Water treatment technology looks for sorbent materials capable of resisting several adsorption-desorption cycles for repetitive use. For regeneration and reusability of nanoadsorbents, surface treatment with alkaline eluents (e.g., NaOH solutions) allowed the regenerations by removing the 99% of arsenic from graphene-oxide composites with metal oxides such as CuFe2O4, Gd2O3, Fe3O4, and CuO), Zn-Fe mixed metal oxides, Fe3O4/Halloysite nanocomposites, Fe/Cu-polyurethane nanoparticles, and Ti-oxides .