Uptake of Some Divalent Metal Ions on Layered α-VOPO4.2.5H2O and Its 1,10-Phenanthroline, 2,2′-Bipyridyl and 4,4′-Bipyridyl Intercalated Products

The crystalline layered α-vanadyl phosphate, α-VOPO4.2.5H2O, was prepared and characterized. Its intercalated products VOPO4(1,10-phen)0.33.0.6H2O, VOPO4(2,2′ -bipy)0.36. 0.25H2O and VOPO4(4,4′ -bipy)0.4, were prepared by direct contact of α-VOPO4.2.5H2O with 0.1M organic ligand in ethanol with stirring for 7 days at room temperature. The resulting products were characterized by chemical and thermal analysis. The distribution coefficients (Kd values) for a mixture of 0.05M nitric acid solution of the divalent metal ions Co2+, Ni2+, Cu2+, Zn2+ , Cd2+ and Pb2+ were determined simultaneously by (ICP) technique after equilibration with VOPO4.2.5H2O and its intercalated products at pH 2 and 4. The (Kd values) for Pb2+ ions were higher than those for other metal ions, especially at pH4. Possible selective separation of Pb2+ is quite evident. The selectivity order was found to be dependent on the pH and on the nature of the intercalated ligand. Partial ligand release of intercalated products at pH 2 observed.