典型污灌区水体中有机氯农药分布及来源分析

Distribution and Source Analysis of Organochlorine Pesticides in Typical Sewage-irrigation Area

在干旱与半干旱地区,工业废水和生活污水灌溉农田作为一种有效的资源一直被广泛利用,但污水中有害成分也对灌区生态环境造成了很大影响。文章以太原小店污灌区为例,根据灌区灌渠和地下水流场分布,分别采集地表水样10个和地下水样20个,利用液液萃取-气相色谱法分析水样中有机氯农药（OCPs）含量。研究结果表明,地表水中OCPs浓度范围为32.21-671.82 ng/L（均值为184.21ng/L）;所有地下水中OCPs浓度均未超过《地下水环境质量标准》中Ⅲ类标准,浓度范围为9.44-84.01 ng/L;污水回灌对地下水中OCPs分布具有一定的影响,不同灌溉方式区域中OCPs浓度依次为：污灌区〉清灌区〉背景点;经过污染物源解析,研究区水环境中,OCPs中滴滴涕主要来源于历史残留,六六六主要来源于林丹的近期使用。

Industrial wastewater and domestic sewage are extensively utilized as an effective resource for cropland irrigation especially in add and semiarid regions, which also have brought more and more adverse effects on the environment. Sewageirrigation area in Xiaodian, Taiyuan was selected in the study and 10 surface water and 20 groundwater samples were collected according to irrigation system and the flow of groundwater. All OCPs in water were determined by liquid-liquid extraction followed by gas chromatography with electron capture detector （LLE-GC-μECD）. Results showed that the content of OCPs in surface water ranged from 32.21-671.82 ng/L with the mean of 184.21 ng/L. All the content of OCPs in groundwater were not beyond Grade Ⅲ of Groundwater Environmental Quality Standard and ranged from 9.44-84.01 ng/L. The reuse of wastewater into groundwater affected the distribution of OCPs, with the content of OCPs as sewage-irrigation area〉groundwater-irrigation area〉background area. In water environment of the study area, source analysis suggested that DDT and HCH residue originally came from its historical use and from recent lindane use respectively.