A New Cationic Poly[1-vinyl-3-ethyl imidazolium iodide], P(VEII) Hydrogel for the Effective Removal of Chromium (VI) from Aqueous Solution

Cationic porous and non-porous hydrogels have been prepared via free radical solution polymerization using newly synthesized 1-vinyl-3-ethyl imidazolium iodide (VEII) monomer and N,N'-methylenebisacrylamide as crosslinker. The hydrogel has been characterized by FT-IR, mercury porosimetery and TGA analysis. Their surface morphology was observed using scanning electron microscope (SEM). The swelling kinetics of porous and non-porous P(VEII) hydrogels in solutions of chromium(VI) was determined using a gravimetric method. A batch system was applied to study the adsorption of chromium(VI) from aqueous solutions by cationic hydrogels. The effect of treatment time, pH of the medium, amount of adsorbent dose and initial feed concentration of metal ion on adsorption of chromium(VI) from their solution were also investigated. Adsorption of chromium(VI) increases with the increase in treatment time, adsorbent dose and initial feed concentration and decreases with the increase in pH of the medium. Desorption of chromium(VI) was carried out using various eluents and almost 100% desorption was observed, so the P[VEII] hydrogel can be used repeatedly for the adsorption of chromium(VI).