chelating agent, 20-30 parts of modified flocculant, 2-6 parts of ferric hydroxide, 15-20 parts of bentonite and 10-15 parts of mesoporous silica; The modified chelating agent is prepared by the following steps: step A1, mixing phytic acid and glycidyl methacrylate, stirring at room temperature until the pH value is constant, and stopping the reaction to obtain an intermediate product 1; Further, the dosage ratio of the phytic acid to the glycidyl methacrylate is 0.1-0.2mol:0.4-0.8mol; In the step A1, the phytic acid and the glycidyl methacrylate are subjected to ring-opening reaction, double bonds are introduced into a system, reaction conditions are provided for the subsequent thiol-ene click reaction, the phytic acid contains a plurality of phosphate groups, and the phosphate groups can be subjected to chelation with heavy metal ions such as lead, copper, cadmium, iron and the like to generate insoluble precipitate or stable complex, so that the insoluble precipitate or stable complex is removed from water, organic pollutants and suspended particles in the water can be adsorbed through electrostatic action, and the clarity ‌ of the water is improved. Step A2, mixing the intermediate product 1, cysteine, triethylamine and tetrahydrofuran, heating to 60 ℃ under the protection of nitrogen, carrying out reflux reaction for 12 hours, cooling to room temperature, rotary steaming, washing, centrifuging and va