Radionuclide partitioning between water and suspended matter

In nuclear environmental impact studies, radionuclide partioning between water and suspended matter is an important process that affects both the geochemical transport and the biological availability of the isotopes. The radionuclide partitioning between water and suspended matter is usually described in terms of distribution coefficients (Kd values), which exhibit a great variability in natural water bodies. In this paper the Kd values for some elements, obtained using different experimental methodologies, are presented both for a riverine and a marine coastal ecosystems. The effect of some parameters as particulate load and total element concentration on the Kd values is investigated within the range of environmental variability. Many measurements of Kd in field are performed on the Po river water (Northern Italy) following the Chernobyl accident. The preferential association of radionuclides with different suspended matter (grain-size types) is given. 11 refs.; 17 figs