I&EC 181 |
| Room-temperature ionic liquids (ILs) are a new class of chemicals being proposed as environmentally-friendly solvent substitutes for industrial applications. While ILs are relatively benign to the atmosphere because they are non-volatile, their impacts on aquatic organisms and communities are unknown. To assess the potential toxicity of imidazolium- and pyridinium-based ILs, we conducted acute and chronic toxicity bioassays using various aquatic organisms. Imidazolium ILs were relatively less toxic to the freshwater snail Physa acuta (LC50 values ranged from 43 to 882 mg L-1, depending on the anion present) than to Daphnia magna (LC50 ranged from 10.8 to 19 mg L-1). In chronic exposures, P. acuta moved less when exposed to intermediate IL concentrations (6 to 25 mg L-1) than when exposed to high IL concentrations or no IL. Egestion rates of P. acuta, however, declined significantly at all IL concentrations. In general, IL toxicity increased with increasing alkyl chain length. Ongoing research with bacteria (Vibrio fisheri), algae (Scenedesmus quadricauda), aquatic plants (Lemna minor), and larval fish (Pimephales promelas) indicate that IL toxicity varies considerably across organisms and trophic levels. Nonetheless, the potential hazards of IL contamination to freshwater ecosystems appear to be greater than the potential risks to the atmosphere. |
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Ionic Liquids: Not Just Solvents Anymore OR Ionic Liquids: Parallel Futures (Sponsored by Green Chemistry and Engineering, Separation Science and Technology and Novel Chemistry with Industrial Applications Sub-Divisions)
8:15 AM-12:30 PM, Monday, 27 March 2006 Georgia World Congress Center -- B314, Oral
Division of Industrial and Engineering Chemistry |