Kinetics of adsorption of sulphonated azo dyes on strong basic anion exchangers

Abstract

The macroporous polystyrene anion exchangers Amberlite IRA‐900 and Amberlite IRA‐910 were used in order to remove sulphonated azo dyes (Allura Red and Sunset Yellow) from aqueous solutions of 100–500 mg/L concentrations. The experimental data obtained at 100, 200, 300 and 500 mg/L initial concentrations at 20 °C were applied to the pseudo‐first‐order, pseudo‐second‐order and Weber–Morris kinetic models. The calculated sorption capacities (qe,cal ) and the rate constant of the first‐order adsorption (k1 ) were determined. The pseudo‐second‐order kinetic constants (k2 ) and capacities were calculated from the plots of t/qt vs t, 1/qt vs 1/t, 1/t vs 1/qt , qt/t vs qt and 1/qe–qt vs t for type 1, type 2, type 3, type 4 and type 5 of the pseudo‐second‐order expression, respectively. The influence of phase contact time, initial dye concentration, solution pH and temperature on Allura Red and Sunset Yellow removal was also discussed.