Removal and recovery of CI reactive red 195 from effluent by solvent extraction using reverse micelles

Abstract

To reduce environmental pollution by CI reactive red 195, solvent extraction of the dye from water was performed by using reverse micelles prepared from hexadecyltrimethylammonium bromide and amyl alcohol. The effects of dye concentration, surfactant concentration, sodium chloride concentration, and pH on the removal percentage of the dye were investigated. A pseudo-first-order kinetic model and an ion-exchange reaction model were used to fit the experimental data. Ultraviolet-visible absorption spectra and particle size distribution were analyzed to evaluate the state of the dyes in the reverse micelles. In addition, the dyes were recovered by backward extraction and then reused for dyeing cotton fabric. The removal percentage of CI reactive red 195 increased with increasing concentrations of surfactant and sodium chloride. Increasing dye concentration and pH values resulted in less removal of dyes. The dye extraction process could be described by the pseudo-first-order kinetic model and by the ion-exchange reaction equations. The state of the dye in the reverse micelles was similar to that in bulk water. The mean particle diameter of the reverse micelles was 10.8 nm. Dye recovery was improved by adding a counterionic surfactant. The recovered CI reactive red 195 had a good dyeing property for cotton fabric.