Preparation of Amidoximated Bacterial Cellulose and Its Adsorption Mechanism for Cu2+ and Pb2+

Amidoximated bacterial cellulose (Am-BC) was prepared through successive polymer analogous reactions of bacterial cellulose with acrylonitrile in an alkaline medium followed by reaction with aqueous hydroxylamine. It was used as an adsorbent to remove Cu2+ and Pb2+ from aqueous solutions. The adsorption behaviors of Cu2+ and Pb2+ onto Am-BC were observed to be pH-dependent. The maximum adsorption capacity of 84 and 67 mg g(-1) was observed, respectively, for Cu2+ and Pb2+ at pH 5. Scanning electronic microscopy (SEM) indicated that the microporous network structure of Am-BC was maintained even after the modifacation. The adsorption mechanisms for Cu2+ and Ph2+ onto Am-BC were investigated by fourier transform infrared spectroscopy (FTIR), zeta potential measurement and X-ray photoelectron spectroscopy (XPS). The results revealed that the mechanism for the adsorption of Cu2+ onto Am-BC could be mainly described as between metal ions and nitrogen atom in the amidoxime groups or oxygen atom in the hydroxyl groups. However, in the adsorption process for Pb2+, precipitation played the important role along with electrostatic interactions, although chelation action also existed in the process accounted for the adsorption process. The regeneration of Am-BC was studied by treatment with a strong complexing agent, ethylenediaminetetracetic acid (EDTA). (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117: 8-15, 2010