土壤中多环芳烃的分布特征及其来源分析

利用气相色谱法分析了南充市10个不同功能区表层土壤中美国环保署规定的16种优控多环芳烃（PAHs）的含量和组分特征,运用同分异构体比率揭示了其污染来源。研究表明,该区土壤中PAHs的含量在9.1～2269.1μg·kg-1之间,而且工业区的残留量大于农业区和居民区的残留量。按PAHs的环数来分,在工业污染区PAHs的含量总的趋势是四环〉二环〉三环〉五环〉六环;农业和居民区二环〉三环〉五环〉四环〉六环。该污染状况与国内外相关研究比较,处于中等污染水平。煤、木材和化石的燃烧是该地区土壤中PAHs污染的主要来源,苯并（a）蒽和菲是主要的超标化合物。

Distribution Characteristics and Sources of Polycyclic Aromatic Hydrocarbons in Surface Soil

The concentration and composition of 16 polycyclic aromatic hydrocarbons（PAHs）on the US EPA priority pollutant list in surface soil of Nanchong were determined by gas chromatography（GC）.The source of PAHs contamination in surface soil was also diagnosed by using PAH isomer ratios.The results showed that the concentration of PAHs in all soil samples from ten different function area were between 9.1 and 2 269.1 μg·kg-1,and the pollution in industrial area was more serious than that of in agricultural and residential zones.In industrial area,the rule of PAHs content in soil was four-ringtwo-ring three-ring five-ring six-ring,while in agricultural and residential zones it was two-ring three-ring five-ring four-ring six-ring.Compared PAHs contents in soils with other regions reported,the degree of PAHs pollution in the areas was at medium level.Coal and wood and fossil fuels combustion were the dominant sources of PAHs in the areas,and benzo（a）anthracene and phenanthrene were major PAHs pollutants.