Copper-modified biochar derived from fig branch as peroxymonosulfate activator for efficient oxytetracycline degradation

Background Antibiotic pollution of water bodies is a major problem to be solved in the current environmental field. Methods In this study, copper modified biochar (CuBC) catalyst was successfully prepared using fig branch as biochar source, and an efficient catalytic oxidation system was constructed for the degradation of oxytetracycline (OTC). Significant findings The obtained CuBC catalyst had a porous structure with irregular surface morphology. The multi valence states of Cu + and Cu 2+ in CuBC were beneficial for peroxymonosulfate (PMS) activation. The removal of OTC reached 91.38% in CuBC/PMS system within 45 min. The CuBC catalyst exhibited excellent stability and catalytic activity over a wide pH range of 3 to 11. The efficient degradation of OTC was due to the synergistic effect of free radical (·OH and SO 4 ·- ) and non-free radical ( 1 O 2 ) pathways in CuBC/PMS system. Furthermore, the degradation pathways were proposed and most intermediates during the degradation process of OTC have reduced toxicity in CuBC/PMS system. This research provides a promising strategy for resource utilization of biomass and antibiotic pollution control.