Response surface optimization of ciprofloxacin degradation using UV/O3 oxidation process

Abstract

Advanced oxidation processes, such as UV/O3, offer a promising alternative for treating wastewater containing pharmaceuticals such as ciprofloxacin. However, ecotoxicity predictions suggest that some degradation by-products may be toxic to aquatic organisms, highlighting the need for complete mineralization. This study systematically evaluates the effects of initial ciprofloxacin concentration (10–45 mg/L), ozone flow rate (0.5–1.5 L/min), and pH (8–10) on degradation efficiency. Response surface methodology was employed with a Box-Behnken design, and optimal conditions were identified: a ciprofloxacin concentration of 10 mg/L, an ozone flow rate of 1.5 L/min, and a pH of 9, resulting in 98.64 % degradation efficiency. The degradation process followed pseudo-first-order kinetics, with a rate constant (k) of 0.223/min. Antibacterial assays confirmed a significant reduction in inhibitory activity, while total organic carbon analysis demonstrated 76.51 % mineralization. These findings highlight the potential of the UV/O3 process to reduce antibiotic contamination in wastewater, contributing to developing more sustainable water treatment technologies.

Keywords

• Ciprofloxacin degradation
• Antibiotic contaminants
• Optimization
• Box-Behnken design
• Wastewater treatment