北京城市道路地表径流及相关介质中多环芳烃的源解析

将道路地表径流及降雨、路面积尘和行道树树冠穿透水作为整体系统,对其中多环芳烃(PAHs)的来源进行分析.选择北京市3种主要类型城市道路(主干路机动车道、主干路自行车道、支路),于2006年雨季对上述4类介质进行采样分析.结果显示,5～6月各介质中PAHs的平均浓度明显高于7～8月.应用因子分析和多元回归方法解析各介质中PAHs的来源.因子分析结果表明,径流中的PAHs更多体现路面积尘的来源特征,但在自行车道和支路,雨水和树冠水的影响也分别得到体现.多元回归结果表明,路面积尘和地表径流中PAHs的来源.在支路和主干路机动车道以机动车排放源为主,在自行车道,机动车源和燃煤源的贡献相近.雨水中的PAHs以燃煤/燃油源为主,行道树树冠水中机动车源的贡献较大.

PAH Sources in Road Runoff System in Beijing

In this study, road runoff, rainwater, ground sediment and roadside tree water samples were collected from three types of roads in Beijing in 2006. The samples were analyzed for polycyclic aromatic hydrocarbons (PAHs). The average PAH concentrations in each media in May-June were generally higher than those in July-August. Factor analysis indicated that PAHs in road runoff were mainly from ground sediment, and rainwater and roadside tree water also had certain influence to road runoff. Multiple regression analysis indicated that PAHs in ground sediment and road runoff mainly come from vehicular emission at the vehicle way and branch road, and at the bicycle way, the contributions of vehicular emission and coal combustion were equal. PAHs in rain were mainly from coal/oil combustion, and PAHs in roadside tree water were dominated by vehicular emission source.