3种微藻对全氟烷基化合物的生物富集效应

摘要

Perfluoroalkyl substances (PFASs) have been considered as one kind of artificial emerging persistem organic compounds.Due to high bioaccumulation ability of long-chain PFASs,short-chain PFASs are used as their substitutes.In this study,the accumulation of 7 PFASs in Scenedesmus obliquus,Spirulina platensis and Chlorella pyrenoidosa was studied to test the influence of the length of carbon chains on bioconcentration,and the bioconcentration factors (BCF) at 24 h was calculated.The results showed that perfluorodecanoic acid had the highest concentrations in the 3 test microalgae,and at 10 μg· L-1 exposure concentration,the alga concentrations were 1 894 ng·g-1,88.0 ng·g-1,990 ng·g-1 in S.obliquus,S.platensis and C.pyrenoidosa,respectively.BCF of perfluoroalkyl sulfonic acids in 3 microalgae were getting higher as carbon chain length increased,and perfluorinated carboxylic acids showed similar trends.However,the BCF of perfluorohexanoic acid were higher than perfluorooctanoic acid in S.platensis.Furthermore,concentrations of PFASs in S.obliquus were higher than S.platensis and C.pyrenoidosa,which was controlled by the surface area and the contents of lipid and protein.%全氟烷基化合物(perfluoroalkyl substances,PFASs)是一系列人工合成的新型有机污染物,由于长链的PFASs具有较高的生物蓄积性,短链PFASs逐渐作为替代品而被广泛利用.为探讨不同碳链长度的PFASs在水生浮游植物中的蓄积能力,选取7种PFASs为目标物,以斜生栅藻(Scenedesmus obliquus)、钝顶螺旋藻(Spirulina platensis)和蛋白核小球藻(Chlorella pyrenoidosa)作为受试生物进行富集动力学实验,测定24 h时的生物富集因子(Bioconcentration factors,BCF).结果表明,染毒浓度为10 μg·L-1时,全氟癸烷羧酸的富集能力最强,在斜生栅藻、钝顶螺旋藻和蛋白核小球藻中的浓度分别为1 894 ng·g-1、88.0 ng·g-1、990 ng·g-1.3种微藻中全氟烷基磺酸的BCF均随碳链长度的增加而增大;全氟烷基羧酸的BCF基本遵循同样的规律,只是在钝顶螺旋藻体内,全氟己烷羧酸的BCF高于全氟辛烷羧酸.此外,PFASs在斜生栅藻中的浓度均高于蛋白核小球藻和钝顶螺旋藻,不同藻类的富集能力与其表面积、脂肪及蛋白质组成有关.