Phase diagrams corresponding to aqueous biphasic systems of salt (the organic ionic liquid of salts [C 4 mim]Cl, [C 6 mim]Cl, and [C 8 mim]Cl) + salt (K 3 PO 4 , K 2 CO 3 ) + water were determined at 298.15 K. The binodal curve was fitted to the Merchuk equation. Tie lines assigned from mass phase ratios according to the lever arm rule were satisfactorily described using the Othmer-Tobias and Bancroft equations.

In this study, binodal curves and tie line data of [Amim]Cl + salt (K 3 PO 4 , K 2 HPO 4 , K 2 CO 3 ) + water aqueous biphasic systems (ABS) were measured and correlated satisfactorily with the Merchuk equation and Othmer-Tobias and Bancroft equations, respectively. [Amim]Cl could be recovered from aqueous solutions using the ABS, and the recovery efficiency could reach 96.80 %. The recovery efficiency was influenced by the concentrations of the salts and their Homeister series: K 3 PO 4 > K 2 HPO 4 > K 2 CO 3 . Our method provides a new and effective route for the recovery of hydrophilic IL using [Amim]Cl + salt + water ABS from aqueous solutions.

No abstract