Magnesite tailing as low-cost adsorbent for the removal of copper (II) ions from aqueous solution

Abstract

The removal of Cu(II) ions from aqueous solution using magnesite tailing was investigated. Batch kinetic and equilibrium experiments were conducted to study the effects of initial pH, adsorbent dosage, contact time, initial concentration and temperature. The pseudo-first-order, pseudo-second-order and intraparticle diffusion models were used to study the kinetic data. The experimental data were best fitted by the pseudo-second-order kinetic model. The linear Langmuir and Freundlich adsorption equations were applied to describe the equilibrium isotherms. The equilib- rium data fit very well the Langmuir model, and the maximum adsorption capacity was estimated as 12.18 mg/g at 45 o C. Thermodynamic parameters such as enthalpy change (ΔH o ), free energy change (ΔG o ) and entropy change (ΔS o ) were calculated, and it was found that the adsorption process was spontaneous and endothermic. The results showed that magnesite tailing is a suitable adsorbent for the removal of Cu(II) ions from aqueous solutions.