Eco-Friendly, Vascular Shape and Interpenetrating Poly (Acrylic Acid) Grafted Pectin Hydrogels; Biosorption and Desorption Investigations

摘要

The synthesis and characterization of poly (acrylic acid) grafted pectin hydrogel followed by biosorption and desorption characteristics of cadmium, as a model heavy metal, have been studied. The grafted eco-friendly pectin based interpenetrating hydrogel was prepared in the presence of gluteraldehyde crosslinker under N_2 atmosphere and characterized using 'H-NMR, FTIR, TGA and SEM techniques. Gluteraldehyde was found to form one-arm and two-arm crosslinks in the copolymer. Upon grafting, two-dimensional sheet structures bounded to tubular and vascular cylindrical rods were observed. The biosorption and desorption data, determined experimentally, were fitted to pseudo-second order reaction kinetics. At higher ionic strength values, the maximum metal uptake value (q_(max)) was lowered and pseudo-second order rate constant (k_2) was increased. Whereas, at higher pH values the maximum metal uptake value (q_(max)) was increased and Pseudo-second order rate constant (k_2) was decreased. 0.1 M HCl solution was a suitable eluent to regenerate the hydrogel surface and recover the adsorbed cadmium metal ions. Pectin based copolymer could be used as an efficient candidature biosorbent for the recovery of cadmium metal ions from aqueous solutions.