Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8080430 | Journal of Environmental Radioactivity | 2018 | 8 Pages |
Abstract
The results presented in this paper highlight the complexity of adsorption and incorporation processes of Nd with dolomite and significantly improve upon previous work investigating trivalent actinide and lanthanide interactions with dolomite. Both batch and mini column experiments were conducted at variable ionic strength. These data highlight the strong chemisorption of Nd to the dolomite surface (equilibrium Kd'sâ¯>â¯3000â¯mL/g) and suggest that equilibrium adsorption processes may not be affected by ionic strength based on similar results at 0.1 and 5.0â¯M ionic strength in column breakthrough and equilibrium batch (>5 days) results. Mini column experiments conducted over approximately one year also represent a significant development in measurement of sorption of Nd in the presence of flow as previous large-scale column experiments did not achieve breakthrough likely due to the high loading capacity of dolomite for Nd (up to 240â¯Î¼g/g). Batch experiments in the absence of flow show that the rate of Nd removal increases with increasing ionic strength (up to 5.0â¯M) with greater removal at greater ionic strength for a 24â¯h sampling point. We suggest that the increasing ionic strength induces increased mineral dissolution and re-precipitation caused by changes in activity with ionic strength that lead to increased removal of Nd through co-precipitation processes.
Keywords
ICP-OESGWBTRLFSEMPASEM-EDSDOEPTFEWIPPPerformance assessmentinductively coupled plasma optical emission spectrometerIncorporationElectron microprobe analysisSorptionDolomiteBETInductively coupled plasma mass spectrometerICP-MSLanthanideNeodymiumDepartment of EnergyXRDX-ray diffractionpolytetrafluoroethyleneWaste Isolation Pilot PlantCarbonates
Related Topics
Physical Sciences and Engineering
Energy
Nuclear Energy and Engineering
Authors
H.P. Emerson, F. Zengotita, M. Richmann, Y. Katsenovich, D.T. Reed, T.M. Dittrich,