Chitosan Based a New Bio-Composite Adsorbent for the Removal of Cr (VI) from Aqueous Solution

This study reports the preparation of glutaraldehyde crosslinked chitosan coated Rosehip (Rosa canina) seed shell (Cth/RS) capsules. Cth/RS was used in batch experiments to evaluate the adsorption of Cr (VI) ions. The effect of adsorbent dose, Cr (VI) concentration, time, initial solution pH on adsorption was also investigated. Adsorption equilibrium was achieved in 90 min. and maximum removal of Cr(VI) was demonstrated at pH value of 2.0. Cth/RS was characterized by FTIR analysis. The equilibrium adsorption data were described by Langmuir, Freundlich, Scatchard and D-R isotherms.Adsorption parameters (k, n, As, Kb, Xm, K, E) were calculated from these isotherms. The data were fitted to the Langmuir adsorption isotherm. The maximum capacity of Cth/RS was determined to 34.13 mg/g. Cth/RS showed high adsorption capacity for Cr (VI) ions. The pseudo-first and pseudo-second orders equation were used to evaluate the kinetic data and the constants are determined. The experimental results suggest that the Cth/RS capsules are effective for the adsorption of Cr (VI) ions.

Keywords: chitosan, glutaraldehyde, Rosehip seed shell, chromium, isotherms, equilibrium