Equilibrium and kinetics characteristics of copper (II) sorption onto gyttja

The sorption characteristics of gyttja to remove copper (Cu(2+)) ions from aqueous solutions were satisfactorily described with the Freundlich, Langmuir and Dubinin-Redushckevich (D-R) models. The sorption capacity (q (max)) of gyttja was 11.76 mg g(-1). The D-R model indicated that the sorption of Cu(2+) by gyttja was almost taken place by chemisorption. Thermodynamic parameters such as change in free energy (DeltaG), enthalpy (DeltaH), and entropy (DeltaS) suggested that the adsorption process of Cu(2+) by gyttja was feasible, spontaneous and endothermic in nature. Kinetic examination of the equilibrium data showed that the sorption processes of Cu(2+) ions followed well pseudo-second-order kinetics model.