多环芳烃及其衍生物在北京纳污河流中的分布及健康风险

为探明北京5座污水处理厂出水及受纳河流中多环芳烃(PAHs)及其衍生物(SPAHs)的污染水平及健康风险水平,采用固相萃取-气相色谱质谱联用仪测定水样中的PAHs及SPAHs的质量浓度,分析其分布特征,同时使用毒性当量因子评价河流中PAHs的健康风险.结果表明,5座污水处理厂出水及受纳河流中PAHs及SPAHs总质量浓度分别为75~584 ng·L~(-1)和91~1822 ng·L~(-1).水样中PAHs以2和3环为主,占PAHs总量的23%~48%.本研究中的SPAHs包括三类物质:氧化PAHs(OPAHs)、甲基PAHs (MPAHs)和氯代PAHs (Cl PAHs).其中,OPAHs占ΣSPAHs的质量分数为75%,MPAHs、Cl PAHs占比总体较低,分别为12%、13%.通过对5条河流中PAHs进行毒性当量浓度计算,表明应在采暖季(12月)对高环PAHs污染引起重视.

Distribution and Risk Assessment of Polycyclic Aromatic Hydrocarbons and Their Derivatives in Wastewater-Receiving Rivers in Beijing

To analyze the pollution levels and health risk assessment of Polycyclic Aromatic Hydrocarbons (PAHs) and their derivatives (SPAHs) in five typical effluents from sewage treatment plants and receiving rivers in Beijing, the concentrations of PAHs and SPAHs in samples were measured by the combined method of solid extraction and gas chromatography-mass spectrometry. The distribution characteristics were also analyzed. At the same time, the probabilistic health risk was assessed using toxic equivalent factors. The results show that the contamination of PAHs and SPAHs in five typical effluents from sewage treatment plants and receiving rivers in Beijing is 75-584 ng·L^-1 and 91-1822 ng·L^-1, respectively. These PAHs are dominated by 2-and 3-ring PAHs, which account for 23%-48% of the total PAHs. The SPAHs in this study include three substances:methyl polycyclic aromatic hydrocarbons (MPAHs), oxygenated polycyclic aromatic hydrocarbons (OPAHs), and chlorinated polycyclic aromatic hydrocarbons (ClPAHs). The proportion of OPAHs in total SPAHs is 75%, while the total proportion of MPAHs and ClPAHs is overall low (12% and 13%, respectively). Calculations of the toxicity equivalents of PAHs in five rivers indicate that attention should be paid to high-PAHs pollution during the heating season (December).