The Performance of Cu Doped Feocl as a Heterogeneous Fenton Catalyst for the Efficient Degradation of Tetracycline

Abstract

Due to their significant need for external energy excitation, possible transition-metal pollution, and limited pH range, Fenton-like catalysts are currently limited in wastewater treatment. To overcome these deficiencies, this study has evaluated the performance of Cu@FeOCl composites, which were firstly synthesized by high temperature calcination of ferric chloride and copper chloride, and used as a novel peroxymonosulfate (PMS) activator for antibiotic removal. It was found that the Cu@FeOCl composite calcined at 220 °C, with a molar ratio of copper at 1%, exhibited an excellent catalytic ability for tetracycline (TC) degradation at neutral pH without any external energy input. More than 80% of TC (Co = 20 mg/L) could be degraded within 30 min by the Cu@FeOCl composite. The variation of catalytic performance with various parameters, including the doping ratio of copper, TC dose, oxidizing agent dose, pH value and temperature, was evaluated. In addition, electron spin-resonance spectroscopy (ESR) tests were employed for the identification of the reactive oxygen species (ROS) in the system. Based on the experimental results, it was demonstrated that the Cu@FeOCl activated H2O2/PMS and produced minor hydroxyl radicals (˙OH) and superoxide radicals (˙O2-), thereby enhancing TC degradation.

Keywords: wastewater treatment, oxidation catalyst, Cu@FeOCl, Fenton-like, Tetracycline degradation, Free radical reaction