The desulfurization by-product (e.g. sulfite) treatment and water pollution are two widespread concerns, while the sulfite activation by transition metals can be adopted to solve both of them simultaneously. In this study, a silica-supported cobalt catalyst (CoSi) was used to activate sulfite for the degradation of organic pollutants in an electrochemical system (the EC/CoSi/sulfite system), which demonstrated remarkable water treatment efficiencies due to sulfate radical oxidation. The synergy mechanisms of the EC/CoSi/sulfite system were revealed. (i) The as-prepared CoSi played the dual roles as an electro-adsorbent and a catalyst for sulfite activation. (ii) The electrolytic oxygenation supported the conversion of cobalt species and the chain reactions of oxysulfur radicals. (iii) The anodic oxidation of sulfite also generated oxysulfur radicals. The influencing factors and operating parameters were investigated and optimized systematically. Moreover, the efficient degradation of highly concentrated X-3B and non-selective oxidation of various organic compounds confirmed the promising application of the EC/CoSi/sulfite system in practical water treatment. Overall, the EC/CoSi/sulfite system created new value of the industrial waste (e.g. sulfite) for further application in the environmental remediation.

脱硫副产物（例如亚硫酸盐）处理和水污染是两个普遍关注的问题，而过渡金属对亚硫酸盐的活化可以同时解决。在这项研究中，使用二氧化硅负载的钴催化剂（CoSi）活化亚硫酸盐，以降解电化学系统（EC / CoSi /亚硫酸盐系统）中的有机污染物，由于硫酸根自由基的氧化，水处理效率显着提高。揭示了EC / CoSi /亚硫酸盐体系的协同作用机理。（i）所制备的CoSi充当电吸附剂和亚硫酸盐活化催化剂的双重作用。（ii）电解氧合支持钴的转化和氧硫自由基的链反应。（iii）亚硫酸盐的阳极氧化也产生了氧硫自由基。对影响因素和运行参数进行了系统的研究和优化。此外，高浓度X-3B的有效降解和各种有机化合物的非选择性氧化证实了EC / CoSi /亚硫酸盐体系在实际水处理中的应用前景。总体而言，EC / CoSi /亚硫酸盐系统为工业废料（例如亚硫酸盐）创造了新的价值，可进一步应用于环境修复。