title: Nano-crystalline hydroxyapatite bio-mineral for the treatment of strontium from aqueous solutions.
abstract: Hydroxyapatites were analysed using electron microscopy, X-ray diffraction (XRD) and X-ray fluorescence (XRF) analysis. Examination of a bacterially produced hydroxyapatite (Bio-HA) by scanning electron microscopy showed agglomerated nano-sized particles; XRD analysis confirmed that the Bio-HA was hydroxyapatite, with an organic matter content of 7.6%; XRF analysis gave a Ca/P ratio of 1.55, also indicative of HA. The size of the Bio-HA crystals was calculated as ~25 nm from XRD data using the Scherrer equation, whereas Comm-HA powder size was measured as ≤ 50 μm. The nano-crystalline Bio-HA was ~7 times more efficient in removing Sr(2+) from synthetic groundwater than Comm-HA. Dissolution of HA as indicated by the release of phosphate into the solution phase was higher in the Comm-HA than the Bio-HA, indicating a more stable biomaterial which has a potential for the remediation of contaminated sites.
authors.affiliation: School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Handley-Sidhu
authors.forename: Joanna C
authors.initials: JC
authors.lastname: Renshaw
authors.forename: Ping
authors.initials: P
authors.lastname: Yong
authors.forename: Robert
authors.initials: R
authors.lastname: Kerley
authors.forename: Lynne E
authors.initials: LE
authors.lastname: Macaskie
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D002118:Calcium / Q000032:analysis; D017886:Durapatite / Q000737:chemistry / Q000378:metabolism*; D008854:Microscopy, Electron; D049329:Nanostructures; D010758:Phosphorus / Q000032:analysis; D012996:Solutions; D013052:Spectrometry, X-Ray Emission; D013324:Strontium / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D018508:Water Purification / Q000379:methods*; D014961:X-Ray Diffraction
chemical_list: D012996:Solutions; D014874:Water Pollutants, Chemical; D010758:Phosphorus; D017886:Durapatite; D002118:Calcium; D013324:Strontium