Enhanced degradation of emerging contaminants by permanganate/quinone process: Case study with bisphenol A.
Enhanced degradation of emerging contaminants by permanganate/quinone process: Case study with bisphenol A.
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DOI：
10.1016/j.watres.2022.118528
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发表时间：
2022-05
期刊：
影响因子：
12.8
通讯作者：
Zheng-Yu Dong;Yi-Li Lin;Tian-Yang Zhang;Chen-yan Hu;Yang Pan;Zheng-Xiong Zheng-Zheng-Xiong-Zheng-2149098385;Yu-Lin Tang;Bin Xu-B
中科院分区：
文献类型：
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作者：
Zheng-Yu Dong;Yi-Li Lin;Tian-Yang Zhang;Chen-yan Hu;Yang Pan;Zheng-Xiong Zheng-Zheng-Xiong-Zheng-2149098385;Yu-Lin Tang;Bin Xu-B
高锰酸盐在水处理中作为一种温和的氧化剂被广泛使用。然而，一些新出现的污染物与Mn(VI)的反应速率极低。在本研究中，作为氧化还原介质的苯二酚(BQ)是溶解有机物(DOM)的重要组成部分，在较宽的pH范围(4.0-10.0)内，它促进了Mn(VII)对双酚A(BPA)的氧化。BQ的氧化还原循环会产生半醌自由基，它可以作为配体稳定体系中形成的Mn(III)，从而促进BPA的氧化。值得注意的是，BQ的存在可能促进了MnO2的形成。提出了单线态氧(1O2)、Mn(III)-配体(Mn(III)-L)和原位生成的MnO2是加速双酚A降解的新机理。在酸性条件下，原位生成的MnO2参与了氧化还原反应，部分Mn(IV)被还原为Mn(III)，说明BQ的电子转移促进了活性Mn物种的形成，提高了Mn(VII)的氧化性能。BQ变换产生的半醌自由基与双酚A的氢取代产物偶联，抑制了双酚A的自偶联，促进了双酚A的开环反应。Mn(VI)/BQ在原水中的处理效果好于在纯水中的处理效果，表明该体系具有较高的实际应用潜力。这项研究为DOM在水处理中促进Mn(VII)氧化的作用提供了见解。
Permanganate (Mn(VII)) is widely used as a mild oxidant in water treatment. However, the reaction rates of some emerging contaminants with Mn(VII) are extremely low. In this study, benzoquinone (BQ), a redox mediator with the important component in dissolved organic matter (DOM), enhanced the oxidation of bisphenol A (BPA) by Mn(VII) in a wide pH range of 4.0-10.0. The redox cycle of BQ would produce semiquinone radicals, which could act as ligands to stabilize the formed Mn(III) in the system to promote the oxidation of BPA. Notably, the presence of BQ might promote the formation of MnO2. A novel mechanism was proposed that singlet oxygen (1O2), Mn(III)-ligands (Mn(III)-L) andin-situformed MnO2were the main contributors to accelerate BPA degradation in the Mn(VII)/BQ system. Under acidic conditions, thein-situformed MnO2involved in the redox reaction and part of the Mn(IV) was reduced to Mn(III), indicating that the electron transfer of BQ promoted the formation of active Mn species and enhanced the Mn(VII) oxidation performance. Semiquinone radicals generated by BQ transformation would couple with the hydrogen substitution products of BPA to inhibit BPA self-coupling and promote the ring-opening reactions of BPA. Mn(VII)/BQ had better effect in raw water than in pure water, indicating that the Mn(VII)/BQ system has high potential for practical application. This study provided insights into the role of DOM in enhancing the Mn(VII) oxidation in water treatment.