Spherically granulated titanium phosphate as exchanger for toxic heavy metals

Spherically granulated titanium phosphate of formula TiO1.25(OH)(0.47)(H2PO 4)(0.77)(HPO4)(0.13) 2.3H(2)O (TiP) was synthesized by a gel method and its Na+, Ca-2+ and Mg2+ ion substituted forms were prepared. Ion exchange of s ome 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 th e ion exchange performance of TiP depends on the ion form it is converted i nto and decreases in the order: Tip-Na > Tip-Mg > Tip-Ca. All TiP samples e xhibit a high affinity for copper and especially lead ion and are able to r emove 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 indu strial wastes and contaminated environmental streams. (C) 1998 Elsevier Sci ence Ltd. All rights reserved.