Efficient degradation of tetracycline by H2O2 catalyzed by FeOCl: A wide range of pH values from 3 to 7

Iron Oxychloride (FeOCl) was prepared by partial thermal decomposition and was studied as a heterogeneous Fenton catalyst to degrade tetracycline (TC). SEM, XRD , XPS technology were used to characterize its performance. The influencing factors of TC degradation efficiency were studied, including pH value, H 2 O 2 content, catalyst dosage and initial TC concentration. The results showed that under the optimal conditions, the degradation rate of 60 mg L −1  TC reached 92.9% within 60 min of reaction. The degradation process follows a second-order kinetic equation. Compared with other iron-based catalysts, FeOCl exhibited better catalytic and degradation effects. Moreover, FeOCl/H 2 O 2 system exhibited a wide pH range (from 3.0 to 7.0) for efficient degradation of TC and showed excellent stability and reusability. Meanwhile, based on the intermediates identified by HPLC-MS, two possible pathways for the degradation of TC were proposed. Further, the results of electron spin-resonance spectroscopy and radical quenching tests suggested that the ·OH formed in the FeOCl/H 2 O 2 system was mainly responsible for the degradation of TC.