Temperature-Sensitive Ionic Liquid-Based Dispersive Microextraction for Removal of Industrial Dyes in Water

Abstract

In this study, a new and effective temperature-sensitive ionic liquid-based dispersive microextraction method was developed for dye removal from water. Through the temperature change, the ionic liquid (IL) could complete dispersion in the aqueous phase to fully contact with the dyes, and then it was recovered as particles enriching target substance by cooling. Parameters including chemical structure and amount of IL, dispersing solvent and its volume, extraction temperature, extraction time, pH adjustment and ionic strength were investigated and optimized in detail. Under the optimized conditions, the extraction recovery was 98.9% of methyl violet, 95.6% of Congo red, and 98.8% of methylene blue, respectively. The results showed that the major driving force for the extraction might be the hydrophobic interaction between the dye and IL. In short, the proposed technique is rapid, simple, relatively inexpensive and effective. This implies meaningful information for further research and application in the field of actual samples.

Keywords

• ionic liquid, temperature-sensitive, microextraction, dye removal