High efficiency removal OBS using a novel Fe-Co co-modified biochar activated peroxymonosulfate: Synergistic effects of Fe and Co

Fluorine-containing wastewater seriously threatens human health due to the wide application of sodium p -perfluorous nonenoxybenzenesulfonate (OBS). Herein, a novel Fe-Co bimetallic biochar (Fe-Co@BC) with abundant pore structure, functional groups and quickly electron transfer capability was prepared using hydrothermal method. Meanwhile, Fe-Co@BC-Ⅰ exhibited a superior catalytic capacity for degradation of OBS in PMS system, and the removal efficiency of OBS reached to 94.1 % within 60 min. After three cycles, the removal efficiency of OBS still up to 80 % and the Fe-Co had almost no leaching (Fe: 0.006 mg/L; Co: 0.023 mg/L). Further mechanistic insights were verified that high catalytic capacity and stability ascribed to the synergistic effects of Fe and Co, where Fe-Co mutual interaction promoted the formation of Fe 2+ and Co 2+ and accelerated electron transfer of catalyst. In addition, the quenching experiments and electron paramagnetic resonance (EPR) proved that the degradation of OBS can be mainly ascribed to indirect oxidation of SO 4 −• , O 2 −• and •OH, and the possible degradation pathway of OBS was proposed in the Fe-Co@BC/PMS system. This study provides an insight into bimetallic prepared and activation PMS degradation fluorinated wastewater.