Preparation and characterization of oxidized graphene for actinides and rare earth elements removal in nitric acid solutions from nuclear wastes

The removal of actinides and rare earth elements (REEs) in nitric acid solutions; produced in nuclear processes; is a challenging job. The present article describes the sorption behavior of oxidized multilayer graphene (o-MG) to actinides and rare earth elements (REEs) in nitric acid solutions (up to 3 mol L-1 HNO3), including nitrogen and phosphorus-containing reagents. The conditions for obtaining new sorption materials in a compact form; by adding directly a reagent (organic ligand) and a suspension of o-MG to nitric acid solutions; were optimized. o-MG was modified by using tetraoctyldiglycolamide, diphenyl-dibutyl-carbamoyl-methyl-phosphine oxide, tri-octyl-phosphinoxide, di-(2-ethylhexyl) phosphoric acid, tributyl phosphate and di-2-ethyl-hexyl-methyl-phosphonate reagents were used. The formation time of the solid-phase extractants compact phase was 20–240 min. The new materials sorption capacity to U (VI), Th (IV), Pu (IV), La (III), Ce (III) and Eu (III) in nitric acid solutions (3 mol L-1 HNO3) was determined. The elements distribution coefficients were Kd ~ 103-104 mL g−1. The efficiency of the obtained materials was confirmed by the data on the solid-phase isolation and separation of actinides and REEs from nitric acid solutions (3 mol L1 HNO3) in the presence of macro components (Cs, Sr, Fe, Mo, Pd, Zr, Co), which can be formed during recycling processes of spent nuclear materials and components used in nuclear medicine.