Effect of Mg-Ca-Sr on the sorption behavior of uranium(VI) on silica

Abstract

The effect of alkaline earth uranyl carbonate complexes on the sorption behavior of U(VI) on quartz was studied by means of well defined batch experiments. In the pure U(VI) – silica system, the pH dependency was minor and about 90% of the uranium sorbed onto quartz. However, in the presence of Ca, Sr, or Mg the sorption of uranium decreased to 10, 30, and 50% respectively. The reduction in sorption behavior is due to the presence of zero valent and anionic complexes of alkaline earth uranyl carbonate species and show the importance to include these species in thermodynamic data bases. It is assumed that, in particular, the zero-valent species are responsible for less sorption in the presence of alkaline earth metals.