氯丹和灭蚁灵在典型污染场地的空间分布研究

测定分析了典型氯丹和灭蚁灵污染场地上的土壤、浅层地下水、地表水和底泥样品,应用地统计学的理论和方法研究了氯丹和灭蚁灵的空间结构与分布特征。结果表明,氯丹、灭蚁灵空间变异性高,随机因素对空间变异起主导作用。厂区内生产车间附近土壤中氯丹和灭蚁灵污染严重,存在明显的水平迁移,污染扩散范围与风向呈现一定相关性。氯丹和灭蚁灵随水的淋溶作用存在显著的竖直迁移,已经扩散至深层土壤中。污染场地附近的浅层地下水和地表水均被污染,底泥污染被限制在排污口附近。通过Kriging法插值画出土壤和浅层地下水中氯丹和灭蚁灵的等值线图,清晰地看出氯丹和灭蚁灵的分布趋势:氯丹和灭蚁灵在表层土壤中污染程度较重,下层土壤和浅层地下水中的污染分布均与上层相对应。土壤、浅层地下水、地表水和底泥中灭蚁灵浓度均小于氯丹,这与氯丹和灭蚁灵的挥发性、迁移性、吸附性等理化性质有关。通过与同类POPs污染场地研究的对比分析发现,此类场地土壤中的POPs分布存在共性特征。

Study on Distribution of Chlordane and Mirex in a Typical Contaminated Site

Soil,shallow groundwater,surface water and sediment samples of a contaminated site in a chlordane and mirex production plant were collected and analyzed,and the spatial structures and distribution characteristics of chlordane and mirex were investigated by means of geo-statistical theories and methods.The results showed that chlordane and mirex demonstrated high spatial variability,and random factors played dominant role in influencing the spatial variability.Soil pollution of chlordane and mirex was severe around the manufacture workshop areas.The pollutants indicated a significantly horizontal migration and the spread compass of contamination showed a certain correlation with the wind direction.There was a significant vertical migration of chlordane and mirex due to water leaching and had spread into deeper soil.Shallow groundwater and surface water around the site were both contaminated,while the sediment contamination was mainly limited to the vicinity of the sewage outfall.The distribution contour maps of chlordane and mirex in soil and shallow groundwater each year,diagramed by applying Kriging interpolation method,indicated the distribution trend of chlordane and mirex clearly.The pollution level of chlordane and mirex in the surface soil was severe.And the contamination of different soil layers and surface water were corresponding to the upper level soil.The contamination of mirex was less than chlordane in soil,groundwater,surface water and sediment due to their volatility,mobility,adsorption and other physical and chemical natures.Contrasting this study with the same type of POPs contaminated sites study found that POPs in the soil of such sites existed in the distribution of common features.