Sorption of Metal Ions on Carboxylic Cation Exchanger

摘要

Sorption of metal ions (Cd(2+), Co(2+), Cu(2+), Zn(2+)) on the carboxylic cation exchanger IRC-50 in various forms has been studied, which depends upon the nature of the resin counter ions, ionic potential and pH of hydrolysis of the metal cations. The smaller values of equilibrium constant indicate the ion exchange mechanism of the process. Various thermodynamic parameters (delta G, delta H, delta S) were also calculated. The positive delta H values show the sorption of the metal ions to be endothermic in nature. The ion exchange kinetics suggest that the process is controlled by particle diffusion on the carboxylic cation exchanger IRC-50. Further, the IR study shows that the sorption of metals ions shifts the assymetric stretching C=0 band from 1700/cm to 1540/cm. This also confirms the ion exchange mechanism for the sorption of the Cd(2+), Co(2+), Zn(2+) on the carboxylic acid exchanger IRC-50.