Facile approach to synthesis super-adsorptive hydrogel based on hyperbranched polymer for water remediation from methylene blue

In this study, a novel adsorbent hydrogel based on hyperbranched poly(amine-ester) (HPAE) was developed by using the in-situ free radical polymerization of sodium acrylate in the presence of N,N′- methylene bisacrylamide as cross-linker. Different ratios from HPAE were used. The resulting hydrogels were characterized by FTIR, TGA and SEM techniques. The results indicated the successful preparation of hydrogels with highly porous structures. The adsorption efficacy of the synthesized hydrogels was investigated for the removal of methylene blue (MB) from aqueous solutions. The highest adsorption capacity was recorded by the hydrogel prepared with 35% HPAE, with a maximum adsorption capacity of 1432 mg/L at a feed dye concentration of 1000 mg/L using an adsorption dose of 0.625 g/L. The effects of different parameters affecting adsorption capacity as pH, contact time, dose, and initial dye concentration were examined. The MB adsorption kinetic and isotherm fit well with the pseudo- second- order and Freundlich models, respectively. Moreover, the desorption studies revealed the efficient recovery and regeneration of the adsorbent hydrogel. Based on the adsorption data, it is expected that the hydrogel based on HPAE has prospective applications in the industrial sector for cationic dyes removal from wastewater.