Preparation and Characterization of Cadmium(II)-Ion-Imprinted Composites Based on Epoxy Resin

In recent years, ion-imprinting technology has been frequently employed to selectively eliminate heavy metals from aqueous solutions. In this study, an environment-friendly porous cadmium-ion-imprinted composite (Cd(II)-IIP) based on epoxy resin was prepared using Cd(II) ion as a template, polyethylene glycol as a porogen, epoxy resin as the carrier, and polyethylene polyamine as complexation agent and curing agent via surface imprinting technique and stepwise polymerization process. Cd(II)-IIP was further characterized using SEM-EDS, FT-IR, TGA, and XPS, the systematic adsorption investigation of Cd(II)-IIP for the Cd(II) ions was explored. The research found that the adsorption capacity of Cd(II) got to the maximum value (qm = 64.74 mg/g) at pH = 4.0 and T = 318 K and the Cd(II)-IIP had high selectivity for Cd(II) in the presence of polymetallic ions and still has good recoverability after five cycles. The results showed that the adsorption process was closer to the pseudo-second-order kinetic model, and the isothermal curves of the experimental data were more consistent with the Langmuir adsorption model, which indicated that the whole process of adsorption was mainly monolayer chemisorption and spontaneous endothermic. In addition, the XPS and FT-IR results indicate that the interaction between Cd(II) and functional groups is related to O or N atoms on Cd(II)-IIP. In summary, Cd(II)-IIP has certain advantages and considerable development prospects for the treatment of wastewater containing Cd(II).