Pore diffusion model for dye adsorption onto peat in batch adsorbers

The adsorption of Acid Blue 25, Basic Blue 69, Basic Orange 2, and Disperse Blue 7, on peat has been studied using a series of batch adsorption runs. A model has been developed based on external mass transfer and internal diffusion to explain the concentration decay curves. Two system variables, namely, adsorbate concentration and adsorbent concentration, have been studied. The paper presents a rapid analytical solution for predicting the concentration decay curve in batch adsorbers using peat as a cheap adsorbent to remove various classes of dyestuffs from aqueous solution. The analytical solution depends on the assumption of a psdeudo-irreversible isotherm and that the internal diffusion process occurs via a pore diffusion mechanism. External mass transfer coefficients and internal diffusivities have been estimated for the various systems.