Bioremediation of metal(loid) contaminated soils using organic amendments

Soil is recognized as the primary medium through which metal(loids) enter the food chain, mainly through plant uptake and wildlife transfer, with land use playing a critical role in waste recycling and disposal practices. There is a rising interest in developing techniques to remediate toxic lands, reflecting an increased awareness of the detrimental effects of hazardous soil on living organisms. Natural biological remediation, which regulates the bioavailability of metal(loids) through the action of soil microbes and higher-growing plants, could be assisted by organic soil modifications. Substantial quantities of organic modifications enhance the physical characteristics and productivity of soils. Several organic contributions include manure compost, biosolids, food and agricultural residues, and municipal debris. Despite their impact on the adsorption, complexation, reduction, and volatilization of metal(loid)s, these organic amendments (OAs) with low metal(loid) levels can serve as a means to reduce the bioavailability of metal(loid)s in contaminated soils. This chapter delves into the mechanisms that underlie the enhanced bioremediation of heavy metals (HMs) through OAs. It also explores the practical implications of these mechanisms for the sequestration and bioavailability of HMs in soil.