Intensified Biological Oxidation of Ciprofloxacin Using Acoustic Cavitation-Based Pretreatment

Abstract

The present work investigates the intensification of biological oxidation of ciprofloxacin-based synthetic effluent using acoustic cavitation-based pretreatment techniques. Cow-dung based sludge acclimatized with the effluent was used for the biological oxidation experiments at a 1:3 sludge to effluent loading for a treatment time of 48 h. Conventional biological oxidation resulted in 48.79% CIP degradation, which was demonstrated to be enhanced through acoustic cavitation-based pretreatment. The optimized conditions for cavitation were 125 W power and a 70% duty cycle, and the optimum oxidant loadings for the combination studies were 150 mg/L H₂O₂, 150 mg/L of potassium persulfate (KPS), and 200 mg/h of O₃. The enhanced CIP degradation after application of pretreatment was 63.27%, 79.23%, 68.27%, and 82.27% for AC, AC + H₂O₂, AC + KPS, and AC + O₃ based pretreated effluents, respectively. Toxicity analysis against test organisms Pseudomonas aeruginosa (P. aeruginosa) and Saccharomyces cerevisiae using the agar well diffusion method confirmed that pretreatment reduced the toxicity leading to enhanced biodegradation. Overall, the current work elucidated the efficiency of acoustic cavitation combined with KPS for the effective biological oxidation of ciprofloxacin.