Gui-Yin Li

PREPARATION AND CHARACTERIZATION OF NOVEL CHITOSAN DERIVATIVES: ADSORPTION EQUILIBRIUM OF IRON(III) ION

The adsorption of Fe(III) ions from aqueous solution by chitosan alpha-ketoglutaric acid (KCTS) and hydroxamated chitosan alpha-ketoglutaric acid (HKCTS) was studied in a batch adsorption system. Experiments were carried out as function of pH, temperature, agitation rate and concentration of Fe(III) ions. The Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms and isotherm constants were determined. The Langmuir model agrees very well with experimental data. The pseudo-first-order and second-order kinetic models were used to describe the kinetic data and the rate constants were evaluated. The dynamical data fit well with the second-order kinetic model. The pseudo second-order kinetic model was indicated with the activation energy of 19.61 and 7.98 kJ/mol for KCTS and HKCTS, respectively. It is suggested that the overall rate of Fe(III) adsorption is likely to be controlled by the chemical process. Results also showed that novel chitosan derivatives (KCTS and HKCTS) were favorable adsorbents.