Highly efficient removal of bisphenol A by a novel Co-doped LaFeO₃ perovskite/PMS system in salinity water

Although it can effectively degrade refractory organic pollutants, advanced oxidation processes (AOPs) can be seriously interfered with the co-existing substance in salinity water. Herein, three-dimensional hierarchical cobalt-doped LaFeO₃ perovskites (LaCo_0.5Fe_0.5O₃) micron spheres composed of nano-rods were hydrothermally synthesized and applied to activate peroxymonosulfate (PMS) for degrading bisphenol A (BPA). Nearly 100% BPA was removed by LaCo_0.5Fe_0.5O₃/PMS system in presence of more than 50 mM Cl^- within only 2 min compared that of 30 min without Cl^-, which was attributed to reactive chlorine species (RCS) including Cl^• and HOCl with higher oxidation capacity. •OH and SO₄^•- produced by LaCo_0.5Fe_0.5O₃ activating PMS played crucial roles as the source of RCS in LaCo_0.5Fe_0.5O₃/Cl^-/PMS system. The synergistic effect between ROS and RCS promoted by the enhanced oxygen vacancies and the efficient redox recycling of Fe^III/Fe^II and Co^III/Co^II. Other anions like SO₄^2- and NO₃^- hardly affected the BPA degradation. BPA degradation efficiency was also improved either in a wide pH range or in the presence of natural organic matters in salty water. This work also demonstrated the potential application of FeCo bimetallic LaCo_0.5Fe_0.5O₃ activating PMS system for degradation of BPA or other organic micropollutants in seawater system.