Removal of copper and cobalt from aqueous solution onto waste containing boron impurity

The main objective of this study was to investigate the possible use of waste containing boron impurity as an adsorbent material for the removal of Cu(II) and Co(II) ions from aqueous solution. Batch experiments were carried out as a function of initial metal ions concentration, initial solution pH, contact time, adsorbent dosage and temperature. Experimental equilibrium data were fitted to the Freundlich and Langmuir isotherms. Adsorption equilibriums of Cu(II) and Co(II) ions were well represented by Langmuir isotherm. The kinetics of the adsorption demonstrated that the fit is in agreement with a pseudo-second-order model with rate constant, k(2), varying from 7.35 x 10(-4) to 1.08 x 10(-3) and 6.10 x 10(-4) to 9.54 x 10(-4) g mg(-1) min(-1) for copper and cobalt, respectively. Thermodynamics quantities that characterize the adsorption phenomena, i.e., enthalpy. Gibbs free energy and entropy of the adsorption, were calculated leading to conclusion about the efficiency of the adsorbing substrates and the properties of the adsorbent-metal ions systems. (C) 2011 Elsevier B.V. All rights reserved.