Photochemical Degradation of Perfluorocarboxylic Acids Induced by Ferric Ion: Effects of pH and Carbon Chain

CORC > 生态环境研究中心 > 中国科学院生态环境研究中心 > 环境化学与生态毒理学国家重点实验室

	Photochemical Degradation of Perfluorocarboxylic Acids Induced by Ferric Ion: Effects of pH and Carbon Chain
	Wang Yuan ; Shi Xiaoyuan
刊名	ACTA CHIMICA SINICA
	2014
卷号	72 期号:6 页码:682-688
关键词	perfluorooctanoic acid short-chain perfluorocarboxylic acid ferric ion UV light decomposition mechanism
ISSN号	0567-7351
中文摘要	Perfluorooctanoic acid (PFOA), as a typical perfluorinated compounds, is one kind of emerging persistent pollutants appearing in natural water. The existence of ferric ion in aquatic system improves the degradation of PFOA under the irradiation of 254 nm UV light. pH is an important factor for not only the distribution of photo activity species of ferric ion but also the degradation of PFOA. When the initial pH of reaction solution was 2.53, 3.04 and 3.71, respectively, PFOA was decomposed effectively and no obvious difference was observed whether for the degradation ratio of PFOA or for its corresponding defluorination ratio. On the contrary, when pH was 4.92 and 7.05, respectively, the degradation and defluorination of PFOA was inhibited markedly, which further confirmed that dissoluble iron played a key role in the decomposition of PFOA. And Fe(OH)(2+) was the dominant species of the hydroxy complexes of Fe3+. At the same time, the degradation of short chain PFCAs bearing C4 similar to C7 caused by ferric ions under the irradiation of 254 nm UV light was also investigated. As for PFCAs with C6 similar to C8, the degradation ratio at 240 min was as follows: PFOA>PFHpA>PFHxA, which showed that the longer the carbon chain was, the easier the degradation of PFCAs was. While, for PFCAs with the number of carbon element less than 6, their degradation ratio at 240 min was as follows: PFHxA>PFBA>PFPeA. The relationship between the degradation of PFCAs and the length of carbon chain of PFCAs was not clear. More short chain PFCAs were identified by LC/MS as the primary intermediates of these short chain PFCAs. Based on these, it was proposed that the degradation of PFCAs bearing C4 similar to C8 was mainly caused by the formation of complexes between ferric ion and PFCAs, and then hydroxyl radical formed from photolysis of Fe(OH)(2+) and the redox cycle of Fe2+/Fe3+ further improved their degradation. As a result, PFCAs were decomposed step by step.
WOS记录号	WOS:000339414100006
公开日期	2015-03-24
内容类型	期刊论文
源URL	[http://ir.rcees.ac.cn/handle/311016/9423]
专题	生态环境研究中心_环境化学与生态毒理学国家重点实验室
推荐引用方式 GB/T 7714	Wang Yuan,Shi Xiaoyuan. Photochemical Degradation of Perfluorocarboxylic Acids Induced by Ferric Ion: Effects of pH and Carbon Chain[J]. ACTA CHIMICA SINICA,2014,72(6):682-688.
APA	Wang Yuan,&Shi Xiaoyuan.(2014).Photochemical Degradation of Perfluorocarboxylic Acids Induced by Ferric Ion: Effects of pH and Carbon Chain.ACTA CHIMICA SINICA,72(6),682-688.
MLA	Wang Yuan,et al."Photochemical Degradation of Perfluorocarboxylic Acids Induced by Ferric Ion: Effects of pH and Carbon Chain".ACTA CHIMICA SINICA 72.6(2014):682-688.