US EPA

8778252 

Journal Article 

Uranium in ground water samples of Northern Greece 

Ioannidou, A; Samaropoulos, I; Efstathiou, M; Pashalidis, I 

2011 

Yes 

Journal of Radioanalytical and Nuclear Chemistry
ISSN: 0236-5731
EISSN: 1588-2780 

289 

2 

551-555 

English 

10.1007/s10967-011-1115-x 

WOS:000292570000035 

http://link.springer.com/10.1007/s10967-011-1115-x
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The activity concentrations of U-238 and U-234 have been determined in groundwater samples of hot springs and deep wells in Northern Greece. The analysis was performed by alpha spectroscopy after pre-concentration and separation of uranium by cation exchange (Chelex 100 resin) and finally its electro-deposition on stainless steel discs. The uranium concentration in deep wells and springs varies strongly between 0.15 and 7.66 mu g L-1 and the corresponding U-238 and U-234 activity concentrations between 1.82-95.3 and 1.70-160.1 mBq L-1, respectively. The obtained isotopic ratio U-234/U-238 varies between 0.95 and 1.74 indicating a disturbed radioactive equilibrium between the two uranium isotopes. In the studied waters uranium concentrations in solution decrease with increasing pH in the pH range between 7 and 9. This is attributed to the fact that at lower pH dissolution of soil minerals occurs and uranium which is adsorbed or forms solid solution with the geological matrix enters the aqueous phase. The strong dependence of the uranium concentration in the studied waters from the dissolution of the geological matrix is corroborated by the strong correlation of the uranium concentration with the electrical conductivity measured in the ground waters under investigation. 

Uranium; Waters; pH effects; Alpha spectroscopy; U-234/U-238 activity ratio; RADIOACTIVITY; CARBONATE; NUCLIDES; ISOTOPES