A novel chelating fiber was prepared by the irradiation-induced grafting copolymerization of glycidyl methacrylate on polypropylene fiber and consequent amination with diethylenetriamine. The effects of the reaction conditions, such as reaction time, temperature, and monomer concentration, on the degree of grafting were investigated. The optimal conditions for grafting were found to be 3 h, 100 degrees C, and a 50% (v/v) glycidyl methacrylate concentration in tetra hydrofuran solution. This fiber showed good adsorption performance at different concentrations of Hg2+, in particular for trace Hg2+. Under the adsorption conditions of pH = 4, initial concentration = 1000 mg/L, and time = 20 h, the adsorption capacity of the chelating fiber for Hg2+ reached 785.28 mg/g. It completely adsorbed the Hg2+ ions in solution within a short contact time, showing a very high adsorption rate for Hg2+. Furthermore, the chelatin fiber also had a high selectivity for mercury, whereas Cu2+ coexisted in different concentrations. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113: 3638-3645, 2009