Oxidative treatment of bisphenol A by Fe(VI) and Fe(VI)/H2O2 and identification of the degradation products
Fitri Widhiastuti, Linhua Fan, Jorge Paz‐Ferreiro, Ken Chiang
Abstract
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 1,000μg 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 (50μg 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]=2,500μg L−1), respectively. BPA degradation using Fe(VI)/H2O2was 99.8%, 85.3%, and 43.8% for an initial concentration of 50, 200, and 1,000μg 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− (350μg 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.