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

The nanoFe(3)O(4)-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 center dot-) and hydroxyl radicals (center dot OH) was determined as the reactive species in the Fe3O4-BC/PMS system, and SO4(center dot-) 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.

Automated summary

The nanoFe(3)O(4)-biochar (Fe3O4-BC) heterogeneous catalyst showed a synergistic effect in the removal of BPA in the Fe3O4-BC/PMS system. Sulfate radical (SO4 center dot-) and hydroxyl radicals (center dot OH) were identified as the active species, with SO4(center dot-) being the major one, contributing to the efficient BPA removal. Fe3O4-BC exhibited high activity and reusability potential after five recycles, indicating practical applications.