Oxygen vacancy-engineered Co–Mn/chitosan-modified natural zeolite: Synergistic regulation of non-radical 1O2-dominated ROS for efficient levofloxacin degradation via heterogeneous catalytic ozonation

Levofloxacin (LEV) residues in water are refractory and ecotoxic, while heterogeneous catalytic ozonation (HCO) systems suffer from limited efficiency and insufficient anti-interference ability. To address this, a composite catalyst, Co–Mn/CTS@NZ, was fabricated by loading Co–Mn bimetallic oxides onto chitosan-modified natural zeolite through wet impregnation–calcination to target non-radical reactive oxygen species (ROS) regulation in HCO for enhanced LEV degradation and anti-interference. Under the optimized conditions (LEV 30 mg/L, O 3 5 mg/L, catalyst 5 g, pH 6.5), the system achieved 99.55% LEV removal and 55.52% mineralization in 60 min, outperforming single ozonation significantly. The catalyst exhibited excellent anti-interference performance and operated efficiently across various real water matrices, with negligible metal leaching. Quenching experiments and electron paramagnetic resonance confirmed that 1 O 2 was the primary ROS, with ·O 2 − and ·OH acting as supplementary radicals. Characterization revealed that abundant oxygen vacancies, metal valence cycles, and surface hydroxyl groups synergistically promoted ozone activation and targeted ROS generation. This study provides a low-cost, high-efficiency catalyst for LEV-contaminated water treatment and offers a theoretical basis for targeted ROS regulation in HCO technology—breaking the reliance of traditional HCO on ·OH and advancing the practical application of advanced oxidation in antibiotic pollution control.