TY  - JOUR
AU  - Ruiz, O.
AU  - Thomson, B.
AU  - Cerrato, J. M.
AU  - Rodriguez-Freire, L.
PY  - 2019//
TI  - Groundwater restoration following in-situ recovery (ISR) mining of uranium
JO  - Applied Geochemistry
SP  - 104418
VL  - 109
KW  - Aquifer stabilization
KW  - Ground water restoration
KW  - In-situ leach mining
KW  - In-situ recovery
KW  - Uranium
N2  - From 1950 through the early 1980’s New Mexico accounted for roughly half of domestic uranium (U) production for the nuclear power industry and the nation’s weapon programs. Increased interest in nuclear energy has led to proposals for renewed development using both underground mining and uranium in situ recovery (ISR). When feasible, ISR greatly reduces waste generated by the mining and milling processes, however, the ability to restore ground water to acceptable quality after ISR ends is uncertain. This research investigated two methods of stabilizing an aquifer following ISR. Batch and column studies were performed to evaluate chemical and biological methods of stabilization. Columns packed with ore were first leached with an aerated NaHCO3 ground water solution to simulate ISR. Constituents present at elevated concentrations after leaching included molybdenum (Mo), selenium (Se), U, and vanadium (V). Chemical stabilization was studied by passing a phosphate (PO43-) amended solution through the ore to achieve passivation of mineral surfaces by P precipitates. Microbial stabilization was studied by passing a lactate solution through the ore to stimulate growth of anaerobic metal- and sulfate-reducing organisms to reduce U and other elements to less soluble phases. Analyses of the solids from the columns after completion of these experiments by X-ray photo electron spectroscopy (XPS) identified phosphate on samples near the column inlet of the chemically stabilized columns. Microbial populations were characterized by Illumina DNA sequencing and confirmed the presence of metal- and sulfate-reducing organisms. Neither chemical nor microbial stabilization method achieved contaminant immobilization, which is believed due to limited mixing of the stabilization solutions with the contaminated leach solutions. These results emphasize that ground water hydrodynamics, especially mixing, must be considered in aquifer restoration of soluble constituents.
SN  - 0883-2927
UR  - https://www.sciencedirect.com/science/article/pii/S0883292719302197
N1  - exported from refbase (http://www.uhydro.de/base/show.php?record=153), last updated on Fri, 26 Jan 2024 13:19:04 +0100
ID  - Ruiz_etal2019
ER  -