Shkutkova H. Sorption of heavy metal ions at hydroxylapatite and its modified forms

The thesis considers the structural-sorption, ion-exchange and electrosurface studies of hydroxylapatite and its modified forms.It is shown that Co2+ and Ni2+ ions interact with exchange centres and functional groups in the surface layer of hydroxylapatite. The Zn2+ ions partially substitute structural Ca2+ ions in the hydroxylapatite, which lead to the formation of the new crystal phase sholzite CaZn2(PO4)2 ? 2Н2О in the hydroxylapatite structure bulk.The hydroxylapatite is shown to be an efficient anion-exchanger for the defluorination of water. It is shown that the modification of the initial hydroxylapatite surface by ferrocyanides and polyphosphates leads to significant increase of its sorption capacity and enhances its selectivity with respect to heavy metal ions; this results in the increase of the distribution coefficient Kp.