Removal of uranyl ions from aqueous solutions using barium titanate

Remediation of water sources contaminated with radioactive waste products is a major environmental issue that demands new and more efficient technologies. For this purpose, we report a highly efficient ion-exchange material for the removal of radioactive nuclides from aqueous solutions. The kinetic characteristics of adsorption of uranyl ions on the surface of barium titanate were investigated using a spectrophotometric method under a wide range of conditions. By controlling the pH it was possible to exert fine control over the speciation of uranium, and by optimizing the temperature and grain size of the exchanger, almost total removal was achieved in a matter of just hours. The highest efficiency (>90 % removal) was realized at high temperature (80 °C). Moreover, the effect of competitive ion adsorption from a range of different cations and anions was quantified. Adsorption was found to follow first-order kinetics and both Freundlich and Langmuir isotherms could be applied to this system. The results of a mathematical treatment of the kinetic data combined with the observation that adsorption was independent of stirring speed and dependent on the ion-exchanger grain size, indicate that the dominant mechanism influencing adsorption is particle spreading. The adsorption behavior was not influenced by exposure to high-intensity gamma radiation, indicating potential for use of this ion-exchanger in systems containing radioactive material. These results will be of use in the development of uranium extraction systems for contaminated water sources.

[1]  B. A. Walker,et al.  Uranium and radium sorption on amorphous ferric oxyhydroxide , 1983 .

[2]  F. E. Bartell,et al.  Adsorption from Aqueous Solutions by Silica , 1928 .

[3]  S. Yamanaka.  Ionic conductivity in anhydrous crystalline zirconium phosphates, Zr(MPO4)2 (M Li, Na, K), with layered structures , 1980 .

[4]  P. K. Sinha,et al.  Uptake of cesium and strontium by crystalline silicotitanates from radioactive wastes , 2011 .

[5]  C. Baes,et al.  Acidity Measurements at Elevated Temperatures: I. Uranium(VI) Hydrolysis at 25 and 94° , 1962 .

[6]  S. Fink,et al.  Mechanisms of strontium and uranium removal from high-level radioactive waste simulant solutions by the sorbent monosodium titanate. , 2004, Environmental science & technology.

[7]  D. Reichenberg.  Properties of Ion-Exchange Resins in Relation to their Structure. III. Kinetics of Exchange , 1953 .

[8]  D. Hobbs.  Phase IV Simulant Testing of Monosodium Titanate Adsorption Kinetics , 1999 .

[9]  M. Barnes.  Strontium and Actinide Removal Testing with Monosodium Titanate and Other Sorbents , 2002 .

[10]  J. Fritz,et al.  Colorimetric uranium determination with arsenazo , 1959 .

[11]  N. Srinivasu,et al.  Ion exchangers in radioactive waste management. II: Radiotracer studies on adsorption of barium ions on sodium titanate , 1992 .

[12]  S. Hasany,et al.  Adsorption studies of cobalt(II) on manganese dioxide from aqueous solutions , 1981 .

[13]  S. Ahrland,et al.  THE ION EXCHANGE PROPERTIES OF SILICA GEL. I. THE SORPTION OF Na$sup +$, Ca$sup 2+$, Ba$sup 2+$, UO$sub 2$$sup 2+$, Gd$sup 3+$, Zr(IV) + Nb, U(IV) AND Pu(IV) , 1960 .

[14]  J. Laurent,et al.  Etude des proprietes de surface du bioxyde de manganese , 1965 .

[15]  D. Langmuir,et al.  Adsorption of uranyl onto ferric oxyhydroxides: Application of the surface complexation site-binding model , 1985 .

[16]  S. Saha,et al.  Adsorption studies of zinc ions on barium titanate from aqueous solution , 2002 .

[17]  N. Srinivasu,et al.  REMOVAL OF BARIUM IONS FROM AQUEOUS SOLUTIONS BY BARIUM TITANATE USING RADIOTRACER TECHNIQUE , 2014 .

[18]  J. Lehto,et al.  Sorption of Strontium(II) and Radio Strontium Ions on Sodium Titanate , 1981 .

[19]  R. Fricke,et al.  Über die chemische Spezifität verschieden energiereicher Formen ein und derselben Krystallart, I. Mitteil.: Verschieden energiereiche Formen von α-Fe2O3 , 1938 .

[20]  P. Benes,et al.  The state and adsorption behaviour of traces of molybdenum(VI) in aqueous solutions , 1973 .

[21]  S. Akyil,et al.  Kinetic studies of uranium(VI) adsorption on a composite ion exchanger , 1996 .

[22]  M. Benjamin,et al.  Effects of Strong Binding of Anionic Adsorbates on Adsorption of Trace Metals on Amorphous Iron Oxyhydroxide , 1981 .

[23]  D. Khandelwal,et al.  The absorption and fluorescence spectra of uranyl nitrate solutions at room temperature , 1959 .

[24]  P. K. Sinha,et al.  Optimization of Nb-substitution and Cs+/Sr+2 ion exchange in crystalline silicotitanates (CST) , 2012, Journal of Radioanalytical and Nuclear Chemistry.

[25]  C. Wu,et al.  Adsorption Studies of Co(II) on Ferric Oxide Particles in Aqueous Solutions , 1983 .

[26]  K. Hachiya,et al.  Kinetic study of the adsorption-desorption of the uranyl ion on a .gamma.-alumina surface using the pressure-jump technique , 1983 .

[27]  S. Hasany,et al.  Adsorption studies of strontium on manganese dioxide from aqueous solutions , 1981 .

[28]  J. Falconer,et al.  Ion exchange in felspathoids as a solid-state reaction , 1956, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[29]  L. Balistrieri,et al.  The adsorption of Cu, Pb, Zn, and Cd on goethite from major ion seawater , 1982 .

[30]  C. Heitner-Wirguin,et al.  KINETICS OF ION EXCHANGE IN THE CHELATING RESIN BIO-CHELEX 100. I. THE EXCHANGE OF THE ALKALINE EARTH IONS , 1963 .