Uranyl Retention on Quartz—New Experimental Data and Blind Prediction Using an Existing Surface Complexation Model

摘要: The adsorption behaviour of uranyl onto seven different samples quartz was studied in batch experiments. Sea-sand (0.1–0.3 mm), Fil-Pro 12/20 (1–2 mm) and five Min-U-Sil with smaller particle sizes (5, 10, 15, 30 40 μm) were used. uptake curves show “pH edges” the range pH 4–5. A good agreement new data literature found when plotting surface-normalised distribution coefficients versus pH. Differences for pre-treated untreated sea-sand detectable resulting a shift edge to higher values after treatment. surface complexation model applied blind predictions experimental results. simulations described observations quite well samples. For two coarser samples, calculated over-predictions explained by larger-than-expected measured specific area measurable amounts associated minerals, sea-sand, respectively. Dissolution as function After 5 days, Si concentrations all than equilibrium solubilities, but lower those amorphous silica. With increasing pH, dissolved silica increased. This strongly suggests that formation uranyl–silicato complexes have be considered based on concentrations.