Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuang-qing Road, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuang-qing Road, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
Chemosphere. 2022 Dec;308(Pt 2):136321. doi: 10.1016/j.chemosphere.2022.136321. Epub 2022 Sep 6.
Permanganate (Mn(VII)) is a widely used oxidant in water treatment, which can oxidize trace organic contaminants (TrOCs) and Mn(II). Interestingly, this study found that presence of Mn(II) could accelerate the abatement of bisphenol A by Mn(VII) only under oxic condition. Herein, the effects of Mn(II) and dissolved oxygen (DO) on the abatement of TrOCs by Mn(VII) oxidation and the related mechanism were investigated. Results indicate that DO was involved in the Mn(VII)/Mn(II) reaction, with the reaction stoichiometry of Δ[Mn(VII)]:Δ[Mn(II)] determined to be 1:2 and 1:1.5 in the presence and absence of DO, respectively. Quenching and electron paramagnetic resonance tests verified that both superoxide radicals (O) and reactive Mn species contributed to the accelerated abatement of TrOCs (bisphenol A, methyl phenyl sulfoxide, and methyl phenyl sulfone) in the Mn(VII)/Mn(II) process. Specifically, O was produced through the one-electron reduction of DO and made an important contribution (32.4%-100%) to the abatement of selected TrOCs. This study reveals that Mn(II) could enhance TrOC abatement by Mn(VII) oxidation, and DO played a pivotal role in the Mn(VII)/Mn(II) process.
高锰酸盐（Mn(VII)）是一种广泛应用于水处理的氧化剂，可氧化痕量有机污染物（TrOCs）和 Mn(II)。有趣的是，本研究发现，只有在有氧条件下，Mn(II)的存在才能加速 Mn(VII)对双酚 A 的去除。本研究考察了 Mn(II)和溶解氧（DO）对 Mn(VII)氧化去除 TrOCs 的影响及其相关机制。结果表明，DO 参与了 Mn(VII)/Mn(II)反应，在有无 DO 的情况下，反应的化学计量比Δ[Mn(VII)]:Δ[Mn(II)]分别确定为 1:2 和 1:1.5。猝灭和电子顺磁共振测试验证了超氧自由基（O）和反应性 Mn 物种都有助于加速 Mn(VII)/Mn(II)过程中 TrOCs（双酚 A、甲基苯基亚砜和甲基苯基亚砜）的去除。具体而言，O 通过 DO 的单电子还原产生，对选定 TrOCs 的去除有重要贡献（32.4%-100%）。本研究揭示了 Mn(II)可增强 Mn(VII)氧化去除 TrOCs 的能力，而 DO 在 Mn(VII)/Mn(II)过程中起着关键作用。
