Heterogeneous activation of persulfate by mechanically activated bentonite-based bismuth ferrite composites under visible light for ethyl xanthate degradation: Application performance and catalytic mechanism

In this work, under visible light irradiation, persulfate (PS) was activated by a mechanically activated bentonite-based bismuth ferrite composite (A-BiFe/Bent) to degrade ethyl xanthate (EX). The result showed that the as-prepared A-BiFe/Bent catalyst exhibited an excellent catalytic ability in the degradation of EX, and a removal ratio of 98.6% was achieved with 1.2 g/L catalyst and 6 mM PS under visible light irradiation at 90 min. According to experimental results and density functional theory calculation, the degradation pathways of EX and possible reaction mechanisms were proposed. Furthermore, the effective degradation of EX in the activated system of PS catalyzed by A-BiFe/Bent under visible light irradiation was confirmed by Chemical oxygen demand test, Fourier transform infrared spectrometry characterization and Toxicity test. The A-BiFe/Bent exhibited high stability and good reusability in use. This study provided a potential approach of A-BiFe/Bent as a photocatalyst combined with PS for the treatment of flotation wastewater. • The Vis-A-BiFe/Bent/PS system has high activity to degrade ethyl xanthate (EX). • The degradation pathways of EX is proposed after DFT calculation and LC-MS. • The mechanism of Vis-A-BiFe/Bent/PS system is analyzed. • The catalyst exhibits high stability and good reusability in the used system.