الفهرس | Only 14 pages are availabe for public view |
Abstract The widespread use of pharmaceuticals and personal care products (PPCPs) inevitably leads to their accumulation in the aquatic environment, especially near the industrial areas inappropriate disposal or storage of PPCPs, specifically antibiotics and drugs, translates into their build-up in surface and ground waters. Among PPCPs, antibiotics are the most resistant compounds in conventional wastewater treatment plants, because of their antibacterial nature, which disrupt the activity of the bacteria responsible of the treatment process, Advanced oxidation processes (AOPs) have been recognized as promising methods for degradation of several pharmaceuticals. In this work, we investigate the activity of bimetallic copper/zero-valent iron nanoparticles (ZVI/Cu) as a heterogeneous Fenton-like catalyst for the degradation of sulfamethazine (SMZ). The characterization of the catalyst by XRD, TEM, and EDS confirmed the growth of Cu0 on the surface of the ZVI particles. Response surface methodology (RSM) coupled with a central composite design (CCD) optimized operating parameters such as pH, catalyst loading, hydrogen peroxide (H2O2) dose, and initial SMZ concentration. Under the optimum conditions, SMZ fell below the detection limit (0.036 mg/L) after 30 min of the reaction. The degradation mechanism revealed that hydroxyl radicals were the dominant oxidant species. However, the accumulated iron oxides on the shell of ZVI contributed to SMZ removal by adsorption. We propose a potential pathway for SMZ degradation based on the detected transformation products. This includes an early cleavage of the mediated sulfonamide group, which suggests an efficacious degradation into tentatively single-ring transformation compounds. |