Separation of europium from aqueous solutions using Al3+- and Fe3+-doped zirconium and titanium phosphates

The sorption of europium from aqueous solutions (Eu-concentration: 10 to 250 mg/l) by Fe3+- and Al3+-doped zirconium- and titanium-phosphates was investigated using a batch technique and Eu-152 tracer. The initial pH of the solutions was adjusted to 3, 4, 5 and 6. All investigations were performed under constant ionic strength, I=0.15 established by NaCl. Although zirconium phosphates generally showed a higher Eu-uptake capacity than the titanium ones, all investigated materials possessed the ability to remove considerable amounts of europium from aqueous solutions. The Eu-sorption properties of the studied phosphate materials seem to be not especially affected by the type of trivalent cations used for the doping (i.e., Al3+ or Fe3+).