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

摘要

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 ℃ were applied to the pseudo-first-order, pseudo-second-order and Weber-Morris kinetic models. The calculated sorption capacities (q_(e,cal)) and the rate constant of the first-order adsorption (k_1) were determined. The pseudo-second-order kinetic constants (k_2) and capacities were calculated from the plots of t/q_t vs t, 1/q_t vs 1/t, 1/t vs 1/q_t, q/t vs q_t and 1/ q_e-q_ 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.