Published online by Cambridge University Press: 06 June 2009
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.
To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Dropbox account. Find out more about saving content to Dropbox.
To save this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Google Drive account. Find out more about saving content to Google Drive.