Photocatalytic oxidation of antibiotic residue and organic dye pollutant using noble metal-doped ZnO: Reducing environmental and health risks

Water pollution associated with antibiotic residues and colored organic pollutants leads to various potential risks to human health and the environment. This work develops an economical method that is suitable for removing both antibiotic residues and colored organic pollutants from water. The oxidation process based on a noble metal (Ag)-doped zinc oxide photocatalyst (Ag-ZnO) was selected as a potential strategy for investigation. Besides, tetracycline antibiotic residues (A-Tc) and methylene blue-colored organic pollutants (D-Mb) were selected as target contaminants. With light assistance, Ag-ZnO showed significantly improved degradation efficiency for A-Tc and D-Mb at 90.6 and 97.3%, respectively. The advantages of Ag-ZnO are also confirmed by the faster degradation rate constants, which are more than twice as fast as those of the undoped sample. The mineralization process shows that 93.5% and 98.7% of organic carbon were removed from the A-Tc and D-Mb solutions, respectively. The result suggests that antibiotic residues and colored organic pollutants are being converted into inorganic substances. In addition, the benefits of using Ag-ZnO to enhance human health safety, reduce the negative effects on the environment, and decrease treatment costs are discussed.