2020 Volume 45 Issue 2 Pages 23-30
A novel polymeric adsorbent for hexavalent chromium (Cr(VI)) ions was developed by photografting 2-(dimethylamino)ethyl methacrylate (DMAEMA) to a polyethylene (PE) mesh substrate. The DMAEMA-grafted PE (PE-g-PDMAEMA) meshes obtained were quaternized with iodoalkanes of different alkyl chain lengths. The grafting of DMAEMA and subsequent quaternization of dimethylamino groups were characterized by the FT-IR measurements. The Cr(VI) ion adsorption capacity at pH 3.0 and 30°C had the maximum value at the grafted amount of 2.6 mmol/g and the adsorption behavior obeyed the mechanism of the pseudo-second order kinetic model and well expressed by Langmuir isotherm. This can suggest that the adsorption occurs through an electrostatic interaction between protonated dimethylamino groups and hydrochromate ions. Cr(VI) ions were successfully desorbed in eluents such as NaOH, NaCl, and NH4Cl. When the PE-g-PDAMEMA meshes were quaternized with the iodoalkanes, the adsorption capacity increased and the maximum adsorption ratio was obtained for the PE-g-PDMAEMA mesh quaternized with iodoheptane. This value was about 1.83 times higher than the original PE-g-PDAMEMA mesh. The results obtained in this study emphasize that the PE-g-PDMAEMA meshes and their quaternized products can be applied as an adsorbent for Cr(VI) ions.
