Publication Date:
2011-10-23
Description:
The effect of Mg-, Ca-, and Sr–Uranyl-Carbonato complexes with respect to sorption on quartz was studied by means of batch experiments with U(VI) concentration of 0.126 × 10 −6 M in the presence and absence of Mg, Ca, and Sr (each 1 mM) at pH from 6.5 to 9. In the absence of alkaline earth elements, 90% of the U(VI) sorbed on the quartz surface at all pH. In the presence of Mg, Ca, and Sr, the sorption of U(VI) on quartz decreased to 50, 10, and 30%, respectively. Sorption kinetics of U(VI) on quartz is faster in the absence of alkaline earth elements and reached equilibrium after 12 h, whereas in the presence of Mg, Ca and Sr, the kinetics of U(VI) sorption on quartz is pH dependent and attained equilibrium after 24 h. Aqueous speciation calculations for alkaline earth uranyl carbonates were carried out by using PHREEQC with the Nuclear Energy Agency thermodynamic database (NEA_2007) by adding constants for MUO 2 (CO 3 ) 3 2− and M 2 UO 2 (CO 3 ) 3 0 (M = Ca, Mg, Sr). This study reveals that alkaline earth elements can have a significant effect on the aqueous speciation of U(VI) under neutral to alkaline pH conditions and subsequently sorption behavior and mobility of U(VI) in aqueous environments. Content Type Journal Article Category Original Paper Pages 209-219 DOI 10.1007/s10498-011-9120-9 Authors Sreejesh Nair, Department of Hydrogeology, Technische Universität Bergakademie Freiberg, Gustav-Zeuner Str.12, 09599 Freiberg, Germany Broder J. Merkel, Department of Hydrogeology, Technische Universität Bergakademie Freiberg, Gustav-Zeuner Str.12, 09599 Freiberg, Germany Journal Aquatic Geochemistry Online ISSN 1573-1421 Print ISSN 1380-6165 Journal Volume Volume 17 Journal Issue Volume 17, Number 3
Print ISSN:
1380-6165
Electronic ISSN:
1573-1421
Topics:
Chemistry and Pharmacology
,
Geosciences
