Nitrogen dioxide radicals mediated mineralization of perfluorooctanoic acid in aqueous nitrate solution with UV irradiation
Nitrogen dioxide radicals mediated mineralization of perfluorooctanoic acid in aqueous nitrate solution with UV irradiation
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紫外线照射下二氧化氮自由基介导硝酸盐水溶液中全氟辛酸的矿化
DOI：
10.1016/j.chemosphere.2017.08.170
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发表时间：
2017
期刊：
影响因子：
8.8
通讯作者：
Gong Jingming
中科院分区：
文献类型：
--
作者：
Li Aimin;Zhang Zhe;Li Peifeng;Cai Lejuan;Zhang Lizhi;Gong Jingming
由于全氟辛酸（PFOA）在全球范围内的存在和对大多数常规处理工艺的抗性，其有效分解近年来受到越来越多的关注。在这项研究中，PFOA的完全矿化是通过紫外光分解的硝酸盐水溶液（UV/Nitrate），其中原位产生的二氧化氮自由基（radical dotNO 2）有效地介导了PFOA的降解。特别是当双胞胎羟基自由基被清除后，更多的dotNO 2自由基的产生实现了PFOA的完全矿化。DFT计算进一步证实了自由基dotNO 2去除PFOA的可行性。在PEOA分解后，在溶液中检测到了近化学计量当量的氟化物释放，而不是相关的中间体，进一步证明了PFOA的完全降解。根据实验结果提出了PFOA可能的降解途径。这项工作提供了一个有效的策略，完全矿化的全氟化学品，也揭示了不可或缺的作用，二氧化氮自由基的环境污染物的去除。
Effective decomposition of perfluorooctanoic acid (PFOA) has received increasing attention in recent years because of its global occurrence and resistance to most conventional treatment processes. In this study, the complete mineralization of PFOA was achieved by the UV-photolysis of nitrate aqueous solution (UV/Nitrate), where the in-situ generated nitrogen dioxide radicals (radical dotNO2) efficiently mediated the degradation of PFOA. In particular, when the twinborn hydroxyl radicals were scavenged, the production of more radical dotNO2radicals realized the complete mineralization of PFOA. DFT calculations further confirm the feasibility of PFOA removal with radical dotNO2. Near-stoichiometric equivalents of fluoride released rather than the related intermediates were detected in solution after decomposition of PEOA, further demonstrating the complete degradation of PFOA. Possible PFOA degradation pathways were proposed on the basis of experimental results. This work offers an efficient strategy for the complete mineralization of perfluorinated chemicals, and also sheds light on the indispensable roles of nitrogen dioxide radicals for environmental pollutants removal.