Spherically granulated titanium phosphate as exchanger for toxic heavy metals

Spherically granulated titanium phosphate of formula TiO1.25(OH)0.47(H2PO4)0.77(HPO4)0.13 2.3H2O (TiP) was synthesized by a gel method and its Na+, Ca2+ and Mg2+ ion substituted forms were prepared. Ion exchange of some divalent metal cations (Pb2+, Cu2+, Ni2+, Mn2+, Cd2+) by TiP-Na, TiP-Mg and TiP-Ca was studied in batch and column conditions. It was found that the ion exchange performance of TiP depends on the ion form it is converted into and decreases in the order: TiP-Na>TiP-Mg>TiP-Ca. All TiP samples exhibit a high affinity for copper and especially lead ion and are able to remove these ions quantitatively in the presence of excess of Ca, Mg and Na ions. Thus spherically granulated titanium phosphate can be recommended for separation and selective recovery of some toxic divalent cations from industrial wastes and contaminated environmental streams.