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CN-119191499-B - Flocculant for coking wastewater and preparation method and application thereof

CN119191499BCN 119191499 BCN119191499 BCN 119191499BCN-119191499-B

Abstract

The invention discloses a flocculant for coking wastewater, a preparation method and application thereof, and the flocculant comprises the following raw materials, by weight, 1-5 parts of polydimethyl diallyl ammonium chloride and 6-12 parts of a compound, wherein the compound is prepared from kaolin loaded with N-succinyl-O-carboxymethyl chitosan and konjak glucomannan. The invention is used for solving the technical problem that the coking wastewater can not reach the discharge standard.

Inventors

  • WANG CHONGPU
  • Kong Xinghua
  • CI XINBO
  • LI HUAN

Assignees

  • 河北协同水处理技术有限公司

Dates

Publication Date
20260508
Application Date
20240820

Claims (8)

  1. 1. The application of the flocculant for the coking wastewater is characterized by comprising the following steps of putting the flocculant into water, uniformly mixing, adding the coking wastewater to be treated in an aeration state, standing, and removing cyanide in the coking wastewater to obtain the treated coking wastewater; The flocculant comprises, by weight, 1-5 parts of polydimethyl diallyl ammonium chloride and 6-12 parts of a compound, wherein the compound is prepared by putting N-succinyl-O-carboxymethyl chitosan into an acetic acid solution, adding konjak glucomannan and hydrogen peroxide, uniformly mixing, heating to raise the temperature to obtain a mixture, adding kaolin, uniformly mixing, continuously heating to raise the temperature, drying and crushing to obtain the compound.
  2. 2. The application of the flocculant for coking wastewater according to claim 1, wherein the weight ratio of the kaolin, the N-succinyl-O-carboxymethyl chitosan and the konjac glucomannan is 1 (0.7-0.9) to 0.3-0.5.
  3. 3. The method for preparing the flocculant for coking wastewater, which is characterized in that the kaolin is pretreated by soaking the kaolin in hydrochloric acid solution before use, taking out, heating in an oil bath, continuously stirring, cooling, washing and drying to obtain pretreated kaolin.
  4. 4. The method for preparing flocculant for coking wastewater according to claim 1, wherein the N-succinyl-O-carboxymethyl chitosan is prepared by the following method: A1, putting chitosan into isopropanol, uniformly mixing, adding sodium hydroxide, standing, adding chloroacetic acid, uniformly mixing, heating, reacting, centrifuging and washing to obtain O-carboxymethyl chitosan; A2, putting O-carboxymethyl chitosan into water, uniformly mixing to obtain a solution A, putting succinic anhydride into acetone, uniformly mixing to obtain a solution B, dropwise adding the solution B into the solution A, heating to raise the temperature after the dropwise adding is finished, continuously stirring, adding absolute ethyl alcohol, centrifuging, washing and drying to obtain the N-succinyl-O-carboxymethyl chitosan.
  5. 5. The method for pretreating the flocculant for coking wastewater according to claim 1, wherein the konjac glucomannan is pretreated by putting sodium dihydrogen phosphate and disodium hydrogen phosphate into water, adding urea, uniformly mixing, adding the konjac glucomannan, uniformly mixing, heating, baking, cooling and cooling to obtain the pretreated konjac glucomannan.
  6. 6. The method for preparing flocculant for coking wastewater according to any one of claims 1 to 5, wherein the preparation method comprises the following steps of uniformly mixing polydimethyldiallyl ammonium chloride and the compound, and drying to obtain the flocculant.
  7. 7. The method according to claim 1, wherein the aeration time is 20-40min.
  8. 8. The method according to claim 1, wherein the flocculant is added in an amount of 0.5 to 0.8wt% of the coking wastewater to be treated.

