Transformation of bisphenol AF and bisphenol S by manganese dioxide and effect of iodide

• Published in: Water research (Oxford) Vol. 143; pp. 47 - 55
• Main Authors: Li, Juan, Pang, Su–Yan, Zhou, Yang, Sun, Shaofang, Wang, Lihong, Wang, Zhen, Gao, Yuan, Yang, Yi, Jiang, Jin
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15.10.2018
• Subjects: Bisphenol AF (BPAF); Bisphenol S (BPS); Bisphenols; Iodide (I−); Iodinated aromatic products; Manganese dioxide (MnO2); Iodinated aromatic products; Iodide (I−); Bisphenol S (BPS); Manganese dioxide (MnO2); Bisphenols; Bisphenol AF (BPAF); Iodide (I(−)); Manganese dioxide (MnO)
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2018.06.029

In this work, transformation of bisphenol A (BPA) alternatives bisphenol AF (BPAF) and bisphenol S (BPS) by manganese dioxide (MnO2) and the effect of iodide (I−) during these processes were investigated in comparison with BPA for the first time. These three bisphenols showed appreciable reactivity towards MnO2 with the half-lives of their loss following the order of BPA < BPAF < BPS under similar conditions, and a higher transformation efficiency was generally obtained at a lower pH. The presence of I− apparently accelerated the transformation of BPAF and BPS by MnO2 at pH ≤ 7 but negligibly affected BPA transformation over the pH range of 5–9. This discrepancy could be well explained by the relative contribution of hypoiodous acid (HOI) in situ formed from I− oxidation by MnO2. Polymers, hydroxylated derivatives, and bond-cleavage products were detected from BPAF and BPS treated by MnO2, where a series of reactions of BPAF/BPS radicals formed from one-electron oxidation of BPAF/BPS were likely involved, similar to the case of BPA reported in literature. A group of iodinated aromatic products were additionally identified from BPAF/BPS treated by MnO2 in the presence of I− (e.g., iodinated BPAF/BPS and iodinated BPAF/BPS dimers), and they could be further transformed. This study suggests that naturally occurring manganese oxides play a significant role in the attenuation of bisphenols released into the environment and the presence of I− can display a great effect on their transformation. [Display omitted] •MnO2 showed considerable reactivity towards bisphenols following the order of BPA > BPAF > BPS.•I− significantly enhanced the transformation of BPAF and BPS by MnO2 at pH ≤ 7.•Polymeric, hydroxylated, and bond-cleavage products were detected from BPAF/BPS treated by MnO2.•Iodinated aromatic products were generated from MnO2/BPAF(BPS)/I− systems.