Uranium migration through intact sandstone: effect of pollutant concentration and the reversibility of uptake

摘要: A series of core flood experiments has been performed to investigate the migration behaviour uranium under rigidly controlled conditions. Intact sandstone cores, pre-equilibrated with synthetic groundwater, were flooded solutions at varying concentrations and transport process monitored as a function pH, tracer concentration competing ion, cadmium. In each case substantial amount was retained by core, implying strong interaction rock matrix. The adsorption found be highly dependent; however, such that finite retention capacity an intact can exhausted within relatively short time. reversibility uptake studied attempting displace adsorbed injected cadmium flushing brine. Most readily recoverable but small percentage is released very slowly on flushing, suggesting conversion more stable form. Prior performing experiment simulation carried out using one-dimensional coupled chemical code, encompassing thermodynamic description electrical double layer. model successful in predicting priori dominant trends which may aid developments for complex geochemical regimes than those here.