Carbon and zeolite-based composites for radionuclide and heavy metal sorption

Zeolites have been investigated as sorbents of heavy metals from water. Since graphene oxide was already re-ported as promising radionuclide sorbent, we developed composite materials containing both a synthetic zeolite (type A, P or Y) and graphene oxide to be multifunctional sorbents. The extension of multifunctionality of sorbents was done by presence of third component, exfoliated graphite, to have additional properties as conductivity. The changing sorption activities of a composite was studied depending on its composition and functional modification. The composites, characterized by X-ray powder diffraction, Raman, FTIR spectroscopy and scanning electron microscopy, were tested for sorption of selected radionuclides (134Cs+, 85Sr2+) and heavy metals (Pb2+, Cd2+). The dependency on composition was found in connection with a high sorption of Pb2+ and Cd2+. Finally, opti-mized multifunctional sorbents (Gr-GO-COOH-A in ratio 40:40:20 and Gr:GO:A in ratio 25:25:50) were found to keep interesting high sorption activities for heavy metals and radionuclides with good conductivity properties.

Automated summary

This study developed composite materials combining zeolites with graphene oxide as sorbents for heavy metals in water. The addition of exfoliated graphite as a third component enhanced the conductivity of the sorbents, making them multifunctional. The sorption activities of the composites were studied depending on their composition and functional modification. Optimized multifunctional sorbents with good conductivity and high sorption activities for heavy metals were discovered.