三氯乙烯在不同土壤中吸附系数的室内试验研究

Laboratory Research on Adsorption Coefficients of Trichloroethylene in Different Soils

三氯乙烯(TCE)是工业污染场地常见的污染物,存在于土壤气相、固相或以高密度非水相液体的形式迁移转化。土壤对三氯乙烯的吸附不仅影响土壤中污染物浓度,还极大影响其迁移转化行为。根据三氯乙烯在土壤中的吸附机制,本次研究采取序批次等温静态吸附试验测定了上海崇明地区浅层四种不同土壤中的吸附系数,并分析了供试土壤类型、不同有机质及黏粒含量对其吸附性能的影响。试验结果表明,土层性质对三氯乙烯的吸附性能有较为明显的影响,黏性土相对于粉性土,呈现出更好的吸附性能。土壤中有机碳含量、黏粒含量对其分配吸附有一定的影响作用,有机碳、黏粒含量越高对其吸附量亦越大。基于吸附试验实测值和理论估算值对比,本次试验的吸附机制除有机分配外,还有矿物质的作用。

Trichloroethylene(TCE)is a common pollutant in industrial polluted sites.It exists the migration and transformation of gas phase,solid phase and high density non-aqueous liquid in soil.Soil adsorption of trichloroethylene not only affects the concentration of pollutants in the soil,but also greatly affects the migration behavior.Based on the adsorption mechanism of trichloroethylene in soil,the adsorption coefficients of four different type soil from Shanghai Chongming area were measured by sequential batch isothermal static adsorption test,and the effect of types,different organic matter and clay content of tested soil on its adsorption performance was analyzed.The results showed that the soil layer had significant effect on the adsorption performance of trichloroethylene,and the clay soil had better adsorption performance than the silt soil.The content of organic carbon and clay particles in soil had a certain effect on the organic distribution,and the higher the content of organic carbon and clay particles,the greater the adsorption capacity.The comparison between the measured value of the adsorption test and the theoretical estimated value proved that the adsorption mechanism of this test was not only the organic distribution,but also the role of minerals.