Preparation and adsorption behaviors of sodium alginate-based adsorbent-immobilized β-cyclodextrin and graphene oxide

Abstract

Highly water soluble graphene oxide (GO) was synthesized via a modified Hummers method. A sodium alginate (SA)-based adsorbent-immobilized β-cyclodextrin (β-CD) and GO gel (SCGG) with excellent regeneration ability were prepared. The adsorptive properties of methylene blue (MB) on the SCGG adsorbent were studied. The results showed that when the dosage of the adsorbent was 1.0 g, pH of the solution was 7, temperature was 35 °C, initial concentration of MB was 50 mg L⁻¹, and adsorption time was 180 min, the removal rate of MB was 84.98% and the adsorption capacity was 133.24 mg g⁻¹. The isotherms and kinetics of adsorption were investigated to reveal that the equilibrium adsorption and kinetics were well-described by the Freundlich model and pseudo-second-order kinetics, respectively. The thermodynamic parameters showed that the adsorption process was spontaneous and endothermic in nature. The mechanical property of the SCGG was improved by the addition of GO. The regeneration removal rate of MB was more than 82% after six recycles.