Key Laboratory of Marine Environment and Ecology, Ministry of Education, Qingdao, 266100, China; College of Environmental Science and Engineering, Ocean University of China, Qingdao, 66100, China.
College of Environmental Science and Engineering, Ocean University of China, Qingdao, 66100, China.
Chemosphere. 2022 Sep;303(Pt 2):135132. doi: 10.1016/j.chemosphere.2022.135132. Epub 2022 May 25.
The oxidation performance of the zero-valent aluminum (ZVAl)/persulfate (PS) combined system had been studied by researchers in the past, which relied on the activation of PS by ZVAl to generate potent oxidizing radicals (•OH and SO) to degrade pollutants. However, ZVAl is a strong reductant and its reduction effect cannot be ignored. The reductive performance of the ZVAl/PS combined system is still unknown. Therefore, carbon tetrachloride (CT), an antioxidant organic pollutant, was selected as the target pollutant to test the reductive performance of the ZVAl/PS system in this study. We found a significant synergistic effect between ZVAl and PS, and the ZVAl/PS combined system could rapidly degrade CT in a wide pH range of 3-11 after an induction period. By SEM-EDS, TEM, XPS, and XRD analysis, it was found that PS could promote the corrosion of the oxide film on the ZVAl surface. The quenching experiment proved that PS could accept the electrons released from ZVAl to produce superoxide radical anion (O), which led to the degradation of CT rather than the oxidative process by •OH and SO. The hydrogen evolution experiment indicated that electronic reduction might play a secondary role in CT degradation. In conclusion, our study further explored the reductive performance of the ZVAl/PS combined system and expanded the pathway of CT degradation without any organic solvent addition, which provides a new strategy for the efficient degradation of refractory halogenated organic pollutants.
过去，研究人员研究了零价铝 (ZVAl)/过硫酸盐 (PS) 联合系统的氧化性能，该系统依赖于 ZVAl 对 PS 的激活来生成强效的氧化自由基 (•OH 和 SO) 以降解污染物。然而，ZVAl 是一种强还原剂，其还原效果不容忽视。ZVAl/PS 联合系统的还原性能仍不清楚。因此，本研究选择四氯化碳 (CT) 作为目标污染物，以测试 ZVAl/PS 系统的还原性能。我们发现 ZVAl 和 PS 之间存在显著的协同作用，ZVAl/PS 联合系统在诱导期后可以在 3-11 的宽 pH 范围内快速降解 CT。通过 SEM-EDS、TEM、XPS 和 XRD 分析，发现 PS 可以促进 ZVAl 表面氧化膜的腐蚀。淬灭实验证明 PS 可以接受 ZVAl 释放的电子来产生超氧自由基阴离子 (O)，这导致 CT 的降解而不是通过 •OH 和 SO 的氧化过程。析氢实验表明，电子还原可能在 CT 降解中起次要作用。总之，我们的研究进一步探索了 ZVAl/PS 联合系统的还原性能，并扩展了 CT 降解的途径，无需添加任何有机溶剂，为高效降解难处理卤代有机污染物提供了新策略。
