北京城市空气中多环芳烃的污染特征

Pollution Characterization of Polycyclic Aromatic Hydrocarbons in Beijing Ambient Air

对北京市分属不同功能区的十三陵、石景山、车公庄和芍药居等地的环境空气进行了采集和测量.采集的样品包括气相和颗粒相中的PAHs,采样流速为450～500 L/min,采集时间不小于13 h,将采集的样品进行预处理,然后用液相色谱进行分析.结果表明:北京城市空气中PAHs污染比较严重,大于4环的PAHs在颗粒相中占主导地位,小于4环的PAHs主要分布在气相中;采暖期的PAHs污染比非采暖期较为严重,取暖所带来的污染占主要地位;同时研究表明,夜间柴油车所产生的污染不容忽视.

Results from measurements of polycyclic aromatic hydrocarbons （PAHs） in ambient air in Beijing were presented. The samples were collected at four sites representing different functional areas, i.e. Shisanling, Shijingshan, Chegongzhuang and Shaoyanju. The sampling equipment was high-volume sampler capable of pulling ambient air through the fiher/sorbent cartridge at the flow rate of 450 - 500 L/min over a 13 h period, and an analysis was conducted by HPLC/UV. The experiment shows that the pollution of PAHs in the ambient air at Beijing is serious, and PAHs with less than four rings are higher in the gas phase than in the particle phase, while PAHs with more than four rings are predominant in the particle phase. The pollution of PAHs in the heating seasons is more serious than that in the non-heating seasons, meaning that the pollution resulted from heating facilities dominates. Meanwhile, the serious pollution in the night produced by the diesel vehicle fuels should not be neglected.