An excess Gibbs free energy model that is composed of the noneelectrolyte NRTL-NRF model as short range contribution and Pitzer-Deby-Huckel equation as long range part is applied to model strong aqueous electrolyte solutions. The ion specific interaction energy parameters appearing in the short range part of the model are obtained for water, various cations including Na+, Li+, K+, Cs+, Rb+, NH4+, H+, Ba2+, Ca2+, Mg2+, Al3+ and Cr3+ and several anions including Cl-, Br-, OH-, NO3-, Ac-, I- , F- and SO42-. The experimental data of activity coefficient of 62 binary aqueous electrolyte solutions at 298 K are simultaneously used to achieve the parameters. The correlation results of the model are in good agreements with the experiment. Comparisons of the activity coefficient correlations with those of E-NRTL model show more accuracy of the present model, however the results of Pitzer model is better than present model. The osmotic coefficients of the binary electrolytes at 298 K are calculated with good accuracy using the present model. Also some binary electrolytes have been taken in to account in temperature range of 273-373 K to obtain temperature dependency of the interaction parameters. The model extension for ternary aqueous electrolytes is done using calculations of phase diagrams and osmotic coefficients of some mixed salt systems.

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