Detoxification of Uranium in Soils and Groundwater Using Recycled Concrete
CX(s) Applied: B3.6
Location(s): Aiken, South Carolina
Office(s): Environmental Management, Savannah River Operations Office
Detoxification of Uranium in Soils and Groundwater Using Recycled Concrete. This effort seeks to demonstrate that U(VI) can be immobilized by inducing precipitation of U(VI) silicates by addition of powdered recycled concrete. Uranium silicates are stable over a wide range of pH and at the oxidizing conditions prevalent at most uranium waste sites. The predominant reactive component of cementitious material is the hydrated calcium silicate gel (C-S-H). If the reaction of C-S-H and U(VI) is sufficiently effective, then powdered clean concrete recycled from D&D operations could be used as the source of C-S-H, resulting in a very inexpensive amendment that would immobilize U in its oxidized form, insuring long-term treatment. The ability of Portland cement pastes to remove U(VI) from water solutions and to immobilize U(VI) in soils will be evaluated.