Calculation and correlation of the Na 2SO 4–NaCl–H 2O 2–H 2O system at the temperature 288.15 K using the extended Pitzer model

Abstract

The extended Pitzer model has been used for calculation and correlation of the ternary NaCl–H 2O 2–H 2O, Na 2SO 4–H 2O 2–H 2O and the quaternary Na 2SO 4–NaCl–H 2O 2–H 2O systems at the temperature of 288.15 K. The necessary thermodynamic functions (binary and ternary parameters of interaction and thermodynamic solubility products) have been derived from a least-squares optimization procedure with couples activity coefficient with solubility data and the theoretical solubility isotherms has been plotted. Good agreement with experimental solubility for ternary and quaternary mixtures indicates that the model can be successfully used to predict the component solubility of the electrolyte–nonelectrolytes–water systems containing peroxide. In addition, the Pitzer interaction parameters and the thermodynamic solubility product of 4Na 2SO 4⋅2H 2O 2⋅NaCl and Na 2SO 4⋅0.5H 2O 2⋅H 2O at 288.15 K are obtained.