Uranium (U) mill tailings in northern Saskatchewan, Canada, contain elevated concentrations of molybdenum (Mo). The potential for long-term (>10,000 years) mobilization of Mo from the tailings management facilities to regional groundwater systems is an environmental concern. To assist in characterizing long-term stability, X-ray absorption spectroscopy was used to define the chemical (redox and molecular) speciation of Mo in tailings samples from the Deilmann Tailings Management Facility (DTMF) at the Key Lake operations of Cameco Corporation. Comparison of Mo K near-edge X-ray absorption spectra of tailings samples and reference compounds of known oxidation states indicates Mo exists mainly as molybdate (+6 oxidation state). Principal component analysis of tailings samples spectra followed by linear combination fitting using spectra of reference compounds indicates that various proportions of NiMoO(4) and CaMoO(4) complexes, as well as molybdate adsorbed onto ferrihydrite, are the Mo species present in the U mine tailings. Tailings samples with low Fe/Mo (<708) and high Ni/Mo (>113) molar ratios are dominated by NiMoO(4), whereas those with high Fe/Mo (>708) and low Ni/Mo (<113) molar ratios are dominated by molybdate adsorbed onto ferrihydrite. This suggests that the speciation of Mo in the tailings is dependent in part on the chemistry of the original ore.
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http://dx.doi.org/10.1021/es102954b | DOI Listing |
Anal Chem
January 2025
State Key Laboratory of Genetic Engineering, School of Life Sciences, Human Phenome Institute, Zhangjiang Fudan International Innovation Center, Metabonomics and Systems Biology Laboratory at Shanghai International Centre for Molecular Phenomics, Zhongshan Hospital, Fudan University, Shanghai 200032, China.
Simultaneous analysis of multiple phosphorylated metabolites (phosphorylated metabolome) in biological samples is vital to reveal their physiological and pathophysiological functions, which is extremely challenging due to their low abundance in some biological matrices, high hydrophilicity, and poor chromatographic behavior. Here, we developed a new method with ion-pair reversed-phase ultrahigh-performance liquid chromatography and mass spectrometry using BEH C18 columns modified with hybrid surface technology. This method demonstrated good performances for various phosphorylated metabolites, including phosphorylated sugars and amino acids, nucleotides, NAD-based cofactors, and acyl-CoAs in a single run using standard LC systems.
View Article and Find Full Text PDFEnviron Pollut
January 2025
Applied Geochemistry, Department of Civil, Environmental and Natural Resource Engineering, Luleå University of Technology, Luleå, Sweden.
Research regarding the geochemistry of beryllium (Be) in terrestrial environments is hindered by its high toxicity to humans and the low concentrations normally occurring in the environment. Although Be is considered an immobile element, extremely high dissolved concentrations have been detected in groundwater in the legacy Tailings Storage Facility (TSF) of Smaltjärnen, Sweden. Therefore, a detailed study was conducted to determine physiochemical parameters affecting the speciation of Be in the groundwater.
View Article and Find Full Text PDFMolecules
December 2024
Department of Environment and Sustainable Development, Singidunum University, Danijelova 32, 11010 Belgrade, Serbia.
The growing demand for metal production promotes the search for alternative sources and novel modalities in metallurgy. Flotation tailings are an important secondary mineral resource; however, they might pose a potential environmental threat due to containing toxic metals. Therefore, proper leaching reagent selection is required.
View Article and Find Full Text PDFPharmaceuticals (Basel)
December 2024
Department of Clinical Pharmacy and Biopharmacy, Poznan University of Medical Sciences, 60-806 Poznan, Poland.
This study aimed to develop an optimized and wide concentration range HPLC-UV method for fluconazole (FLU) determination and its adaptation for pharmacokinetics (PK) studies in the pediatric population. The following parameters of chromatographic separation were optimized: retention time, tailing factor, peak height, and the sample preconditioning parameter, such as recovery. The optimization process involved the use of a central composite design (CCD) and Box-Behnken design (BBD) in the design of experiments (DoE) approach and a multilayer perceptron (MLP) for artificial neural network (ANN) application.
View Article and Find Full Text PDFEcotoxicol Environ Saf
January 2025
SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Environmental Theoretical Chemistry, South China Normal University, Guangzhou 510006, China. Electronic address:
Mining activities produce large quantities of tailings and acid mine drainage, which contain varieties of heavy metals, thereby affecting the downstream farmland soils and crops. Heavy metals could induce antibiotic resistance through co-selection pressure. However, the profiles of antibiotic resistance genes (ARGs) in the mining-affected farmland soils and crops are still unclear.
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