Biodegradability of Ionic Liquids – Test Procedures and Structural Design

Abstract

Biodegradability of Ionic Liquids -Test Procedures and Structural DesignBiotic and the abiotic degradabilities of organic chemicals are largely influenced by the potential exposure of substances to organisms and, hence, are key parameters in risk assessment for predicting spatio-temporal environmental concentrations and long-term adverse effects. Degradability in particular could be a bottleneck in designing inherently safer and sustainable ILs, because the tendency of certain ILs to be thermally and chemically very stable is often reflected by their great vis-à-vis biological degradation processes. The following review article will provide an introduction to biodegradation test procedures and will present an overview of existing aerobic and anaerobic IL biodegradation data. The discussion of this data should help to improve the future design of inherently safer ILs, thereby reducing the risks they may pose to humans and the environment.

Composition and structural effects on the adsorption of ionic liquids onto activated carbon

“…Among the most studied destructive techniques the advanced oxidation [13][14][15] and biological treatments can be included. [16][17][18] It is important to consider that in the framework of the development of sustainable processes, the ILs recycling aer regeneration or recovery must be envisaged. 8 Amongst the available non-destructive technologies, distillation, 19 crystallization, 20 nanoltration, 21 pervaporation, 22 separation treatment by using salts 23 and adsorption onto solids [24][25][26][27][28][29][30][31][32] are being increasingly studied.…”

Low melting mixtures in organic synthesis – an alternative to ionic liquids?

“…25 Although the melts consist of chiral components, no asymmetric induction was observed in the catalytic hydrogenation of acetamido α-cinnamate. 20 Quinazoline derivatives were synthesised in high yields via a one-pot three-component coupling reaction of 2-aminoaryl ketones, aldehydes, and ammonium acetate using maltose-DMU-NH 4 Cl. 70 The use of the sweet solutions is still limited due to their relatively high melting points.…”

“…However, one property still in question -their impact on the environment -is intensively discussed. 4,5 Ideally, the components of a green solvent exhibit low acute toxicity and are rapidly degraded in the environment. The current consensus is that ionic liquids cannot be generalised as either green or toxic, but that their environmental impact is strongly dependent on the kind of cation and anion used to produce the IL.…”

Funding activities by the German Federal Environmental Foundation (Deutsche Bundesstiftung Umwelt) in the field of sustainable chemistry

“…Despite their non-volatility they are not necessarily environmentally benign. Actual results show that many of them are persistent and quite a few also are bio-accumulative and/or toxic [23] .…”