Kinetic modeling of liquid-phase adsorption of reactive dyes and metal ions on chitosan

The rates of adsorption of three commercial reactive dyes and Cu(II) from w ater in the absence and presence of complexing agents using chitosan were m easured at 30 degreesC. Three simplified kinetic models, i.e,, pseudo-first -order, pseudo-second-order, and intraparticle diffusion, were tested to in vestigate the adsorption mechanisms. It was shown that the adsorption of re active dyes and Cu(II) in the absence of complexing agents could be best de scribed by the intraparticle diffusion model, whereas that of Cu(II) in the absence of complexing agents such as EDTA, citric acid, and tartaric acid by the pseudo-second-order equation. Kinetic parameters of the three models and the normalized standard deviations between the measured and predicted results were also calculated and discussed. (C) 2001 Elsevier Science Ltd. All rights reserved.