U and Th speciation in river sediments

A study of the distribution of some natural radionuclides in different chemical fractions of river bottom sediments has been carried out. The study has shown that the majority of the total U in sediments is located in the non-residual fractions, while Th is more likely to be present in the residual...

Descripción completa

Detalles Bibliográficos
Autores: Martínez Aguirre, Aránzazu, García León, Manuel, Ivanovich, M.
Tipo de recurso: artículo
Estado:Versión enviada para evaluación y publicación
Fecha de publicación:1995
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/137190
Acceso en línea:https://hdl.handle.net/11441/137190
https://doi.org/10.1016/0048-9697(95)04759-X
Access Level:acceso abierto
Palabra clave:Radionuclide pollution
Uranium (U)
Thorium (Th)
River sediments
Fertilizer industries
Descripción
Sumario:A study of the distribution of some natural radionuclides in different chemical fractions of river bottom sediments has been carried out. The study has shown that the majority of the total U in sediments is located in the non-residual fractions, while Th is more likely to be present in the residual ones. This difference between U and Th reflects largely a much higher mobility of U relative to Th in surface and near-surface environments. Coprecipitation with amorphous ferromanganese oxyhydroxides is the main process of U and Th incorporation from the water column into the soil particles. Moreover, the distribution of the radionuclides and the analysis of the Th/U mass ratios in different chemical fractions of sediments has made an unequivocal connection between the enhanced U content in river sediments and the wastes discharged into the rivers by the operation of fertilizer industries.