College of Environmental Science and Engineering, Hunan University, Changsha, Hunan 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, Hunan 410082, China.
Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China; College of Environment and Ecology, Chongqing University, Chongqing 400045, China.
Sci Total Environ. 2022 Mar 10;811:151421. doi: 10.1016/j.scitotenv.2021.151421. Epub 2021 Nov 6.
The internal Fe/Fe cycle is important for peroxymonosulfate (PMS) activation by iron-based materials to produce the reactive oxidative species (ROS) for the breakdown of organic contaminants. Previous studies have focused on the contribution of heterogeneous sulfur species to the Fe/Fe cycle such as lattice S(-II) and surface SO of iron sulfides. In this study, we found that the dissolved S(-II) from mackinawite (FeS) had a substantial contribution to the Fe/Fe cycle. Furthermore, the oxidation intermediates of the dissolved S(-II) such as SO and SO ions could convert Fe to Fe in solution. The elimination of target organic pollutant bisphenol A (BPA) derived from PMS activation triggered by the dissolved Fe might be enhanced by the equivalent dissolved S(-II) in the FeS/PMS system. These results revealed that previous studies underestimated the significance of PMS activation by dissolved Fe of iron sulfides to organic pollutant degradation. Moreover, SO and •OH were more likely to be the main ROS for BPA degradation in the FeS/PMS system compared with FeO. Considering that the metal sulfides have been widely used to activate PMS, HO and peroxydisulfate, this study offers a new perspective on the function of sulfur in these advanced oxidation processes.
内的铁/铁循环对于铁基材料活化过一硫酸盐（PMS）以产生用于有机污染物分解的活性氧化物种（ROS）非常重要。先前的研究集中于非均相硫物种对铁/铁循环的贡献，例如晶格 S(-II)和铁硫化物的表面 SO。在这项研究中，我们发现来自磁黄铁矿（FeS）的溶解 S(-II)对铁/铁循环有很大的贡献。此外，溶解 S(-II)的氧化中间体，如 SO 和 SO 离子，可以将 Fe 转化为溶液中的 Fe。通过溶解的 Fe 触发的 PMS 活化所产生的目标有机污染物双酚 A (BPA)的消除可能会被 FeS/PMS 系统中的等效溶解 S(-II)增强。这些结果表明，先前的研究低估了溶解的铁硫化物的 PMS 活化对有机污染物降解的重要性。此外，与 FeO 相比，SO 和 •OH 更可能是 FeS/PMS 体系中 BPA 降解的主要 ROS。考虑到金属硫化物已被广泛用于活化过一硫酸盐、HO 和过二硫酸盐，本研究为这些高级氧化过程中硫的作用提供了新的视角。
