Background: The aim of this study was to investigate the removal of chromium (VI) by Nanocomposites Chitosan-tragacanth solution from aqueous solution.

Methods: In this study, chitosan-tragacanth nanocomposites were synthesized and analyzed by electron microscopy (SEM), (TEM) and Fourier transform spectroscopy (FT-IR) for the size and shape of the surface. The nano-composite of chitosan-tragacanth, for the adsorption of chromium (VI) in aqueous solution was used as adsorbent.

Results: The optimum conditions with multiple experiments to enhance the absorption were evaluated. The highest absorption of Cr (VI) was occurred in the adsorbent dosage of 0.2 g, 8 ppm concentration of chromium ions, the pH=6 and also retention time of 50 min; in 298 ˚K temperature. After determining optimal conditions of adsorption, isotherms equations and study and thermodynamic parameters were applied. Adsorption process of chromium (VI) on nano-composite chitosan - Tragacanth was conformed with Temkin isotherm.

Conclusion: The thermodynamic parameters such as standard Gibbs free energy changes, changes in enthalpy and entropy changes in the standard showed that the adsorption process of Cr (VI) is spontaneous and heating, and kinetics studies of models Lagergren, Ho , Alovich and intraparticle is used, the results show that the adsorption kinetics follows the pseudo-second order.