Separation and Purification Technology, Vol.138, 71-76, 2014
Removal of Reactive Blue 19 using nonionic surfactant in cloud point extraction
Textile wastewater represents a serious environmental issue due to the presence of toxic dyes. The cloud point extraction, which involves the application of nonionic surfactants at temperatures above the cloud point, was applied in this research to remove Reactive Blue 19 dye from a synthetic wastewater. Nonylphenol with 9.5 ethoxylation degree was used as nonionic surfactant. Dye removal was evaluated considering the influence of surfactant concentration, temperature, and initial dye concentration. Equilibrium data followed the Langmuir isotherm model. Negative Gibbs energy, enthalpy, and entropy showed that the process was spontaneous and exothermal. Dye removal reached 91% when using 7.5 wt% surfactant, at 65.0 degrees C. Cloud point extraction can be used as an efficient alternative for treating textile wastewater containing Reactive Blue 19. (C) 2014 Elsevier B.V. All rights reserved.
Keywords:Reactive Blue 19;Nonionic surfactant;Cloud point extraction;Coacervate phase;Langmuir isotherm