USING AEROBIC SYNTROPHIC ASSOCIATIONS OF MICROORGANISMS FOR THE DECONTAMINATION OF LIQUID RADIOACTIVE WASTE

The primary objective of the study was to test the possibility of cesium-137 transmutation into a stable barium isotope in contact with an aerobic syntrophic association (SA - a conglomerate of several thousands of different species of bacteria, protozoa and fungi living in symbiosis with each other) together with a set of macro- and microelements. The study was performed sequentially on two different SA. In the course of the work, the transmutation of cesium-137 into stable barium with the use of SA was not experimentally revealed, but the phenomenon of cesium-137 biosorption by both SA was detected to different degrees. In the course of the experiment the possibility of cesium-137 sorption by SA from the solution in the pH range of 7.7 - 8.6 was shown. In the process of the work, the time dependence of cesium-137 distribution in the liquid phase and the phase of SA was determined. The time dependence of the sorption capacity of the syntrophic association was revealed. With further continuation of the study, it is possible to obtain a mixture of SA capable of selectively extracting and concentrating prescribed radionuclides from the liquid phase.The result of this work may be the development of a technology for processing and conditioning low-level liquid radioactive waste (RW) by transferring the bulk of radioisotopes in the phase of SA (the so-called "nanosorbent of biological origin"), with multiple volume reduction.The cost of such a technology compared to existing technologies using synthetic sorbents should be several times less due to the cheapness of the SA and the reagents required for it. Besides, the new technology is more environmentally friendly. The process of biotechnologyoxidation of sulfide ores and concentrates based on the activity of chemolitotrophic bacteria that translate insoluble metal sulfides into soluble metal sulfates can serve as analogue for hardware design of RW purification technology using nanosorbent of biological origin.