Activated peroxymonosulfate with ferric chloride-modified biochar to degrade bisphenol A: Characteristics, influencing factors, reaction mechanism and reuse performance

Water environment pollution caused by a large amount usage of bisphenol A (BPA) in industry has attracted widespread attention, since BPA may destroy the endocrine system of organisms and even the human body. Peroxymonosulfate (PMS) catalyzed by biochar (BC) for the removal of emerging pollutants (including BPA) from water body has entered the researcher's field of vision. A ferric chloride- modified rice husk BC was prepared via one pot method and characterized by BET, SEM, XPS, and Raman spectroscopy. A series of batch experiments were conducted to investigate the performance, influencing factors, and reaction mechanism of BC/PMS system for the degradation of BPA. The results showed that more than 97 % of BPA was removed with 1.0 g/L F2BC3 and 1.6 g/L PMS from the artificial solution containing 20 mg/L BPA within 150 min at different pH (3, 6, and 10); the degradation of BPA was not associated with humic acid (HA), was inhibited by HCO3−, NO3−, H2PO4−, and Cl− (at low concentration), and was promoted by Cl− (at high concentration) based on the concentration range set in this study; the removal rate of BPA by F2BC3/PMS decreased from 94.3 % to 84.8 % after four cycles of F2BC3, which meant stable performance was demonstrated. It could be confirmed that BPA was degraded into intermediates and final products H2O and CO2 via co-attack of major free radicals (SO4−, OH, and O2−) and minor non-radical 1O2. Therefore, F2BC3/PMS system could be considered as a potential process for the treatment of BPA.