TITLE:
Surface and Physicochemical Characterization of Phosphates Vivianite, Fe2(PO4)3 and Hydroxyapatite, Ca5(PO4)3OH
AUTHORS:
D. Luna-Zaragoza, E. T. Romero-Guzmán, L. R. Reyes-Gutiérrez
KEYWORDS:
Phosphates, surface, site density, mass titration
JOURNAL NAME:
Journal of Minerals and Materials Characterization and Engineering,
Vol.8 No.8,
August
20,
2009
ABSTRACT: Hydroxyapatite is a calcium phosphate in the apatite group. It has numerous applications due to
its particular properties including the sorption of metallic ions. This makes it useful for the
treatment of contaminated groundwater and for soil decontamination. The least expensive
source of hydroxyapatite for synthesis is bovine bone, since this is a waste material. Vivianite is
an iron phosphate which has received little study. Like hydroxyapatite, it has particular
properties. This paper describes the method of obtaining these phosphates; calcium phosphate
from bovine bone, and iron phosphate by synthesis. Also described are the methods of purifying
the materials and characterization of these two phosphates by X-ray diffraction, infrared
analysis, thermogravimetric and differential scanning calorimetric analysis, scanning electron
microscopy, and surface area by the BET method. Physicochemical characteristics of
hydroxyapatite obtained from bovine bone are described, and preliminary results are presented
of an investigation into whether hydroxyapatite and iron phosphate are suitable as a permeable
reactive barrier for the treatment of metallic and radionuclide contaminants.