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Regenerated cellulose wood pulp was grafted with the vinyl monomer glycidyl methacrylate (GMA) using ceric ammonium nitrate as initiator and was further fuctionalised with imidazole to produce a novel adsorbent material, cellulose-g-GMA-imidazole. All cellulose, grafted cellulose and functionalized cellulose grafts were physically and chemically characterized using a number of analytical techniques, including elemental analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis, differential thermal analysis, and scanning electron microscopy. The cellulose-g-GMA material was found to contain 1.75 mmol g Ϫ1 epoxy groups. These epoxy groups permitted introduction of metal binding functionality to produce the cellulose-g-GMA-imidazole final product. Following characterization, a series of adsorption studies were carried out on the cellulose-g-GMA-imidazole to assess its capacity in the removal of Cu 2ϩ ions from solution. Cellulose-g-GMA-imidazole sorbent showed an uptake of ϳ70 mg g Ϫ1 of copper from aqueous solution. The adsorption process is best described by the Langmuir model of adsorption, and the thermodynamics of the process suggest that the binding process is mildly exothermic. The kinetics of the adsorption process indicated that copper uptake occurred within 30 min and that pseudo-second-order kinetics best describe the overall process.

A series of adsorption studies was carried out on a glycidyl methacrylate-modified cellulose material functionalised with imidazole (Cellulose-g-GMA-Imidazole) to assess its capacity in the removal of Ni(II) ions from aqueous solution. The study sought to establish the effect of a number of parameters on the removal of Ni(II) from solution by the Cellulose-g-GMA-Imidazole. In particular, the influence of initial metal concentration, contact time, solution temperature and pH were assessed. The studies indicated a Ni(II) uptake on the Celluloseg-GMA-Imidazole sorbent of approximately 48 mg g −1 of nickel from aqueous solution. The adsorption process fitted the Langmuir model of adsorption and the binding process was mildly endothermic. The kinetics of the adsorption process indicated that nickel uptake occurred within 400 min and that pseudo-second order kinetics best describe the overall adsorption process. Nickel(II) adsorption, recovery and re-adsorption studies indicated that at highly acidic pH values the adsorbent material becomes unstable, but in the range pH 3-6, the adsorbent is stable and shows limited but significant Ni(II) recovery and re-adsorption capability.

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