A treatment method for high-concentration heavy metal polluted construction waste

Abstract

The invention relates to a treating method of high-concentration heavy metal polluted building waste. The method includes: stripping surfaces of the building waste, smashing, washing, separating solid and liquid to obtain the cleaned building waste the water-soluble heavy metal of which is removed, adding an isopropylamine glyphosate solution into the cleaned building waste, eluting to remove the heavy metals, adjusting the pH value to be neutral, separating solid and liquid, washing the waste after elution with water and separating solid and liquid. The heavy metal contents in the building waste after air drying are lower than the three-level standard thresholds of the environmental quality standards (GB15618-1995). The building waste after air drying is subjected to a leaching test by utilization of an HJ / T229 leaching method, and the heavy metal contents in the leachate are lower than the thresholds of the standards for hazardous wastes (GB5085.3-2007). The building waste after air drying can be directly buried and stacked without pollution to the soil, and can be used as a regenerated roadbed material and a concrete aggregate. The method is simple in process and capable of completely eliminating the hazard of the polluted building waste, and has good environmental benefit, economic benefit and social benefit.

Description

technical field [0001] A method for treating construction waste polluted by high-concentration heavy metals, which relates to a method for elution and purification of construction waste polluted by various high-concentration heavy metals (Cu / Zn / Cr / Ni), and belongs to the technical field of construction waste treatment, disposal and resource utilization . Background technique [0002] As the largest developing country, China has experienced rapid industrialization and urbanization in the past three decades, and the problem of environmental pollution has become increasingly prominent. Polluting enterprises such as chemical plants and metallurgical plants located in urban areas or suburbs have been relocated one after another. Especially after the severe smog occurred in recent years, the State Council decided to eliminate industries with excess production capacity such as coal chemical industry, steel, and cement, which will generate a large amount of pollution. Construction ...

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Problems solved by technology

The method aims at the gap of chemical elution in the field of construction waste pollution remediation polluted by various heavy metals (Cu / Zn / Cr / Ni), and overcomes the limitations of using EDTA, inorganic salts, inorganic acids and organic acids as eluents. The existing elution technology has problems such as high cost, large damage, and easy to produce secondary pollution, so that the heavy metal content of the treated construction waste is lower than the third-level standard threshold of the soil environmental quality standard GB15618-1995 (due to the total amount of heavy metals in construction waste There is no relevant standard in terms of content), and the HJ / T299 leaching method was used to conduct leaching experiments on the treated construction waste, and the concentration of heavy metals in the leachate was lower than the threshold of the hazardous waste standard GB5085.3-2007

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