Removal of acetic acid from aqueous solutions using bulk ionic liquid membranes: A transport and experimental design study

In this research, the removal of acetic acid from aqueous solutions using bulk ionic liquid membrane (BILM) containing tributyl phosphate (TBP) was investigated. The effects of various parameters in BILM like the stirring, the initial acetic acid concentration in feed phase, the extractant (TBP) concentration and the selectivity of different ionic liquids in the membrane phase and the stripping phase type and concentration were investigated. For this purpose, a statistical experimental design study was applied. Face-centered central composite design (FCCCD) was utilized as the experimental design. The values of extraction and stripping removal efficiencies of different BILM systems were determined, and compared. Also, the optimal conditions to acquire the higher removal efficiency were determined. The higher removal efficiency values were obtained in systems where the TBP concentration in the membrane phase was 2 mol/L and NaOH concentration in the stripping phase was 4 N. The removal study shows that BILM can be used as an effective method for the removal of acetic acid from its aqueous solutions.