This study evaluated the equilibrium, kinetics, and thermodynamics of vanadium sorption from
aqueous solution onto nanocomposite functionalized with diethylene triamine in batch conditions.
The effects of temperature, solution pH, and initial concentration of vanadium were examined. The
maximum sorption capacity of vanadium on the tested sorbent was achieved at pH 6. The sorption
capacity increased with increasing temperature and initial concentration. The equilibrium adsorption
data were analyzed using Langmuir, Freundlich, Temkin, Jovanovic, Toth, Sips, Khan, and RedlichPeterson isotherm models. The kinetics data were studied using pseudo-first-order, pseudo-secondorder, the fractional power, Elovich, and Avrami models. A non-linear fitting method was used to
compare the best fitting of the equilibrium and kinetic data. The sorption equilibrium data were best
represented by the Langmuir, Khan, Toth, and Redlich–Peterson isotherms. The adsorption kinetics
was estimated to follow the pseudo-second-order kinetic model. The mechanism of vanadium
sorption was analyzed with intra-particle, Bangham, Boyd, and liquid film diffusion models. It was
observed that the sorption process was controlled by the film-diffusion as well as the pore-diffusion.
Thermodynamic parameters (change of standard enthalpy (ΔH°), standard entropy (ΔS°), and
standard free energy (ΔG°)) suggested that the sorption of vanadium onto functionalized
nanocomposite was a spontaneous and endothermic process.
