Enhanced Catalytic Ozonation of Norfloxacin by In Situ Construction of Ce-Ni@WSA Catalysts

Ce-Ni@WSA (WSA = water-resistant silica–alumina gel) ozone catalyst was prepared with an impregnation–calcination method using WSA as the support and characterized by SEM, XRD, BET, XRF, and XPS analyses. The operating conditions and reaction mechanism of the Ce-Ni@WSA catalytic ozonation of norfloxacin (Nor)-simulated wastewater were systematically studied. A data-envelopment analysis model (DEA-B2C) was then established to evaluate the catalytic ozonation process. Under the optimal conditions of initial pH 7.42 (raw water), ozone dosage = 0.4 g/L/h, catalyst-filling ratio = 5%, humic acid dosage = 0 mg/L, the removal rates of chemical oxygen demand (COD) and Nor reached 84.95% and 93.52%, respectively. Ce-Ni@WSA retained its high catalytic performance and mechanical strength after 50 cycles of repeated use. Mechanistic studies showed that •OH oxidation was dominant in the catalytic-ozonation system, and Nor can be degraded into small molecules through three different pathways and eventually mineralized. The DEA-B2C model analysis showed that the treatment cost was low and the catalytic efficiency was high under the optimal operating conditions.