A study on adsorption behavior of newly synthesized banana pseudo-stem derived superabsorbent hydrogels for cationic and anionic dye removal from effluents.

In this work, an environmentally benign superabsorbent hydrogel based on banana pseudo-stem has been synthesized by free radical graft co-polymerization of sodium acrylate (NaAc) and acrylamide (AM) on to modified banana pseudo-stem cellulose backbone using ammonium persulfate (APS) and N,N-methylene-bis-acrylamide (MBA) as initiator and crosslinker respectively.The optimum condition for initiator, monomers and crosslinker concentrations was found to be 0.0032molL, 0.013molL and 0.00048molL respectively. Structural confirmation of the hydrogel prepared is performed by FT-IR spectroscopy whereas the morphology and thermal properties assessments were performed by SEM and TGA analysis respectively. Swelling behavior in solutions with different pH (2, 4, 7, 9 and 12) and contact time (5-750min) indicated 323.54gg in pH 7 solutions for 570min. The optimized hydrogel was used as adsorbent for methylene blue (MB) and methyl orange (MO) with a maximum adsorption of 333.3 and 124 mgg respectively. Kinetics and Isotherm adsorption studies revealed pseudo second-order and Freundlich isotherm as befitting models.