Rapid photochemical decomposition of perfluorooctanoic acid mediated by a comprehensive effect of nitrogen dioxide radicals and Fe3(+/)Fe(2+) redox cycle
Rapid photochemical decomposition of perfluorooctanoic acid mediated by a comprehensive effect of nitrogen dioxide radicals and Fe3(+/)Fe(2+) redox cycle
复制标题
二氧化氮自由基和Fe3(/)Fe(2)氧化还原循环综合作用介导全氟辛酸快速光化学分解
DOI：
10.1016/j.jhazmat.2019.121730
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发表时间：
2020
影响因子：
13.6
通讯作者：
Gong Jingming
中科院分区：
文献类型：
--
作者：
Yuan Yijin;Feng Lizhen;Xie Ning;Zhang Lizhi;Gong Jingming
由于全氟化合物（PFCs）的持久性、高毒性和对大多数常规处理程序的抗性，近年来迫切需要开发有效的方法来降解PFCs，这是一类新兴的高度难降解的污染物。本文报道了一种通过紫外光照射硝酸铁水溶液高效矿化全氟辛酸（PFOA）的体系，其中原位生成·NO2和有效的Fe3 +/Fe2+氧化还原循环协同作用对PFOA的快速矿化起着重要的介导作用。在PFOA初始浓度为5 ppm（50 mL体积）时，观察到快速的PFOA去除动力学，一级动力学常数为2.262 h − 1，仅在0.5小时照射内就达到约92%的去除效率。接近化学计量的氟离子释放和高的总有机碳（TOC）去除效率（> 100%）进一步验证了完全破坏性去除PFOA的能力。提出了PFOA降解的初步途径。本研究通过紫外光降解自然环境中大量存在的铁/硝酸盐体系，为全氟化学品的完全矿化提供了一种经济、可持续和高效的方法。
Developing efficient methods to degrade perfluorochemicals (PFCs), an emerging class of highly recalcitrant contaminants, are urgently needed in recent years, due to their persistence, high toxicity, and resistance to most regular treatment procedures. Here, a UV-photolysis system is reported for efficient mineralization of perfluorooctanoic acid (PFOA) via irradiation of ferric nitrate aqueous solution, where in-situ generating •NO2and the effective Fe3+/Fe2+redox cycle synergistically play great roles on rapidly mediating the mineralization of PFOA. A fast PFOA removal kinetics with first-order kinetic constants of 2.262 h−1is observed at initial PFOA concentration of 5 ppm (50 mL volume), reaching ∼ 92 % removal efficiency within only 0.5-h irradiation. Near-stoichiometric fluoride ions liberation and high total organic carbon (TOC) removal efficiency (∼100 %) further validated the capability for completely destructive removal of PFOA. A tentative pathway for PFOA destruction is proposed. This work, by UV photolysis of abundant existing iron/nitrate-based systems in natural environment, provides an economical, sustainable and highly efficient approach for complete mineralization of perfluorinated chemicals.