Removal and separation of mixed ionic dyes by solvent extraction

Abstract

To reduce environmental pollution from dyeing wastewater, reverse micelles were prepared and used for the removal and separation of anionic Color Index (CI) Reactive Yellow 3 and cationic CI Basic Red 14 in mixed dye aqueous solution. The effect of the amount of dye and surfactant on removal rates of dyes was investigated. An ion-exchange reaction model was used to fit the experimental data. Ultraviolet-visible absorption spectra were employed to evaluate the state of dyes in mixed dye aqueous solution during the removal process. In addition, the removed dyes were recovered by back extraction and reused for dyeing fabrics. The results obtained indicated that the removal of dyes was increased with increasing the amount of surfactants, while the dye concentration exhibited the reverse trend. The dye extraction process could be described by the ion-exchange reaction equations. The mixed dyes could be removed and separated for the attractive force between dyes and the counter ionic surfactant. The mixed dyes were separated and recovered, which exhibited a good dyeing property.