LAUSR

ABSTRACT Graphene-based materials have been extensively employed for the removal of heavy metals and radionuclides from water and wastewater. This work critically reviews the current status of research works on the use of graphene, as well as its modified materials, and their efficacy for the adsorption of heavy metals and radionuclides. It focuses on the examination of different factors influencing the adsorption capacity, including the properties of graphene-based materials, solution pH, contact time, initial concentration of metal ions, initial dosage of graphene-based materials, temperature, organic acid ligands, coexisting ions, and competitive adsorption. Adsorption dynamics, isotherms, and thermodynamics are addressed in some detail. The proposed adsorption mechanisms deduced by various characterization methods and analytical techniques involve in one or combination of the electrostatic interaction, surface complexation, ion exchange, reduction, and precipitation. Many graphene-based materials have proved to be stable and regenerable over a number of adsorption–desorption cycles. Further research trends on the practical application of graphene-based materials are also given.