中文摘要：

研究了南水北调中线源头区降雨径流中多环芳烃的分布特征及来源.根据不同土地利用类型修建了5组径流场收集径流,采用GC/MS对径流中美国EPA优先控制的16种PAHs进行了检测分析.结果表明,3种土地利用类型降雨径流水相中PAHs含量平均值为：耕地（26.53 ng·L^-1）〉栎林（20.91 ng·L^-1）〉果园（17.59 ng·L^-1）;颗粒相中PAHs含量平均值为：耕地（1 073.72 ng·g^-1）〉果园（652.29 ng·g^-1）〉栎林（385.46 ng·g^-1）.耕地和果园两期径流中均检测出高环致癌组分Bap,检出率为30%;与美国EPA 2006年颁布的《国家推荐的优先有毒污染物水质标准》比较发现组分Chr超过标准,超标率为40%,其在样品中的检出率则高达100%.降雨径流量随坡度的增加呈明显的上升趋势,径流两相中总PAHs含量随坡度的增加也呈明显的上升趋势,可见同种利用类型土地径流中PAHs流失量与坡度的大小密切相关.使用分子标志物指示法对研究区径流中PAHs来源进行解析,结果表明研究区径流中PAHs主要来源是煤、木材等燃烧源,少量来源于汽车尾气排放.研究区降雨径流中PAHs污染存在一定的生态风险,值得进一步关注.

英文摘要：

The distribution characteristics of polycyclic aromatic hydrocarbons in runoff from the middle line source area of south-to-north water diversion project were studied.Five groups of artificial runoff fields were established to collect runoff based on the different types of land-use,the contents of 16 USEPA priority PAHs in the runoff were determined using GC/MS method.The results showed that the average concentrations of PAHs of the aqueous phase in the collected runoff samples of different land-use types decreased in the order：cultivated land（26.53 ng·L^-1）〉oak forest（20.91 ng·L^-1）〉orchard（17.59 ng·L^-1）,and the average concentrations of PAHs of the particle phase were cultivated land（1 073.72 ng·g^-1） 〉orchard（652.29 ng·g^-1）〉oak forest（385.46 ng·g^-1）.The high carcinogenic components Bap were detected in both run off of cultivated land and orchard with a detected rate of 30%.According to National Recommended Water Quality Standards of priority toxic pollutants（2006 USEPA）,it was found that Chr exceed standard 40%,with a detected rate of 100%.It was also found that the runoff volume and the total PAHs content in runoff increase with the slope,and PAHs loss and slope were closely related in same land-use types.Based on the Molecular Markers Indicative Law,it can be concluded that the dominant source of PAHs in runoff of study area was combustion of coal,and a small amount came from vehicle exhaust emissions.There is a certain degree of ecological risk about runoff PAHs pollution in the study area,which is worth further attention.