Ultrahigh-efficiency mineralization of butyl xanthate via peroxydisulfate activation by carbon cobalt composite catalyst

Butyl xanthates (BX) are the most important agents utilized in the processing of metallic sulfide ores, and residual BX in beneficiation wastewater pollutes the mining environment. In this study, a cobalt carbon composite catalyst (Co@C800-1) was prepared to activate peroxydisulfate (PDS) for the degradation of BX, accompanied by a COD removal rate of up to 97.7% and an extremely high mineralization rate of 91.5%. After six cycles, Co@C800-1 still retained 96% of its catalytic performance. Moreover, this catalytic system demonstrated excellent degradation efficiency (>96 %) within a wide pH range (3–9) and exhibited good salt tolerance (SiO 3 2− and HCO 3 − ). Electron spin resonance analysis suggested that SO 4 − and OH are the main active species, while a small amount of 1 O 2 is present in the Co@C800–1/PDS system. The cobalt particles on the Co@C800-1 surface and the delocalized π-electrons from edge defects are the active sites for generating SO 4 − and OH. The C O groups on the Co@C800-1 surface are the active sites for producing 1 O 2 . Therefore, the synergistic effect of free radical and non-free radical reactions enables the Co@C800-1/PDS system to exhibit excellent degradation performance. The introduction of cobalt ions not only expedites the generation of SO 4 − and OH but also ensures the high stability of Co@C800-1 through cyclic reactions between cobalt ions. This provides a theoretical basis for the development of heterogeneous catalysts for BX degradation.