Fes Encapsulated Chitosan-G-Polyacrylamide Nanocomposite For The Removal Of Model Anionic Eosin Y From Water: Isotherm, Kinetics And Equilibrium Studies

Abstract

A novel bio-nanocomposite, FeS/chitosan grafted polyacrylamide, was successfully synthesized by means of a grafting technique that employs microwave irradiation. Employing FTIR, SEM, XRD, TEM and SAED analysis, the synthesized nanocomposites were characterized. Thermodynamic and kinetic studies were performed using the batch mode via the adsorption of eosin yellow from aqueous solution using the nanocomposite. The adsorption process was tailored to the pseudo-second order kinetic model and the Freundlich isotherm model. The enthalpy change, ∆H° (-12.243 kJ/mol), was an exothermic process. The Gibbs energy, ∆G° (from -5.492 kJ/mol.K to -5.078 kJ/mol.K for temperatures from 300 K to 318 K respectively) values were indications of a thermodynamically feasible reaction process which was spontaneous within the temperature domain. The change in entropy, ∆S° (-0.023 kJ/mol), showed a reduced randomness during the adsorption process. The mean free energy of adsorption was 0.408 kJ/mol, which was an indication of physisorption. These results show the possible use of the graft copolymer as an adsorbent in water treatment.