Removal of phenolic compounds from aqueous solutions by emulsion liquid membrane containing Ionic Liquid [BMIM]+[PF6]− in Tributyl phosphate Original Research Article

An experimental study on removal of phenolic compounds from aqueous solutions using Ionic Liquid Mixed Carrier (ILMC) containing 1-Butyl 3 Methylimidazolium Hexafluorophosphate [BMIM]+[PF6]− dissolved in Tributyl phosphate (TBP) in an Emulsion Liquid Membrane (ELM) was carried out. The effects of various operating parameters such as TBP Concentration, stripping reagent concentration, surfactant concentration, emulsification time, phase volume ratio, treat ratio, stirring speed, external phase pH and [BMIM]+[PF6]− concentration in TBP on removal of phenol has been experimentally investigated. It was found that addition of 0.02% (v/v) of [BMIM]+[PF6]− in membrane phase has enhanced the emulsion stability by 5 times and this was carried out using Rose Bengal dye to visualise the emulsion separation. An FTIR spectrum for TBP, ILMC and membrane phase before and after loading of phenol was generated to indicate their interactions and bonding. By selecting appropriate operating conditions, it was found to remove 99.5% of phenol and more than 90% of chlorophenols from aqueous solutions at the treat ratio of 3.