Effect of complexing agents on liquid-phase adsorption and desorption of copper(II) using chitosan

The effect of complexing agents on adsorption and desorption of Cu(II) from aqueous solutions using chitosan was investigated. Three complexing agents were used including EDTA (ethylenediaminetetraacetic acid), citric acid, a nd tartaric acid. It was shown that the isotherm data could be fitted by th e Langmuir equation under a limited concentration range. Furthermore, the a dsorption processes were analyzed by an intraparticle diffusion model and t he rate parameters of intraparticle diffusion for Cu(II) adsorption could b e correlated with the initial Cu(II) concentrations. Finally, the desorptio n of Cu(II) and its complexes from the loaded chitosan was tested using com plexing agent solutions. Under comparable conditions, tartaric acid solutio n gave the best desorption efficiency. (C) 1999 Society of Chemical Industr y.