长江三角洲典型地区农田土壤多环芳烃分布特征与源解析

DISTRIBUTION AND SOURCES ANALYSIS OF PAHs IN FARMLAND SOILS IN AREAS TYPICAL OF THE YANGTZE RIVER DELTA,CHINA

采集了长江三角洲地区苏州市的96个和嘉兴市的324个农田土壤样品,较为系统地分析了土壤中15种优控多环芳烃组成及含量,并运用比值法和主成分分析法判断了土壤中多环芳烃的来源。结果显示,苏州和嘉兴农田土壤中15种多环芳烃的总量范围分别为45.4-3 703μg kg-1和9.0-2 421μg kg-1,其平均值分别为312.5μg kg-1和152.4μg kg-1。苏州农田土壤苯并[a]芘含量平均值达21.4μg kg-1,超过了前苏联制定的土壤苯并[a]芘最高允许值（20.0μg kg-1）。苏州农田土壤中多环芳烃的含量从南部的吴江到北部的相城呈不断增加的趋势。嘉兴农田土壤多环芳烃含量远低于苏州,而在嘉兴毗邻吴江和上海的嘉善县土壤中多环芳烃含量较高。菲、荧蒽、苯并[b]荧蒽、芘、茚并[1,2,3-cd]芘是苏州土壤中多环芳烃的主要成分,而嘉兴土壤中多环芳烃的主要成分为菲、荧蒽、苯并[b]荧蒽、芘、屈。两个地区农田土壤多环芳烃的来源较为相似,主要为生物质和煤的燃烧以及石油源。

A total of 420 farmland soil samples were collected,96 from Suzhou area and 324 from Jiaxing area,for analysis of composition of PAHs and concentrations of the 15 types of PAHs under priority control with the aid of HPLC and for exploration of sources of the PAHs in the soil,using the ratioing technology and PCA.Results show that the total content of PAHs varied in the range from 45.4 μg kg-1 to 3 703 μg kg-1 and from 9.00 μg kg-1 to 2 421 μg kg-1 in Suzhou and Jiaxing,respectively.The mean concentration of B[a]P in the soils of Suzhou reached 21.4 μg kg-1,far beyond the maximum allowable value of 20.0 μg kg-1 set by the Former USSR.The content of PAHs in Suzhou displayed an increasing trend from south（Wujiang County） to north（Xiangcheng County）,and much higher than in Jiaxing.And the content of PAHs in soils of Wujiang County and Jiashan County of Shanghai was rather higher.Phe,FluA,BbF,IP,and Pyr were the dominant PAHs in Suzhou,while Phe,FluA,Pyr,Chry,and BbF were in Jiaxing.The sources of the PAHs in the soils of the two regions were quite similar,mainly biomass,coal combustion and petroleum.