CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei, China; Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400044, China; College of Environment and Ecology, Chongqing University, Chongqing 400044, China.
CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei, China.
Water Res. 2021 Mar 1;191:116799. doi: 10.1016/j.watres.2020.116799. Epub 2020 Dec 30.
Peroxymonosulfate (PMS)-based advanced oxidation processes (AOPs) for wastewater treatment have recently attracted widespread interests. However, the degradation of organic pollutants via traditional radical-dominated pathway is severely limited by the side reactions between radicals and the co-existing inorganic anions, especially under high salinity conditions. Herein, an efficient Fe/O co-doped g-CNnanosheet catalyst was synthesized to dominantly activate PMS through a dual non-radical pathway with the singlet oxygen and high-valent iron-oxo species (Fe(V)=O). The rapid degradation of model pollutant bisphenol A (BPA) was achieved by dosing PMS (1 mM), catalyst (0.1 g/L) in a simulated high-salt wastewater (≥200 mM) of the developed Fe/O-doped g-CN+PMS system with a reaction rate constant of 1204-fold higher than that in g-CN+PMS system. The O and Fe co-dopants could reconfigurate the electronic structure of pristine g-CN to produce more non-radical active species. The formed Fe(V)=O played a main role in the BPA degradation by promoting electron transfer from BPA molecule to the "metastable PMS/catalyst complex", which was verified by electrochemical tests and density functional theory calculations. The auxiliary transient productions of ·OH+SO· species were also favorable for the pollutant degradation. Excellent reusability in a wide pH range confirmed the practical application prospects of the Fe/O-doped g-CN+PMS system. The successive addition of PMS with a low dosage into the system rich in pollutants was confirmed to favor the PMS utilization. Our work unveils the potential applications of a non-radical dominated process for the decontamination of organic pollutants in saline water.
基于过一硫酸盐（PMS）的高级氧化工艺（AOPs）最近引起了广泛关注。然而，通过传统的自由基主导途径降解有机污染物受到自由基与共存无机阴离子之间的副反应的严重限制，特别是在高盐条件下。在此，合成了一种高效的 Fe/O 共掺杂 g-CN 纳米片催化剂，通过单线态氧和高价铁氧物种（Fe(V)=O）的双重非自由基途径来主要激活 PMS。通过在模拟高盐废水中（≥200mM）投加 PMS（1mM）和催化剂（0.1g/L），在开发的 Fe/O 掺杂 g-CN+PMS 体系中，模型污染物双酚 A（BPA）的快速降解得以实现，其反应速率常数比 g-CN+PMS 体系高 1204 倍。O 和 Fe 共掺杂剂可以重新配置原始 g-CN 的电子结构，产生更多的非自由基活性物质。形成的 Fe(V)=O 通过促进从 BPA 分子到“亚稳 PMS/催化剂配合物”的电子转移，在 BPA 降解中起主要作用，这通过电化学测试和密度泛函理论计算得到了验证。·OH+SO·等辅助瞬态产物也有利于污染物降解。在宽 pH 范围内的优异可重复使用性证实了 Fe/O 掺杂 g-CN+PMS 体系的实际应用前景。确认连续向富含污染物的系统中添加低剂量的 PMS 有利于 PMS 的利用。我们的工作揭示了非自由基主导过程在含盐水中有机污染物净化方面的潜在应用。
