六六六在典型污染场地中空间分布研究

在受某六六六（HCH）生产企业污染的场地上采集土壤样品，分析和研究了土壤中六六六的污染水平和污染分布趋势。结果表明，六六六的浓度范围是0．34～2287．6mg·kg^-1，六六六污染主要集中在-1m土层，平均浓度高达467．75mg·kg^-1。在-3m和-5m土层中污染中心位置与-1m层土壤保持一致。通过Kriging法插值画出-1、-3、-5m土层等值线图，可清晰地看出六六六的分布趋势。六六六浓度随土壤深度增加迅速降低。然而，在-5m土层由于土壤类型为淤泥质粘土，六六六浓度相对于-3m土壤反而升高，该层的平均浓度为89．86mg·kg^-1。纵观整个污染场地六六六的污染分布情况，在地下水作用下污染物浓度向东南方向扩散，且六六六在垂直方向的迁移和残留浓度与土壤有机质含量有一定的相关性。

Spatial Distribution of HCH in A Typical Contaminated Site

Soil samples in contaminated site of a historical HCH plant were collected and the levels and the distribution of HCH were analyzed and studied. The results showed that, the concentration range of HCH was 0.34-2 287.6 mg.kg^-1, the contamination of HCH main in -1 m depth of soil, and the average concentration in -1 m depth of soil sample was 467.75 mg.kg^-1. In -3 m and -5 m depth the location of contaminated center keep uniform with -1 m depth of soil. The distribution of HCH in -1, -3 and -5 m depth of soil was calculated by Kriging model. HCH concentration decreased with the increase of depth in soil, especially from -1 m to -3 m depth. However, because -5 m depth of soil was silt clay, the average concentration was 89. 86 mg.kg^-1. Taking a wide view of the HCH contaminated distribution, HCH concentration diffused to southeast by groundwater. The migration and residual concentration of HCH in vertical direction in this contaminated site had relationship with organic matter content.