摘要
以K+、Ca2+和Fe3+为研究对象,考察屏障材料Soil-Bentonite(SB)对不同价态金属离子的阻截性能,并对其吸附机理、运移规律和穿透行为进行探讨,为污染场地封存材料设计提供理论依据。研究结果表明:屏障材料SB对不同价态的金属离子的吸附过程快速,且离子价态越高吸附量越大;吸附过程的拟合符合二级吸附动力学和Langmuir-Freundlich方程。K+、Ca2+和Fe3+在SB中渗透时,渗透系数存在极值,离子价态越高则出现极值的时间越短;各种离子在屏障材料中穿透时,离子价态越高,完全穿透屏障墙体所需时间就越短。因此,在污染场地阻截封存时,高价态金属离子的存在会严重影响屏障材料对污染物的阻截性能。
In this paper,with K＋,Ca2＋and Fe3＋as the objects of study,the retardation of Soil-Bentonite（ SB）barrier materials for metal ions with different valence is inspected,meanwhile its adsorption mechanism,migration patterns and permeation behavior are explored so as to provide a theoretical basis for the design of confinement materials in contaminated sites. The results show that SB barrier materials＇ adsorption process for metal ions with different valence is fast,and the higher the valence is,the greater the adsorption capacity is; the fitting of adsorption process conforms to pseudo-second-order adsorption kinetics and Langmuir-Freundlich adsorption equation.Permeability coefficient of K＋,Ca2＋and Fe3＋in SB all has a maximum,and the higher the valence is,the sooner the maximum appears; the high the valence is,the sooner the ion breaks through the barrier wall completely. As a result,during the blocking process the existence of metal ions with higher valence has a strong impact on blocking effect for contaminants by blocking materials.
出处
《地下空间与工程学报》
CSCD
北大核心
2015年第3期695-699,共5页
Chinese Journal of Underground Space and Engineering
基金
国家环保公益性行业科研专项(201309004)
