Reaction of calcium hydroxyapatite with Cd2+ and Pb2+ ions

EDTA impact on Cd2+ migration in apatite–water system

“…In Cd(NO 3 ) 2 , EDTA and Cd(II)EDTA complex solutions, the equilibrium pH value depends on pH in and Ca/P ratio of the apatite (Tables 2 and 3) and is the lowest (5.0-6.1) in Cd(NO 3 ) 2 -containing solution. The drop in equilibrium pH in the solutions containing metal cations has been explained by liberation of H + ions from the apatite surface during surface sorption of cations [15,25]. In our experiments the amount of Ca 2+ ions released was also high in Cd(NO 3 ) 2 .…”

Electrokinetic properties of hydroxyapatite under flotation conditions

“…Much of the research was focused on the investigation of the surface characteristics of hydroxyapatite [58][59][60][61][62][63][64][65][66][67][68]. Kukura et al [64] determined the concentration of lattice ions on the synthetic HA surface as 3.02 and 4.50 ions/nm 2 for PO 3À 4 and Ca 2+ , respectively, from isotope exchange and crystallographic data.…”

Compositional changes in fish scale hydroxylapatite during early diagenesis; an example from an abandoned meander

“…There is a great deal of data on the rapidity of heavy metal retention by fish scale hydroxylapatite and on the reaction of artificial hydroxylapatite with heavy and other metals in duration from minutes and hours to days (Ma et al 1993(Ma et al , 1994Basu et al 2007;Xu et al 2007;Sheha 2007;Yasukawa et al 2007;Nadeem et al 2008). What is lacking, however, are the observations as to how a single fish scale reacts with its environment over a time span of several years, i.e.…”