Performance of Mn-Co@γ-Al2O3 activated peroxymonosulfate to mineralize ciprofloxacin wastewater

A bimetallic Mn-Co@γ-Al 2 O 3 catalyst was prepared • The catalyst effectively activates PMS for the mineralization of CIP • The catalyst enhances PMS activation via electronic, structural and active-site synergy • 1 O 2 is synergistically generated by LAS, oxygen vacancies and bimetallic redox cycles Ciprofloxacin (CIP) is recalcitrant to complete degradation by conventional treatment methods, and persulfate-based advanced oxidation processes often suffer low activation efficiency. In this study, a bimetallic Mn-Co@γ-Al 2 O 3 catalyst was developed to activate peroxymonosulfate (PMS) for the efficient mineralization of CIP. Under optimal conditions (1 mmol·L -1 PMS, pH=9), CIP was completely mineralized within 60 min. The catalytic activity of the bimetallic catalyst surpassed that of the single-metal Mn@γ-Al 2 O 3 and Co@γ-Al 2 O 3 , with a synergistic factor ( SF =1.12, >1) confirming a strong Mn-Co synergy. This synergistic effect results from coupled redox cycles, the inhibition of manganese oxide aggregation, and the presence of abundant Lewis acid sites and oxygen vacancies. The PMS system, primarily governed by singlet oxygen ( 1 O 2 ), effectively reduced the biotoxicity of CIP wastewater, increasing the germination rate of fescue seeds from 80% to 92%. A total of 14 degradation intermediates were identified. The excellent mineralization performance is closely associated with the unique CIP degradation pathway driven by 1 O 2 .