Kinetic study of pentavalent vanadium sorption on magnetic macroporous copolymer of glycidyl methacrylate

Abstract

Chelating copolymers show high efficiency in sorption of different ionic species in aqueous solutions. The specific structure of chelating macroporous copolymers made by the porous matrix and functional groups with the heteroatoms N, O, S and P; allows them to establish various types of interactions with ions and molecules from the immediate surroundings. Furthermore amino-functionalized macroporous copolymer of glycidyl methacrylate and ethylene glycol dimethacrylate poli (GME) has a high capacity and good selectivity for the precious and heavy metal ions over alkali and alkaline earth metals. In this study, aminofunctionalized magnetic macroporous m-poli (GME)-deta was fully characterized in terms of its structural properties using: FTIR, SEM/EDX and XRD analysis. The macroporous copolymer was further used to investigate the sorption of pentavalent vanadium oxyanions from diluted aqueous solutions (Ci = 25 ppm) in a batch system, at room temperature (298 K). The oxyanion concentrations in a solution was determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES).The pseudo-first-order (PFO), pseudo-second-order (PSO), Elovich and intra-particle diffusion (IPD) models were used to analyze the kinetic data. The study has shown that sorption is rapid, i.e. the half-sorption time, t1/2 is approximately 1 minute. Initially, it has been the dominant sorption on the surface of the particles and the process has been best described by the PSO model (which takes into account the binding between sorbate and sorbent). The moment it has reached saturation of the sorbents surface active sites, sorption rate decreases significantly because the sorption has been limited by the rate of diffusion through the pores and kinetic has been controlled by the intraparticle diffusion process. IPD kinetic model showed a good fit to the experimental data with R2 values > 0.95.