膨润土中离子扩散特征试验研究  

Test of ions diffusion in bentonite

作　　者：何俊[1] 施建勇[1] 廖智强[1] 朱宁[1] 

机构地区：[1]河海大学岩土工程研究所,南京210098

出　　处：《岩土力学》2007年第4期831-835,共5页Rock and Soil Mechanics

摘　　要：膨润土在填埋场中有较为广泛的应用。膨润土材料作为衬垫时,扩散是污染物运移的重要方式。为深入了解不同应力状态下膨润土阻滞污染物运移的能力,对Ca2+,Cl-和Zn2+在不同孔隙率膨润土中的扩散进行了试验研究,得到的结果与已有文献有较好的一致性。随着孔隙率的增加,离子扩散系数增加,验证了二者之间的指数关系。讨论了在一定孔隙率范围内离子有效扩散系数的估算方法,估算结果与实测值接近。Bentonite is widely used in landfills. When bentonite is used as a material of liner, diffusion through bentonite is a very important transport mechanism. To understand the ability of retard migration of contaminant in different stress states, the diffusion coefficients of Ca^2＋, Cl^- and Zn^2＋ diffusing in bentonite of different dry densities were measured. The diffusion coefficients of this study are well in the range of previously published results. With the increasing of porosity, the diffusion coefficients of Ca^2＋ and Cl^- increase in exponential form. The estimating method of diffusion coefficient in a given range of porosity is proposed. The estimation is approximate to the measured values.

关 键 词：膨润土 扩散 孔隙率 扩散系数 

分 类 号：TU411[建筑科学—岩土工程]