Research Progress on Remediation of Heavy Metal Contaminated Soil

Abstract

Heavy metals (arsenic, cadmium, chromium, mercury, lead, etc.) are widely polluted in the world. Correct understanding of the forms of heavy metals in the soil is conducive to adopting appropriate methods for soil remediation. The existing remediation technologies can be divided into physical, chemical, biological, electrical and thermal remediation according to the principle of remediation, and the specific methods include capping, encapsulation, landfill, soil washing, electric extraction, stabilization/solidification, vitrification, phytoremediation and bioremediation. These technologies have specific advantages and disadvantages and applicability. Capping, encapsulation and landfill are suitable for areas with serious pollution and small area. Because of the large amount of soil washing, it is necessary to treat the chelating agent. Electric extraction is suitable for shallow and low concentration contaminated sites, and the treatment time is long. Stabilization/solidification is widely used but does not remove heavy metals from the soil. Phytoremediation needs to be more efficient. Appropriate remediation technology is crucial for the reuse of heavy metal contaminated soil, which should be combined with the type and degree of pollution, remediation objectives, site characteristics, cost-effectiveness, and remediation time.