Effect of temperature and humic acid on the U(VI) diffusion in compacted opalinus clay

Abstract

The diffusion of 233U(VI) in compacted Opalinus Clay from the Mont Terri test site, Switzerland was studied in the absence and presence of humic acid for two different temperatures (25, 60°C). The diffusion experiments were carried out under anaerobic conditions and a synthetic Opalinus Clay pore water (pH 7.6, I = 0.36 M) as background electrolyte was used. At 25°C as well as at 60°C humic acid has no influence on 233U(VI) diffusion. In addition, the results showed that the interaction of 233U(VI) with the clay is stronger at 60°C.