某场地三氯甲烷污染分布特征及垂向迁移分析

Spatial Distribution Characteristics and Vertical Migration Analysis of Trichloromethane in a Contaminated Site

通过对土壤和地下水的布点采样和测试,研究了南方某三氯甲烷污染场地土壤和地下水中三氯甲烷的污染特征,并结合土壤-水分配系数、相对迁移率等因素对三氯甲烷在包气带中的垂向迁移进行了分析。结果表明:(1)调查场地地下水中三氯甲烷的浓度范围为0.5~31 300μg/L,土壤中三氯甲烷的污染主要分布在0~8m,最大浓度检出深度在0.5~2.5m;(2)土壤-水分配系数数值大小表现为粉质黏土>粉土>中砂,三氯甲烷对水的相对迁移率为2.34倍,三氯甲烷在包气带垂向迁移速率比水快,且三氯甲烷的垂向迁移能力表现为粉质黏土<粉土<中砂。

This paper takes the soil and groundwater samples to study the spatial distribution of Trichloromethane(CF)from the contaminated sites in southern China.It analyzes the vertical migration of CF in the vadose zone by using soil-water distribution/partition coefficient and relative mobility.The results show that the content of CF is in the range of 0.5 to 31 300μg/L in the groundwater;the depth of CF in soil is generally between 0 and 8 m,and the maximum depth between 0.5 m to 2.5 m;numerical value of soil-water distribution/partition coefficient is:silty clay>silt>medium sand;relative mobility of CF is 2.34 times that of water;the vertical migration velocity of CF is faster than that of water in the vadose zone;vertical migration ability of CF is:silty clay<silt<medium sand.