Comparative study of Eu and U sorption on cementitious materials in the presence of organic substances.

A comparative study of the sorption behavior of europium, a chemical analogue of trivalent actinides, and uranium was performed on hydrated cement paste (HCP) CEM I and calcium-silicate-hydrates (CSH) phase. Kinetic experiments proved that Eu sorption is faster than that of U depending on the phase ratio L/S and the sorption material, whereas EDTA has no significant effect. Same conclusions can be made for equilibrium experiments with HCP and U while with Eu EDTA clearly influenced the distribution ratio Rd with sorption reduction factor (SRF) below 0.5. Uranium sorption on CSH compared to HCP is higher with SRF above 1.2. [ABSTRACT FROM AUTHOR]