On April 14-17, 2025, scientists of the State Institution “IGNS of the National Academy of Sciences of Ukraine”, Senior Researcher of the Department of Environmental Geology and Thermodynamics of Geospheres, Doctor of Geological Sciences Ivan Mykhalchenko and Senior Researcher of the Department of Experimental Geochemistry, Candidate of Technical Sciences Kostiantyn Yaroshenko took part in the XVIII International Scientific Conference “Monitoring of Geological Hazards and Ecological Condition of the Environment”, which was held under the auspices of EAGE at the Institute of Geology of Taras Shevchenko National University of Kyiv in Kyiv, Ukraine. Kyiv, Ukraine.
On April 15, 2025, Senior Research Scientist of the Department of Experimental Geochemistry, Candidate of Technical Sciences Konstantin Yaroshenko presented a scientific report to the World on the topic “Efficiency of nano anatase (TiO2) based sorbents for 137Cs and 90Sr removal from simulated NPP wastewater solutions“ (co-authors – B. H. Shabalin, O.M. Lavrynenko, K.K. Yaroshenko, N.B. Mitsiuk) in which he presented the results of the study of the processes of sorption of Cs and Sr ions on nanosized anatase powder, which was synthesized by chemical method using titanium tetraisopropoxide as a precursor in an alkaline medium. The anatase particles were analyzed before and after sorption using electron microscopy, XRD, thermographic analysis, and infrared spectroscopy. To study the sorption efficiency, radioactive indicators 137Cs and 90Sr were added to the modeled solution. The sorption characteristics (degree of sorption, %) and distribution coefficients (Kd, ml/g) of cesium-137 and strontium-90 ions between anatase and modeled NPP wastewater are presented. The sorbed forms of 90Sr and 137Cs on anatase (water-soluble, ion-exchange and fixed forms) were determined by the method of sequential leaching. The high sorption capacity of nanosized anatase for strontium-90 (with a minimum percentage of water-soluble form) and lower sorption capacity for cesium-137 radionuclides were shown. Sorption of Cs and Sr ions on nanosized anatase powder can be used simultaneously with other selective radionuclide sorbents.
On April 17, 2025, Senior Research Scientist of the Department of Environmental Geology and Thermodynamics of Geospheres, Doctor of Geological Sciences Ivan Mikhalchenko presented to the World a scientific report on “Variations of Europium Anomaly Estimates in Lanthanide Spectra of Natural Monazite-Group Minerals” in which he reported on the results of a study of the variation of Europium anomaly estimates Eu/Eu* in the spectra oflanthanides (La-Gd) of currently known types of naturalmonazite – monazite-(Ce), monazite-(La), monazite-(Nd), monazite-(Sm), monazite-(Gd) and nodular monazites – monazites of metamorphic, igneous and hydrothermal genesis. The authors also tested a proposal to classify natural monazite species into subspecies based on the first three dominant elements of the lanthanide group in their chemical composition.
During the report, it was noted that the high variability of Eu/Eu* in the studied spectra of monazite lanthanides is the result not only of fractionation of E2+ and E3+ ions during mineralization processes, but also of other lanthanides. This is confirmed by the extreme variations of Eu/Eu* for the spectra of the rare lanthanides monazite-(La) 6.64 (Eu/Eu*min 2.41 – Eu/Eu*max 9.05) and monazite-(Sm) 0.05 (Eu/Eu*min 0.06 – Eu/Eu*max 0.11).
During the discussion of the report, attention was drawn to the small number of chemical analyzes of monazite from Ukrainian rocks in the chemical composition of which the mass fractions of sesquioxides La, Ce, Pr, Nd, Sm, Eu, Gd would be measured and the problem of providing the analytical base with appropriate standards.
