title: Adsorption and desorption kinetics of (60)Co and (137)Cs in fresh water rivers.
abstract: Radionuclides released in water systems--as well as heavy metals and organic toxicants--sorb to both the suspended solid particles and the bed sediments. Sorption is usually represented mathematically by the distribution coefficient. This approach implies equilibrium between phases and instantaneous fixation (release) of the pollutant onto (from) the surface of the soil particle. However, empirical evidence suggests that for some radionuclides the fixation is not achieved instantaneously and that the reversibility of the process can be slow. Here the adsorption/desorption kinetics of (60)Co and (137)Cs in fresh water environments were simulated experimentally and later on modelled mathematically, while the influence of the most relevant factors affecting the sorption were taken into account. The experimental results suggest that for adsorption and the desorption more than 24 h are needed to reach equilibrium, moreover, It was observed that the desorption rate constants for (60)Co and (137)Cs lie within ranges which are of two to three orders of magnitude lower than the adsorption rate constants.
authors.affiliation: Department of Hydrology and Hydraulic Engineering, Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050, Brussels, Belgium; Biosphere Impact Studies, Belgian Nuclear Research Centre SCK•CEN, Boeretang 200, BE-2400, Mol, Belgium. Electronic address: ffperez@sckcen.be.
authors.forename: Fabricio
authors.initials: F
authors.lastname: Fiengo Pérez
authors.affiliation: Biosphere Impact Studies, Belgian Nuclear Research Centre SCK•CEN, Boeretang 200, BE-2400, Mol, Belgium.
authors.forename: Lieve
authors.initials: L
authors.lastname: Sweeck
authors.affiliation: Department of Hydrology and Hydraulic Engineering, Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050, Brussels, Belgium.
authors.forename: Willy
authors.initials: W
authors.lastname: Bauwens
authors.affiliation: Biosphere Impact Studies, Belgian Nuclear Research Centre SCK•CEN, Boeretang 200, BE-2400, Mol, Belgium.
authors.forename: May
authors.initials: M
authors.lastname: Van Hees
authors.affiliation: Laboratory of Analytical and Environmental Chemistry, Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050, Brussels, Belgium.
authors.forename: Marc
authors.initials: M
authors.lastname: Elskens
mesh_terms: D000327:Adsorption; D001530:Belgium; D002588:Cesium Radioisotopes / Q000032:analysis*; D003037:Cobalt Radioisotopes / Q000032:analysis*; D005618:Fresh Water / Q000737:chemistry*; D019015:Geologic Sediments / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008962:Models, Theoretical; D045483:Rivers / Q000737:chemistry*
chemical_list: D002588:Cesium Radioisotopes; D003037:Cobalt Radioisotopes
keywords: Adsorption; Desorption; Distribution coefficient; Kinetics; Radionuclides; Uncertainty analysis