Adsorption of acid dyes from aqueous solutions onto sepiolite

Abstract

This research deals with an investigation of the adsorption of two acid dyes, namely Acid Red 57 (AR57) and Acid Blue 294 (AB294) onto sepiolite. Batch kinetics and isotherm studies were carried out. The results indicate that the adsorption of acid dyes obeys Freundlich isotherm and the second-order kinetics model. In addition, the effectiveness of sepiolite on adsorption of AR57 and AB294 from aqueous solution was studied as a function of time, pH, and temperature. Thermodynamic parameters for the adsorption of dyes were calculated and are discussed., The maximum removals of acid dyes was observed around 90% and 75% at pH = 2 for AR57 and AB294, respectively.