A new research article titled, Single-Well Push–Pull Tracer Test Analyses to Determine Aquifer Reactive Transport Parameters at a Former Uranium Mill Site (Grand Junction, Colorado), was recently published in the scientific journal Minerals. This research used PHREEQC (geochemistry), PHT-USG (flow and transport), and PEST (calibration) to understand the importance of cation exchange, sorption, and gypsum dissolution on the fate and transport of uranium at a former mill tailings site.
Figure 9. Model fit for uranium in all PPT wells, with and without gypsum addition for wells 0120 and 0121. Phases are: (1) traced river water injection, (2) untraced river water injection (chase), (3) drift phase, and (4) pumping phase. Posted values are the GC_s uranium sorption parameter values (moles/kg-water) for the upper and lower sensitivity testing (gray dashed curve) and the calibrated value from Table 4 (solid blue curve). GC_s values in bold italics indicate the authors’ picks for the best final values.