Lead Removal from Aqueous Solutions by 732 Cation-Exchange Resin

Kinetics and thermodynamics of the removal of Pb2+ from an aqueous solution by 732 cation-exchange resin in hydrogen type (732-CR) were studied in the temperature range of 298-328 K and Pb2+ concentration range of 5-50 mol/m(3). The effects of ion exchange temperature and initial lead ion concentration on the time evolution of the experimental concentration for the metal ion were investigated. Ion exchange kinetics of Pb2+ onto 732-CR follow the Nernst-Planck equation and unreacted-core model (UCM). The diffusion coefficients of counter ions and the efficient diffusion coefficient of lead ions within the resin were calculated. The results show that the ion exchange process is favoured under the particle diffusion control mechanism. The ion exchange isotherm data agreed closely with the Langmuir isotherm. The maximum monolayer exchange capacity for Pb2+ was found to be 484.0 mg/g at 308 K. Thermodynamic studies show that Pb2+ onto 732-CR is spontaneous and exothermic in nature. The ion exchange processes were verified by Energy Disperse Spectroscopy ( EDS).