INVESTIGATION OF THE PHENOMENON OF MIGRATION OF MOBILE FLUORINE COMPOUNDS IN THE SOILS OF THE COASTAL ZONE IN THE GUSKA RIVER

Abstract

Today, there is significant contamination of soils with various chemical substances due to the action of the anthropogenic factor. Fluorine compounds are one of the dangerous pollutants contaminating the soil. The main source of their entry into the soil is the application of phosphate fertilizers, which contain fluorides in the form of impurities. In Ukraine, the problem of soil contamination with fluorides is particularly relevant due to the significant volumes of agro-industrial production. Fluorine compounds pose a particular danger due to the ability of their mobile (soluble) forms to spread (migrate) over considerable distances in the soil solution. This leads to the possibility of contamination of territories that were not directly fertilized. The article describes the importance of fluorine compounds for living organisms, as well as the consequences of their lack and excess in plant and animal organisms. Forms of the existence of Fluorine compounds in soils have been established: mobile form (soluble fluorides: NaF, KF) and immobile form (insoluble fluorides: CaF2, AlF3, FeF3), which are in constant dynamic equilibrium. The main factors affecting the relationship between the specified forms in the soil are described. In the course of the research, the content of mobile compounds of Fluorine in the soils of the coastal zone of the Huska River was measured. During the analysis of soil samples in 2021, a significant level of contamination was revealed. Exceeding the MPC was found in 9 samples out of 18 (MPC of mobile fluorides in soils – 2.8 mg/kg). On average, the samples exceeding the MPC had a fluoride content of 4.95 mg/kg. In 2022, none of the 20 samples exceeded the MPC of mobile fluorides. During the analysis of the obtained results, the phenomenon of migration of mobile compounds of Fluorine was investigated. To detect the phenomenon of migration of mobile compounds of Fluoride in the soils of the coastal zone of the Huska River, a sampling scheme was drawn up in order to monitor the content of fluorides along the potential direction of their migration. That is why the soil samples were taken in pairs: "field" - "shore", where "field" is the territory where phosphate fertilizers were applied, and "shore" is the coastal area that is close to the point of sampling from the field. Therefore, according to the results of research in 2021, a significant level of migration of mobile compounds of Fluorine was revealed. In particular, in 3 out of 9 pairs of samples, the MPC was exceeded both on the territory of the "field" and on the "shore" site. This indicates a certain contribution of the phenomenon of migration to the pollution of the environment by mobile compounds of Fluorine. Thus, according to the results of the study, the presence of the phenomenon of migration of mobile fluorides in these territories was revealed. This is evidenced by the exceedance of the MPC of fluorides in areas where fertilizers were not applied. A likely factor contributing to migration is the topography of the studied area.