Biochar: A Sustainable Product for Remediation of Contaminated Soils

Combustion of biological residue under less condition of oxygen resulting in less density carbon material is biochar. As thermal decomposition of biomass under limited oxygen condition is responsible for producing biochar, this method is getting attention in soil remediation and waste disposal in recent years. On the advantages of biochar, interest increases nowadays and it may discover multidisciplinary field in science and engineering. Biochar has large area of surface and has greater capacity to absorb heavy metals from contaminated soil. It can be used to reduce the availability of heavy metals and organic pollutants in soil through adsorption as well as other physicochemical reactions. Basically, biochar is an alkaline material which can increase the pH of soil and responsible for heavy metal stabilization. Phytoremediation and biochar are two sound environmental technologies which could be at the forefront to mitigate soil pollution. For remediation of polluted soil, biochar applications may provide new solution for contaminated soil problems. The provided biochar application may include sequestration of carbon, improvement fertility of soil, remediation, and recycling of agricultural waste. For controlling its properties, the key parameters include pyrolysis temperature, time of residence, heat transfer rate, and feedstock type. This article will provide an overview of the biochar impact on the environment and movement of heavy metals in polluted soil as well as methods for remediation of contaminated soil through biochar. Also, in this review, a succinct overview of current biochar use as a sorbent for contaminant management in soil will be summarized and discussed.