Enhanced antibiotic mineralization and detoxification through photoregeneration of FeOCl surface active site

The in-depth mineralization and detoxification of trace antibiotics in water by advanced oxidation process (AOPs) is crucial for its industrial application. In this work, deep mineralization and detoxification of antibiotics are achieved through FeOCl/H2O2/Vis system, and regeneration mechanism of light-induced electron transfer surface active sites has been proposed. The system can degrade multitudinous antibiotics and increase mineralization rate by 3–10 times. Toxicity of treated wastewater decreases sharply, allowing bacteria to survive normally. Mechanistic studies show that intermediates containing carboxyl groups formed by free radical oxidation complex with Fe(Ⅲ) on surface of FeOCl, thereby hindering Fe(Ⅲ)/Fe(Ⅱ) cycle and further mineralization of antibiotics. While electron transfer occurs between catalyst and intermediates through visible light irradiation, breaking though oxidation of intermediates and reduction of Fe(Ⅲ), and Fe(Ⅲ)/Fe(Ⅱ) ratio decreases from 2.57 to 1.5. This work provides a promising strategy for solving the problems of low mineralization and difficult detoxification of antibiotics by AOPs.