Publications by authors named "Camille Baya"
Thermococcales, a major order of hyperthermophilic archaea inhabiting iron- and sulfur-rich anaerobic parts of hydrothermal deep-sea vents, are known to induce the formation of iron phosphates, greigite (FeS) and abundant quantities of pyrite (FeS), including pyrite spherules. In the present study, we report the characterization of the sulfide and phosphate minerals produced in the presence of Thermococcales using X-ray diffraction, synchrotron-based X ray absorption spectroscopy and scanning and transmission electron microscopies. Mixed valence Fe(II)-Fe(III) phosphates are interpreted as resulting from the activity of Thermococcales controlling phosphorus-iron-sulfur dynamics.
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- Uranium-contaminated sediments in former mining areas pose significant environmental challenges, particularly regarding their long-term management and understanding of uranium immobilization mechanisms.
- A study of sediments from Lake Nègre reveals changes in uranium speciation over 3,300 years, showing that initial mononuclear U(IV) species transformed into more complex U(IV)-silica structures, which may have led to a partial conversion into a nanocrystalline coffinite-like phase within 700 years.
- The findings highlight the importance of silica availability and suggest that while transformation reduces uranium reactivity, there remains a risk concerning the long-term management of uranium-contaminated sites and waste in similar environments.