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The distribution and chemical species of tellurium (Te) in contaminated soil were determined by a combination of microfocused X-ray fluorescence (μ-XRF), X-ray diffraction (μ-XRD), and X-ray absorption fine structure (μ-XAFS) techniques. Results showed that Te was present as a mixture of Te(VI) and Te(IV) species, while selenium (Se) was predominantly present in the form of Se(IV) in the soil contaminated by abandoned mine tailings. In the contaminated soil, Fe(III) hydroxides were the host phases for Se(IV), Te(IV), and Te(VI), but Te(IV) could be also retained by illite. The difference in speciation and solubility of Se and Te in soil can result from different structures of surface complexes for Se and Te onto Fe(III) hydroxides. Furthermore, our results suggest that the retention of Te(IV) in soil could be relatively weaker than that of Te(VI) due to structural incorporation of Te(VI) into Fe(III) hydroxides. These findings are of geochemical and environmental significance for better understanding the solubility, mobility, and bioavailability of Te in the surface environment. To the best of our knowledge, this is the first study reporting the speciation and host phases of Te in field soil by the μ-XRF-XRD-XAFS techniques.
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http://dx.doi.org/10.1021/acs.est.7b00955 | DOI Listing |
J Appl Physiol (1985)
September 2025
Department of Human Physiology and Nutrition, William J. Hybl Sport Medicine and Performance Center, University of Colorado Colorado Springs, Colorado Springs, CO, USA.
Chronic exposure to high altitude leads to increases in hemoglobin mass (Hbmass), which may improve exercise performance and decrease acute mountain sickness (AMS) symptoms. We evaluated the influence of intravenous iron or erythropoietin (EPO) treatment on Hbmass, exercise performance, and AMS during a 14-day exposure to 3094 m. Thirty-nine participants (12F) completed the study conducted in Eugene, Oregon (sea level (SL), 130 m) and Leadville, Colorado (3094 m).
View Article and Find Full Text PDFEnviron Sci Technol
August 2025
State Key Laboratory of Water Pollution Control and Green Resource Recycling, School of the Environment, Nanjing University, Nanjing 210023, P.R. China.
Anthropogenic inputs of engineered carbon materials into aquatic and terrestrial environments potentially influence electron transfer processes in redox biogeochemical reactions due to their electron-shuttling capacities. However, the impact of carbonaceous materials on the oxidative transformation of iron sulfide (FeS), a widespread ferrous mineral in sediments and soils, and the underlying mechanisms remain insufficiently understood. In this study, we demonstrated that activated carbon (AC) facilitated FeS oxidation, resulting in enhanced hydroxyl radicals (OH) production.
View Article and Find Full Text PDFJ Nanobiotechnology
June 2025
Research Center for Tissue Engineering and Regenerative Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
Therapeutic generation of reactive oxygen species (ROS) through catalytic therapy demonstrates antibacterial efficacy against wound infections. However, prolonged and unregulated ROS production risks inducing intolerable oxidative stress alongside exacerbated inflammatory responses, creating a microenvironment counterproductive to wound healing. Here, inspired by rechargeable batteries, we have developed a catalytic activity-controllable nanozyme by integrating Fe and Fe within metal-organic frameworks (FeNZ).
View Article and Find Full Text PDFJ Phys Chem A
June 2025
Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark.
Recent research has identified a new photocatalytic mechanism that generates significant amounts of chlorine over the North Atlantic, involving iron from mineral dust, chloride from sea spray, and sunlight. While it is known that charge transfer absorption in iron chlorides (FeCl) reduces Fe to Fe and oxidizes Cl to neutral chlorine (Cl), important questions remain regarding the chemical state of iron before and after the reaction and the mechanism of chlorine release. Brines and solid precipitates form from iron, sodium, and chloride in atmospheric particles, and iron is distributed among hydrated Fe(II) and Fe(III) chlorides, oxides, and hydroxides, depending on the concentration, pH, and humidity.
View Article and Find Full Text PDFEnviron Sci Technol
July 2025
Department of Environmental Science, Zhejiang University, Hangzhou 310058, China.
Pyrogenic carbon (PC) is redox-active and facilitates the microbial reduction of Fe(III) (oxyhydr)oxides to Fe(II) under conditions. The oxygenation of Fe(II) under conditions produces hydroxyl radicals (OH). However, the influence of PC on this process remains largely unknown.
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