I&EC 180 |
| A category of alternative solvents known as room temperature ionic liquids (RTILs) has been considered for the extraction of organic soil contaminants. A hydrophobic RTIL, 1-butyl-3-methyl imidazolium hexafluorophosphate ([bmim]PF6) and a hydrophilic RTIL,1-butyl-3-methyl imidazolium chloride ([bmim]Cl), were selected as representative imidazolium-based RTILs to assess the extraction of several organic contaminants (OCs) from two model soils. The two soils were montmorillonite (with clay minerals, high surface area, and no organic matter) and glacial till (with organic matter). The soils were spiked separately with DDT, dieldrin, hexachlorobenzene and pentachlorophenol. For comparison with RTILs, the OCs were extracted from soils using several organic solvents. With the exception of DDT, extractions of OCs from montmorillonite with [bmim]PF6 (79 to 92 percent) were nearly as effective as extractions with acetone and ethanol (85 to 100 percent). The extractions of OCs from glacial till with RTILs (15 to 61 percent) were less effective than extractions with organic solvents (59 to 100 percent). The [bmim]Cl was as efficient as [bmim]PF6 for extraction of OCs from glacial till, while [bmim]PF6 was more efficient than [bmim]Cl for extraction of OCs from montmorillonite. The two RTILs were most effective for the extraction of dieldrin (the heaviest OC) from both soils, and were least effective for extraction of DDT and HCB from montmorillonite and glacial till soils, respectively. The extraction results for glacial till show dependence of OC extraction on the viscosity and melting point of RTILs. |
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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 |