新江湾城开发区表层土壤中有机氯农药和多氯联苯的分布特征

利用电子捕获检测器气相色谱法(GC-ECD)测定新江湾城表层土壤中有机氯农药(OCPs)和多氯联苯(PCBs),六六六类(HCHs)和滴滴涕类(DDTs)化合物均被检出,HCHs含量为0.81~2.84 ng/g,平均1.90 ng/g;DDTs含量为9.37~130.8 ng/g,平均43.9 ng/g。HCHs都未超过国家土壤环境质量标准的一级水平,但是有两个站点的DDTs超过国家土壤环境质量标准的一级水平。7种多氯联苯(7PCBs)含量为1.83~8.46 ng/g,平均3.99 ng/g,以四氯代PCB 52和六氯代PCB 138残留最高。PCBs污染主要集中在火力发电厂处,并向周边蔓延,反映了PCBs污染的来源与电力设备有关,其污染来源很有可能来自历史上变压器油泄漏物的残留及来自工业区的新的PCBs输入。

Distribution Characteristics of Organochlorine Pesticides and Polychlorinated Biphenyls in Top Soils from Development Zone in New Jiangwan City

The top soil samples collected from the development zone of New Jiangwan City were analyzed by gas chromatography with electron capture detector(GC-ECD).The total concentration of hexachlorocyclohexane(HCHs) and dichloro-diphenl-trichloroethane(DDTs) were in the range of 0.81～2.84 ng/g and 9.37～130.8 ng/g with the average of 1.90 ng/g and 43.9 ng/g respectively.The HCHs were within the Level Ⅰ of National Soil Quality Criteria,but DDTs in top soils from the two sampling sites exceeded the Level Ⅰ.The concentration of seven kinds of PCBs were in the range of 1.83～8.46 ng/g with average value of 3.99 ng/g,dominated by tetra-PCB 52 and followed by hexa-PCB 138.The PCBs pollution was mainly concentrated in the power plant area and spread to the surroundings,indicating that PCBs pollution was associated with residual leakage of transformer oil from the past and new pollution sources in the industrial zone.