Research progress in biochar and its composites activated persulfate

Advanced oxidation process based on sulfate radical (SO4-center dot) is recognized as one of the effective methods to degrade organic wastewater. In recent years, as an economical and readily available carbon containing material, biochar has been gradually applied in the advanced oxidation field. Biochar and its composite activated persulfate have become a promising system for organic pollutants degradation. The latest research progress of different typical biochar-based catalysts for persulfate activation was analyzed, including pristine biochar, transition metal loaded biochar, non-metallic doping biochar, and metallic and non-metallic co-doping biochar. In addition, the synthesis methods and physicochemical properties were summarized. Furthermore, the activation performance and mechanism of biochar-based catalysts for persulfate and the degradation mechanism of organic pollutants were discussed, respectively. Finally, based on the current research progress, from the perspectives of different biomass sources, metallic and non-metallic co-modified biochar technology and the dynamic change of ecotoxicity in the degradation process, relevant discussions and future suggestions for biochar and its composites were put forward in terms of degradation mechanism exploration, potential catalyst development and practical catalytic system application.