The new chelate resins, abbreviated as PNBMZs and PBBMZs based on epoxide polymer, were synthesized by polycondensation of N,N-diglycidyl-4-glycidyloxyaniline or l,4-bis(2,3-epoxypropyl)benzene with the primary amine group of l,3-bis(benzimidazol-2yl)propylamine (BBPAH). The ion exchangers contain 2.71-3.23 mmol of the ligand contents per gram of the resin. Batch extraction capacities were determined for the metal chloride salts in buffer solutions in the pH range from -1 to 6.0. The chelate resins were very selective for Cu2+, Zn2+, Cd2+ in the presence of other divalent transition metal ions. The maximum uptake capacities of PNBMZ (synthetic molar ratio = 1:1.5) under non-competitive condition were found to be 0.94 mmol/g for Cu2+ at pH = 2, 1.3 mmol/g for Cd2+ at pH = 1 and 1.75 mmol/g for Zn2+ at pH = -1 respectively. While in the case of PBBMZ, it was 1.39 mmol/g for Cd2+ at pH = 1. The metal-uptake behaviors for both of them showed strong pH dependence, and their extraction capacities increase with decreasing pH. The uptake of Cu2+ by the resin PNBMZs at pH = 1 was found to be rather fast with t1/2 =18 min. Metal-uptake experiments under competitive conditions also confirm that the chelate resins have a high selectivity for Cu2+, Zn2+, Cd2+ and the contrary pH dependence.
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