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Radionuclides behavior in natural water estimate based upon determination physicochemical state of their stable chemical analogs
Published online by Cambridge University Press: 06 June 2009
Abstract
The physicochemical state of radionuclides of Sr, U, REE and Th(IV) and their natural analogs in the river Techya (Chelyabinsk reg., RF) is analyzed in connection with seasonal variations of the chemical composition of water. It is shown that the chemical state of Sr(II) and U(VI) strongly depends on the level of CO2 in the river water. A high level of soluble carbonate leads to co-precipitation of to 10–15% Sr(II) and to 20% U(VI) on the surface of mineral (Ca - Si - Al - O + Fe - O phase mixture) and biological suspensions with the size of >3 micron. The rest of Sr(II) exists in the river water in the form of aqua-cations. Uranium (VI) is present in the water as a set of hydroxo- and carbonate complexes which do not interact with the cation-exchanger and in the form of Ca2UO2(CO3)3 which may be involved in the ion-exchange interaction. Th(IV) and La (III) are found to exist in the water as hydroxo-complexes (<80%) and in the form of suspension (<20%). When the concentration of CO2 in the river water decreases to the level typical of the autumn period, the suspended CaCO3 vanishes and the fraction of Ca2UO2(CO3)3 in the water changes.
- Type
- Research Article
- Information
- Radioprotection , Volume 44 , Issue 5: ECORAD 2008 - Radioecology and Environmental Radioactivity , 2009 , pp. 209 - 215
- Copyright
- © EDP Sciences, 2009
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