Orange peels biochar doping with Fe-Cu bimetal for PMS activation on the degradation of bisphenol A: A synergy of SO4−, OH, 1O2 and electron transfer

Recently, the usage of biomass wastes has attracted considerable attention, especially in water purification. Herein, the modified orange peels biochar with Fe-Cu bimetal (FeCu/OPB-1) was prepared by one-step carbonization for activating peroxymonosulfate (PMS) to remove bisphenol A (BPA). The prepared FeCu/OPB-1 could degrade 90% of BPA by activating PMS at pH 5.2–9.0. HCO3− could significantly enhance BPA degradation and reduce the amount of leached metal ions. SO4− and OH were produced on the surface of FeCu/OPB-1, and the catalytic process was demonstrated to take place primarily on the catalyst surface. One of the main reactive oxygen species (ROSs) identified was 1O2. Moreover, Fe-Cu bimetal and the C = O functional group on FeCu/OPB-1 accelerated the electronic migration in the activation process. Relying on the produced intermediates, three feasible degradation pathways were suggested. Besides, further insight into the use of OPB-based catalysts for the degradation of organic pollutants was hereby provided through the activation of PMS.