Application of Silicon-Containing Mixtures Slows down the Migration Rates of Radionuclides in Soil-Plant System

Abstract

After the Chernobyl disaster in 1986 large areas of agricultural land were contaminated with radionuclides. Most of them had short periods of half-life time and are inactive now. However several radionuclides with relatively long periods of half-life time – especially 137Cs and 90Sr are not. Even small amounts of them still may be dangerous both plants and animals due to low-dose effect. In this paper we study impact of silicon-containing mixtures (nanoparticles of tripoli and analcime mixed with sapropel and peat) on the migration rates of 137Cs and 90Sr in soil-plant system. In order to conduct the research we chose the experimental plots located in Kyiv Polesie on Gleyic Phaeozems (0-20 cm). Humus content was 1.48±0.51 %, рНKCl 4.91‑5.08. 137Cs and 90Sr contents were determined by ICP-MS method. Nonparametrical statistical analysis of experimental data was made. The difference was considered significant when P < 0.05. In the course of research we have found that application of the proposed mixtures leads to the immobilization of cesium and strontium in soil and significantly reduced their activity in plants by over 35 %. We suggest this fact to be caused by accumulation of sols of polysilicic acids in soil according to the scheme: (SiO2) x + 2H2O ↔ H4SiO4 + (SiO2) x-1, 2H4SiO4 → (HO)3SiOSi (OH)3 + H2O. Additional experiments are needed to determine whether partial dehydration of these sols due to summer droughts may intensify transport of radionuclides from soil to plants. To conclude, application of the mixtures that consist of nanoparticles of tripoli and analcime mixed with sapropel and peat slows down the migration rates of 137Cs and 90Sr from soil to plants on Gleyic Phaeozems.

Keywords

• cesium
• strontium
• silicon
• analcime
• tripoli