Ionic liquid-modified composites for the adsorptive removal of emerging water contaminants: A review

In last decade, the application of ionic liquids (ILs), as green materials, in more sustainable technologies has received great attention. They have attractive properties, which make them valuable materials to be used in a wide range of fields, especially in separation and purification technologies. In recent years, it was shown that immobilizing and modifying the solid supports with ILs are efficient ways to exploit IL capability in the adsorptive removal processes. This review highlights the recent developments in the application of IL-modified adsorbents in the removal of contaminants from aqueous solutions. The gathered information indicates that they can effectively enhance the adsorption affinity and capacity of sorbent for treating both organic and inorganic pollutants. Effect of several parameters such as sorbent dosage, pH, contact time, concentration and temperature on the removal efficiency was studied. Among them, pH was found to be the most important parameter and different trends were observed, depend on the nature of both ILs' composite adsorbent and adsorbate. Also, the adsorption improvements and mechanisms are comprehensively discussed. On the other hand, the good reusability of these adsorbents compensated for the high cost of ILs. Although the applications of ILs in adsorption treatment have been developing rapidly, it is still far from achieving the ultimate goal of commercialization.