Synergistic multiple active species for the degradation of sulfamethoxazole by peroxymonosulfate in the presence of CuO@FeOx@Fe0

In this study, bimetallic particles (CuO@FeO x @Fe 0 ) were prepared by displacement plating and calcination to activate peroxymonosulfate (PMS) for the degradation of sulfamethoxazole (SMX). First, the key preparation parameters (i.e., theoretical Cu mass loading (TML Cu ) and calcination temperature) of CuO@FeO x @Fe 0 preparation were investigated by single-factor experiments. Then the properties of CuO@FeO x @Fe 0 were analyzed by scanning electron microscope energy dispersive spectrometry (SEM-EDS), energy dispersive spectrometry mapping (EDS-mapping), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Subsequently, effects of PMS dosage, CuO@FeO x @Fe 0 dosage and initial pH on the degradation of sulfamethoxazole were studied respectively. Meanwhile, the results of control experiments indicated that the initial SMX degradation efficiency of CuO@FeO x @Fe 0 system was slower, but the final degradation rate was higher than that of Fe 0 /PMS system, which was due to the sustained release effect of Fe 2+ . In addition, the quantitative experiment of SO 4 − indicated that SO 4 − generated continuously in CuO@FeO x @Fe 0 /PMS system. Furthermore, the detection results of quenching tests and electron paramagnetic resonance (EPR) revealed the generation of multiple reactive oxygen species (i.e., SO 4 − , HO , O 2 − , 1 O 2 ) in CuO@FeO x @Fe 0 /PMS system, which degraded SMX synergistically. Finally, the SMX degradation pathways were proposed based on the intermediates detected by Liquid Chromatography-Quadrupole time of flight – Mass Spectrum (LC-QTOF-MS/MS) and the activation mechanism of CuO@FeO x @Fe 0 /PMS system was analyzed in detail. This study provided a new insight on the application of CuO@FeO x @Fe 0 on organic pollutant degradation.