State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China.
Environ Sci Technol. 2021 Nov 16;55(22):15390-15399. doi: 10.1021/acs.est.1c04563. Epub 2021 Nov 3.
The iron(II)-activated peroxymonosulfate [Fe(II)/PMS] process is effective in degrading organic contaminants with a rapid oxidation stage followed by a slow one. Nevertheless, prior studies have greatly underestimated the degradation rates of organic contaminants in the rapid oxidation stage and ignored the differences in the kinetics and mechanism of organic contaminants degradation in these two oxidation stages. In this work, we investigated the kinetics and mechanisms of organic contaminants in this process under acidic conditions by combining the stopped-flow spectrophotometric method and batch experiments. The organic contaminants were rapidly oxidized with rate constants of 0.18-2.9 s in the rapid oxidation stage. Meanwhile, both Fe(IV) and SO were active oxidants and contributed differently to the degradation of different organic contaminants in this stage. Additionally, the presence of Cl promoted the degradation of both phenol and estradiol but the effects of Br and humic acid on phenol degradation differed from those on estradiol degradation in the rapid oxidation stage. In contrast, the degradation of phenol and estradiol was slow and the amounts of Fe(IV) and SO generated were small in the slow oxidation stage. This work updates the fundamental understanding of the degradation of organic contaminants in this process.
亚铁激活过一硫酸盐（Fe(II)/PMS）工艺在降解有机污染物方面非常有效，具有快速氧化阶段和缓慢氧化阶段。然而，先前的研究大大低估了有机污染物在快速氧化阶段的降解速率，并且忽略了这两个氧化阶段中有机污染物降解的动力学和机制的差异。在这项工作中，我们通过结合停流分光光度法和批量实验，在酸性条件下研究了该过程中有机污染物的动力学和机制。在快速氧化阶段，有机污染物迅速被氧化，速率常数为 0.18-2.9 s。同时，Fe(IV)和 SO 都是活性氧化剂，在该阶段对不同有机污染物的降解贡献不同。此外，Cl 的存在促进了苯酚和雌二醇的降解，但 Br 和腐殖酸对苯酚降解的影响与对雌二醇降解的影响不同。相比之下，在缓慢氧化阶段，苯酚和雌二醇的降解速度较慢，生成的 Fe(IV)和 SO 的量较小。这项工作更新了对该过程中有机污染物降解的基本认识。
