Synthesis and characterization of a new iminodiacetate chelating resin for removal of toxic heavy metal ions from aqueous solution by batch and fixed bed column methods

摘要

New porous chelating resin beads CPN-IDA were prepared by the reaction of poly (acrylonitrile-co-N,N'- methylenebisacrylamide) with etheylenediamine and sodium chloroacetate, respectively. The composition and morphology of the chelating resin was characterized by Fourier transform infrared spectroscopy (FTIR), thermal analysis (TGA and DrTGA), scanning electron microscopy (SEM),surface area measurements by N2adsorption (S (BET) ) and water regain (w%). Batch adsorption experiments were employed to study the impact of some factors that control the adsorption of metal ions including solution pH, concentration of metal ions, contact time and the temperature of the solution. Batch sorption results showed that the chelating resin had high affinity towards Cu(II), Cd(II) and Pb(II). The saturated adsorption capacity at 25 oC was 2.43, 1.93 and 1.45mmolg-1 resin for Cu(II), Cd(II) and Pb(II), respectively. Among the empirical isotherm models, the equilibrium adsorption results were obviously fitted with Langmuir model. The kinetics was analyzed using pseudo-first-order, pseudo-second-order, and intra-particle diffusion equations. The adsorption kinetic data were well elucidated with pseudo-second-order kinetic model. Thermodynamic parameters were calculated for the uptake of the metal ions under study and it was found to be a spontaneous process. Moreover, the adsorption of metal ions has been studied using column technique. The regeneration of CPN-IDA was experimentally performed by using nitric acid. The chelating resin was used repeatedly for five times with a little decrease in sorption of metal ions.