Efficient acetaminophen degradation via peroxymonosulfate activation by Mn/N co-doped biochar: Performance, mechanism and approach

Advanced oxidation methods (AOPs) are frequently used to remove stubborn pollutants from the aquatic environment, and developing an eco-friendly and high-performance catalyst is an effective strategy to enhance the efficiency of AOPs. In this study, Mn nanoparticle-loaded nitrogen-doped kelp biochar catalysts were synthesized at varying temperatures to activate peroxymonosulfate (PMS) and degrade acetaminophen (ACT). The findings show that, under ideal circumstances, the Mn@NBC-800/PMS system can fully remove ACT (20 mg/L) in 10 min. Electrochemical tests, electron paramagnetic resonance (EPR) analysis and quenching experiments reveal that the primary mechanism of ACT degradation was a non-radical pathway dominated by electron transfer and singlet oxygen (1O2). In addition, mechanism studies indicate that Mn species, C=O groups and graphite N were possible catalytically active sites. The Mn@NBC-800/PMS system demonstrates excellent catalytic activity across various pH values, inorganic anions, and water conditions, making it highly suitable for practical applications. This study emphasizes the significant potential of Mn/N co-doped biochar and provides invaluable insights for designing efficient carbon-based catalysts for wastewater treatment.