Characterizations of strontium(II) and barium(II) adsorption from aqueous solutions using dolomite powder

In this research, adsorption technique was applied for strontium and barium removal from aqueous solution using dolomite powder. The process has been investigated as a function of pH, contact time, temperature and adsorbate concentration. The experimental data was analyzed using equilibrium isotherm, kinetic and thermodynamic models. The isotherm data was well described by Langmuir isotherm model. The maximum adsorption capacity was found to be 1.172 and 3.958 mg/g for Sr(II) and Ba(II) from the Langmuir isotherm model at 293 K. respectively. The kinetic data was tested using first and pseudo-second order models. The results indicated that adsorption fitted well with the pseudo-second order kinetic model. The thermodynamic parameters (Delta G degrees, Delta H degrees, and Delta S degrees) were also determined using the equilibrium constant value obtained at different temperatures. The results showed that the adsorption for both ions was feasible and exothermic. (C) 2011 Elsevier B.V. All rights reserved.