内蒙古土默川黄灌区表层土壤中HCHs的分布特征及来源解析

Distribution characteristics and source apportionment of HCHs in surface soil in Inner Mongolia Irrigation Area of Yellow River in Tumochuan

选取土默川黄灌区镫口扬水灌区与民族团结灌区为研究区域,采用GC-ECD分析表层土壤样品中HCHs的含量。结果表明,HCHs总含量在ND^32.51 ng·g^(-1)之间,平均浓度为7.2 ng·g^(-1)。δ-HCH在4种异构体中占主要成分,平均值为3.69 ng·g^(-1),且平均值含量顺序为δ-HCH>γ-HCH>β-HCH>α-HCH。总体来说,土默川镫口扬水灌区与民族团结灌区表层土壤中HCHs残留水平处于较低水平。采用反距离加权法对HCHs在研究区的空间分布进行分析可知,基本呈东西走向,水平分布上东部要略高于西部,向南北两侧分别呈递增趋势。此外,分析探讨了不同影响因素下HCHs的分布特征,并通过α-HCH/γ-HCH的比值对HCHs进行来源分析,其比值介于0.15~1.59之间,表明土默川镫口扬水灌区与民族团结灌区表层土壤中发生了环境变化,且一小部分土样中α-HCH/γ-HCH比值接近于1,说明本地区有新的γ-HCH输入。

Selecting Tumochuan Dengkou pumping irrigation area and Minzutuanjie irrigation area as the study area,and analyzing the content o f HCHs in surface soil samples by using GC-ECD method.The results showed that the total content of HCHs was between ND ～32.51ng·g^-1, and the average concentration was 7.27 ng·g^-1.δ-HCH is the main ingredient in four kinds of isomer, the average concentration was3.69 ng·g^-1, the average concentration in order was δ-HCH〉γ-HCH〉β-HCH〉α-HCH. Overall, HCHs residue levels in the surface soil of Tumochuan Dengkou pumping irrigation area and Minzutuanjie irrigation area was lower. Secondly, the spatial distribution of HCHs in the study area was analyzed by using the inverse distance weighting method. The basic level in East-West distribution was Eastern slightly higher than that of the west, to the north and south sides respectively showed increasing trend. Also analyzed and discussed the influence of different factors on the distribution characteristics of HCHs. The source of HCHs was analyzed by the ratio of α-HCH /γ-HCH. Due to its ratio was between 0.15～1.59, which indicates that the environmental changes have taken place in the surface soil of Tumochuan Dengkou pumping irrigation area and Minzutuanjie irrigation area, and a small fraction of the α-HCH/γ-HCH ratio in the soil sample is close to 1, which indicates that there is a new γ-HCH input in the local area.