A theoretical technique to predict the distribution of radionuclides bound to particles in surface sediments

Distribution coefficients, kd, are widely used as a first approach to the understanding and determination of the eventual fates of metals and radionuclides released into aquatic environments. The theoretical description of their dependence on particle size allows us to identify and separate in environmental samples of superficial bottom sediments the contributions of both naturally occurring particles and contaminated ones coming from radioactive emulsion wastes released into aquatic ecosystems. In this paper, we present the theoretical basis of this technique as well as its application to environmental samples from the Odiel river, an area affected by the phosphate industry, in Southwest Spain. The application of this technique provides both direct information about the extent of the radiological impact and a suitable data set for environmental modelling purposes