Ozone based advanced oxidation for antibiotic amoxicillin removal from aqueous environment with kinetic and economic...

Antibiotics are among pollutants detected in aquatic environments including effluents of wastewater treatment plants, surface and groundwater and also drinking water. Long term exposure to these compounds pose a threat not only to the health of human but also for aquatic organisms. In this work the removal of amoxicillin from aqueous environments using O₃ and O₃/H₂O₂ was investigated on lab scale and kinetic studies along with cost analysis was conducted. Operational parameters including pH, amoxicillin concentration, reaction time and applied O₃ concentration in gas phase were systematically varied to determine optimal conditions. Results indicate favorable amoxicillin apparent removal efficacy under optimal conditions: a reaction time of 30 minutes, pH of 10, amoxicillin concentration of 50 ppm, and gas phase O₃ concentration of 833.3 mg/L, yielding an 89% apparent removal efficiency alongside reductions of 21.93% in COD and 43.03% in TOC during ozonation. Additionally, the O₃/H₂O₂ process was explored to enhance antibiotic removal efficiency. The H₂O₂ dose used was 0-0.3 g/L and maximum apparent removal efficiency of approximately 97% for amoxicillin with H₂O₂ volume of 4 mL (0.2 g/L) was achieved under optimal conditions of ozonation. Application of tert-butanol as radical scavenger confirmed the vital role of hydroxyl radicals in amoxicillin decomposition. Kinetic analysis revealed that both processes adhere to first-order kinetics. A cost analysis for these processes was performed to give an insight into the costs associated with these processes in large scale.