Kinetic modeling of heavy metal sorption by vinyl pyridine based copolymer

Commercial macroporous poly(4-vinylpyridine-co-divinylbenzene) [P4VPD], known as REILLEX-425 was characterized by mercury porosimetry, nitrogen physisorption, Fourier transformed infrared (FTIR) spectroscopy and elemental analysis. Sorption rates of P4VPD for Cu(II), Co(II) and Cr(VI) ions were determined in static non-competitive experiments, at room temperature (298 K). Rapid sorption was observed, especially for Co(II), with half time, t1/2, of 1.5 min and high experimental maximal capacity, Qmax, of 3.08 mmol g-1. Four kinetic models (pseudo-first and pseudo-second order model, intraparticle diffusion and Boyd model) were used for analyzing metal sorption by P4VPD. Metal ions sorption is well represented by the pseudo-second-order model, with definite influence of pore and film diffusion on sorption rates.