Removal of Cr(VI) from aqueous solution by a highly efficient chelating resin

The poly([(2-methacryloyloxy)ethyl]trimethylammonium chloride) [P(MOTA)] based chelating resin was synthesized by radical polymerization and employed for Cr(VI) removal. The sorption capacity of this resin was very high with a fast sorption rate for Cr(VI) obeying a pseudo-second order kinetic model. In agreement to diffusion model equations, the rate determining step was film diffusion according to the infinite solution volume (ISV) model and reacted layer in accordance with the unreacted core (UC) model. In a column-mode sorption study, the breakthrough capacity obtained was 24.3 mg Cr/mL-resin. The elution of Cr(VI) from the resin was achieved using a mixture of 1.0 mol/L NaOH and 1.0 mol/L NaCl with an elution efficiency of about 100 %. Based on FT-IR measurements, it was clearly understood that Cr(VI) was sorbed by the resin through the quaternary amine functional groups.