Sorption of sunset yellow dye by weak base anion exchanger-kinetic and equilibrium studies

The sorption equilibrium and kinetics of Sunset Yellow dye in aqueous solutions on the weak base anion exchange resin Amberlite FPA51 were examined in this paper. The influences of phase contact time, solution pH, initial dye concentration and temperature were studied by the batch method. The amounts of dye sorbed at equilibrium changed from 9.9 to 48.7 mg/g with increasing initial dye concentration in the range 100-500 mg/L. The experimental data were analysed by the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich models of adsorption. The maximum monolayer capacity was 130.6 mg/g. The sorption free energy was equal to 14.6 kJ/mol and revealed the nature of the ion exchange mechanism in this system. The kinetic data were modelled using the pseudo-first-order, pseudo-second-order (types 1-5) and intraparticle diffusion equations. The experimental data were well described by types 1-3 of the pseudo-second-order kinetic model.