Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, PR China; State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China.
Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan, Guangdong 523808, PR China.
Sci Total Environ. 2021 Mar 1;758:143666. doi: 10.1016/j.scitotenv.2020.143666. Epub 2020 Nov 20.
The decomposition of long-chain perfluorocarboxylic acids (PFCAs), including perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA), were investigated by electrochemical activation of peroxymonosulfate (PMS) on porous Ti/SnO-Sb membrane anode. The results indicated that PMS activation could efficiently promote PFNA/PFDA decomposition, with pseudo-first-order rate constants about 3.12/2.06 times as compared with that of direct electro-oxidations. The energy consumptions of PFNA and PFDA decomposition were 36.31 and 37.46 kWh·m·order, respectively. The quantitative detection results of •OH with electron paramagnetic resonance (EPR) demonstrated that PMS activation promoted •OH formation. The inhibited performance in radical scavengers indicated both •OH and SO might be mainly involved in PFNA decomposition, while SO might be mainly involved in PFDA decomposition during PMS activation process. The mineralization mechanism for long-chain PFCAs decomposition which was mainly by repeating CF-unzipping cycle via radical reaction based on the intermediates verification and mass balance of C and F, was proposed. These results suggested that electrochemical activation of PMS on porous Ti/SnO-Sb membrane anode exhibited high efficiency in mineralizing PFNA and PFDA under mild conditions. This work might provide an efficient way for persistent organic pollutants, including, but not limited to long-chain PFCAs elimination from wastewater.
通过在多孔 Ti/SnO-Sb 膜阳极上电化学激活过一硫酸盐 (PMS)，研究了长链全氟羧酸 (PFCAs)，包括全氟壬酸 (PFNA) 和全氟癸酸 (PFDA) 的分解。结果表明，PMS 激活可以有效地促进 PFNA/PFDA 分解，其假一级速率常数分别比直接电氧化高约 3.12/2.06 倍。PFNA 和 PFDA 分解的能量消耗分别为 36.31 和 37.46 kWh·m·order。电子顺磁共振 (EPR) 对 •OH 的定量检测结果表明，PMS 激活促进了 •OH 的形成。自由基清除剂的抑制性能表明，在 PMS 激活过程中，•OH 和 SO 可能主要参与 PFNA 的分解，而 SO 可能主要参与 PFDA 的分解。基于中间产物验证和 C 和 F 的质量平衡，提出了长链 PFCAs 分解的矿化机理，主要是通过自由基反应重复 CF 解拉链循环。这些结果表明，在温和条件下，多孔 Ti/SnO-Sb 膜阳极上的 PMS 电化学激活在矿化 PFNA 和 PFDA 方面表现出高效率。这项工作可能为包括长链 PFCAs 在内的持久性有机污染物的消除提供一种有效的方法，从废水中去除，但不限于长链 PFCAs。
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