Kinetic and thermodynamic studies on the adsorption behavior of Rhodamine B dye on Duolite C-20 resin

The adsorption behavior of Rhodamine B dye from aqueous solutions was investigated onto the cation-exchange resin, Duolite C-20 (hydrogen form). The effects of various experimental factors; sorbent amount, contact time, dye concentration and temperature, were studied by using the batch technique. Lagergren pseudo-first-order equation shows good applicability with high correlation coefficients for all ranges of initial dye concentrations and at different temperatures. This equation was used to describe the kinetics of the dye adsorption process. The adsorption constants were evaluated by using both the Langmuir and Freundlich adsorption isotherm models. Thermodynamic parameters were obtained and it was found that the adsorption of Rhodamine B dye onto Duolite C-20 resin was an endothermic and spontaneous process at the temperatures under investigation.