Photocatalytic Ozonation-Electroflucculation Process for the Treatment of Pharmaceutical Wastewater Using Modified Bentonite /UV/TiO<sub>2</sub>/ZnO

The study aims to investigate the effectiveness of photocatalyst (Clay/UV/TiO<sub>2</sub>/ZnO) for antibiotic removal from real pharmaceutical wastewater by Combined ultraviolet (UV), Catalytic Ozonation-Electroflucculation process. The experiments were performed in a modified hybrid batch reactor with UV-C lamp. The effect of four operational variables such as the applied voltage of (5-15 V), ozone dose of (0.2- 0.8 mg/min), pH (5-10), and catalyst dose (0.5- 1.5 g/L) on turbidity and Chemical oxygen demand (COD) removal was investigated. Removal efficiencies of antibiotics (carbamazepine and amoxicillin) were evaluated and compared with ozonation (O<sub>3</sub>), photocatalytic Ozonation (UV/O<sub>3</sub>), Electroflucculation (EF)/UV, catalytic ozonation/UV, and Hybrid O<sub>3</sub>/catalytic ozonation/UV/EF. The results showed that the modified hybrid process with UV irradiations provided the highest removal efficiency of 86.9% for COD, and turbidity of 81.66% under optimized conditions of (DC volts of 10 V; catalyst dose of 1 g/L, and ozone dose of 0.6 mg/min). The pharmaceuticals removal obtained for amoxicillin was 100% and 95% for carbamazepine. The detailed mechanism was also explored for better understanding of each process. The combined process was effective for treating pharmaceutical wastewater. Therefore, it was suggested that the novel photocatalyst and hybrid system can be used for treating real effluents in large scale and to meet (United nations) UN sustainability goals.