Authors: Bernice Y. Danu, Eric S. Agorku, Francis K. Ampong, Johannes A.M. Awudza, Bismark Owusu, Patrick N.O. Brown, Onoyivwe M. Ama, Peter O. Osifo and Suprakas S. Ray,
A hybrid vanadium pentoxide (V2 O5 )/chitosan-graft-sodium alginate nanocomposite was synthesized via the graft co-polymerization technique. The nanocomposite was characterized by X-ray diffraction analysis, Fourier transform infra-red spectroscopy, scanning electron microscopy and transmission electron spectroscopy. Batch studies was employed for the adsorption of model methyl violet onto V2 O5 /chitosan-graft-sodium alginate from aqueous solution. The adsorption best suited the Langmuir isotherm and pseudo-second order kinetic model. The positive value of the change in enthalpy, ΔH° (6.62 kJ/mol.) established an endothermic process. The negative values of the free Gibbs energy, ΔG° ( -4.19 to -4.87 kJ/mol.K) within the range of temperatures of 300 K to 318 K, indicated that the adsorption process was thermodynamically favourable and spontaneous. The value of the change in entropy, ΔS° (0.035 kJ/mol) revealed a randomness in the adsorption process. These outcomes show a potential use of V2 O5 /chitosan-graft-sodium alginate composite for the removal of organic dyes from polluted water.
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