Abstract
Adsorption and migration experiments of 85Sr in a coastal sand have been performed by a batch and a column methods respectively, in order to study influence of coexistent humic acid on adsorption and migration behavior of radionuclide in a geological medium.
Humic compounds of 85Sr, which were hardly adsorbed on the sand, were formed in the solution containing humic acid. However, distribution coefficient of 85Sr for the sand, determined by the batch method, was not affected by coexistent humic acid. This was attributed to that the binding force between 85Sr and humic acid was significantly smaller than that between 85Sr and the sand. Migration amounts of 85Sr into a deeper region of sand layer in the column increased under coexistence of humic acid, because a dissociation process of the humic compounds did not equilibrate in experimental condition of the column method. Such migration behavior of 85Sr could be evaluated by applying the migration model talking account of kinetics in the dissociation process.
