Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States; Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee 37996, United States; Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States.
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
Water Res. 2023 May 15;235:119787. doi: 10.1016/j.watres.2023.119787. Epub 2023 Feb 23.
Bisphenol A (BPA) is a high production volume chemical with potential estrogenic effects susceptible to abiotic degradation by MnO. BPA transformation products and reaction mechanisms with MnO have been investigated, but detailed process understanding of Mn(III)-mediated degradation has not been attained. Rapid consumption of BPA occurred in batch reaction vessels with 1 mM Mn(III) and 63.9 ± 0.7% of 1.76 ± 0.02 μmol BPA was degraded in 1 hour at circumneutral pH. BPA was consumed at 1.86 ± 0.09-fold higher rates in vessels with synthetic MnO comprising approximately 13 mol% surface-associated Mn(III) versus surface-Mn(III)-free MnO, and 10-35% of BPA transformation could be attributed to Mn(III) during the initial 10-min reaction phase. High-resolution tandem mass spectrometry (HRMS/MS) analysis detected eight transformation intermediates in reactions with Mn(III), and quantum calculations proposed 14 BPA degradation products, nine of which had not been observed during MnO-mediated BPA degradation, suggesting mechanistic differences between Mn(III)- versus MnO-mediated BPA degradation. The findings demonstrate that both Mn(III) and Mn(IV) can effectively degrade BPA and indicate that surface-associated Mn(III) increases the reactivity of synthetic MnO, offering opportunities for engineering more reactive oxidized Mn species for BPA removal.
双酚 A（BPA）是一种高产量化学品，具有潜在的雌激素效应，容易被 MnO 进行非生物降解。已经研究了 BPA 转化产物和 MnO 的反应机制，但对 Mn(III)介导的降解的详细过程理解尚未达成。在具有 1 mM Mn(III)的批量反应容器中，BPA 迅速消耗，在近中性 pH 下 1 小时内降解了 1.76 ± 0.02 μmol BPA 的 63.9 ± 0.7%。在包含约 13 mol%表面结合的 Mn(III)的合成 MnO 与表面无 Mn(III)的 MnO 相比，BPA 的消耗速率高出 1.86 ± 0.09 倍，在最初的 10 分钟反应阶段，10-35%的 BPA 转化可归因于 Mn(III)。高分辨率串联质谱（HRMS/MS）分析在 Mn(III)反应中检测到 8 种转化中间体，量子计算提出了 14 种 BPA 降解产物，其中 9 种在 MnO 介导的 BPA 降解中未观察到，表明 Mn(III)与 MnO 介导的 BPA 降解之间存在机制差异。这些发现表明，Mn(III)和 Mn(IV)都可以有效地降解 BPA，并表明表面结合的 Mn(III)增加了合成 MnO 的反应性，为去除 BPA 提供了更具反应性的氧化 Mn 物种的工程机会。