Description

Flocculant for coking wastewater and preparation method and application thereof Technical Field The invention belongs to the technical field of wastewater treatment, and particularly relates to a flocculant for coking wastewater as well as a preparation method and application thereof. Background Coke is a widely used reductant in the iron industry. China is the largest producer of coke, and produces coking wastewater during the production of coke. Coking wastewater is a typical toxic and difficult-to-degrade organic wastewater, mainly from the primary cooling of coke oven gas and the process water and steam condensation wastewater in the coke production process. In order to effectively treat the coking wastewater and reduce COD, chromaticity and cyanide content in the coking wastewater, flocculant is generally required to treat the coking wastewater. At present, the flocculant in the market is mainly an aluminum flocculant and an iron flocculant, after the aluminum flocculant treats wastewater, the aluminum content in the wastewater is increased, aluminum is easy to cause various diseases after entering drinking water through water circulation, ecological health is threatened, the removal efficiency of the iron flocculant on COD is higher, but the chromaticity of the discharged water often cannot meet the discharge requirement due to the color of iron ions, so that the flocculant for coking wastewater is needed. Disclosure of Invention The invention provides a flocculant for coking wastewater, a preparation method and application thereof, and aims to solve the technical problem that the existing coking wastewater cannot meet the discharge requirement. In view of the above, the flocculant for coking wastewater provided by the invention comprises, by weight, 1-5 parts of polydimethyl diallyl ammonium chloride and 6-12 parts of a compound, wherein the compound is prepared from kaolin loaded N-succinyl-O-carboxymethyl chitosan and konjac glucomannan. Optionally, the compound is prepared by putting N-succinyl-O-carboxymethyl chitosan into acetic acid solution, adding konjak mannan and hydrogen peroxide, uniformly mixing, heating and heating to obtain a mixture, adding kaolin, uniformly mixing, continuously heating and heating, drying and crushing to obtain the compound. The preparation process includes adding N-succinyl-O-carboxymethyl chitosan into acetic acid solution, adding konjak glycane and hydrogen peroxide, mixing, heating to 40-60 deg.c to obtain mixture, adding kaolin, mixing, heating to 70-90 deg.c, drying and crushing to obtain composite; wherein the addition amount of the acetic acid solution is 2%, the addition amount of the acetic acid solution in each 1g of N-succinyl-O-carboxymethyl chitosan is 4-6mL, and the weight ratio of the N-succinyl-O-carboxymethyl chitosan to the hydrogen peroxide is 1 (0.1-0.3). Optionally, the weight ratio of the kaolin to the N-succinyl-O-carboxymethyl chitosan to the konjac glucomannan is1 (0.7-0.9) to 0.3-0.5. Optionally, the kaolin is pretreated by soaking the kaolin in hydrochloric acid solution before use, taking out, heating in an oil bath, continuously stirring, cooling, washing, and drying to obtain pretreated kaolin. Further, the kaolin is pretreated by the following method before use, namely, the kaolin is put into hydrochloric acid solution for soaking, and is heated in an oil bath at the temperature of 90-100 ℃ after being taken out, continuously stirred for 1-3 hours, cooled to 22+/-3 ℃, washed for 3-5 times by water, and dried to obtain pretreated kaolin; wherein the mass fraction of the hydrochloric acid solution is 20%, and the addition amount of the hydrochloric acid solution in each 1g of kaolin is 6-8mL. Optionally, the N-succinyl-O-carboxymethyl chitosan is prepared by the following method: A1, putting chitosan into isopropanol, uniformly mixing, adding sodium hydroxide, standing, adding chloroacetic acid, uniformly mixing, heating, reacting, centrifuging and washing to obtain O-carboxymethyl chitosan; A2, putting O-carboxymethyl chitosan into water, uniformly mixing to obtain a solution A, putting succinic anhydride into acetone, uniformly mixing to obtain a solution B, dropwise adding the solution B into the solution A, heating to raise the temperature after the dropwise adding is finished, continuously stirring, adding absolute ethyl alcohol, centrifuging, washing and drying to obtain the N-succinyl-O-carboxymethyl chitosan. Further, the N-succinyl-O-carboxymethyl chitosan is prepared by the following method: A1, putting chitosan into isopropanol, uniformly mixing, adding sodium hydroxide, standing for 1-3h, adding chloroacetic acid, uniformly mixing, heating to 40-60 ℃, reacting for 1-3h, centrifuging, and washing with water for 3-5 times to obtain O-carboxymethyl chitosan; A2, putting O-carboxymethyl chitosan into water, uniformly mixing to obtain a solution A, putting succinic anhydride into acetone, uniformly mixing to obtain a solution B, d