Catalytic ozonation for removal of antibiotic oxy-tetracycline using zinc oxide nanoparticles

Abstract

The traditional wastewater treatment plants are mostly not designed to deal with polar micropollutants such as pharmaceuticals. Therefore, antibiotics must be completely removed before their emission to ecosystems. Catalytic ozonation is used to increase the efficiency of sole ozonation further. In the present study, semi-batch experiments were conducted to investigate the efficiency of sole ozonation and catalytic ozonation in the degradation of oxy-tetracycline (OTC) as an environmental hazards contaminant in an aqueous solutions. Zinc oxide nanoparticles (ZnO) were used as a catalytic agent with ozone (ZnO/{mathrm{O}}_{3}). The influence of operational parameters such as pH (3–11), initial oxy-tetracycline concentration (10–100) mg/l, temperature (15–35)°C, ozone generation rate (0.138–1.38)mg/s and catalyst dosage (25–200) mg/l on the ZnO/{mathrm{O}}_{3} process was investigated. Ozone dosage was found to have the noticeable effect on the degradation process; however, the ZnO dosage was found to be less effective. The optimum condition was 1.38 mg/s at pH = 7, and after 35 min, a 94% of OTC removal was achieved. The results demonstrated that catalytic ozonation was a very effective method for degradation and mineralization of OTC in aqueous solution.