Improved performance of a cellulose-based anion exchanger with tertiary amine functionality for the adsorption of chromium(VI) from aqueous solutions

Abstract

A cellulose-based anion exchanger (Cell-AE) bearing –N +H(CH 3) 2Cl − functional groups was tested for its potential application in the removal of chromium(VI) from aqueous solutions. The Cell-AE was prepared through graft copolymerization of glycidylmethacrylate onto cellulose (Cell) in the presence of N,N′-methylenebisacrylamide as a cross linker using benzoyl peroxide initiator, followed by amination and acidification. The adsorbent was characterized by infrared spectroscopy and X-ray diffraction studies. Batch experiments were performed to evaluate the adsorption efficiency of Cell-AE towards Cr(VI) ions. The contact time necessary to attain equilibrium and the optimum pH were found to be 1 h and 3.5, respectively. The adsorption process performed more than 99.4% of Cr(VI) removal from an initial concentration of 25.0 mg L −1. The process followed a pseudo-second-order kinetics. Equilibrium data fitted very well with Sips isotherm. The maximum adsorption capacity of Cell-AE towards Cr(VI) was determined to be 126.87 mg g −1. The electroplating industrial wastewater samples were treated with Cell-AE to demonstrate its efficiency in removing Cr(VI) from wastewater.