Adsorption behaviors of Eu(III) on granite: batch, electron probe micro-analysis and modeling studies
- 47 Downloads
Although granite has been widely considered as the host rock of the high-level radioactive waste (HLRW) repository in the world, the adsorption behaviors of radionuclides on granite are quite complicated and still unclear, especially at molecular scales. In this study, the adsorption behaviors of europium(III) on Beishan granite (BSG), a preliminary selection of host rock for the HLRW repository in China, were explored under environmental conditions combining batch, electron probe micro-analyzer (EPMA), and modeling approaches. X-ray diffraction (XRD) pattern confirmed that albite, quartz and biotite were the main mineralogical components for the BSG grains. Eu(III) species on BSG grains are predominant as the ion exchange (≡X3Eu0) and the inner sphere complexes of ≡SwOEu(OH)20, ≡SsOEu(OH)2,0 ≡SsOEu2+, and ≡SwOEu2+. EPMA showed that the distribution of Eu(III) on BSG grains was strongly correlated to the biotite, which suggested that biotite is the host phase for retarding trivalent actinides in the BSG grains. The presence of soil humic and fulvic acids could enhance Eu(III) adsorption on BSG grains under low-pH conditions, and inhibit the adsorption under higher pH range.
KeywordsGranite Eu(III) Adsorption/desorption Modeling EPMA
This study was supported by the Natural National Science Foundation of China (Grant nos. 21601179, 41573128, 21876172, and 21601169), the Key Laboratory Project of Gansu Province (Grant no. 1309RTSA041), Natural Science Foundation of Jiangxi Province (Grant no. 2016BAB203100) and by the “100-Talent” Program from the Chinese Academy of Sciences.
- Fan QH, Wu WS, Song XP, Xu JZ, Hu JH, Niu ZW (2008) Effect of humic acid, fulvic acid, pH and temperature on the sorption–desorption of Th(IV) on attapulgite. Radiochim Acta 96(3):159–165Google Scholar
- Huang XF, He JG, Xu GQ (2009) Pre-selection research on granite mass for high level radioactive waste repository. World Nucl Geosci 26(4):219–227Google Scholar
- Pan DQ (2014) Sorption of U(VI), Th(IV) and Eu(III) on mineralogical components of granite and bentonite [D]. Lanzhou University, LanzhouGoogle Scholar
- Qi W, Tian LL, Liu B, Lin J, Liu D, Tu PC, Liu D, Li Z, Chen XL, Wu WS (2015) Adsorption of Eu(III) on defective magnetic FeNi/RGO composites: effect of pH, ion strength, ions and humic acid. J Radioanal Nucl Chem 303(3):2211–2220Google Scholar
- Yu T (2012) Study on sorption of Eu(III) and Am(III) onto red earth and bentonite [D]. Lanzhou University, LanzhouGoogle Scholar
- Zhang YJ, Fan XH, Su XG, Zeng JS, Wang Y, Zhou D, Liu DJ, Yao J (2005) Sorption behavior of Pu on granite. J Nucl Radiochem 27(3):137–137Google Scholar
- Zhong X, Wang J, Hung ST, Wang SH (2012) The quantitative study of Pluton selection for the disposal repository of high level waste in Beishan. Uranium Geol 28(3):187–192Google Scholar