LAUSR

Abstract Removal of pollutants by bio-superadsorbent is currently in the limelight due to their low cost and biocompatibility with the environment. This research, we investigated the potential of cellulose nanofibers (CNFs) treated starch-g-poly(acrylic acid) (St-g-PAA) superadsorbent hydrogels in removing Cu2+ ions from water. It was found that CNFs-incorporated starch-g-poly(acrylic acid) hydrogel exhibit the highest amount of Cu2+ uptake in a solution containing 0.1 g/L Cu2+ ions, and that adsorption capacity rises significantly with the increase in Cu2+ concentration from 0.1 to 0.6 g/L. The influence of CNFs on the adsorption of Cu2+ ions was studied by Langmuir and Freundlich adsorption isotherm models, the graphs verged on linearity in Langmuir model while the maximum monolayer adsorption capacity was found to be 0.736 g/g for the untreated St-g-PAA hydrogels and 0.957 g/g for the CNFs-treated hydrogels in 0.6 g/L Cu2+ solution at pH 5. In this study, the adsorption capacity was enhanced by increasing the contact time between the bio-adsorbent and solution up to 5 h while longer contact time resulted in reduced adsorption and desorption phenomenon. In addition, desorption results showed that maximum adsorbent recovery for pH near to 1–2. This study confirms that the starch-based hydrogel is promising to be used for removal of pollutants from water efficiently.