Catalytic Ozonation of Norfloxacin Using Co-Mn/CeO2 as a Multi-Component Composite Catalyst

Abstract

In this study, a Co-Mn/CeO2 composite was prepared through a facile sol-gel method and used as an efficient catalyst for the ozonation of norfloxacin (NOR). The Co-Mn/CeO2 composite was characterized via XRD, SEM, BET and XPS analysis. The catalytic ozonation of NOR by Co-Mn/CeO2 under different conditions was systematically investigated, including the effect of the initial solution’s pH, Co-Mn/CeO2 composite dose, O3 dose and NOR concentration on degradation kinetics. Only about 3.33% of total organic carbon (TOC) and 72.17% of NOR could be removed within 150 min by single ozonation under the conditions of 60 mg/L of NOR and 200 mL/min of O3 at pH= 7 and room temperature, whereas in the presence of 0.60 g/L of the Co-Mn/CeO2 composite under the same conditions, 87.24% NOR removal was obtained through the catalytic ozonation process. The results showed that catalytic ozonation with the Co-Mn/CeO2 composite could effectively enhance the degradation and mineralization of NOR compared to a single ozonation system alone. The catalytic performance of CeO2 was significantly improved by the modification with Mn and Co. Co-Mn/CeO2 represents a promising way to prepare efficient catalysts for the catalytic ozonation of organic polluted water. The removal efficiency of NOR in five cycles indicates that Co-Mn/CeO2 is stable and recyclable for catalytic ozonation in water treatment.