Sorption of ions of heavy metals from aqueous solutions on hydroxylapatite

Comprehensive electric-surface, adsorption, X-ray investigations of interaction between ions of heavy 3-d metals with the hydroxylapatite surface have been carried out within a broad range of the pH and concentration of electrolytes. At low concentrations of ions of heavy metals the values of their sorption are less than the amount of Ca2 exchange cations outgoing to the solution. At higher concentrations of ions of heavy metals one can observe a reverse phenomenon: the amount of ions being sorbed exceeds the amount of outcoming Ca2 ions. The paper provides an explanation for the phenomena being observed. It is shown that the interaction of the zinc chloride solution at low values of the pH with hydroxylapatite a new mineral—scholzite—is formed.