成都市春季土壤和扬尘中饱和烃的污染特征与来源分析

Pollution Characteristic and Sources of Saturated Hydrocarbon in Soil and Dust of Chengdu City in Spring

用GC-MS分析了成都市不同方位区域内具有代表性的土壤和扬尘样品中饱和烃的组成与分布特征。研究表明,在土壤和扬尘中均检测出了丰富的正构烷烃和甾、萜烷化合物等饱和烃。正构烷烃在土壤和扬尘中差别明显,其浓度分别为7.54~40.37μg g-1和26.61~71.52μg g-1,峰形分别主要呈前峰型和后峰型。成都市土壤中正构烷烃含量的趋势是东〉北〉中〉西〉南,扬尘为南〉西〉东〉中〉北。在土壤和扬尘中均检测出包括C27~C29规则甾烷、重排甾烷和孕甾烷等甾烷系列化合物和萜类化合物,主要来源于化石燃料和生物质不完全燃烧的产物等。

Soil and dust samples were collected in Chengdu area and their chemical composition and distribution of saturated hydrocarbons were analyzed by GC-MS.Results showed that the saturated hydrocarbons including normal alkane,steranes and hopanes were all detected in all samples which could give abundant geochemical information.Concentrations of n-alkanes in soil（7.54-40.37 μg g-1） and dust（26.61-71.52 μg g-1） were significantly different,and their peak shapes were advanced or delayed peaks.Distributions of n-alkanes concentration in soil samples showed the highest content was in the eastern area,followed by the northern,the middle,the western and the southern area of Chengdu.However,concentration of n-alkanes in dust samples showed the highest content was in the south,followed by the west,the east,the middle and the north.The steranes including C27-C29 steranes,rearranged steranes and pregnant sterane and terpene compounds were detected which suggested the major sources of them were from the incomplete combustion of fossil fuel and biomass.