Method for treating mercury-containing wastewater with three-section continuous process

Abstract

The invention relates to a method for treating mercury-containing wastewater in polyvinyl chloride (PVC) resin production, comprising the following steps: regulating the pH value of the mercury-containing wastewater to be 9-11, and pumping the mercury-containing wastewater into a reaction tank by a pump, and adding sinking agent with the mass concentration of 0.5-0.6 into the reaction tank for full reaction at the meantime, wherein the sinking agent is a Na2S solution, and the mass concentration ratio of the Hg and Na2S of the sinking agent is equal to (1:5)-(1:20); and then adding inorganic coagulant with the mass concentration of 0.01-0.03, naturally precipitating the generated HgS flocculent precipitate, filtering to obtain the supernate which reaches emission standard, and transmitting the precipitated HgS flocculent precipitate to a sludge concentration tank. By utilizing the method in the invention, the problem of environment pollution caused by poor treatment effect on high-concentration mercury-containing wastewater produced in the polrvinyl chloride (PVC) resin industry is solved. The method has the advantage of simple and reasonable process, and the like, is easy to implement, can be widely applied to the treatment of mercury-containing wastewater and is especially suitable for treatment of the mercury-containing wastewater in the polrvinyl chloride (PVC) resin production.

Description

Technical field: [0001] The invention relates to a method for advanced treatment of industrial mercury-containing wastewater, in particular to a method for treating mercury-containing wastewater in polyvinyl chloride resin production. Background technique: [0002] Polyvinyl chloride is one of the five general-purpose plastics. It is widely used in important fields such as industry, agriculture, national defense, and chemical building materials. Its commonly used production methods mainly include ethylene oxychlorination and calcium carbide acetylene. With the increasing maturity of the calcium carbide process technology, the production of calcium carbide polyvinyl chloride accounts for 63.4% of the total production of polyvinyl chloride in my country (by the end of 2009), but mercury pollution will be generated in its production, which is manifested in: the production process of calcium carbide polyvinyl chloride The whereabouts of mercury in China are mainly waste mercury ca...

AI Technical Summary

Problems solved by technology

[0004] The present invention solves the problem of environmental pollution caused by the poor treatment effect of the high-concentration mercury-containing wastewater produced in the synthesis process of the industrial furnace for producing polyvinyl chloride resin by the calcium carbide method, and further provides a Hg 2+ A three-stage continuous process method for advanced treatment of mercury-containing wastewater with thorough treatment, low pollution, low investment, simple and reasonable process, easy implementation, and quick results

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