Pore diffusion model in the adsorption of lead onto activated carbon

The batch removal of Pb(II) from aqueous solution onto activate carbon was investigated. The effect of various parameters such as weight of adsorbent, pH-value, contact time, and initial metal ion concentration were studied in this work. The adsorption isotherm studies were analysis using Langmuir and Freundlich isotherm models. These adsorption isotherm data were seen to be consistent with the Langmuir model. In this work pore diffusion model (PDM) was applied to the adsorption of Pb(II) in abatch agitation vessel. The model includes external mass transfer, pore diffusion and adsorption using non-linear isotherm. The non-linear isotherm used is Langmuir isotherm. Results of the pore diffusion are in term of the theoretical concentration decaycurve. Kinetic experiments were carried out to obtain the experimental concentration decay curve and external mass transfer coefficient at optimum agitation speed. Pore diffusion model can be obtained by minimizing the differences between the experimental and theoretical concentration decay curves.