Adsorption of cobalt from aqueous solutions onto Bark of Eucalyptus

Abstract

In this work, we used the bark of eucalyptus grafted with acrylic acid (EAA) as an adsorbent for removing of Co2+ ions from aqueous solutions. EAA was characterized using Fourier Transformed Infrared Spectroscopy (FTIR), X-Ray diffraction (XRD), and bohemian method. The bulk density and the zero-charge point (pzch) were also determined. The results showed that eucalyptus grafted with acrylic acid (EAA) is rich in COOH and OH groups and pzch is acidic. We also valorized the Bark of Eucalyptus (EB) in the removing of Co2+ ions from aqueous solutions. The kinetic study showed that the extraction equilibrium of Co2+ ions by EB is reached after 40 min and the extraction process is expressed by the second-order kinetic model. The effect of Co2+ concentration and initial pH on the removal efficiency showed that the binding capacity increases with increasing in the pHi and the concentration of Co2+ ions and the maximum capacity is 55.55 mg/g. The mathematical modelling study of the adsorption of Co2+ ions on the BE showed that the adsorption process follows the Langmuir model. The kinetics of desorption is 8 times faster than the extraction and our material is regenerated with higher performance.