南昌市周边农田土壤中多环芳烃的污染特征及来源分析

Analysis of Pollution Characteristics and Sources of PAHs in Farmland Soil Around Nanchang City

采集南昌市周边三个县的18个农田表层土壤样品,采用液固萃取-层析净化-高效液相色谱分析技术,研究了土壤中16种优控多环芳烃类物质的含量和组分特征,运用主成分因子荷载方法分析了其污染来源,并初步评价了其风险水平。结果表明,该区域内农田土壤33.3%轻度污染,最高污染样点PAHs含量为422.8ng/g,最低污染样点PAHs含量为75.2ng/g,平均含量为197.9ng/g,且远离城市的农田土壤残留水平明显低于靠近城市的农田土壤;PAHs的组分特征为以毒性水平较低的低环化合物为主;其污染来源主要是煤、天然气和汽油燃烧组成的混合源。

Collecting farmland topsoil sample of three counties around Nanchang city,studying contens and characteristics of the component of 16 kinds of optimal control PAHs in soil using technologies of liquid-solid extraction,chromatography purification and HPLC,analysis their sources with principal constituent factor load method,and preliminarily assessing their levels of risks.The result shows that 33.3% of the farmland soil of this area has been polluted slightly,the content of the top polluted sampling point is 422.8ng/g,the content of the bottom polluted sampling point is 75.2ng/g,the average content is 197.9ng/g,and the vestigital level in farmland soil far from city is remarkably lower than those which is near city.The characteristic of the component of PAHs is that they are mainly low cyclic compounds with low toxic level;those optimal control PAHs primarily originate from combustion of coal,natural gas and petrol.