Process and apparatus for treating industrial hazardous waste containing hexavalent chromium

Abstract

The invention discloses a process and an apparatus for treating industrial hazardous waste containing hexavalent chromium. The treatment process comprises the following steps of: crushing the waste, adding water thereto, and obtaining slurry having moisture content of 55%-75%; adding sulfuric acid to the slurry to adjust the pH of the slurry to 2-3, and acid leaching for 30-60 min; adding a reducing agent to the slurry to reduce the hexavalent chromium ions in the slurry to trivalent chromium; adding a 10% lime milk solution to the slurry to adjust the pH to 9; and separating a filtrate from afilter residue in the slurry. In the above process, the industrial hazardous waste containing hexavalent chromium is crushed into small particles, acid leaching is carried out by using sulfuric acid,so that the acid dissolved hexavalent chromium in solid solution is released. The reducing agent and the 10% lime milk are added to convert the hexavalent chromium into a trivalent chromium precipitate to achieve the purpose of detoxification. The leaching toxicity of the hexavalent chromium in the filter residue is less than 1.5 mg / L and the total chromium leaching toxicity is less than 2.0 mg / L, which meets the hazardous waste landfill pollution control standard.

Description

technical field [0001] The invention relates to the field of hazardous waste treatment, in particular to a process and device for treating hexavalent chromium industrial hazardous waste. Background technique [0002] Hazardous waste containing hexavalent chromium is representative in the field of industrial hazardous waste. Hexavalent chromium has strong oxidizing properties, which can cause damage to humans, microorganisms, animals and plants, and has strong carcinogenic and mutagenic properties. Health poses a great risk. With the development of the national economy and the advancement of science and technology, environmental protection has gradually been put on the agenda, government departments have intervened, and the treatment and comprehensive utilization of chromium-containing pollutants have generally been carried out in various places. According to the state's management regulations and technical specifications on hazardous waste, industrial hazardous waste contai...

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Problems solved by technology

[0005] Based on this, it is necessary to deal with the existing industrial hazardous wastes of hexavalent chromium. Wet reduction is not suitable for high-concentration hexavalent chromium-containing wastes, the consumption of raw materials is large, the content of hexavalent chromium in wastewater is high, and the degree of automation is low. To solve the problem of centralized disposal demand, provide a hexavalent chromium industrial hazardous waste treatment process and device

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