Preparation of a magnetic reduced-graphene oxide/tea waste composite for high-efficiency sorption of uranium

The preparation and application of adsorptive materials with low cost and high-efficiency recovery of uranium from nuclear waste is necessary for the development of sustainable, clean energy resources and to avoid nuclear pollution. In this work, the capacity of tea waste and tea waste hybrids as inexpensive sorbents for uranium removal from water solutions was investigated. Composites of graphene oxide (GO) and tea waste (TW) exhibited a promising adsorption performance for uranium from aqueous solutions. The composites GOTW and magnetic rGO/Fe3O4/TW show high adsorption capacities (Qm (TW) = 91.72 mg/g, Qm (GOTW) = 111.61 mg/g and Qm (rGO/Fe3O4/TW) = 104.95 mg/g) and removal rates (~99%) for U(VI). The equilibrium sorption of the adsorbents fitted well to the Langmuir model, and the sorption rate fitted well to a pseudo-second-order kinetic model. The thermodynamic parameters indicated that sorption was spontaneous and favourable. The prepared adsorbents were used for the removal of uranium from real water samples as well. The results revealed that GOTW and rGO/Fe3O4/TW can be used to remediate nuclear industrial effluent as a potential adsorbent.