ABSTRACT
Environmental contamination by heavy metals is a serious problem throughout the world. Heavy metals are non-biodegradable and persistent and can be differentially toxic to microbes, plants, animals, and humans. Remediation techniques for heavy metal-contaminated soils are based on the extraction or an in-situ stabilization of contaminants. The extraction is generally carried out either ex situ or in situ by using some plants. Phytoextraction of metals can be enhanced by using some amendments. The “in situ” stabilization techniques are less expensive and achieved by using some organic or inorganic amendments. Soils can naturally reduce mobility and bioavailability of heavy metals, as they are retained in soil through sorption, precipitation, and complexation reactions. This natural attenuation process (natural remediation) can be accelerated by the addition of amendments. It is important to apply suitable remedial technologies to reduce the risk of metal contamination in polluted soil. This chapter focuses on the various amendments for heavy metal remediation either through mobilization or immobilization metals in polluted soil. A short overview of the sources of metal contaminations in soil and effect of metal contamination are also presented herein. Post remediation effects of amendments on soil properties have been also discussed in this chapter.
