Ternary liquid-liquid equilibrium (LLE) data for the mixtures of water + 1,4-butanediol + organic solvent (cyclohexanol, 2-ethyl-1-hexanol, and 1-decanol) were determined at 298.2 K and atmospheric pressure. These three ternary systems exhibit type-1 behavior of LLE. The immiscibility region was found to be larger for the branched aliphatic alcohol, 2-ethyl-1-hexanol. The experimental ternary LLE data were correlated using the UNIQUAC and NRTL models, and the binary interaction parameters were obtained. The reliability of the experimental tie-line data was tested through the Othmer-Tobias and Bachman correlation equations. Distribution coefficients and separation factors were calculated to evaluate the extracting capability of the solvents. The LLE results show that 2-ethyl-1-hexanol may be considered to be a reliable organic solvent for the extraction of 1,4-butanediol from aqueous solutions.

Various ternary and quaternary liquid-liquid phase equilibrium data for water þ phosphoric acid þ solvent(s) have been reported. Salting-out, solvent, and temperature effects on the binodal curve and the tie lines have been highlighted and the capability of solvents with different functional groups to extract phosphoric acid from water has been compared. Studying of influence of magnetic, electromagnetic, and ultrasonic fields on the separation factors and distribution coefficients of aqueous phosphoric acid mixtures has been proposed. Moreover, a summary of the optimized binary interaction values, which resulted from non-random two-liquid (NRTL) and universal quasi-chemical (UNIQUAC) thermodynamic models using genetic algorithm (GA), bee algorithm (BA), and simulated annealing (SA), has been presented. Group method of data handling (GMDH) and linear solvation energy relationship (LSER) methods for the correlation of experimental liquid-liquid equilibrium (LLE) data have been used.