Simulation of strontium sorption onto rocks at high concentrations of sodium nitrate in the solution

Abstract

Geochemical simulation of strontium sorption was considered within the framework of studying the radionuclide geomigration. A chemical model describing the interaction in the solution–surrounding rock system under the experimental conditions was constructed on the basis of the experimental data. The influence of the geochemical simulation detailedness on the calculation results was evaluated in numerical experiments performed using the GeRa code developed by the authors. Three sorption models were used: traditional model of linear sorption with the tabulated value of K_d; new model with variable K_d, measured experimentally and functionally depending on the NaNO₃ concentration; model with direct calculation of chemical interactions, in which the sorption is considered within the framework of the ion-exchange model.