Modification of chitosan through copolymerisation with maleic anhydride for uranium extraction

A new promising chitosan styrene maleic anhydride (CsSMA), was applied to adsorb uranium from its sulphate solution. FT-IR, XPS, BET, SEM-EDX, TGA, DLS, XRD, and Zeta potential analyses were used to evaluate the produced CsSMA, both before and after uranium adsorption. It is evident from the former that the adsorption of uranium by CsSMA was successful. A thorough analysis was conducted on the pertinent variables that affect the uranium’s adsorption onto the synthesised CsSMA, including temperature, solid-liquid ratio, pH of the solution, initial uranium concentration, and Co-ions. CsSMA polymer successfully adsorped the uranium with adsorption efficiency 99.5%. The uranium adsorption capacity of the synthesised CsSMA is predicted to be 129.87 mg/g based on the Langmuir adsorption model, which fits the observed results into the various adsorption isotherms. The kinetic data obtained indicates that the pseudo-second order model is a better fit for explaining the uranium adsorption kinetics on synthesised CsSMA. The adsorption reaction is ultimately shown by the thermodynamic characteristics to be a spontaneous process. This finding is further supported by the thermodynamic parameters ΔS (0.171 kJ/mol), ΔH (48.945 kJ/mol), and ∆G values at 298 K and 328 K, which range from −2.152 kJ/mol to −7.296 kJ/mol.