在不同浸出条件下铅离子污染土的固化试验研究

An Experimental Study of Solidification of Pb-Contaminated Soil in Different Leaching Conditions

利用水泥来固化/稳定污染土中的重金属离子是一种常用的处置方法。着重讨论了添加蒙脱土后的复合固化剂对铅离子的固化效果。设计了不同蒙脱土和水泥掺量的12组固化剂,通过污染土制备、压实成型、强度测试和溶出试验4个步骤来获得试验数据。其中在溶出试验过程中,设定了4种不同的溶出条件以进行对比分析。结果表明:即使已经远远满足TCLP条件的固化产物,但在更加恶劣的试验条件下,浸出液的浓度非常高,远远达不到标准,所以在固化应用于实际工程时,根据条件不同,要考虑到更加恶劣的条件。

Using cement to solidify/stabilize the heavy metal contaminated soil is a common method of disposal. This article focused on the effects of solidification of Pb-contaminated soil which is disposed by composite curing agent added montmorillonite. The experiment adopted design of 12 groups curing agent with different content of montmorillonite and cement. There were four steps to obtain experimental data, i.e., preparation of contaminated soil, compaction molding, strength test and dissolution test. Four different leaching conditions were analyzed in the leaching test. The results showed that even though solidification product met the standards of the TCLP, but the concentration of leaching solution was very high in the worse conditions, far below the standards. So according to different conditions, it is necessary to consider to worse conditions in the actual projects.