京津潮白河多环芳烃及其衍生物分布

Distribution of Polycyclic Aromatic Hydrocarbons and Their Derivatives in Chaobai River of Beijing-Tianjin Area

采用固相萃取-气相色谱质谱联用仪测定京津潮白河中的多环芳烃(PAHs)及其衍生物(SPAHs)的污染水平,并采用絮凝法分析水样中自由态PAHs/SPAHs和结合态PAHs/SPAHs的分布。结果表明,京津潮白河中PAHs和SPAHs总质量浓度分别为55.06~215.02ng·L^-1和92.37~227.33ng·L^-1,上游河段PAHs和SPAHs质量浓度均低于下游河段。7种致癌PAHs占比为22%~41%,需引起重视。本研究中的SPAHs包括三类物质:氧化PAHs(OPAHs)、甲基PAHs(MPAHs)和氯代PAHs(ClPAHs)。其中,OPAHs对SPAHs贡献最大(59%~71%),其次是ClPAHs(22%~32%)和MPAHs(7%~14%)。京津潮白河中PAHs和SPAHs主要以自由态形式存在,总浓度可以准确估计污染物的环境风险。

The pollution levels of polycyclic aromatic hydrocarbons (PAHs) and their derivatives (SPAHs) in Chaobai River of Beijing-Tianjin Area were determined by the combined method of solid-extraction and gas chromatography- mass spectrometer.Meantime,the distribution characteristics of freely dissolved PAHs/SPAHs and combined PAHs/SPAHs in water samples were analyzed by flocculation.The results showed that the total mass concentrations of PAHs and SPAHs in Chaobai River of Beijing-Tianjin Area were 55.06 -215.02 ng·L^-1 and 92.37- 227.33 ng·L^-1,respectively.The mass concentrations of PAHs and SPAHs in the upper reaches of the river were lower than that of the downstream sections.It is worth noting that the proportion of seven kinds of carcinogenic PAHs in the whole PAHs is 22%-41%.There are three types of SPAHs in this study,including methyl polycyclic aromatic hydrocarbons (MPAHs),oxygenated polycyclic aromatic hydrocarbons (OPAHs) and chlorinated polycyclic aromatic hydrocarbons (ClPAHs).Among them,OPAHs show the main contribution to the SPAHs with the proportion of 59%-71%,followed by ClPAHs (22%-32%) and MPAHs (7%-14%).In the Chaobai River of Beijing-Tianjin Area,PAHs and SPAHs mainly exist in the form of freely dissolved state,and the environmental risk of pollutants can be accurately estimated by the total concentration.