Document Type

Theses, Ph.D

Abstract

Soil contamination with priority heavy metals and metalloids of anthropogenic origin represents one of the most pressing environmental challenges of the present day, directly associated with risks to public health, ecosystem degradation, and the achievement of the Sustainable Development Goals, particularly those of the World Health Organization and the United Nations aimed at ensuring a healthy environment, safe ecosystems, and sustainable land management. Under conditions of long-term technogenic pressure, compounded by the additional impact of military activities on the territory of Ukraine, the search for scientifically substantiated, environmentally safe, and economically feasible approaches to reducing soil contamination has become especially urgent.

This doctoral research is devoted to the assessment of the phytoremediation potential of selected plant species for reducing contamination of anthropogenically polluted soils of Ukraine with priority heavy metals and metalloids (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), lead (Pb), zinc (Zn)). The study was conducted within the integrated “soil–plant–air” system in areas of high anthropogenic load in the city of Dnipro. The content and distribution of metals in soils, plants, and atmospheric air were determined using inductively coupled plasma atomic emission spectrometry, with particular attention to mobile metal fractions and their bioavailability.

The results demonstrate that the bioavailability of heavy metals in the soil–plant system is governed primarily by their mobile forms and uptake pathways (root and foliar), rather than by total concentrations in soil. Among the studied elements (As, Cd, Cr, Cu, Hg, Pb, Zn), Cr, Cu, Pb, and Zn were identified as having the highest ecological significance within the “soil–plant air” system, due to their stable occurrence and dominant contribution to bioaccumulation and phytoremediation processes.

Zinc and copper exhibited the highest bioavailability for Ambrosia artemisiifolia L. and Erigeron canadensis L., whereas lead was predominantly retained in the root system and showed limited translocation to aboveground biomass. These patterns were observed under the conditions of Ukrainian chernozem soils, characterized by high buffering capacity and substantial organic matter content, which significantly influence metal mobility and availability.

For the first time in Ukraine, the phytoremediation potential of Erigeron canadensis L. and Ambrosia artemisiifolia L. was comprehensively investigated under conditions of chernozem soils subjected to intense anthropogenic contamination. The results indicate that Erigeron canadensis L. is a promising species for the phytoextraction of Zn, Cu, and Cr and for the phytostabilization of Pb, whereas Ambrosia artemisiifolia L. combines high tolerance to elevated contamination levels with effective extraction of Zn, Cu, and Cr and immobilization of Pb in soil. These findings expand current understanding of phytoremediation mechanisms in chernozem ecosystems and substantiate the targeted use of these species for the restoration of anthropogenically and war-disturbed territories of Ukraine.

For the first time for the territory of Ukraine, the positive matrix factorization (PMF) method was applied to identify sources of atmospheric contamination with heavy metals, confirming their predominantly anthropogenic origin and revealing linkages between atmospheric emissions, soil contamination, and subsequent metal bioaccumulation in plants. Integration of PMF results with bioaccumulation indicators supports the selection of plant species for phytoremediation according to dominant contamination sources and their application as bioindicators in long-term environmental monitoring systems.

Overall, the obtained results provide a scientific basis for the implementation of phytoremediation technologies in the restoration of anthropogenically disturbed soils in Ukraine and are consistent with the principles of sustainable development, particularly those related to reducing environmental risks, protecting public health, and promoting the rational use of natural resources.

The possibility of utilizing biomass from experimental plants after phytoremediation as a biofuel suggests the feasibility of further research. This will minimise the potential risks of secondary pollution and provide conditions for the creation of a closed ecological cycle of sustainable management.  The versatility of the positive matrix factorisation method (the possibility of studying both atmospheric air and soil) makes it possible to scale its use in environmental monitoring programmes in Ukraine.  Further research should focus on interdisciplinary assessments of ecological, socio-economic, and risk-oriented aspects of phytoremediation, as well as on harmonizing remediation strategies with European Union regulatory frameworks.

DOI

https://doi.org/10.21427/8qj0-nx56

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