Der Pharma Chemica
Journal for Medicinal Chemistry, Pharmaceutical Chemistry, Pharmaceutical Sciences and Computational Chemistry


Biosorption of heavy metals by chitin and the chitosan

Author(s): Bensaha Sofiane and Kara Slimane Sofia

In the present work, the usefulness of chitin and chitosan has been investigated for the removal of Zn2+, Cd2+ and Cu2+. Kinetic data and equilibrium sorption isotherm were measured in batch conditions. The influence of different experimental parameters such as time contact, initial concentration of zinc, chitin mass, initial pH of solution and temperature on the kinetics of zinc removal was studied. The main parameters that play an important part in removal phenomenon were initial zinc concentration, chitin mass and initial pH of solution. The process follows a pseudo second-order kinetics. The zinc uptake of chitin was quantitatively evaluated using sorption isotherms. In order to describe the isotherm mathematically, the experimental data of the removal equilibrium were correlated by either the Langmuir or Freundlich equations. Results indicated that the Langmuir model gave a better fit to the experimental data than the Freundlich equation. Scanning electron microscopy dispersed analysis for zincequilibrated chitin, demonstrated that zinc existed on its surface. The biosorption of the metals studied by chitin and the chitosane varies in the same order : Cu (ІІ) > Cd (ІІ) > Zn (ІІ) and the quantities biosorbed in equilibrium by the chitosan are higher than that of chitin.