上海市市政污水中全氟有机酸污染特征

选择上海市9座市政污水处理厂(WWTPs)作为研究对象,检测其进水和出水中全氟有机酸(PFAs)污染水平.结果表明,市政污水中总PFAs浓度为903~4628ng/L,且中短链(C2~C10)全氟羧酸(PFCAs)的检出率一般高于长链(>C10)PFCAs,而对全氟烷基磺酸(PFSAs)而言,全氟辛磺酸(PFOS)的检出率远高于全氟丁磺酸(PFBS)和全氟己磺酸(PFHxS).三氟乙酸(TFA)一般是市政污水中污染水平最高的PFAs,浓度为359~4129ng/L,占总PFAs的20%~93%.尽管全氟辛酸(PFOA)和PFOS的浓度一般低于TFA,甚至在某些情况下还会低于其他PFAs,但在绝大多数情况下它们依然是2种主要的PFAs类污染物,浓度分别为40.6~1571ng/L和21.3~1027ng/L,分别占总PFAs的2%~57%和1%~30%.在污水处理过程中,短链(C2~C5)和长链(>C10)PFCAs浓度的显著下降,而中等链长(C6~C10)PFCAs和PFSAs浓度则显著增加.此外,PFAs浓度和工业废水比例之间并不存在明显的正相关关系.

Pollution profiles of perfluorinated acids in municipal sewage in Shanghai,China

Nine municipal wastewater treatment plants(WWTPs) located in Shanghai,China were selected for quantitative determination of perfluorinated acids(PFAs) in the influent and effluent.The total PFAs concentrations ranged from 903ng/L to 4628ng/L.The detection rates of short-and median-chain(C2-C10) perfluorocarboxylates(PFCAs) were generally higher than long-chain(>C10) PFCAs,while the detection rates of perfluorootanesulfonate(PFOS) were much higher than perfluorobutanesulfonate(PFBS) and perfluorohexanesulfonate(PFHxS).Trifluoroacetic acid(TFA) was generally the predominant PFAs in municipal sewages and its concentrations were in a range of 359~4129ng/L,accounted 20%~93% for the total PFAs.Although the levels of PFOA and PFOS were not only lower than TFA,but also lower than some the other PFAs in some individual cases,they were still the major pollutants in most cases and their concentrations were 40.6~1571ng/L and 21.3~1027ng/L,and they constituted 2%~57% and 1%~30% of the total PFAs,respectively.During wastewater treatment process,the concentrations of short-and long-chain PFCAs decreased significantly while median-chain PFCAs and PFSAs increased significantly.In addition,there was no obvious positive correlation between the PFAs concentrations in municipal sewages and the ratios of industrial wastewater in the influents of WWTPs.