Konjac glucomannan/graphene oxide hydrogel with enhanced dyes adsorption capability for methyl blue and methyl orange

the present study, the graphene oxide (GO) filled konjac glucomannan (KGM) hydrogel was prepared by using calcium oxide as the crosslinker. The structure of the prepared KGM/GO hydrogel was characterized. The prepared hydrogel was then used to adsorb methyl orange (MO) and methyl blue (MB) in aqueous solutions. Due to the presence of GO, KGM/GO hydrogel showed much enhanced adsorbing performance to both MO and MB compared to neat KGM hydrogel. The adsorption kinetics of the hydrogel was studied. The prepared hydrogel fitted for the pseudo-second-order kinetics model better. The adsorption isotherm of the MO and MB onto KGM/GO hydrogel was also studied and the results suggested that the both MO and MB adsorption behaviors fitted for the Freundlich isotherm model better. The prepared KGM/GO has application potentials to be as the adsorbent for water purifications. (C) 2015 Elsevier B.V. All rights reserved.