Kinetic study of adsorption of Cu(II) and Pb(II) from aqueous solutions using manganese oxide coated zeolite in batch mode

The effect of solution temperature and the determination of the kinetic parameters of adsorption of Cu(II) and Pb(II) from aqueous solution on manganese oxide coated zeolite (MOCZ) is important in understanding the adsorption mechanism. Variables of the system include adsorption time, particle size and initial solution concentration. The pseudo-second-order model was the best choice among all the kinetic models to describe the adsorption behavior of Cu(II) and Pb(II) onto MOCZ, suggesting that the adsorption mechanism might be a chemisorption process. The activation energy of adsorption (E-a) was determined as Cu(II) 9.72 U mol(-1) and Pb(II) 11.9 U mol(-1), respectively. The low value of E. shows that Cu(II) and Pb(II) adsorption process by MOCZ may be an activated chemical adsorption. The thermodynamic parameters (Delta G(0), Delta H-0, and Delta S-0) were also determined from the temperature dependence. The results show that the process of adsorption Cu(II) and Pb(II) is spontaneous and endothermic process and rise in temperature favors the adsorption. (c) 2006 Elsevier B.V. All rights reserved.