Background concentrations and remediation strategies for heavy metals in soil ecosystems

Abstract

The relevance of the present study is related to the growing anthropogenic pressure on Ukraine’s land resources. This pressure has been further intensified by the consequences of Russia’s full-scale war against Ukraine, which has continued since 2022. The destruction of industrial infrastructure and the extensive use of ammunition became the reasons of the uncontrolled accumulation of toxic elements in the soil profile. The purpose of the study was to systematise and summarise scientific data on the natural content of barium, zirconium, strontium, lead, arsenic, zinc, copper, and nickel in the Earth’s crust and soil ecosystems. The study also examined existing strategies for the remediation of contaminated soils. To achieve this aim, a critical analysis and systematisation of scientific literature were carried out within the framework of the research. The study summarised data on regional background concentrations of heavy metals and identified critical determinants, which influence the mobility and bioavailability in the soil-plant system. These factors include pH level, organic matter content and the adsorption capacity of soil. The analysis also revealed gaps in Ukrainian legislation concerning the regulation of several studied metals in agricultural products and animal feed. This points out the need to improve the existing regulatory framework. Given the international experience, several effective hyperaccumulator plants for soil clean-up were defined. These plants encompassed industrial hemp for the phytoextraction of lead and nickel, sunflower and Cortaderia nitida for zinc, Indian mustard for barium and nickel, as well as specific aquatic plants such as cattail and papyrus. The findings showed that the use of local wild-growing species adapted to particular ecological niches may provide a basis for highly effective and biologically safe strategies for the reclamation of degraded land. The practical value of the study lies in its justification of phytoremediation as one of the most cost-effective and environmentally neutral methods for restoring damaged areas