Crystal Chemistry of Vanadium-Bearing Ellestadite Waste Forms.
Yanan FangSam J PageGregory J ReesMaxim AvdeevJohn V HannaTim J WhitePublished in: Inorganic chemistry (2018)
Vanadate ellestadites Ca10(SiO4) x(VO4)6-2 x(SO4) xCl2, serving as prototype crystalline matrices for the fixation of pentavalent toxic metals (V, Cr, As), were synthesized and characterized by powder X-ray and neutron diffraction (PXRD and PND), electron probe microanalysis (EPMA), Fourier transform infrared spectroscopy (FTIR), and solid-state nuclear magnetic resonance (SS-NMR). The ellestadites 0.19 < x < 3 adopt the P63/ m structure, while the vanadate endmember Ca10(VO4)6Cl2 is triclinic with space group P1̅. A miscibility gap exists for 0.77 < x < 2.44. The deficiency of Cl in the structure leads to short-range disorder in the tunnel. Toxicity characteristic leaching testing (TCLP) showed the incorporation of vanadium increases ellestadite solubility, and defined a waste loading limit that should not exceed 25 atom % V to ensure small release levels.
Keyphrases
- solid state
- heavy metals
- magnetic resonance
- sewage sludge
- municipal solid waste
- health risk assessment
- electron microscopy
- health risk
- high resolution
- risk assessment
- minimally invasive
- protein kinase
- life cycle
- oxidative stress
- molecular dynamics
- contrast enhanced
- living cells
- anaerobic digestion
- electron transfer
- quantum dots
- human health
- computed tomography
- crystal structure
- dual energy
- drug discovery
- replacement therapy