Preparation of Fe-Cu bimetal from copper slag by carbothermic reduction–magnetic process for activating persulfate to degrade bisphenol A

Abstract

BackgroundFe-Cu bimetal (Fe-Cu) was prepared from copper slag via a carbothermic reduction–magnetic separation process, and used as persulfate (PS) activator to degrade bisphenol A (BPA). MethodsThe characteristic of Fe-Cu was detected by XRD, SEM-EDS, and XPS. Significant findingsThe Fe-Cu is mainly composed of copper containing metallic iron, iron containing metallic copper, and copper-iron sulfide. The batch experiments results showed that the Fe-Cu offered highly effective BPA removal up to 400 mg/g in the presence of PS within 60 min, and the degradation of total organic carbon was 72.32% under optimal conditions, which proved that Fe-Cu is a highly active PS activator. Electron paramagnetic resonance and radical scavenging experiments showed that sulfate radical (SO4•−) and hydroxyl radical contributed to the degradation of BPA, and SO4•− was dominant. The reuse experiments showed that the degradation efficiency of BPA was still as high as 96.92% after the fourth use. Moreover, the possible BPA degradation pathway was proposed on the basis of intermediates analyzed by gas chromatography–mass spectrometry. This study offers a novel idea for preparing Fe-Cu and suggests that the Fe-Cu/PS system has good potential for removing refractory organic pollutants in wastewater.