新疆典型地区土壤／松针中多环芳烃分布特征

Distribution of PAHs between soils and pine needles collected from typical areas of Xinjiang

考察了新疆典型地区(石河子、北屯和喀纳斯)土壤和松针中多环芳烃(PAHs)的浓度水平和分布特征。与国内外典型地区相比,新疆土壤和松针中PAHs的污染水平较低。与受人类活动影响明显的石河子地区相比,人迹罕至的喀纳斯地区土壤和松针中低分子量PAHs的比例较高,而高分子量PAHs的比例较低,不同环数PAHs呈现出明显的'局部分馏'现象。PAHs在土壤/松针中的分布系数与其过冷液体饱和蒸气压具有显著的对数线性关系,表明PAHs在土壤/松针中的分布受其物理化学参数的影响,PAHs在土壤/松针中的分布可以看作是在气/固间分配的'镜像'。

Concentrations of polycyclic aromatic hydrocarbons （PAHs） in soils and pine needles collected from typical areas of Xinjiang （Shihezi, Beitun and Kanas） were measured to investigate their distribution between the two environmental media. The concentrations of PAHs in soils and pine needles samples from the three regions were lower than that from other typical regions. The proportion of low molecular weight PAHs was higher and that of high molecular weight species was lower for Shihezi＇s sample than that for Kanas＇s one. The ring distribution of PAHs in samples from the three regions was a result of ＂local atmospheric distillation＂. Significant log/log-linear relationship was observed between the sub-cooled liquid vapor pressure and the soil/needle quotient, which was similar to one between the gas/solid partition coefficient and the sub-cooled liquid vapor pressure of atmospheric PAHs. These results indicated that the soil/needle quotient can be considered as a ＂mirror image＂ of the gas/solid partition coefficient.