Hybrid advanced oxidation process for rapid ciprofloxacin removal: coupling hydrodynamic cavitation with UV/H2O2

In this study, an innovative integration of hydrodynamic cavitation (HC), ultraviolet (UV) irradiation, and hydrogen peroxide (H₂O₂) was employed to effectively degrade ciprofloxacin (CIP), a representative antibiotic, in a 12-litre treatment system. The study systematically investigated the cavitation characteristics, synergistic interactions, and the influence of key operating parameters (inlet pressure, initial solution pH, H₂O₂ concentration, and initial CIP concentration) on the performance of the HC/UV/H₂O₂ system. Additionally, the potential degradation mechanism, practical applicability, and economic feasibility of the integrated process were thoroughly evaluated. The results demonstrated that the integrated system achieved a synergistic index as high as 8.174 under suboptimal conditions, and completely degraded CIP within 70 min under optimal operational parameters. This performance can be attributed to the synergistic cavitation effects comprising mechanical disruption of molecular bonds, pyrolytic decomposition, and radical oxidation through •OH/•H generation via water dissociation, along with enhanced mass transfer induced by HC-generated turbulence, and the accelerated decomposition of H₂O₂ into additional •OH radicals facilitated by the combined UV and HC effects. In addition, under sub-optimal conditions, the system achieved complete degradation of rhodamine B (RhB) and doxycycline hydrochloride (DOX), along with a 93.9% degradation efficiency for malachite green (MG) within 60 min. The system demonstrated superior treatment effectiveness and time efficiency compared to previously reported methods. These findings highlight the HC/UV/H₂O₂ process as a promising, scalable, and energy-efficient solution for treating industrial wastewater containing antibiotics.