Fixed-bed column studies on a modified chitosan hydrogel for detoxification of aqueous solutions from copper (II)

A new efficient, low cost chitosan based biosorbent was successfully prepared and employed for the biosorption of copper ions from an aqueous solution using a fixed bed column. Pyromellitic dianhydride crosslinked chitosan as the new adsorbent was characterized by SEM, FTIR spectroscopy, X-ray diffraction, thermogravimetric analysis and solid state 13C NMR analysis. Scanning electron microscopy coupled with an X-ray energy dispersed analysis for the copper-equilibrated biomass confirmed the presence of Cu(II) ions on the surface of the hydrogel. Thermogravimetric analysis showed a significant improvement in the thermal stability of the new hydrogel compared to pure chitosan. Kinetic models were applied to predict the breakthrough curves. This study shows that the prepared hydrogel based on modified chitosan could be utilized as an efficient bioadsorbent for the removal of copper ions from wastewater.