Fate of Ionic Liquids in Soils and Sediments

The fate of ionic liquids in soils and sediments is significant for the sustainable application of ILs in industry. We are obliged to understand how these compounds are transformed in (bio-) chemical processes and how long they will persist in the environment. In addition, we must understand how ionic liquids interact in complex systems. This review analyzes and summarizes the results obtained to date by a significant number of research groups on solution and surface interactions of ionic liquids. Due to the structural similarity of ionic liquids with surfactants, it is possible to determine the interaction mechanism of the ionic liquids, with soils and sediments. It was found that highly lipophilic ILs possessing long alkyl substituents or large organic anions are expected to interact with soils/sediments organic matter thus being rather immobile. Conversely, the weak lipophilic ILs probably be the most mobile in the soil and water, due to their high water solubility as well as their lower affinity to organic matter. For this reason they are thought to present the greatest threat for ground water contamination. Keywords: Ionic liquids, environmental fate, sorption, sediments, surface activity, xenobiotics, abiotic environment, electrospray, high performance liquid chromatography (HPLC), Micelle formation, L-type isotherm, H-type isotherm, S-type isotherm