Chitosan Fiber as Green Material for Removing Cr(VI) and Cu(II) Contaminants:Adsorption Properties,Kinetics and Machanism

Abstract

\n Chitosan (CS) fiber is used as a new green material to remove Cu(II) and Cr(VI) in wastewater.Varying factors, including pH value, dosage of CS, reaction time and original Cr (VI) contents and Cu(II) were studied to investigate the Cr (VI) and Cu(II) removal efficiency.The adsorption of two metal ions by chitosan fiber conforms to the second-order kinetic equation, and can be fitted with Langmuir isotherms. The adsorption process is a spontaneous thermal reaction with both physical adsorption and chemical adsorption, and copper ions reach adsorption equilibrium. It takes longer than chromium ions, but the adsorption effect of copper ions is better. The maximum actual adsorption capacity of copper ions is 539.6 mg/g, and the maximum adsorption capacity of chromium ions is 75 mg/g. SEM, FTIR and XRD were used to characterize the physicochemical properties of CS fiber. The result shows that the complex process of the Cr (VI) and Cu(II) removal involves physical and chemical adsorption, CS fiber have exerted significant role in Cr (VI) and Cu(II) removal.