Adsorption of erbium ions on activated charcoal from aqueous solutions

Adsorption of erbium ions onto activated charcoal from aqueous solution has been investigated. Conditions leading to maximum adsorption have been established in terms of shaking time, pH, erbium ions concentration and temperature. The adsorption of erbium ions obeys the Langmuir isothermal equation well in the concentration range studied. Thermodynamic quantities DeltaH, DeltaS and DeltaG were calculated for the adsorption process. The results indicate that the adsorption of erbium ions on activated charcoal is endothermic in nature. The effect of different anions and cations on the adsorption of erbium ions has also been examined. The adsorption of other metal ions on activated charcoal has been measured under specified conditions to evaluate the selectivity. (C) 2004 Elsevier B.V. All rights reserved.