MOSCOW, October 1 – Novosti. Russian scientists have proposed effective methods for cleaning marsh pasture meadows from radioactive contamination, Novosti was told in the Ministry of Science and Higher Education of the Russian Federation.
Radioactive substances entering the environment are included in the biogeochemical processes in the soil and, ultimately, in the human food chain. The experience of liquidation of the consequences of the Chernobyl accident has shown that contamination of organic soils with radioactive caesium-137 has become a long-term problem, since this isotope has a high mobility in soils of this type.
In order to make such soils suitable for growing pure forage grasses, it is necessary to develop effective methods for their improvement in order to eliminate the consequences of radioactive contamination. To do this, it is necessary to study the main properties of soils that affect the migration of radionuclides.
Methods for cleaning soils from radioactive contamination are widely known and developed mainly for agricultural soils.
Now employees of the Vernadsky Institute of Geochemistry and Analytical Chemistry (GEOKHI RAS), subordinate to the Ministry of Education and Science of the Russian Federation, together with the All-Russian Research Institute of Radiology and Agroecology (VNIIRAE), have studied the soils of marsh pasture meadows, which differ significantly in their properties from typical soils used in agriculture and suggested effective methods for their purification.
Scientists have studied the distribution of cesium-137 of Chernobyl origin in the peat-bog soils of the grasslands of the Novozybkovsky district of the Bryansk region of Russia, which are characterized by excessive moisture.
It turned out that a significant part of the cesium-137 that fell out of the destroyed Chernobyl reactor is still in the upper root layers of the soil, without going down.
The authors of the work took into account the fact that the movement of cesium-137 is significantly affected by moisture acting on soil microbes. Those control the processes of nitrification (oxidation of organic nitrogen to ammonia and ammonia to nitrate). It turned out that the rate of immersion of radioactive cesium from the upper layers of the soil to the depth is directly proportional to the concentration of ammonium in the soil.
“Based on the results of the study, we proposed agro-ameliorative measures aimed at enhancing the mineralization of organic nitrogen. This will increase the vertical migration of radiocesium and accelerate the processes of purification of the upper root layers from the radionuclide,” said Irina Konopleva, Ph.D. .
Among the measures proposed by the authors of the work are the moistening of dry peatlands, the introduction of lime fertilizers, nitrogen fertilizers in the form of ammonium salts and substances that suppress nitrification into acidic soils.