Catalyst bridging-mediated electron transfer for nonradical degradation of bisphenol A via natural manganese ore-cornstalk biochar composite activated peroxymonosulfate

Designing efficient, low-cost and eco-friendly catalysts is important for activating peroxymonosulfate (PMS) to remediate the water environment. Hence, two eco-friendly substances, natural manganese ore and agricultural waste cornstalks, were selected as raw materials to prepare biochar-based composite catalyst (MCC) for removing bisphenol A by activating PMS. Quenching studies, electron paramagnetic resonance analysis, and electrochemical measurements were used to elucidate the activation mechanism, indicating the nonradical pathway with catalyst bridging-mediated electron transfer resulted in BPA degradation. In addition, the loading of natural manganese ore in MCC greatly enhanced the electrochemical properties of biochar and improved the electron transfer capacity of the composite, thus promoting the degradation of pollutants. Peculiarly, the excellent degradation rate in actual water demonstrated that the MCC/PMS system was highly resistant to surrounding organic or inorganic compounds. Meanwhile, toxicology experiments also showed the extremely high practical application potential of the MCC/PMS system. Overall, the study developed a PMS activator with low cost, excellent performance and high practical potential, which gave a new direction for the application of natural minerals and agricultural waste.