Adsorption behaviour of Cu(II) ions from aqueous solution on chitosan

The chemical contamination of water with a wide range of toxic substances, in particular heavy metals, is a serious environmental problem due to their potential toxicity to humans. Therefore, there is a need to develop technologies that can remove toxic pollutants found in wastewaters. Adsorption is one of the more popular methods for the removal of pollutants from the wastewater. Chitosan is a derivative from N-deacetylation of chitin - a naturally occurring polysaccharide from crustacean and fungal biomass - and it has been found to be capable of chemically or physically adsorbing various heavy metal ions, including lead, vanadium, platinum, silver, cadmium, chromium and copper, from wastewaters. In this study, a batch adsorption system was applied to study the adsorption of Cu (II) ions from aqueous solution by chitosan. The adsorption capacities and rates of Cu (II) ions onto chitosan were evaluated. Experiments were carried out as function of time, adsorbent mass and concentration of Cu (H) ions. Langmuir and Freundlich adsorption models were applied to describe the isotherms. Equilibrium data agreed very well with the Langmuir model. The kinetic experimental data correlated well with the second-order kinetic model, indicating that the chemical sorption was the rate-limiting step.