The ternary complexation of calcium uranyl tricarbonate species, CaUO2(CO3)32− and Ca2UO2(CO3)3(aq), which are the predominant U(vi) complexes in groundwater and seawater, was investigated at variable temperatures from 10 to 70 °C.
The ternary alkaline earth metal uranyl tricarbonate complexes, MnUO2(CO3)32n−4 (M = Mg and Ca), have been considered to be the major U(vi) species contributing to uranium mobility in natural water.