Research Advances of the Mechanism of Aqueous U(VI) Immobilization by Goethite

The purification of U(VI) in radioactive contaminated water has always been a hot research issue. The goethite is the most stable hydroxyl iron oxide in nature, with a南华大学学报(自然科学版) 2021 年 6 月 bundant surface sites and high affinity for many anions, cations and radioactive elements. The immobilization mechanisms of aqueous U(VI) by goethite are reviewed, including the surface complexation between goethite particles and uranyl with the formation of the bidentate corner-sharingand bidentate edge-sharingsurface complexes, as well as the lattice embedding of uranium into goethite structure during the Fe(II) induced morphology transformation of the ferrihydrite or the coprecipitation process of Fe(II) and U(VI). The effects of carbonate and phosphate on the retention of U(VI) by goethite are discussed. The further research directions of uranium immobilization by the goethite are prospected. key words:uranium-containing water;goethite;surface complexation;lattice incorporation