包气带对三氯乙烯的吸附行为研究

有机污染物在包气带的吸附行为,直接影响有机污染物在环境中的迁移、转化等过程。采用浅层和深层包气带样品,利用批实验的方法研究不同有机碳含量的样品对三氯乙烯(TCE)的吸附行为。研究表明,包气带表层土壤比深层土壤的有机碳含量高,可能存在竞争吸附的问题,说明该土壤的吸附行为是以矿物吸附为主、有机质吸附为辅的类型;表层土壤的吸附具有较好的线性行为,不存在饱和吸附量;深层土壤有机碳含量低,其吸附为非线性的。

The adsorption of trichlorinated hydrocarbon in the unsaturated zone

The adsorption of organic contaminants in the vadose is one of the most important factors affecting their migration and transformation process.Based on batch experiments,this paper deals with the adsorption behavior of trichlorinated hydrocarbon(TCE) on soil samples with different contents of organic carbon.The results indicate that the content of organic carbon in samples from the surface part is higher than that collected from the deep part.Generally speaking,the adsorption capacity increases with the increasing content of organic carbon,but the difference of the adsorption capacity can reach as high as 5 times for samples with the same organic carbon content,suggesting that there probably exists competition adsorption,and that mineral adsorption might be the major mechanism.The adsorption of surface soil fits the liner adsorption well,and there exists no saturated adsorption capacity.In deeper soil with lower organic carbon,however,the adsorption seems to be nonlinear.