Synthesis of several hydrophobic ionic liquids (ILs), which might be selected as good candidates for degradation of hydrophobic volatile organic compounds in a two-phase partitioning bioreactor (TPPB), were carried out. Several bioassays were also realized, such as toxicity evaluation on activated sludge and zebrafish, cytotoxicity, fluoride release in aqueous phase and biodegradability in order to verify their possible effects in case of discharge in the aquatic environment and/or human contact during industrial manipulation. The synthesized compounds consist of alkylimidazoliums, functionalized imidazoliums, isoqinoliniums, triazoliums, sulfoniums, pyrrolidiniums and morpholiniums and various counter-ions such as: PF6(-), NTf2(-) and NfO(-). Toxicity evaluation on activated sludge of each compound (5% v/v of IL) was assessed by using a glucose uptake inhibition test. Toxicity against zebrafish and cytotoxicity were evaluated by the ImPACCell platform of Rennes (France). Fluoride release in water was estimated by regular measurements using ion chromatography equipment. IL biodegradability was determined by measuring BOD28 of aqueous samples (compound concentration,1mM). All ILs tested were not biodegradable; while some of them were toxic toward activated sludge. Isoquinolinium ILs were toxic to human cancerous cell lines. Nevertheless no toxicity was found against zebrafish Danio rerio. Only one IL released fluoride after long-time agitation.

International audienceRecently, it has been highlighted that Volatile Organic Compounds (VOCs) could be removed through through the coupling of an absorption step in a solvent followed by biodegradation mainly at the liquid/liquid (solvent/water) interface. Among the solvents fulfilling the required characteristics (non toxicity and no biodegradability, high affinity for VOCs, solvent regeneration, good mass transfer, ...), octyl isoquinolium bis(trifluoromethyl)sulfonimide ionic liquid (IL), [octiq+][Tf2N−], appears especially promising. The first step of the process consists in the absorption of the VOC contained in the air to be treated by the IL as the VOC vapor contacts the IL. In this work we report molecular dynamics simulations of {IL+toluene}/vapor and IL/toluene vapor interfaces to elucidate the physical phenomena ruling the interfacial adsorption of toluene and its absorption by the IL. We first predicted a high affinity between [octiq+][Tf2N−] and toluene, in agreement with experimental data. Moreover, we evidenced an enhancement of the interfacial toluene density, which allowed us improving the understanding of the interfacial capture and degradation of toluene