Enhanced Catalytic Degradation of Norfloxacin by Lignin-Derived Biochar-CoMn2O4 Activated Peroxymonosulfate: Synergistic Effect and Mechanism

Heterogeneous catalysts with high activity, environmental adaptability, and stability are urgently needed for water pollutanion treatment. In this study, biochar (NLSBC) with a large specific surface area and multiple active sites was obtained by activating lignosulfonate with CaC 2 O 4 and CH 4 N 2 O, which was used to load CoMn 2 O 4 (CMO) to prepare NLSBC/CoMn 2 O 4 to activate peroxymonosulfate (PMS) to achieve efficient degradation of norfloxacin (NOR). The degradation rate of NOR by the NLSBC/CMO-PMS system under optimal conditions (NOR-30 mg/L, PMS-0.25 mM, and catalyst-20 mg) was as high as 99.42%, and the degradation rate remained at 79.09% after five cycles, which was suitable for various natural water sources. Combined with quenching experiments, EPR analysis, and electrochemical analysis, it was proven that , 1 O 2 and electron transfer were the main reaction pathways of the NLSBC/CMO-PMS system. The ecotoxicity assessment showed that the toxicity level was significantly reduced after treatment with NLSBC/CMO catalyst. In summary, NLSBC/CMO provides a new idea for developing friendly catalysts and has potential applications in treating organic wastewater. Graphical This study demonstrates that a spinel metal oxide supported on biochar catalyst (2NLSBC/CMO) successfully activates PMS to degrade NOR. The catalyst, characterized by its rich Co/Mn active sites and efficient electron transfer, achieves an 99.42% NOR degradation rate within 60 min. The 2NLSBC/CMO/PMS system produces reactive species, including SO4•-, •OH, •O2- and 1O2, thereby removing NOR.