The binodal data for the systems containing the POELE10 and KC6H11O7/K2C2O4/K3C6H5O7 were determined at the T = (288.15, 298.15, 308.15) K. The three experiential equations were used to fit the binodal data and they achieved the satisfactory fitting effect. The effect of salt type on the phase-seperation ability of salt was studied. It was found that the phase-seperation ability of the salt with the higher valence anion is stronger than that with lower valence anion, namely, the order of the phase-seperation ability for the investigated salts is potassium citrate > potassium oxalate > potassium gluconate, which is also validated by the effective excluded volume (EEV). The (liquid + liquid) equilibrium data for the studied systems were determined and correlated by using the Pitzer-Debye-Huckel equation and Chen-NRTL model along with the Flory-Huggins equation, and good agreement was obtained with using these thermodynamic models. (C) 2013 Elsevier Ltd. All rights reserved.