文献类型：期刊文献

英文题名：Characterization of diatomite and its application for the retention of radiocobalt: role of environmental parameters

作者：Sheng, Guodong[1,2];Dong, Huaping[1];Li, Yimin[1]

机构：[1]Shaoxing Univ, Sch Chem & Chem Engn, Shaoxing 312000, Peoples R China;[2]Chinese Acad Sci, Inst Plasma Phys, Key Lab Novel Thin Film Solar Cells, Hefei 230031, Peoples R China

年份：2012

卷号：113

起止页码：108

外文期刊名：JOURNAL OF ENVIRONMENTAL RADIOACTIVITY

收录：SCI-EXPANDED(收录号：WOS:000309087700015)、、EI(收录号：20123615397079)、Scopus(收录号：2-s2.0-84861819420)、WOS

基金：Financial supports from the National Natural Science Foundation of China (21001002: 20907055: 21071147: 20971126), 973 project (2011CB933700), the Knowledge Innovation Program of CAS and Special Foundation for High-level Waste Disposal (2007-840) are greatly acknowledged.

语种：英文

外文关键词：Co(II); Retention; Diatomite; Temperature; Thermodynamic data

外文摘要：Clay minerals have been extensively studied because of their strong sorption and complexation ability. In this work, diatomite was characterized by using acid-base titration. Retention of radionuclide Co-60(II) from aqueous solution by sorption onto diatomite was investigated by using batch technique under various environmental conditions such as pH, ionic strength, humic acid (HA), fulvic acid (FA), and temperature. The results indicated that the sorption of Co(II) onto diatomite was strongly dependent on pH. At low pH value, the sorption of co(II) was dominated by outer-sphere surface complexation and ion exchange with Na+/H+ on diatomite surfaces, whereas inner-sphere surface complexation was the main sorption mechanism at high pH value. The D-R model fitted the sorption isotherms better than the Langmuir and Freundlich models. The thermodynamic parameters (Delta H-0, Delta S-0 and Delta G(0)) calculated from the temperature-dependent sorption isotherms suggested that the sorption of Co(II) was an endothermic and spontaneous process. In addition, diatomite showed higher sorption capacity than that of lots of the sorbents reported in the literatures we surveyed. From the results of Co(II) removal by diatomite, the optimum reaction conditions can be obtained for the maximum removal of Co(II) from water. It is clear that the best pH values of the system to remove Co(II) from solution by using diatomite are 7-8. Considering the low cost and effective disposal of Co(II)-contaminated wastewaters, the best condition for Co(II) removal is at room temperature and solid content of 0.5 g/L The results might be important for assessing the potential of practical application of diatomite in Co(II) and related radionuclide pollution management. (C) 2012 Elsevier Ltd. All rights reserved.