REMOVAL OF LEAD (II) AND CADMIUM (II) CATIONS FROM WATER USING SURFACE-MODIFIED GRAPHENE

With its unique structure, graphene exhibits a number of outstanding mechanical, optical, and electronic properties, thus promising several potential applications. In the current work, graphene sheets were prepared from graphite and surface-modified via an acid treatment. The synthesized material physicochemical properties were assessed using X-ray diffraction, nitrogen adsorption and BET analysis, transmission electron microscopy, and Raman as well as X-ray photoelectron spectroscopy techniques. The ability of the surface-modified graphene in the adsorptive elimination of Pb(II) and Cd(II) cations from aqueous solutions was investigated batchwise under numerous experimental conditions. A pseudo-second order kinetic model described adequately the adsorption kinetic profiles. The adsorption isotherms were compared to the Langmuir and Freundlich models. It was found that for both heavy metal cations, adsorption isotherms were reasonably described by Langmuir model equation. Maximum adsorption capacities reached 0.946 and 1.779mmolion/g for Pb(II) and Cd(II), respectively.