Adsorption removal of copper(II) using chitosan from simulated rinse solutions containing chelating agents

The adsorption ability of Cu(II) using chitosan from simulated rinse solutions containing chelating agents was studied. Four chelating agents including ethylenediaminetetraacetic acid (EDTA), citric acid, tartaric acid and sodium gluconate were selected. It was shown that the concentration ratio of chelating agent to Cu(II) as well as the NaOH concentration significantly affected the adsorption capacity. Competition between coordination of Cu(II) with unprotonated chitosan and electrostatic interaction of Cu(II) chelates with protonated chitosan played an important role in this adsorption system. The maximum adsorption capacity was found within each optimal pH range. This work provided a simple criteria for adsorption removal of Cu(II) from such industrial rinse solutions (0.3–5.0 mol/m3) using chitosan.