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Enhancement of uranium 234 in springwaters of Águas da Prata, São Paulo, Brazil

1993; Wiley; Volume: 29; Issue: 7 Linguagem: Inglês

10.1029/93wr00607

1944-7973

Daniel Marcos Bonotto,

Radioactive element chemistry and processing

Springwater samples were collected at Águas da Prata, an important spa in Sāo Paulo State, Brazil. The 238 U and 234 U isotopes were evaluated for Platina, Paiol, Villela, Prata‐Radioativa, Prata‐Nova, Boi, Vitória, and Prata‐Antiga springs. An inverse logarithmic correlation was found between 234 U/ 238 U activity ratio and 222 Rn content of the studied waters, which was related to different solution mechanisms of 222 Rn and 234 U nuclides at the rock‐water interface. A linear correlation also exists between the 234 U/ 238 U activity ratios of the studied waters and total dissolved solids, ionic strength, CO 2 partial pressure, and index of base exchange, which indicates that the enhancement of 234 U in solution increases with the degree of weathering in the aquifers. A higher 234 U/ 238 U activity ratio was found to be directly related to a higher value of dissolution rate.