Catalytic ozonation process using ZnO/Fe2O3 nanocomposite for efficient removal of captopril from aqueous solution

The presence of pharmaceutical compounds in aqueous media, even in low concentrations, has caused adverse effects on human, animal, and environmental health. Captopril is a widely used pharmaceutical compound detected in the environment at different concentrations. Because of the concern and problems caused by the presence of captopril in water and the aquatic ecosystem, it appears necessary to remove it from the environment. The current study investigated captopril removal by a catalytic ozonation process using ZnO/Fe2O3 nanocomposite as a low-cost catalyst. The effects of variables such as ZnO/Fe2O3 nanocomposite dosage (0.5-2.5 g L-1), solution pH (3- 11), initial captopril concentration (10-70 mg L-1), and ozone dosage (0.2-1.5 mg min-1) on captopril removal were investigated. The removal captopril of 99.4% was obtained in the optimum condition, including ZnO/Fe2O3 nanocomposite dosage of 2.0 g L-1, solution pH of 5.0, initial captopril concentration of 40 mg L-1, and ozone dosage of 0.5 mg min-1. The ZnO/Fe2O3 nanocomposite as a catalyst was a critical component in the catalytic ozonation process. According to the obtained results, the catalytic ozonation process in the presence of ZnO/Fe2O3 nanocomposite has high efficiency in removing captopril from water sources.