Ciprofloxacin聽(CIP) is a fluoroquinolone antibiotic that is widely used across the globe and its release is a serious concern due to its persistent nature, partial聽degradation, and simple transport through different environmental matrices. Pharmaceuticals have been degraded effectively by electrochemical oxidation. Exploring ways to in-crease the mineralization聽of聽these compounds while maintaining low power consumption is important. In this study, the treatability and聽degradation聽of聽CIP were investigated by聽using聽cobalt oxide-coated聽stainless聽steel聽(SS)聽electrodes聽in a lab-scale electrochemical (EC) reactor. The performance聽of聽the electrochemical reactor was determined under various operational conditions. The feed wastewater was synthetically prepared in the laboratory with varying concentrations聽of聽CIP ranging from 8 to 41 mg/L and the EC reactor was operated with an applied voltage and airflow rate聽of聽2.6-9.3 volts and 1.6-3.5 L/min, respectively. A 3-factor central composite experimental design (CCD) was developed by聽using聽response surface methodology (RSM) in Design-Expert software. At a residence time聽of聽27 min, initial concentration聽of聽25 mg/L, airflow rate聽of聽2.5 L/min, and applied voltage聽of聽6 volts, the EC reactor achieved a removal efficiency聽of聽70.8% for CIP with SS聽electrodes. On the contrary, the removal efficiency was increased to 91.5% at a reduced residence time聽of聽21 min with cobalt oxide (Co3O4)聽coated聽over SS plates. The results indicated that聽Co3O4@SS聽electrodes聽resulted in better removal efficiency聽of聽CIP at a lower residence time. This system can be used as a robust benchmark for a single or consortium聽of聽antibiotics present in domestic and hospital wastewater.
