Cr(VI) Adsorption on Ethylenediamine Functionalized Grafted Sodium Alginate Beads: Effect of Process Parameters

In the presented study, a series of physically crosslinked sodium alginate beads-g-poly(glycidyl methacrylate) was synthesized at different conditions, then the copolymer with the highest grafting efficiency percentage was functionalized with ethylenediamine for Cr(VI) adsorption from aqua solutions. FTIR (Fourier transform infrared) and SEM (scanning electron microscopy) analyses were used to display the changes in the adsorbent structure. pH, adsorbent amount, adsorption time, initial Cr(VI) ion concentration, and process temperature were used as the adsorption parameters to optimize the process. The kinetic and equilibrium data were fitted to pseudo-second order and Langmuir model, respectively. In addition, the thermodynamic studies displayed the endothermic and spontaneous nature of the Cr(VI) adsorption process. While the adsorption capacity of the functionalized polymer was 238.45 mg.g(-1), it was found 26.79 and 46.89 mg.g(-1) for the crosslinked sodium alginate beads and the grafted beads, respectively, at the temperature of 25 degrees C, pH of 2, and initial Cr(VI) ion concentration of 100 ppm. The obtained results revealed the high adsorption efficiency and reusability of the functionalized grafted sodium alginate beads.