Acidification Chicken Feather as Sorbent for Selectively Achicken feather as sorbent for selectively adsorbing of Cr(VI) ions in aqueous solution

Abstract

Chicken feathers (CFs) were acidized by nitric acid, and the structure and morphology of acid treated feathers (NF) were characterized by FT-IR, XRD and SEM. The adsorption performance of Cr(VI) ions by NF was explored by batch and fixed bed experiments. Some of the amino groups of keratin were cationic after being treated with nitric acid, indicating that NF is a potential adsorbent for eliminating Cr(VI) ions from water. For Cu(II), Mn(II) and Co(II) ions, NF did not show any adsorption, while Cr(VI) could be adsorbed by NF. And NF still shows higher selectivity to Cr (VI) ions even in the presence of Cl−, SO42-, or NO3− ions. Langmuir and Freundlich isotherm models were used to fit the equilibrium sorption isotherms of Cr(VI) ions. In addition, breakthrough and desorption curves were obtained by using fixed bed columns packed with NF at different desorption flow rates and NaOH concentrations. The results showed that 0.05 mol·L-1 of an aqueous NaOH solution is an appropriate desorption agent, with 5 times the theoretical desorption amount and a flow rate lower than 12.3 mL⋅min-1. An aqueous solution of HNO3 with a mass fraction of 0.34 % is a feasible regeneration regent. The fixed bed adsorption capacity of NF was 39.04 mg⋅g-1 (0.751 mmol⋅g-1). CFs can serve as a low-cost alternative for adsorbing acid and selectively enriching toxic Cr(VI) ions from water.