上海交通沿线农田土壤中PAHs分布特征及源解析

Distribution characteristics and source analysis of PAHs in farmland soils along Shanghai traffic artery

为探讨交通干线对周围农田土壤环境中16种优先多环芳烃(PAHs)累积的影响,采集了上海市交通干线旁与道路垂向分布的70个农田土壤表层样品及2个土壤柱样品,系统分析了土壤中16种优控PAHs的含量、组成及来源.结果表明上海交通干线旁农田表层土壤PAHs含量范围为23.16～21250.25ng/g,平均值为928.16ng/g,且随着与防护林距离的增加呈现出先下降后增加而后又下降的趋势,农田土壤柱中PAHs含量则表现出随着距土壤深度的增加而上升的趋势.基于正定矩阵因子分析(PMF)模型及特征因子比值法的来源辨析结果,表明表层土壤和土壤柱中的PAHs均主要来源于煤、生物质的燃烧及交通排放.

In order to investigate the influence of traffic emission on the accumulation of 16 polycyclic aromatic hydrocarbons(PAHs)known as priority pollutants in the surrounding farmland soils,seventy soil surface samples and two soil cores samples were collected within 500m of the Shanghai traffic artery.The concentrations,compositions and sources of 16PAHs were systematically analyzed.The results showed that the concentrations of Σ16 PAHs in the surface soils of the farmland along the Shanghai traffic artery was 23.16~21250.25ng/g,with an average of 928.16ng/g.Along the increase of distance from roadside shelterbelts,the concentrations of Σ16 PAHs showed a trend of decrease first remove then increase,and finally decrease.The concentrations of Σ16 PAHs in farmland soil cores showed an increasing trend with the decreasing distance from the soil surface.Positive definite matrix factor analysis(PMF)models and isomer ratios were used to distinguish PAHs sources in soil surfaces and core samples.It was found that they were mainly derived from the combustion of coal and biomass and traffic emissions.