Geochemistry and Determination Possibilities of Uranium in Natural Waters

Abstract

Uranium concentration levels in aquatic environment are of great importance for environmental and safety assessment. In this work the chemical properties of uranium ions and complexes in aqueous solutions especially in geological environment are presented. Different methods for uranium determination in water samples are also discussed. The chemical behaviour of uranium species in aqueous solutions can be influenced by several factors such as the inclination of uranium towards complex formation (in the presence of inorganic and organic ligands), the hydrolytic processes and the redox properties. In natural waters it is also dependent on sorption processes to surfaces of minerals and/or colloids. Four different oxidation states of uranium ( + 3 U , U + 4 , UO+2 and UO + 22 ) are soluble and therefore can be studied in aqueous solutions. The most dominant form of uranium in aqueous solutions is the uranyl cation ( UO + 22 ).