Comparison of Three Bacterial Toxicity Assays for Imidazolium-Derived Ionic Liquids

Abstract

Ionic liquids have become leading candidates for replacing many common organic solvents used in the chemical process industry. There is, however, a general lack of toxicology data relevant to wastewater treatment facility microbes for these compounds. In this study, we performed three bacterial-based toxicity assays on several imidazolium-derived compounds as well as the precursor compound 1-methylimidazole. Two of the assays, the Shk1 and Microtox assays, are used as surrogate assays for toxicity to bacterial respiration in activated sludge wastewater treatment plants. The third assay was a direct measure of the effect of toxicity on mixed bacterial culture respiration, using a commercially available consortium of naturally occurring bacteria to obtain