百色市工业区表层土壤中多环芳烃污染特征及来源分析

为完善我国实地的不同的PAHs污染特征数据库,系统采集了百色市5个工业区表层土壤样品,利用HPLC分析了16种US EPA 优控PAHs的含量和组分特征,运用同分异构体比率法和主成分因子载荷法揭示其污染来源.结果表明,工业区土壤中PAHs总含量范围在18.7~6437μg/kg之间,电厂2土壤中PAHs平均含量最高,达1923.4μg/kg.与国内外相关研究比较,处于中高等污染水平.5个工业区表层土壤样品中PAHs的残留大小顺序为:电厂2>电厂1>炼油厂>润滑油厂>水泥厂;电厂2、电厂1、炼油厂和润滑油厂4个工业区土壤中PAHs污染以4环为主,毒性较高的4环和5环PAHs均高于其他环数PAHs;水泥厂附近土壤中PAHs污染以2、3环为主.研究区域内土壤中Baa、Bkf、Chr和Fla等单体超标严重.工业区土壤中PAHs污染主要来自于燃烧源、石油源及石油源和燃烧源的混合源,燃烧源贡献最大(占45.0%),石油源和燃烧源混合贡献率为36.8%,而石油源所占比例相对较小(占18.2%).

Characteristics and sources of polycyclic aromatic hydrocarbons in surface soil from industrial areas of Baise,Guangxi.

To expand and improve the database of polycyclic aromatic hydrocarbon (PAH) pollution signatures in different environmental samples from sites in China, surface soil samples were collected from five industrial areas of Baise, a prefecture-level city of the Guangxi Zhuang Autonomous Region. The concentration and composition of 16 PAHs listed for prior control by the US EPA were determined using high performance liquid chromatography. Selected diagnostic ratios and principal component analysis were used to identify possible sources of soil PAHs. Concentrations of ∑16 PAHs in the present study were shown to vary greatly, and ranged from 18.7 to 6347 μg/kg, depending on the sampling location. The highest concentrations of Σ16 PAHs were observed in Power plant 2 soils with a value of 1923.4 μg/kg. Compared with domestic and foreign research, PAH pollution in the five Baise industrial areas reached medium to high levels. Soil PAH concentrations showed a strong Power plant 2–Power plant 1–Refinery–Lubricants plant–Cement plant gradient. Four- and five-ring PAHs, which have strong carcinogenic mutagenicity and distortion, dominated in the industrial areas with power plants and lubricant plants, while two- and three-ring PAHs dominated the surface soil near cement plants. Among the PAHs detected in the study-area soil, benza]anthracene (BaA), benzok]fluoranthene (BkF), chrysene (Chr), and fluoranthene (Fla) were the major pollutants occurring above standard levels. The study also suggested that the major sources of soil PAHs in Baise were coal and petroleum combustion (45.0%) and petroleum leakage (18.2%), or a combination of the two (36.8%).