Non-radical activation of peroxymonosulfate by Co 3 O 4 for naproxen degradation: singlet oxygen-mediated pathway

Abstract Radical and non-radical peroxymonosufate (PMS) activation using heterogeneous metal-based catalysts has received particular focus for its efficiency in the removal of refractory contaminants across diverse water matrices. In this study, Co 3 O 4 was synthesized through a mild wet chemical process. The resulting catalyst was then characterized using various technics (XRD, FT-IR, SEM, and BET). The catalytic activity of Co 3 O 4 in activating PMS to degrade naproxen (NPX) was investigated, revealing 90.7 % NPX degradation rate in just 15 min and total organic carbon removal of 67.95 %. Key parameters such as PMS dosage and pH were optimized and their impact on NPX degradation was assessed. Furthermore, the contribution of reactive species was evaluated via quenching tests and the results identified singlet oxygen ( 1 O 2 ) as the primary species involved in the degradation of NPX. The efficiency of the process was assessed in various water matrices, and the results revealed that ubiquitous inorganic anions had a negligible effect, whereas organic matter inhibited the process. Finally NPX mineralization was evaluated using total organic carbon (TOC) analysis.