文献类型：期刊文献

英文题名：New insights into Th(IV) speciation on sepiolite: Evidence for EXAFS and modeling investigation

作者：Hu, Baowei[1];Hu, Qingyuan[2];Chen, Chengguang[2];Sun, Yubing[3,4];Xu, Di[5];Sheng, Guodong[1]

机构：[1]Shaoxing Univ, Sch Life Sci, Huancheng West Rd 508, Shaoxing 312000, Peoples R China;[2]Shaoxing Univ, Yuanpei Coll, Dept Architectural Engn, Shaoxing 312000, Peoples R China;[3]Chinese Acad Sci, Inst Plasma Phys, Key Lab Novel Thin Film Solar Cells, POB 1126, Hefei 230031, Peoples R China;[4]Soochow Univ, Sch Radiol & Interdisciplinary Sci, Suzhou 215123, Peoples R China;[5]Chinese Acad Sci, Nanjing Inst Geog & Limnol, State Key Lab Lake Sci & Environm, Nanjing 210008, Jiangsu, Peoples R China

年份：2017

卷号：322

起止页码：66

外文期刊名：CHEMICAL ENGINEERING JOURNAL

收录：SCI-EXPANDED(收录号：WOS:000401594200007)、、EI(收录号：20171503557067)、Scopus(收录号：2-s2.0-85017098096)、WOS

基金：We want to thank Prof. Yuying Huang from Shanghai Institute of Applied Physics, Chinese Academy of Sciences for the measurement and analysis of EXAFS spectra. Financial supports from the Natural Science Foundation of China (21207092, 21577093) and Science and Technology Project of Shaoxing (2014B70041) are acknowledged.

语种：英文

外文关键词：Sepiolite; Th(IV); EXAFS; Surface complexation modeling; Adsorption mechanism

外文摘要：The interaction mechanism of Th(IV) on sepiolite was investigated by batch, EXAFS and surface complexation modeling. The batch experiments revealed that the sorption of Th(IV) on sepiolite remarkably decreased with increasing of ionic strength at pH <5.0, while no effect of ionic strength on Th(IV) removal was observed at pH >5.0. The removal kinetics and isotherms of Th(IV) on sepiolite can be satisfactorily simulated by the pseudo-second-order and Langmuir model, respectively. The analysis of EXAFS spectra for sepiolite-Th(IV) at pH 5.0 and 7.5 indicated that the sorption of Th(IV) on sepiolite at pH 5.0 and 7.5 was inner-sphere surface complexation and surface precipitation, respectively. The results of surface complexation modeling showed that Th(IV) sorption on sepiolite can be fitted by a cation exchange sites (X4Th species) at pH <4.5, an inner-sphere surface complexation (SOTh3+ species) at near neutral and a surface precipitation at pH >7.0 very well. These findings are crucial for the evaluation of fate and transport of Th(IV) at water-mineral interface. (C) 2017 Elsevier B.V. All rights reserved.