ASSESSMENT OF ENVIRONMENTAL IMPACT OF PYRIDINIUM-BASED IONIC LIQUID

Ionic liquids seemed to be primary alternatives to commonly used solvents because of their attractive properties e.g. low volatility, non-flammability, adjustable miscibility, reusability as well as high thermal, chemical and electrochemical stability. However, their solubility in water could lead to water pollution and their high stability results in persistence in the environment. The aim of our study was to assess environmental risks of ionic liquid 1-butyl-3-methylpyridinium dicyanamide ([bmpyr][dca]) and to compare it to some commonly used solvents. For acute toxicity assessment several biotests were performed with: bacteria Vibrio fischeri, mixed bacterial culture (activated sludge), duckweed Lemna minor, white mustard Sinapis alba, garden cress Lepidium sativum and brine shrimp Artemia sauna. Toxicity testing showed high toxicity of investigated ionic liquid to all organisms, especially to Lemna minor and Vibrio fischeri. In spite of excellent properties of ionic liquids in comparison to commonly used solvents, investigated ionic liquid [bmpyr][dca] showed much higher toxicity to chosen test organisms than common solvents. It was not biodegradable and thus possibility of its persistence in the environment can be expected.