Adsorption of ^133Cs and ^87Sr on pumice tuff：A comparative study between powder and intact solid phase  

作　　者：Mohammad Rajib Chiaki T.Oguchi 

机构地区：[1]Graduate School of Science and Engineering, Saitama University, 255, Shimo Okubo, Sakura ku, Saitama shi, Saitama 338-8570, Japan [2]Bangladesh Atomic Energy Commission, Paramanu Bhaban, E-12/A, Sher-e-Banglanagar, Dhaka 1207, Bangladesh [3]Department of Civil and Environmental Engineering, Saitama University, 255, Shimo Okubo, Sakura ku, Saitama shi, Saitama 338-8570, Japan

出　　处：《Acta Geochimica》2017年第2期224-231,共8页地球化学学报（英文）

摘　　要：This study examines the use of intact samples as an alternative to powder in conventional batch sorption studies to determine the distribution coefficient(K_d).Stable cesium(^(133)Cs) and strontium(^(87)Sr) were used under specified geochemical conditions to compare the Kdvalues of powder and block pumice tuff samples. The aim of the study was to infer any Kddifference under laboratory and field conditions. Kdvalues for block samples were found to be less than one order of magnitude lower than powder materials for both Cs and Sr on fresh tuff, and more than one order of magnitude lower in oxidized tuff. Destruction of micropores in oxidized tuff was estimated to be mainly responsible for reducing Kdvalues in oxidized tuff. However, approximately one order of magnitude difference in Kdvalues indicates that homogenously prepared intact samples can be used for sorption coefficient measurement at closer to in situ conditions. Pore size distribution analysis using mercury intrusion porosimetry revealed that lower Kdvalues on block samples result from lower surface area available as sorption sites due to inaccessible closed pores in the intact solid.This study examines the use of intact samples as an alternative to powder in conventional batch sorption studies to determine the distribution coefficient（Kd）.Stable cesium（^133Cs） and strontium（^87Sr） were used under specified geochemical conditions to compare the Kdvalues of powder and block pumice tuff samples. The aim of the study was to infer any Kddifference under laboratory and field conditions. Kdvalues for block samples were found to be less than one order of magnitude lower than powder materials for both Cs and Sr on fresh tuff, and more than one order of magnitude lower in oxidized tuff. Destruction of micropores in oxidized tuff was estimated to be mainly responsible for reducing Kdvalues in oxidized tuff. However, approximately one order of magnitude difference in Kdvalues indicates that homogenously prepared intact samples can be used for sorption coefficient measurement at closer to in situ conditions. Pore size distribution analysis using mercury intrusion porosimetry revealed that lower Kdvalues on block samples result from lower surface area available as sorption sites due to inaccessible closed pores in the intact solid.

关 键 词：CESIUM STRONTIUM Pumice tuff ADSORPTION 

分 类 号：P589[天文地球—岩石学] X591[天文地球—地质学]