Adsorption of CI Reactive Red 228 dye from aqueous solution by modified cellulose from flax shive: Kinetics, equilibrium, and thermodynamics

Cellulose from flax shive was modified with quaternary ammonium groups to facilitate removal of C.I. Reactive Red 228 (RR228) dye from aqueous media. The adsorption of RR228 was investigated at various temperatures, adsorbent doses, initial dye concentrations and pH values. Two kinetic models were used to describe the adsorption process. Two isotherm models were applied to evaluate the adsorption equilibrium, and its thermodynamic parameters were calculated. The maximum capacity of the modified flax shive cellulose for adsorption of RR228 was 190 mg g(-1) at pH 3 under dose of 0.4 g L-1 and initial concentration of 80 mg L-1. The adsorption process and equilibrium of RR228 were well fitted by a pseudo-second-order kinetic model and Langmuir model, respectively. Thermodynamic evaluation indicated that the adsorption is exothermic, spontaneous, and favorable. (C) 2012 Elsevier B.V. All rights reserved.