Synergistic catalysis by Fe3O4-biochar/peroxymonosulfate system for the removal of bisphenol a

The nanoFe3O4-biochar (Fe3O4-BC) heterogeneous catalyst was synthesized by coprecipitation method and the mechanism of Fe3O4-BC/peroxymonosulfate (Fe3O4-BC/PMS) system adsorption and synergistic catalysis for the removal of bisphenol A (BPA) were studied. The effect of initial pH, Fe3O4-BC load, PMS concentration on the catalyst activity were systematically evaluated. The results showed the synergistic effect between BC and Fe3O4 can greatly improve the removal efficiency of BPA in the Fe3O4-BC/PMS system. BPA removal efficiency gained 100% in 90 min at pH 3.0 with PMS 5 mM, Fe3O4-BC load 2.0 g/L and BPA 20 mg/L. Sulfate radical (SO4•−) and hydroxyl radicals (•OH) was determined as the reactive species in the Fe3O4-BC/PMS system, and SO4•− was the major reactive species. Fe3O4-BC remained high active and the iron loss was only 2.13 mg/L when the pH was 3.0 after five recycles, which indicates that Fe3O4-BC catalyst has a good reusability potential and practical applications.