Pollution characteristics of PAHs in urban runoffs from main roads in urban area
城市交通干道降雨径流中PAHs的污染特征

Road runoff samples were collected from two typical roads in Shanghai and Wenzhou city during the rainy season in 2010.Sixteen PAHs in both dissolved and particulate phases in runoff samples were analyzed in order to characterize the PAHs dynamic transportation between two phases in runoff samples.PAH concentrations in runoff samples varied from 919.8 to 16711.6 ng·L-1.Dissolved PAH concentrations (4.9~1558.0 ng·L-1) were much lower than those in particulates (635.4~16624.0 ng·L-1).PAH concentration variations were investigated during three rainfall events,and the first flush effect (FFE) was not obvious during all of the runoff events.The occurrence of an FFE was dependent on multiple factors including pre-rain dry period,rainfall intensity,runoff volume,etc.Therefore,the initial runoff interception may not control the PAH contaminations in urban road runoff effectively.Partition coefficient (Kp) values changed from 2.3×104 to 2.5×106 L·kg-1.Kp values decreased with the total suspended solid (TSS) contents in the road runoff samples,which could be related to the particle size fractions in the runoff.