ADSORPTION OF ASTRAZON RED 6B ONTO SEPIOLITE BY FULL FACTORIAL DESIGN

Abstract

In this study, adsorption of Astrazon Red 6B (AR6B) in aqueous solutions by sepiolite was studied using full factorial experimental design. The interactive effects of the three most important operating variables, initial AR6B concentration (75-175 mg/L), initial pH (2-8) and temperature (20-40 degrees C), on the amount of dye adsorbed at equilibrium were studied in batch adsorption experiments. A total of 63 experimental runs were set, and the experimental data fitted to the empirical second-order polynomial model for maximum adsorption of AR6B from aqueous solutions by sepiolite. An initial concentration of 175 mg/L, pH 8 and 20 degrees C were found to be optimal for the maximum removal of AR6B from aqueous solutions. Analysis of variance of the quadratic model showed that the model was highly significant (R-2 = 0.9962). The result showed that adsorption capacity of dye increased with increasing dye concentration and pH while it was decreasing with increasing temperature. The equilibrium data were also analyzed by the Langmuir and Freundlich adsorption isotherm models. The adsorption isotherm data fitted well to Freundlich isotherm.