Removal of Hg (II) and Cd (II) Ions from Aqueous Solution Using Chitosan: Kinetics and Equilibrium Studies

Background and purpose: the discharge of toxic heavy metal ions into the environment is aserious pollution problem. heavy metal ions pose adverse toxic risks to human health at very lowconcentrations. the aim of this paper is the adsorption potential of chitosan (cs) in the removalof hg(ii) and cd(ii) ions from aqueous solution.materials and methods: this study was conducted in laboratory scale. in this research, cs wasused as an adsorbent for the removal of hg(ii) and cd(ii) from aqueous solutions. in batch tests,the effects of various parameters such as metals concentration (40-350 mg/l), ph solution (2-8),contact time (5-120 min), and adsorbent dose (0.25-2 g) were investigated.results: the results showed that adsorption of hg(ii) and cd(ii) ions on cs strongly depends onph. the experimental data were analyzed using the langmuir and freundlich isotherm models.equilibrium data fitted well with the langmuir model and the maximum adsorption capacity ofthe cs for hg(ii) and cd(ii) were 52.63 and 58.8 mg/g, respectively. kinetic analysis showedthat adsorption was most accurately represented by a pseudo-second-order model.conclusion: the obtained results showed that cs is a readily, available, economic adsorbent andwas found suitable for removing hg(ii) and cd(ii) ions from aqueous solution.