Two cross-hole tracer tests and one infiltration tracer test were completed at a former uranium mill site in Grand Junction, Colorado. Reactive transport modeling was completed to derive physical and geochemical parameters. The observed data from saturated zone cross-hole tracer testing was adequately simulated using PHT-USG (reactive transport model) and PEST++ (calibration routine) with reasonable estimates of hydraulic conductivity, dispersion, effective porosity, cation exchange, calcite saturation index, and uranium sorption potential. The use of multiple layering in one cross-hole model was able to capture hydraulic conductivity variations with depth, which produced a double hump in the tracer concentrations. The complete article can be downloaded here: https://www.mdpi.com/2075-163X/13/7/947
100-series well constructions with injection and pumping pattern in relation to hydrogeology and solid-phase uranium concentrations. Red shading indicates depths with solid-phase uranium concentrations that are above background. Depths are to scale with two times horizontal exaggeration. Well 0105 is beyond the plane of the page (Figure 2). Arrows indicate flow directions.
The Paradis Lab contributed to research lead by UWM’s School of Freshwater Sciences that was focused on Halophilic bacteria in a Lake Michigan drainage basin as potential biological indicators of chloride-impacted freshwaters and published in the journal Science of The Total Environment (LINK HERE). Below is a graphical abstract of this research.
Dr. Martin Dangelmayr’s research on uranium sorption to four different types of rocks (organic-rich phosphorite, a bituminous marl, a chalk, and a sandstone) in the Negev Desert in Israel was recently published in Minerals (link to open source). These rocks are being considered as potential hosts for spent nuclear fuel, thus their sorption capacity for uranium is very important.
New method just published to estimate groundwater velocity from a single-well injection-drift tracer test. The early-view publication can be found online in the journal, Groundwater.
Correlation between uranium and the relative content of clay minerals among mineral constituents, total aluminum content, and cell counts
A research article entitled, “Characterization of subsurface media from locations up- and down-gradient of a uranium-contaminated aquifer” was accepted for publication in the peer-reviewed scientific journal Chemosphere. Dr. Paradis is a co-author of the article and the corresponding author is Dr. Terry Hazen (firstname.lastname@example.org) from the University of Tennessee at Knoxville and Oak Ridge National Laboratory.
Hypothesized distributions of dissolved sulfate 3 years after emplacement of PFBs and HPIs, assuming no consumption of sulfate in the aquifer.
A research article co-authored by Dr. Paradis entitled, “Enhancing Microbial Sulfate Reduction of Hydrocarbons in Groundwater Using Permeable Filled Borings“, is among the top 10% most downloaded papers in Ground Water Monitoring & Remediation (GWMR). Special thanks to Tim Buscheck (email@example.com), Chevron Fellow and Senior Consulting Hydrogeologist, for serving as lead and corresponding author on this cutting‐edge technical paper.