Microsphere Sorbents Based on Cenosphere Supported Zirconium Molybdates and Zirconium Silicates for Cesium-137 and Strontium-90 Removal from Radioactive Waste Solutions
T. A. VERESHCHAGINA1, E. A. KUTIKHINA1, E. V. FOMENKO1, A. G. ANSHITS1,2
1Institute of Chemistry and Chemical Technology SB RAS FRC "Krasnoyarsk Science Center SB RAS", Krasnoyarsk, Russia
tatiana@icct.ru
2Siberian Federal University, Krasnoyarsk, Russia
anshits@icct.ru
Keywords: cenospheres, sorbents, zirconium molybdates, zirconium silicates, radioactive waste
Pages: 261-268
Abstract
The microsphere composites were prepared by covering microsphere glass-crystalline supports with as-synthesized crystalline zirconium molybdate (Mo/Zr = 1.7) and pre-synthesized microporous sodium zirconium silicates of hilairite and gaidonnayite structural types. Narrow fractions of coal fly ash cenospheres with (SiO2/Al2O3)wt of 2.7 and 3.0 were used as precursors of the supports. The composites were studied by means of SEM, EDX and PXRD. The efficiency for Cs+ and Sr2+ removal from simulated wastewater was evaluated on the basis of parameters, such as the distribution coefficient K d (for low Cs+/Sr2+ concentrations) and the maximum sorption capacity a m (for high Cs+/Sr2+ concentrations) determined from the Langmuir sorption isotherms. It was established that the composites trap Cs+ and Sr2+ with K d of up to 104 mL/g. The influence of zirconium molybdate and sodium zirconium silicate composition and structure on their sorption abilities was demonstrated. The proposed resource-saving approach to the preparation of composite sorbents along with their high sorption parameters favours their application for decontamination of 137Cs and 90Sr bearing wastewater including aquatic environment and technological solutions.
DOI: 10.15372/CSD2021304
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