A novel cost-effective flow-through electrode based on polyacrylonitrile carbon fiber for enhancing micropollutant degradation via electro-Fenton

Electrochemical filtration is an effective technology for treating the wastewater that containing low-concentration organic micropollutants. However, its practical application has been hindered by the lack of feasible flow-through electrodes. Herein, a physically assembled flow-through cathode, based on commercial polyacrylonitrile-based (PAN) carbon fiber (CF), was introduced in an electro-Fenton (EF) system. The conductive filtration element, created by coiling the FeOCl-functionalized CF onto a cylindrical support, exhibited effective and consistent degradation of diverse micropollutants (77.9–94.5 %, TOC: 32.4–50.5 %) after a single-pass filtration. The excellent two-electron (2 e−) oxygen reduction reaction (ORR) performance of PAN-CF, along with the enhanced mass transfer in the flow-through configuration, contributed to the pollutant degradation by generating considerable reactive oxygen species (ROSs, including H2O2 and •OH) and facilitating adequate contact between pollutants and ROSs. The integration of electrochemistry significantly improved the antifouling performance of the filter, making it promising for real wastewater treatment. Detailed calculations and comparisons further confirmed the cost advantages of the proposed flow-through electrodes. This study provides a unique solution for the design and fabrication of engineeringly and economically feasible flow-through electrodes in electrochemical filtration systems.