Adsorption efficiency of chemically modified chitosan towards copper and cobalt ions from industrial waste water

Abstract

IN THIS study, chitosan was produced and characterized using NMR, IR, DSC and TGA analyses. Its molecular weight was determined using GPC analysis. The produced chitosan was chemically modified by reaction with glycine and chloroacetic acid. Its adsorption capacity for Cu(II) and Co(II) ions from industrial wastewater was determined and compared to the virgin chitosan. The chemical structures of the prepared biosorbents were confirmed by FTIR and 1H-NMR. The adsorption efficiencies of the two biosorbents in neutral (pH=7) and alkaline medium (pH=9) at 25°C were determined using atomic absorption spectroscopy (AAS) and thermo-gravimetric analysis (TGA). The two biosorbents show lower adsorption efficiency towards copper and cobalt ions compared to the virgin biosorbent (pure chitosan). Furthermore, the adsorption capacity of glycine-chitosan was higher than the chloroacetic acid-chitosan biosorbents, which is attributed to the chelating effect of the amino groups than the chloro-substituted polymer.