Experimental and modeling study for the removal of formic acid through bulk ionic liquid membrane using response surface methodology

Abstract

In this study, formic acid removal from its aqueous solutions through bulk ionic liquid membrane (BILM) was investigated. Tributyl phosphate (TBP) as a carrier in imidazolium-based ionic liquids was used. D-optimal design based on response surface methodology has been applied to investigate the effect of various operating factors. Initial formic acid concentration, TBP concentration, and NaOH concentration were selected as numerical factors, and ionic liquid type was chosen as a categorical factor. The model equations were obtained to determine BILM process behavior. The removal efficiencies, represented by the extraction and stripping efficiencies, were calculated from the experimental data. The highest removal efficiencies were determined at higher concentration values of TBP and NaOH. All ionic liquids studied in this study had good transport selectivity for the removal of formic acid. The design study showed that BILM is an effective method for the removal of formic acid from the water.

Keywords:

• Bulk ionic liquid membrane (BILM)
• D-optimal design
• Formic acid
• Ionic liquids
• Response surface methodology (RSM)
• Tributyl phosphate

Acknowledgements

We also wish to thank TUBITAK for financial support through the program as 2211-C Priority Areas Doctorate Programme Scholarship.

Additional information

Funding

This study was funded by Istanbul University (Bilimsel Araştirma Projeleri Birimi, Istanbul Üniversitesi) with the Project Number 53978.