Sorption of Eu(Ⅲ) on GMZ bentonite in the absence/presence of humic acid studied by batch and XAFS techniques  

作　　者：HU Jun1,2,XIE Zhi3,HE Bo3,SHENG GuoDong1,CHEN ChangLun1,LI JiaXing1,CHEN YiXue2 & WANG XiangKe1 1Key Laboratory of Novel Thin Film Solar Cells Institute of Plasma Physics,Chinese Academy of Sciences,Hefei 230031,China 2School of Nuclear Science and Engineering,North China Electric Power University,Beijing 102206,China 3National Synchrotron Radiation Laboratory,University of Science & Technology of China,Hefei 230029,China 

出　　处：《Science China Chemistry》2010年第6期1420-1428,共9页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China (20971126, 20907055 & 20677058);973 project from Ministry of Science and Technology of China;Special Foundation of High-level Waste Disposal (2007-840)

摘　　要：Bentonite has been extensively studied because of its strong sorption ability and low permeability.In this work,the Na-bentonite from Gaomiaozi County (China) has been characterized by XRD,FTIR and acid-base titration.The sorption of Eu(III) on Na-bentonite in the absence/presence of humic acid (HA) was studied at T = 25 ± 2 °C and in 0.01 mol/L NaClO4 solution.The effects of pH,HA,contact time and initial Eu(III) concentrations were also investigated.The results indicate that the sorption of Eu(III) on Na-bentonite was dependent on pH values.The presence of HA had little effect on Eu(III) sorption at low pH values,but decreased Eu(III) sorption at high pH values.X-ray absorption fine structure spectroscopy (XAFS) was applied to characterize the local structural environment of the adsorbed Eu(III) on bare Na-bentonite and HA-bentonite hybrids.The re- sults indicate that Eu(III) was bound to O atoms at a distance of about 2.39  at pH 4.15.The results are crucial for the evalua- tion of the sorption and migration of other trivalent lanthanides and actinides in bentonite as backfill materials.Bentonite has been extensively studied because of its strong sorption ability and low permeability.In this work,the Na-bentonite from Gaomiaozi County (China) has been characterized by XRD,FTIR and acid-base titration.The sorption of Eu(III) on Na-bentonite in the absence/presence of humic acid (HA) was studied at T = 25 ± 2 °C and in 0.01 mol/L NaClO4 solution.The effects of pH,HA,contact time and initial Eu(III) concentrations were also investigated.The results indicate that the sorption of Eu(III) on Na-bentonite was dependent on pH values.The presence of HA had little effect on Eu(III) sorption at low pH values,but decreased Eu(III) sorption at high pH values.X-ray absorption fine structure spectroscopy (XAFS) was applied to characterize the local structural environment of the adsorbed Eu(III) on bare Na-bentonite and HA-bentonite hybrids.The re- sults indicate that Eu(III) was bound to O atoms at a distance of about 2.39  at pH 4.15.The results are crucial for the evalua- tion of the sorption and migration of other trivalent lanthanides and actinides in bentonite as backfill materials.

关 键 词：NA-BENTONITE EU(III) SORPTION HUMIC acid XAFS 

分 类 号：X771[环境科学与工程—环境工程]