Restoration method of construction waste polluted by hexavalent chromium

Abstract

The invention relates to the field of soil pollution restoration, and in particular, provides a restoration method for hexavalent chromium-contaminated construction waste. The repairing method includes: repairing construction waste with a concentration of hexavalent chromium >500 mg / kg by means of enhanced heap leaching. Then, a reducing agent, organic fertilizer and / or glucose are added to the construction waste pile to carry out a reduction reaction. The outside of the pile is covered with a biological film, and then samples of construction waste are collected for testing. If the concentration of hexavalent chromium does not meet the standard, the The reduction reaction and detection are carried out in sequence until the concentration of hexavalent chromium reaches the standard, and finally the liquid in the heap leaching tank is discharged; the reducing agent includes dilute sulfuric acid and ferrous sulfate solution. The method is suitable for repairing large particle pollutants such as construction waste, and has the advantages of simple and mature technology, good reduction effect of hexavalent chromium and low cost.

Description

technical field [0001] The invention relates to the field of soil pollution remediation, in particular to a method for remediating construction waste polluted by hexavalent chromium. Background technique [0002] Hexavalent chromium is an ingestion poison / inhalation extremely poison, skin contact may cause sensitivity, more likely to cause genetic defects, inhalation may cause cancer, and has persistent danger to the environment; but these are the characteristics of hexavalent chromium, chromium metal , trivalent chromium or tetravalent chromium do not have these toxicity. Hexavalent chromium is easily absorbed by the human body, and it can invade the human body through digestion, respiratory tract, skin and mucous membranes. According to reports, after the air containing different concentrations of chromic anhydride is inhaled by the human body, people will experience different degrees of hoarseness, atrophy of the nasal mucosa, and in severe cases, perforation of the nasa...

AI Technical Summary

Problems solved by technology

[0002] Hexavalent chromium is an ingestion poison / inhalation extremely poison, skin contact may cause sensitivity, more likely to cause genetic defects, inhalation may cause cancer, and has persistent danger to the environment; but these are the characteristics of hexavalent chromium, chromium metal , trivalent chromium or tetravalent chromium do not have these toxicity

[0004] The current domestic treatment process for hexavalent chromium is mainly wet detoxification. Wet detoxification first needs to grind hexavalent chromium pollution particles to 200 meshes, then leaching with concentrated sulfuric acid, reduction of ferrous iron, oxidation of quicklime oxidant, and separation Disposal and other complex processes, the cost of disposal of large particles such as construction waste is quite expensive, and the technology is not mature enough

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