Efficient removal of hazardous lead, cadmium, and arsenic from aqueous environment by iron oxide modified clay-activated carbon composite beads

The present communication addresses the removal of toxic lead, cadmium, and arsenic using iron oxide modified clay-activated carbon composite beads from aqueous solutions. The SEM-EDX analysis was conducted to study the heterogeneity of the surface and the elemental composition of the composite beads. The specific surface area of the composite beads was found to be 433m(2)/g. Furthermore, the XRD pattern indicates the intercalation of iron particles between the layers of bentonite clay. The FT-IR analysis suggests that the hydroxyl, carboxyl, and Fe-O were the major functional groups responsible for the removal of lead, cadmium, and arsenic. The Langmuir monolayer sorption capacity of Pb(II), Cd(II) and As(V) were observed to be 74.2, 41.3 and 5.0 mg/g respectively. Kinetic studies indicate that intra-particle diffusion plays a significant role in the removal of these three toxic pollutants. In addition, the composite beads were applied for the adsorption of a ternary mixture of subjected pollutants at low concentrations and found efficient to remove these pollutants up to an acceptable permissible limit of drinking water. The significances of this study propose the potential of composite beads for purifying the water containing toxic pollutants, viz., lead, cadmium, and arsenic.