Title
Chicken feathers derived materials for the removal of chromium from aqueous solutions: kinetics, isotherms, thermodynamics and regeneration studies
Document Abstract
In the present study, chicken feathers (CFs), obtained from animal waste, were used as bio-adsorbent
for the removal of hazardous Cr(VI) ions from aqueous solutions. Fourier transform infrared spectroscopy
(FTIR), scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX), x-ray diffraction
(XRD), adsorption of N2 at 196 C, thermogravimetric analysis (TGA), and point of zero
charge (pHpzc) determination were used to characterize the adsorbent. The N2 adsorption results
revealed high surface area and microporous structure for the adsorbent. The experimental results in
batch adsorption show that optimum conditions are: pH 2.5, equilibrium contact time 180minutes,
concentration of CFs 11 g L1, and initial Cr(VI) concentration 25mg L1. The experimental data on
Cr(VI) adsorption were fitted using the Langmuir and Freundlich equations at different temperatures.
The Langmuir adsorption model showed the best fit. The maximum monolayer capacity (qmax) of CFs
was found to be 333.33mg/g. The kinetic results of Cr(VI) ion were fitted to four kinetic models:
pseudo-first-order, pseudo-second-order, intra-particle diffusion, and Elovich . The pseudo-secondorder
chemisorption model had a higher coefficient. The thermodynamics data showed that the
adsorption process of Cr(VI) on CFs was endothermic and spontaneous. The desorption efficiency and
reusability of CFs were determined for three adsorption–desorption cycles, which proved to be very
effective for the removal of Cr(VI) ions from aqueous solutions.