Oxidative treatment of bisphenol A by Fe(VI) and Fe(VI)/H2O2 and identification of the degradation products

Bisphenol A (BPA) is classified as a xenoestrogen compound and has caused adverse effects in humans and animals. Ferrate(VI) (Fe(VI)) and the combination of Fe(VI) and hydrogen peroxide (H2O2) were investigated to degrade BPA in water. This study evaluated the impact of BPA initial concentration (50, 200, and 1,000 mu g L-1) and background anions (Cl- , PO43- , and NO3-) on the degradation efficiency of the combined oxidants. The results showed that Fe(VI)/H2O2 performed significantly better than Fe(VI) or H2O2 alone. BPA degradation (50 mu g L-1) using Fe(VI)/H2O2 was recorded at 99.8% within 60 min at pH 8.0 with [Fe(VI)]/[H2O2] molar concentration ratio of 250:2,500. At the same initial concentration of BPA and pH condition, the degradation of BPA using Fe(VI) and H2O2 was recorded as 89% ([Fe(VI)]/[BPA]=5) and 33.5% ([H2O2]=2,500 mu g L-1), respectively. BPA degradation using Fe(VI)/H(2)O(2 )was 99.8%, 85.3%, and 43.8% for an initial concentration of 50, 200, and 1,000 mu g L-1 , respectively. The presence of Cl- and NO3- ions had no obvious effects on BPA degradation; however, a considerable reduction in the degradation efficiency was observed for PO43- (350 mu g L-1) due to the complexation between PO43- ion and ferric oxy/hydroxides. There were eleven intermediates detected in BPA degradation using Fe(VI)/H2O2 , and three degradation pathways were proposed, including hydroxylation, cleavage of the C-C bond, and oxidation to form ring opening products. A reduction in ecotoxicity was observed after 60 min of reaction for both Fe(VI) and Fe(VI)/H2O2.(C) 2022 The Author(s). Published by Elsevier B.V.

Automated summary

In water, Fe(VI)/H2O2 showed significantly better degradation of BPA compared to Fe(VI) or H2O2 alone. The initial concentration of BPA and background anions had an impact on the degradation efficiency of the combined oxidants, with Cl- and NO3- ions showing no significant effect on BPA degradation, while PO43- ions significantly reducing the efficiency. Three degradation pathways were proposed, and a reduction in ecotoxicity was observed after 60 minutes of reaction for both Fe(VI) and Fe(VI)/H2O2.