Behavior of hydrophobic ionic liquids as liquid membranes on phenol removal: Experimental study and optimization

TL;DR

This study investigates the use of hydrophobic ionic liquids as stable, efficient liquid membranes for phenol removal, demonstrating high extraction and stripping efficiencies with optimized parameters and comparing favorably to organic membranes.

Contribution

It provides experimental evidence that hydrophobic ionic liquids can serve as effective, stable liquid membranes for phenol removal, with optimized conditions enhancing performance.

Findings

Phenol removal efficiency up to 96.21%

Stripping efficiency up to 98.10%

Lower membrane loss compared to organic solvents

Abstract

Room temperature ionic liquids show potential as an alternative to conventional organic membrane solvents mainly due to their properties of low vapor pressure, low volatility and they are often stable. In the present work, the technical feasibilities of room temperature ionic liquids as bulk liquid membranes for phenol removal were investigated experimentally. Three ionic liquids with high hydrophobicity were used and their phenol removal efficiency, membrane stability and membrane loss were studied. Besides that, the effects of several parameters, namely feed phase pH, feed concentration, NaOH concentration and stirring speeds on the performance of best ionic liquid membrane were also evaluated. Lastly, an optimization study on bulk ionic liquid membrane was conducted and the maximum phenol removal efficiency was compared with the organic liquid membranes. The preliminary study shows that high phenol extraction and stripping efficiencies of 96.21% and 98.10%, respectively can be achieved by ionic liquid membrane with a low membrane loss which offers a better choice to organic membrane solvents.