Heterogeneous Fenton-like Photocatalytic Process towards the Eradication of Tetracycline under UV Irradiation: Mechanism Elucidation and Environmental Risk Analysis

Abstract

The problem of the deep elimination of antibiotics in environmental bodies is exceptionally warranted. In this work, a ternary nanocomposite of FeNi3/SiO2/CuS (FSC) was fabricated and then integrated with UV light irradiation and hydrogen peroxide as the heterogeneous Fenton-like photocatalytic system for the decomposition of tetracycline (TC) from aqueous media. During this process, various influencing parameters such as pH, catalyst dosage, initial content of TC, hydrogen peroxide (H2O2) dose, and operating time were explored. At optimized circumstances, i.e., 5 of pH, 10 mg/L of TC concentration, 150 mg/L of H2O2 dosage, and 200 min of degradation time, the elimination proportion of TC was 96%. The results of capture agent tests clarified that hydroxyl radical (HO•) played the predominant role in the photocatalytic decontamination of TC. Moreover, with the elevated contact time and content of H2O2, the efficiency of TC decontamination increased significantly. Additionally, the findings of the stability and reusability experiments of the fabricated nanocomposite showed that the percentage of TC removal decreased by only about 5% after six cycles. Furthermore, the photocatalytic mechanism of the decontamination of TC over the FSC photocatalyst was elucidated. Eventually, the non-carcinogenic risk analysis in the surface water sample was carried out using multiple photocatalytic processes for the first time. These outcomes obtained in this study validate that coupling the photocatalytic system and the H2O2 oxidation agent facilitates the elimination of a great variety of pharmaceutical contaminants from aqueous media.