The relationship of the activity ratios (ARs) of U/Th-series nuclides and associated factors (pH, Eh, and the concentrations of Cl⁻ and SO₄²⁻) in the hot spring area of Taipei were determined. The contents of U and Th in water decreased with increasing pH. The ²³⁴U/²³⁸U ARs have been ascribed to alpha recoil and selective leaching of ²³⁴U, while the ²³⁴U/²³⁸U disequilibrium was not significant with regard to the statistical error. Variations of ²³⁰Th/²³⁴U ARs can be attributed to the different chemical properties of ²³⁰Th and ²³⁴U. The disequilibrium of ²²⁶Ra/²³⁰Th can be ascribed to the complexation of thorium with Cl⁻and SO₄²⁻, and to the co-precipitation of radium with sulfates. The disequilibrium of²²⁸Th/²³²Th can be due to the co-precipitation of ²²⁸Ra with (Ba,Pb)SO₄ and to the migration of ²²⁸Th from the sediment into the water.
關聯:
Journal of Radioanalytical and Nuclear Chemistry vol. 258, no. 2 pp.281-286
