Immobilization of uranium into magnetite from aqueous solution by electrodepositing approach

Immobilization of uranium into magnetite (Fe3O4), which was generated from metallic iron by electrochemical method, was proposed to rapidly remove uranium from aqueous solution. The effects of electrochemical parameters such as electrode materials, voltage, electrode gap, reaction time and pH value on the crystallization of Fe3O4 and uranium removal efficiencies were investigated. More than 90% uranium in the solution was precipitated with Fe3O4 under laboratory conditions when uranium concentration range from 0.5 mg/L to 10 mg/L. The Fe3O4 crystallization mechanism and immobilization of uranium was proved by XPS, XRD, TEM, FTIR and VSM methods. The results indicated that the cationic (including Fe2+, Fe3+ and U(VI)) migrate to cathode side under the electric field and the uranium was incorporated or adsorbed by Fe3O4 which was generated at cathode while the pH ranges between 2-7. The uranium-containing precipitate of Fe3O4 can exist stably at the acid concentration below 60 g/L. Furthermore, the precipitate may be used as valuable resources for uranium or iron recycling, which resulted in no secondary pollution in the removal of uranium from aqueous solution. (C) 2017 Published by Elsevier B.V.