Removal of methyl orange by adsorption onto γ-Fe2O3/activated carbon nanocomposite: Equilibrium and kinetics studies

In the water and wastewater treatment field, activated carbon has wide applications in adsorption of pollutants. However, the applications are limited by problems and difficulties encountered in the separation of activated carbon from water because of the small particle size. Activated carbon/γ-Fe2O3 nanocomposites have not only the adsorption properties of activated carbon powder but also the magnetic features of iron oxide nanoparticles. In this study, removal of methyl orange (MO) as an anionic dye from aqueous solution by prepared activated carbon/γ-Fe2O3 nanocomposites was investigated. The effect of pH, adsorbent dosage, contact time and initial dye concentration were studied. The adsorption capacity of MO onto the magnetic activated carbon (MAC) was between 75- 140 mg g-1. Adsorption experiments data indicated that the adsorption process of MO onto magnetic activated carbon (MAC) obeyed pseudo-second order kinetic model. The promising results indicated that the MO can adsorb to MAC and separate from solutions by an external magnetic field which can be an alternative to complicated separation methods such as centrifugation or filtration.