Application of modified cellulose for Pb2+ and Cu2+ removal from aqueous solutions: Kinetic and isotherms studies

Abstract

In this work, acrylamide grafted Kolanut Pod Husk cellulose adsorbents were successfully prepared via chemical modification of Kola nut pod husk cellulose with acrylamide and N, N’- methylenebisacrylamide. The modified adsorbents were successfully applied for the adsorptive removal of Pb2+ and Cu2+ ions from aqueous solutions at different parameters, such as pH of the solution, adsorbent dosage, contact time, and initial metal ion concentrations were optimized. Qualitative analysis of the modified adsorbents was performed by Fourier Transformed Infra-Red Spectroscopy and Scanning Electron Microscopy. Characterization analyses portrayed the surface of adsorbents as being short elongated shaped with dispersed pores and composed of hydroxyl and carbonyl groups as the main binding sites. The optimum conditions for adsorption of Pb2+ and Cu2+ were found to be: pH; 5, adsorbent dosage; 3.5 and 4 g L-1 , concentration; 60 mg L-1 and contact time; 160 min. Adsorption data were fully fitted with the Freundlich, Langmuir isotherm model, and a pseudo-second order, Elovich kinetic model. The adsorption of metal ion was heterogenous in nature with qmax of 55.14 mg g-1 and 62.09 mg g-1 for Pb2+, 54.82 mg g-1 , and 60.43 mg gfor Cu2+ respectively. These results showed that the modified adsorbents were able to efficiently remove Pb2+ and Cu2+ from aqueous solutions.