Study on the sorption properties of (NH4)(2)TiOF4 particles

Prevention of water from the pollution with hard metals ions and radionuclides, as well as water treatment motivate for the research and investigations in the field of the new effective sorbents. This paper presents the results on (NH4)(2)TiOF4 sorption properties in the context of the synthesis conditions and related particle formation. It was demonstrated that proper control of the precipitation process could result with either spherical particles of 50-80 nm diameter or rod-like particles of length up to 10 mu m. Moreover, it was found that respective of synthesis conditions, (NH4)(2)TiOF4 particles exhibited high sorption efficiency towards lanthanum, yttrium, scandium, europium, and cerium, above 95% at pH greater than 3. The highest sorption capacity performed spherical particles synthesized at room temperature. Their respective capacities towards cerium, europium, lanthanum, yttrium, and scandium at pH 5.5 were 350, 300, 240, 200, and 270 mg/g. The researches indicated that increased precipitation temperature reduced sorption capacity by 50% and even 70% due to the larger dimensions of the obtained particles. The tests performed for static and dynamic equilibrium revealed selectivity of the (NH4)2TiOF4 particles towards the rare earth elements in the presence of divalent and monovalent ions.