ADSORPTION METYLENE BLUE FROM AQUEOUS SOLUTION BY THE ACID MODIFIED GRAPHENE – RED MUD

Abstract

   The HNO3-modified graphene - red mud (G-RM) was used as an adsorbent to removeefficiently methylene blue (MB), from aqueous solution. Scanning electron microscopy(SEM) images of G-RM reveal a highly porous surface structure of the adsopbent. Theadsorption properties for MB of G-RM were investigated by batch method. Theinfluence of pH (2-14), contact time (10-150 min), and the amount of adsorbent (0.02-0.08g) on MB removal efficiency by the G-RM were also determined. The results showthat the time to reach adsorption equilibrium, the optimal pH value, and mass ofadsopbent are 90 min, 12, and 0.05g, respectively. The maximum monolayeradsorption capacity of G-RM is 270.27 mg/g. G-RM acts as a promising adsorbent forthe removal of methylene blue from aqueous solution.

Keywords: Adsorption; graphene, red mud; Langmuir isotherm; methylene blue.