TY  - JOUR
AU  - Silva, M. L. da
AU  - Bonotto, D. M.
PY  - 2015//
TI  - Uranium isotopes in groundwater occurring at Amazonas State, Brazil
JO  - Applied Radiation and Isotopes
SP  - 24
EP  - 33
VL  - 97
KW  - Amazon area
KW  - Dissolved uranium
KW  - Groundwater
KW  - Tube wells
KW  - U/U activity ratio
N2  - This paper reports the behavior of the dissolved U-isotopes 238U and 234U in groundwater providing from 15 cities in Amazonas State, Brazil. The isotope dilution technique accompanied by alpha spectrometry were utilized for acquiring the U content and 234U/238U activity ratio (AR) data, 0.01–1.4µgL−1 and 1.0–3.5, respectively. These results suggest that the water is circulating in a reducing environment and leaching strata containing minerals with low uranium concentration. A tendency to increasing ARs values following the groundwater flow direction is identified in Manaus city. The AR also increases according to the SW–NE directions: Uarini→Tefé; Manacapuru→Manaus; Presidente Figueiredo→São Sebastião do Uatumã; and Boa Vista do Ramos→Parintins. Such trends are possibly related to several factors, among them the increasing acid character of the waters. The waters analyzed are used for human consumption and the highest dissolved U content is much lower than the maximum established by the World Health Organization. Therefore, in view of this radiological parameter they can be used for drinking purposes.
SN  - 0969-8043
UR  - https://www.sciencedirect.com/science/article/pii/S096980431400431X
N1  - exported from refbase (http://www.uhydro.de/base/show.php?record=140), last updated on Fri, 26 Jan 2024 13:19:04 +0100
ID  - Silva+Bonotto2015
ER  -