Ectopic classification leaching repair complete process of arsenic and heavy metal contaminated soil

Abstract

The invention discloses an ectopic classification leaching repair complete process of arsenic and heavy metal contaminated soil. The repair process comprises the following steps: the contaminated soil is magnetically separated to extract and recover target metals; a nonmagnetic component is divided into three grades by a vibrating screen after being primarily crushed; stones and boulders are flushed by clear water to directly serve as building materials; thick and fine soil particles obtained through screening respectively enter second-grade leaching mixing equipment for washing; the solid-liquid separation is performed for mud generated by washing through a two-stage hydraulic cyclone device; leaching waste liquid is purified and regenerated for recycling; sludge is added with such repair materials as curing / stabilizing agents for safety treatment after being dehydrated; and after the treatment, the soil particles can be backfilled, or can serve as roadbeds, building materials and the like. Based on the characteristic of large difference of arsenic and heavy metal contents in soils with different particle sizes, the soil leaching treatment according to the particle size is performed, so that the process has such advantages as low repair cost, high treatment efficiency and saving of energy consumption, provides a new method for soil heavy metal pollution abatement, and is broad in application prospect.

Description

technical field [0001] The invention relates to the field of environmental protection, in particular to the field of remediation of soil heavy metal pollution. Background technique [0002] With the development of industry and the advancement of urbanization, human activities such as mining, electroplating, smelting, and coal combustion have caused soil heavy metal pollution to become one of the most serious and widely distributed major environmental problems today, and has attracted widespread attention from all over the world. . Heavy metal pollution in soil has the characteristics of wide pollution range, long duration of pollution concealment, and irreversibility. It can be transmitted and enriched through the food chain, which poses a great threat to human health. The restoration and treatment of heavy metal-contaminated soil is urgent. [0003] After decades of development, a variety of heavy metal-contaminated soil remediation technologies have been developed in the ...

AI Technical Summary

Problems solved by technology

[0005] At present, the research of Chinese scholars on leaching technology is mostly focused on the screening of leaching agents, the compounding of multi-element leaching agents, and the optimization of leaching conditions for full-size contaminated soil, and most of them stay in the laboratory research stage. There are few reports on the combined remediation of heavy metal-contaminated soil with different particle sizes by separate techniques and chemical leaching. The research on the effect of leaching and remediation of soil particles with different particle sizes and its influencing factors has not been involved. The establishment of an integrated process system is still missing

Images