Lignocellulosic biomass-based engineered biochar composites: A facile strategy for abatement of emerging pollutants and utilization in industrial applications

There has been considerable growing interest in the production and application of biochar derived from various sources, especially from the lignocellulosic biomass (crop residues), sewage sludge, plastic wastes, etc. Biochar have emerged as potential candidates as catalysts in different chemical and bioprocesses, and for soil remediation and amelioration, agrochemical removal, carbon sequestration, removal of organic and inorganic wastes, wastewater treatment, supercapacitor, electrode material, etc. Recently, to increase the adsorption efficiency of conventional biochar, modifications to create composite biochar have been initiated. Modification may alter surface functionality, ash content, surface charges, and surface area, subsequently enhancing fixation and removal of toxic compounds. High carbon content, high specific surface area, high cation exchange capacity, porous structure, and stability of engineered biochar composite has raised their utility in environmental remediation. Therefore, to proffer a detailed mechanism and application of engineered biochar, this review conceptualizes the effect of biochar composites on pollutant eradication. Moreover, various synthesis mechanisms, modification processes, properties, and composition of lignocellulosic biochar composites along with the mechanism of pollutant removal are expounded. In summary, engineered biochar composites have wide application prospects in providing sustainable bioeconomy however the mechanism and impact of engineered biochar should be further investigated.