沙颍河流域水环境中多环芳烃污染及风险评价

Pollution and ecological risk assessment of polycyclic aromatic hydrocarbons in the water environment of Shaying River Basin,China

为了研究沙颍河流域上覆水与表层沉积物中多环芳烃(PAHs)的空间分布、来源与生态风险,2018年7月对沙颍河流域30个采样点的上覆水与表层沉积物中16种PAHs使用气相色谱/质谱技术(GC/MS)进行调查研究。结果表明,在上覆水与表层沉积物中ΣPAHs的浓度范围分别为:356.60~2275.04 ng·L^-1、64.27~11433.63 ng·g^-1,平均浓度分别为1051.23 ng·L^-1、965.77 ng·g^-1;各支流上覆水中PAHs含量呈现贾鲁河>颍河>沙河>澧河趋势,表层沉积物中PAHs含量呈现沙河>澧河>颍河>贾鲁河趋势,上覆水与表层沉积物中均以4~6环高环多环芳烃为主,与国内外其他河流相比沙颍河流域上覆水中PAHs处于较高污染水平,表层沉积物中PAHs污染水平相对较低;来源分析表明沙颍河流域上覆水与沉积物中多环芳烃主要来自高温燃烧源;生态风险评估表明上覆水中荧蒽(Fla)、芘(Pyr)、苯并[a]蒽(BaA)、苯并[b]荧蒽(BbF)、苯并[a]芘(BaP)、茚并[1,2,3-cd]芘(IcdP)和苯并[g,h,i]苝(BghiP)等PAHs单体为高风险多环芳烃单体,高分子量多环芳烃(4~6环)对生态风险贡献最大,沙颍河流域上覆水中PAHs属于高风险水平;沉积物中各PAHs单体的浓度除点位S27外均未超过效应区间中值(ERM)与频繁效应浓度值(FEL),表明沙颍河流域沉积物中PAHs潜在生态风险发生概率并不高。

To investigate the spatial distribution,source,and ecological risk of polycyclic aromatic hydrocarbons(PAHs)in the water envi⁃ronment of Shaying River Basin,16 PAHs in the overlying water and sediment samples obtained from 30 sites were analyzed in July 2018;the samples were analyzed using Gas Chromatography/Mass Spectrometry(GC/MS)techniques.The concentrations of total PAHs detected in the samples was found to be in the range of 356.60~2275.04 ng·L^-1 in the overlying water and 64.27~11433.63 ng·g^-1 in the sediments,with average concentrations of 1051.23 ng·L^-1 and 965.77 ng·g^-1,respectively.The PAHs concentration in the overlying water of each trib⁃utary was in the sequence of Jialu River>Yinghe>Shahe>Lihe,whereas a roughly opposite trend was observed for the surface sediments.The PAHs with 4~6 rings were the dominant PAHs monomers in the overlying water and sediments.Compared with other rivers in China and foreign countries,a higher pollution level was observed in the overlying water,and a lower pollution level was observed in the surface sediments.A source analysis indicated that the PAHs in overlying water and sediment mainly originated due to high temperature combus⁃tion.Furthermore,an ecological risk assessment revealed that the PAHs in the surface water were at high risk levels,especially for PAHs monomers with high molecular weight(4~6 rings),such as Fla,Pyr,BaA,BbF,BaP,IcdP,and BghiP.The concentration of each PAHs monomer in the surface sediment did not exceed the Effect range median(ERM)and the Frequent effect level(FEL),except in site S27.This reveales the low probability of potential ecological risk due to PAHs in the surface sediments of the Shaying River Basin.