A thermal elution method suitable for ex-situ remediation of chromium-contaminated soil

Abstract

The invention discloses hot elution equipment and method applicable to ex-situ remediation of chromium-contaminated soil. The hot elution equipment comprises a heating pipe. A heater is mounted on theheating pipe; the heating pipe is connected with a hot elution pool; the heater is a circular ring consisting of a gas inlet pipe, a communicating pipe, a burner and a bracket; and a distance from the bracket to the circle center of the heater is equal to the outer diameter of the heating pipe. The chromium-contaminated soil is firstly dissociated by a crushing sieve and a drum mud machine. Afterbeing dissociated, the soil is immersed in the elution pool, and then immersed and eluted mud enters the hot elution pool after being heated; and the mud is subjected to leaching grading and solid-liquid separation after being subjected to hot elution remediation to obtain clean soil. The equipment disclosed by the invention is simple in structure, reasonable in design and high in operability. After the chromium-contaminated soil is treated by the hot elution equipment, the content of hexavalent chromium in the soil is substantially reduced, a field remediation goal is achieved, and secondarypollution of the hexavalent chromium to the surrounding environment is avoided; a foundation is laid for the ex-situ remediation and treatment of the soil in a chromium-contaminated site.

Description

technical field [0001] The invention relates to the field of ectopic remediation of polluted soil, in particular to a thermal elution device and method suitable for chromium-contaminated soil ectopic remediation. Background technique [0002] With the continuous acceleration of industrialization and urbanization in our country, heavy industry factories have moved from the city to the outer suburbs. Most of the relocated factory sites are polluted by waste water, waste gas, and waste residues containing heavy metals, including heavy metals, radioactive metal substances, and organic pollutants. Pollutants in the soil stay for a long time and are not easy to be completely degraded by natural organisms and microorganisms. This poses a threat to the sustainable use of land resources and the ecological safety of agricultural products. It is urgent to remediate the contaminated soil. [0003] Pollutants in polluted sites such as electroplating factories and leather factories are m...

AI Technical Summary

Problems solved by technology

Although the leaching agent can contact most of the hexavalent chromium on the surface and inside of the soil, only the hexavalent chromium in the exchangeable state, carbonate state, part of iron manganese iron oxide and part of the organic state can be removed by the leaching agent. The hexavalent chromium in most iron and manganese oxidation states, most organic states and residual states cannot be removed by leaching agents, resulting in a high total amount of hexavalent chromium in the soil, which cannot meet the requirements of site restoration

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