Unravelling the Impact of Potentially Toxic Elements and Biochar on Soil: A Review

Abstract

Industrial activities, urbanization and mismanagement of toxic waste, have caused global environmental degra- dation. Biochar has lately gained considerable recognition and popularity for remediation of contaminated soil. Even though it is organic in nature, biochar may need further processing in order to safely remove contaminants, for soil augmentation and to enhance its treatment efficiency. In this study, areas that have been under-researched regarding safe precautionary measures in biochar preparation, and biochar safety towards soil environment, have been reviewed. The review has determined that, in order for biochar to have minimal negative impact on soil and its microorganisms, soil type and concentration of contaminants to be treated have to be pre-determined. Furthermore, the groups of microorganisms that are not tolerant to long-term application of biochar have to be known. Biochar itself may sometimes be a source of contaminants due to its substrate or method of its prepara- tion, therefore prior biological tests should be done. Variations in experimental and climatic conditions have to be considered prior to reporting on how soil behaves when conditioned or treated with biochar. Furthermore, long-term field research should also be considered in order to provide different insights on biochar suitability to soil amelioration. Further areas of research are also identified, for holistical reporting of biochar and impact on the environment.