Optimization of Vancomycin Antibiotic Removal from Synthetic and Real Wastewaters Using UV/Fe۳O۴@Alg-ZnO nanocomposite Photocatalysis: Response Surface Methodology Based on Box-Behnken Design

AbstractBackground: Vancomycin (VCM) is a critical antibiotic due to its high consumption and side effects, including increased bacterialresistance affecting treatment processes. This research investigated the efficiency of VCM antibiotic removal from an aqueoussolution using a UV/Fe۳O۴@Alg-ZnO integrated process.Methods: Response surface methodology (RSM) and a Box-Behnken design were applied using Design-Expert software tooptimize the number of samples and simultaneously understand the interactive effects between variables. X-ray diffraction (XRD),a vibrating-sample magnetometer (VSM), field effect scanning electron microscopy (FE-SEM), and Fourier transform infrared(FTIR) analyses were used to check the structural characteristics. The effects of initial catalyst concentration (۰.۱, ۰.۳, and ۰.۵g/L), initial pollutant concentration (۱۰, ۳۰, and ۵۰ mg/L), contact time (۱۰, ۳۰, and ۵۰ minutes), and pH (۳, ۷, and ۱۱) on VCMdecomposition rate were investigated. Spectrophotometry, total organic carbon (TOC), and GC-MS analyses were used to checkthe efficiency of the process.Results: In this study, VCM and TOC removal efficiency was ۹۲.۶۴% and ۸۵.۳۸%, respectively, under optimal conditions. Thereason for the reduction in the efficiency of the combined UV/Fe۳O۴@Alg-ZnO process in real raw sewage, after activated sludge(۱۳%) and after activated sludge and stabilization ponds (۲۴%), is the high COD, which causes the active radicals produced tobe spent on other species instead of the VCM antibiotic.Conclusion: The current study showed that the UV/Fe۳O۴@Alg-ZnO process performs well in removing VCM and TOC. In realwastewater, this efficiency was significantly reduced.