Batch and column adsorption of methylene blue by graphene/alginate nanocomposite: Comparison of single-network and double-network hydrogels

The alginate nanocomposite prepared by immobilizing nanomaterials into alginate has been widely studied to remove pollutants from water. However, how to prepare the alginate beads with better stability and reusability is important to its practiclal application. In this study, a new kind of porous graphene/alginate double network nanocomposite beads (GAD) are prepared and compared with graphene/alginate single network nanocomposite beads (GAS). The results show that GAD has higher specific surface area and better thermal stability than GAS. Moreover, GAD is more stable than GAS in NaCl solution. Furthermore, both batch and column adsorption experiments of methylene blue (MB) were applied to evaluate its adsorption performance. The obtained results indicated that GAD has better potential than GAS to be applied as adsorbent for the removal of organic pollutants.