Predicting mobility of alkylimidazolium ionic liquids in soils

Background, aim, and scope Ionic liquids (ILs) are a new class of alternative solvents that make ideal non-volatile media for a variety of industrial processes such as organic synthesis and biocatalysis, as alternative electrolytes, as phases and phase modifications in separation techniques, and as alternative lubricants. Once the large-scale implementation of ILs begins, the industrial application will follow. In view of their great stability, they could slip through classical treatment systems to become persistent components of the environment, where the long-term consequences of their presence are still unknown. Sorption on soils has a critical effect on the transport, reactivity, and bioavailability of organic compounds in the environment. So far, the IL sorption mechanism was investigated solely on the basis of batch experiments, which precluded any assessment of the dynamics of the process. An understanding of the mobility of ILs in soil columns is crucial for an accurate prediction of their fate in the soil. The aim of this study therefore was to investigate in detail the mobility of selected imidazolium ILs on three soil types. Moreover, it was decided to study these processes in soils from the coastal region (Gdansk, Poland), which usually constitute a very important geochemical compartment, participating in the transport of contaminants on their way to the sea.