Studies on the Use of Ionic Liquids as Potential Extractants of Phenolic Compounds and Metal Ions

Abstract

Abstract The present work was aimed at investigating the usefulness of 1‐(n‐alkyl)‐3‐methylimidazolium‐derived ionic liquids (ILs) in liquid–liquid separation processes. For this purpose, a series of 1‐(n‐alkyl)‐3‐methylimidazolium tetrafluoroborates and hexafluorophosphates were prepared by standard synthetic methods and characterized by 1H NMR. Experiments were performed to assess the influence of the alkyl group and the anion on the physical properties of the IL. Equilibrium studies on the extraction of heavy metal ions (copper, zinc, and chromium) and some common pollutant aromatic compounds (phenol, tyrosol, and p‐hydroxybenzoic acid) from aqueous media then were performed with some selected ILs. The effects of temperature and the pH on the distribution ratio of solutes between the IL/aqueous phases also were analyzed. The results suggest that some of the ionic liquids tested are adequate to extract metal ions and organic compounds from aqueous solutions, with a high efficiency in some instances.