北京地区表层土壤中多环芳烃的分布特征及污染源分析

根据北京地区不同环境功能区62个样品的分析结果,讨论了研究区表层土壤中多环芳烃的分布特征及污染源类型。结果表明：（1）研究区表层土壤中检测到的多环芳烃主要包括萘、苊、菲、惹烯、三芴、荧蒽、芘、、苯并蒽、苯并b]荧蒽、苯并k]荧蒽、苯并e]芘、苯并a]芘、苝、二苯并a,h]蒽、茚并1,2,3–cd]芘、苯并g,h,i]苝及其同系物;（2）不同环境功能区表层土壤中多环芳烃的组成及质量分数均存在一定的差别,16种优先控制的多环芳烃质量分数为175.1~10 344 ng.g-1,其中城市中心区表层土壤中多环芳烃的质量分数最高,交通干线附近、工矿企业附近表层土壤中PAHs的质量分数较高,林地、果园和农田表层土壤中PAHs的质量分数较低;（3）表层土壤中PAHs既有来源于石油源,也有来源于化石燃料燃烧产物的,但不同功能区二者贡献存在差别,其中农业用地（林地、果园、农田）中PAHs主要来源于石油源（或部分来源于土壤母岩中的有机质）,城区、交通干线附近及工矿企业附近表层土壤中PAHs污染源以化石燃料燃烧产物输入为主。

Distribution and sources of polycyclic aromatic hydrocarbon compounds in topsoil of Beijing, China

Sixty–two topsoil samples collected in Beijing were detected and analyzed.The distribution and contamination sources of Polycyclic Aromatic Hydrocarbon Compounds（PAHs） were discussed.The results showed that（1） many kinds of PAHs in topsoil samples of Beijing were found,mainly including naphthalene,acenaphthene,phenanthrene,retene,fluorene,dibenzofuran,dibenzothiophene,fluoranthene,pyrene,chrysene,benzanthracene,benzob]fluoranthene,benzok]fluoranthene,benzoe]pyrene,benzoa]pyrene,perylene,dibenzoanthracene,indeno1,2,3-cd]pyrene,benzoperylene and their homologous compounds;（2） the composition and concentration of PAHs in topsoil samples from different environmental function areas were different.The concentration of sixteen prior pollutants PAHs was between 175.1 and 10344 ng？g-1 in topsoil samples.The concentration of PAHs in topsoil of city center was the highest.The concentration of PAHs was high in topsoil of the vicinity of transportation routes and industrial enterprises,and it was low in topsoil of woodland,orchard and farmland;（3） the sources of PAHs were not only oil but also fossil fuel combustion products,and their relative contribution varied in different environmental function areas.PAHs in agricultural land（forest land,orchards and farmland） were mainly from oil or partly from soil organic matter.PAHs in topsoil of city center,the vicinity of transportation routes and industrial enterprises were mainly from fossil fuel combustion products.