Remediation of Contaminated Soils

Abstract Soil contamination is caused by a variety of industrial, agricultural, and domestic activities, and poses a major threat to the environment. Although soil contamination can result from a variety of organic and inorganic chemicals, this article focuses on remediation of metal‐contaminated soils. Heavy metals such as Pb, Cr, Cd, Zn, Cu, and Hg can cause significant damage to environmental and human health, particularly because of their indefinite persistence in the environment. In the United States alone, 1200 sites are on the National Priority List (NPL) for remediation of contaminated soils, of which 63% are contaminated with toxic heavy metals. A plethora of remediation techniques are now available for the cleanup of such contaminated sites. The selection of the most appropriate site remediation technique depends on various factors such as site characteristics, concentration, types of pollutants to be removed, and end use of the contaminated medium. The major technologies available to date can be grouped under the following categories: isolation, immobilization, toxicity reduction, physical separation, and extraction. This article provides an overview of the various sources of heavy metal pollution in soils, the common remediation technologies available for soil cleanup, and the various factors that influence the type of remediation method that would be most appropriate for effectively remediating metal‐contaminated soils.