Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.


Issue 3, 2015
Previous Article Next Article

When can ionic liquids be considered readily biodegradable? Biodegradation pathways of pyridinium, pyrrolidinium and ammonium-based ionic liquids

Author affiliations

Abstract

Ionic liquids have been the subject of intense interest over the past decade due to their unique structures which can be tuned to modify the physicochemical properties of the solvent. Nevertheless, industrial processes rarely involve ILs, partly because our understanding of their environmental impact and biodegradability is still in its infancy. The biodegradability criteria for chemical compounds have been defined by the OECD, according to standard protocols in which a chemical is exposed to microbes in an activated sludge over a period of 28 days. However, most reports on IL biodegradation have concentrated on ultimate biodegradability, and have neglected to identify the metabolites along the biodegradative pathway. In fact, intermediate metabolites can be more toxic than the parent molecule and may have a completely different environmental profile. We have studied the antimicrobial activities and biodegradation kinetics of ten pyridinium, pyrrolidinium and ammonium-based ionic liquids incubated with either a pure strain of Rhodococcus rhodochrous ATCC 29672 or an activated sludge, and have also determined their degradation pathways using 1H NMR and LC-MS, with accompanying control experiments under abiotic conditions. Several intermediary metabolites were identified and quantified. All the ILs (except a long-chain alkylpyridinium in C6) proved to be “readily biodegradable” with the pure strain (80–100% degradation) under the conditions of the test, which was not the case with the activated sludges; however, in 3 cases of 10, the biodegradation resulted in an undesirable accumulation of metabolites.

Graphical abstract: When can ionic liquids be considered readily biodegradable? Biodegradation pathways of pyridinium, pyrrolidinium and ammonium-based ionic liquids

Back to tab navigation

Supplementary files

Article information


Submitted
01 Oct 2014
Accepted
27 Nov 2014
First published
27 Nov 2014

Green Chem., 2015,17, 1479-1491
Article type
Paper
Author version available

When can ionic liquids be considered readily biodegradable? Biodegradation pathways of pyridinium, pyrrolidinium and ammonium-based ionic liquids

Y. Deng, I. Beadham, M. Ghavre, M. F. Costa Gomes, N. Gathergood, P. Husson, B. Légeret, B. Quilty, M. Sancelme and P. Besse-Hoggan, Green Chem., 2015, 17, 1479
DOI: 10.1039/C4GC01904K

Social activity

Search articles by author

Spotlight

Advertisements