Composite dechlorination agent for removing high-concentration chlorine-containing wastewater and application method thereof

Abstract

The invention discloses a composite dechlorination agent for removing high-concentration chlorine-containing wastewater and an application method thereof, which belong to the field of sewage treatment in environment protection. The composite dechlorination agent is prepared by compounding organic acids and inorganic salts, wherein the organic acids include two or more than two of nicotinic acid, citric acid, succinic acid, beta-ketoglutaric acid, and ketosuccinic acid; the inorganic salts include one or two of mercury sulfate, cadmium sulfate and copper sulfate; and the weight percentages of the organic acids and inorganic salts are 15-80% and 20-85% respectively. The application method comprises the steps of: adding the prepared composite dechlorination agent in percentage by weight of 0.05-0.5% into the high-concentration chlorine-containing wastewater and continuously stirring for 10-30min; adding a methylene dichloride solvent; standing for layering, separating, and subjecting obtained wastewater to air flotation treatment; and finally scraping off a layer of residue floating on the surface of the wastewater by a residue scraping machine to obtain the dechlorinated wastewater as the yielding water, wherein the dechlorinated wastewater can be lower than the national emission standard I. The composite dechlorination agent and the application method disclosed by the invention have the characteristics of simple technological process, smaller dosage of chemical agent, lower running expense, no sludge, high removal rate of chlorine ions in the wastewater, and the like; and the removal rate of chlorine ions in the wastewater can reach above 99.9%.

Description

technical field [0001] The invention relates to a compound dechlorination agent for removing high-concentration chlorine-containing waste water and an application method thereof, relates to the removal of chloride ions in waste water, and belongs to the field of waste water treatment in environmental protection. Background technique [0002] In industrial reverse osmosis treatment process, oil recovery process, printing and dyeing process, some high-concentration chlorine-containing wastewater with a chloride ion content greater than 1000 mg / L is often produced. Excessive chlorine ion content in wastewater will damage the water quality and inhibit the growth of microorganisms. Chlorine will chemically react with organic matter in the water to generate a series of chlorinated hydrocarbons, which will cause cancer to a certain extent on the human body. Therefore, high concentrations of chlorine The treatment of wastewater plays an extremely important role in environmental gove...

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Problems solved by technology

[0003] At present, there are several methods for removing high-concentration chloride ions in wastewater: (1) Precipitation method, using silver nitrate to precipitate chloride ions, which is too expensive in industry , is not widely used, and is limited to laboratory use; (2) Ion exchange method, using multiple beds or mixed beds to remove chloride ions, is a traditional process with low equipment investment and low operating costs, but the anion exchange resin is easily saturated. Regeneration is required; (3) Electrodialysis is suitable for treating low-concentration chlorine-containing wastewater, with high water and power consumption; (4) The removal rate of reverse osmosis (RO membrane method) is higher than that of electrodialysis, and it is easy to operate, but the investment is large. Moreover, the membrane is easy to clog, so it is not suitable for treating wastewater with high conductivity and high ion concentration.

[0004] Publication No. is CN101121549, and the name is called "method for treating waste water containing ammonium and chlorine and recycling ammonium and chlorine". Concentrated sulfuric acid is added to the wastewater, followed by heating and distillation to remove chloride ions, but the use of concentrated sulfuric acid is very dangerous and not suitable for the removal of high-concentration chloride ions; the publication number is CN101723486A, and the name is "a salt-containing, chlorine-containing Wastewater Treatment Method” patent describes the use of electrochemical catalytic oxidation method to treat chlorine-containing wastewater. This method is complex in operation, low in treatment effect, and high in cost, making it difficult to apply industrially.