Critical review of biochar for the removal of emerging inorganic pollutants from wastewater

Current research primarily focuses on emerging organic pollutants, with limited attention to emerging inorganic pollutants (EIPs). However, due to advances in detection technology and the escalating environmental and health challenges posed by pollution, there is a growing interest in treating waters contaminated with EIPs. This paper explores biochar characteristics and modification methods, encompassing physical, chemical, and biological approaches for adsorbing EIPs. It offers a comprehensive review of research advancements in employing biochar for EIPs remediation in water, outlines the adsorption mechanisms of EIPs by biochar, and presents an environmental and economic analysis. It can be concluded that using biochar for the adsorption of EIPs in wastewater exhibits promising potential. Nonetheless, it is noteworthy that certain EIPs like Au(III), Rh(III), Ir(III), Ru(III), Os(III), Sc(III), and Y(III), have not been extensively investigated regarding their adsorption onto biochar. This comprehensive review will catalyze further inquiry into the biochar-based adsorption of EIPs, addressing current research deficiencies and advancing the practical implementation of biochar as a potent substrate for EIP removal from wastewater streams.