Activation of peroxymonosulfate and recycled effluent filtration over cathode membrane CNFs-CoFe2O4/PVDF in a photocatalytic fuel cell for water pollution control

Few studies integrate catalytic membrane in photocatalytic fuel cell (PFC) with peroxymonosulfate (PMS) activation process. In the present work, a novel PFC-membrane reactor system integrating PMS activation (abbreviated as PMS/PFC-MR) was constructed for wastewater treatment, consisting of CNFs-CoFe2O4/PVDF membrane cathode (CNFs-CoFe2O4/PM) and Ag/ZnO NA/NiF photo-anode. The PMS/PFC-MR with enlarged volume exhibited favorable performance, increased berbine degradation by 65.9% and electricity production by 0.33 V, comparing with PFC-MR after 1 h operation. Relative to CNFs/PM (0.89 h−1) and PM (0.53 h−1), the PMS/PFC-MR with CNFs-CoFe2O4/PM had greatly enhanced rate constant (4.32 h−1). The results also indicate that recycled filtration over membrane accelerates catalytic degradation of organic pollutant in PMS/PFC-MR. Revealed by the radical quenching and EPR tests, hydroxyl radicals (OH), singlet oxygen (1O2), superoxide radical (O2−) and sulfate radicals (SO4−) were all confirmed present and responsible for pollutant degradation in PMS/PFC-MR. Consequently, the system expands the radical reactions to enhance degradation and electricity generation, due to the synergy of accelerated Co(II)/PMS oxidation with membrane filtration and photo-electro catalysis. This system provides a new efficient strategy towards wastewater treatment with energy recovery.