Elimination of hazardous methylene blue from contaminated solutions by electrochemically magnetized graphene oxide as a recyclable adsorbent

In this study, magnetic graphene oxide (MGO) was used as an adsorbent for an effective removal of methylene blue (MB) from aqueous solution. Graphene oxide (GO) nanosheets were synthesized using improved hummer method and magnetized electrochemically using iron electrodes by applying different currents (0.2 to 0.5 A) for different duration. The synthesized MGO was characterized using FTIR, XRD, FESEM, EDS, and BET analysis. It was confirmed that Fe3O4 nanoparticles were successfully incorporated into the structure of GO. MGO was evaluated for the adsorption of MB from simulated colored wastewater by studying the effect of electrochemical synthesis conditions (time and current), adsorbent dosage, pH of the solution, initial MB concentration and the presence of salt in wastewater. The results indicated that 0.16 g/L of MGO synthesized by applying 0.4 A for 10 min can remove 93% of MB (10 mg/L) from alkali solution through monolayer adsorption following Langmuir isotherm with the maximum adsorption capacity of 78.13 mg/g. This study introduces MGO as a recyclable and reusable adsorbent with the removal efficiency above 90% that can be potentially used in wastewater treatment. (C) 2019 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.