The mechanism changes during bisphenol A degradation in three iron functionalized biochar/peroxymonosulfate systems: The crucial roles of iron contents and graphitized carbon layers

Three magnetic biochar nanocomposites named as C800-1, C800-2 and C800-3 with increased iron deposition amount, decreased graphitized degree and gradually destroyed graphitized carbon layers, respectively, were prepared using potassium ferrate as activator and corn straw as biomass. C800-1, C800-2 and C800-3 exhibited much different bisphenol A degradation effect in presence of peroxymonosulfate among which C800-3 owned the best catalytic performance. For the degradation mechanism, the dominant role of electron transfer pathway was gradually replaced by the SO 4 •– pathway with the increase of iron amount and the destruction of graphitized carbon layers. This work would provide a simple and feasible method, namely changing the ratio of potassium ferrate and biochar, to manipulate the radical and nonradical degradation pathway in PMS-based organic wastewater purification.