ISSN 1000-3665 CN 11-2202/P

    北运河流域(北京段)表层土壤多环芳烃空间分布特征及来源解析

    Spatial distribution and sources of PAHs in topsoil in the Beiyun River Basin (Beijing section)

    • 摘要: 土壤中的多环芳烃(PAHs)会威胁人类健康和生态环境安全。为掌握北运河流域(北京段)土壤中PAHs的分布特征及其形成机制,采用克里格插值、主成分分析-多元线性回归等多元统计方法,结合同分异构体比值法对该区域表层土壤中16种优控PAHs的质量分数、分布趋势、空间分布特征及其污染来源进行了研究。结果表明:(1)研究区216件土壤样品中16种PAHs均被检出,且主要为高环PAHs(4~6环),总PAHs的质量分数范围在10.5~19466.5 μg/kg,受污染土壤样品占29.63% ;(2)表层土壤中的PAHs在东西及南北方向上均呈现出中部高、两端低的趋势,在空间分布上总体表现为北部区域及中部城区含量较高、其他地区相对较低的特征,且由于人为活动影响导致个别点位PAHs富集,存在点源污染或局部污染;(3)PAHs同分异构体比值法及主成分分析法研究表明,研究区内PAHs的来源为以煤/生物质燃烧及交通燃烧为主、石油泄漏等石油化工源为辅的混合源,多元线性回归方法分析后得到 2 者的贡献率分别为89%和11%。研究结果可为研究区的污染防控、土地质量评价和国土空间规划等工作提供有力支撑。

       

      Abstract: Organic pollution of polycyclic aromatic hydrocarbons (PAHs) in topsoil has threatened human health and ecological environment. In order to understand the distribution and pollution characteristics of PAHs in topsoil in the Beiyun River Basin in Beijing, an investigation is carried out to examine the contents, distribution trends, spatial distribution and pollution sources of 16 optimal PAHs in topsoil of the study area by means of multivariate statistical methods including the Kriging interpolation, principal component analysis-multiple linear regression and the concentration ratio among certain components. The results are as follows (1) all 16 PAHs are detected, and most of them are high loop PAHs (4−6 rings). The total contents of PAHs in topsoil range from 10.5 to 19466.5 μg/kg, about 29.63% of the samples are polluted in the study area. (2) The PAHs contents in topsoil show a trend of higher in the middle and lower at ends in both east-west and south-north direction. In terms of spatial distribution, the PAHs contents in topsoil are higher in the northern region and the central urban area, while the PAHs contents are lower in other areas. Due to the accumulation of PAHs caused by human activities at some points, point source pollution or local pollution exist. (3)The ratio of specific PAHs components and principal component analysis indicate that the sources of 16 PAHs in the study area are mainly coal, biomass combustion and traffic combustion. Multiple linear regression shows that the contribution rates of the two are 89% and 11% respectively. The research results can provide strong support for pollution prevention and control, land quality evaluation and territorial space planning in the study area.

       

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