Membrane behavior of bentonite-amended Fukakusa clay in K, Na and Ca solutions  

作　　者：唐强 刘维 王恒宇 程蓉 钱寅飞 

机构地区：[1]School of Urban Rail Transportation, Soochow University, Suzhou 215131, China [2]Research Center of Coastal and Urban Geotechnical Engineering, Zhejiang University, Hangzhou 310058, China [3]Environmental Sanitation Administration Agency, Suzhou 215131, China

出　　处：《Journal of Central South University》2016年第12期3122-3131,共10页中南大学学报（英文版）

基　　金：Projects(51179168,51308310)supported by National Natural Science Foundation of China;Project(LQ13E080007)supported by Zhejiang Provincial Natural Science Foundation of China;Project supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars(Chinese State Education Ministry)

摘　　要：Bentonite has been proven to be effective in enhancing the membrane property of clay, by which landfill liners can have better barrier performance with regard to the migration of contaminants. In this work, 5% sodium bentonite amended with locally available Fukakusa clay was utilized to evaluate the membrane behavior toward different kinds of ions： K, Na and Ca. The chemico-osmotic efficiency coefficient, co, was obtained in electrolyte solution with different concentrations of 0.5, 1, 5, 10, and 50 mmol/L. According to the results, solute type and ion valence have a significant effect on membrane behaviors. Additionally, co continually decreased as the Na and Ca concentrations increased, which is consistent with the Gouy-Chapman theory. The membrane behavior toward Na was similar to that toward K, according to the chemico-osmotic efficiency coefficient co. In the case of the divalent ion Ca, the membrane behavior was lower compared to monovalent ions Na and K at the same concentration. The mechanisms of the membrane performance change were discussed with the assistance of XRD patterns, free-swelling results and SEM images.Bentonite has been proven to be effective in enhancing the membrane property of clay,by which landfill liners can have better barrier performance with regard to the migration of contaminants.In this work,5% sodium bentonite amended with locally available Fukakusa clay was utilized to evaluate the membrane behavior toward different kinds of ions: K,Na and Ca.The chemico-osmotic efficiency coefficient,ω,was obtained in electrolyte solution with different concentrations of 0.5,1,5,10,and 50 mmol/L.According to the results,solute type and ion valence have a significant effect on membrane behaviors.Additionally,ω continually decreased as the Na and Ca concentrations increased,which is consistent with the Gouy-Chapman theory.The membrane behavior toward Na was similar to that toward K,according to the chemico-osmotic efficiency coefficient ω.In the case of the divalent ion Ca,the membrane behavior was lower compared to monovalent ions Na and K at the same concentration.The mechanisms of the membrane performance change were discussed with the assistance of XRD patterns,free-swelling results and SEM images.

关 键 词：bentonite-amended Fukakusa clay chemico-osmotic efficiency coefficient mechanism membrane behavior 

分 类 号：X705[环境科学与工程—环境工程] X505