Film-pore diffusion modeling for the sorption of metal ions from aqueous effluents onto peat

The sorption of three metal ions, namely, copper, nickel and lead onto spha gnum peat moss has been studied using an agitated batch sorber system. The equilibrium isotherms were determined and kinetic runs were performed over a range of concentrations for each metal ion. A film-pore diffusion mass tr ansfer model has been developed based on a single effective diffusion coeff icient for each system. Error analysis of the experimental and theoretical data indicated relatively large errors at low initial metal ion concentrati ons. Therefore the model was modified to introduce a surface coverage conce ntration dependent effective diffusivity to account for a contribution from surface diffusion. (C) 2001 Elsevier Science Ltd. Alt rights reserved.