State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
School of Municipal and Environmental Engineering, Jilin Jianzhu University, Changchun 130118, China.
Water Res. 2018 Oct 15;143:47-55. doi: 10.1016/j.watres.2018.06.029. Epub 2018 Jun 18.
In this work, transformation of bisphenol A (BPA) alternatives bisphenol AF (BPAF) and bisphenol S (BPS) by manganese dioxide (MnO) 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 MnO 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 MnO 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 MnO. Polymers, hydroxylated derivatives, and bond-cleavage products were detected from BPAF and BPS treated by MnO, 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 MnO 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.
本工作首次研究了二氧化锰（MnO）对双酚 A（BPA）替代品双酚 AF（BPAF）和双酚 S（BPS）的转化作用，以及碘化物（I）在此过程中的影响，并与 BPA 进行了对比。这三种双酚类化合物在 MnO 存在下表现出相当的反应活性，在相似条件下，它们的半衰期损失顺序为 BPA < BPAF < BPS，且在较低 pH 值下通常获得更高的转化效率。在 pH 值≤7 时，I 的存在明显加速了 MnO 对 BPAF 和 BPS 的转化，但在 pH 值为 5-9 范围内对 BPA 的转化影响可以忽略不计。这种差异可以很好地用 MnO 氧化 I 原位生成的次碘酸（HOI）的相对贡献来解释。在 MnO 处理的 BPAF 和 BPS 中检测到聚合物、羟基化衍生物和键断裂产物，其中可能涉及到 BPAF/BPS 自由基的一系列反应，类似于文献中报道的 BPA 情况。在 I 存在下，MnO 处理的 BPAF/BPS 中还鉴定出了一组碘代芳族产物（例如，碘代 BPAF/BPS 和碘代 BPAF/BPS 二聚体），它们可以进一步转化。本研究表明，天然存在的锰氧化物在环境中释放的双酚类化合物的衰减中起着重要作用，而 I 的存在可能对它们的转化产生很大的影响。
