Phytomigration of Residual Heavy Metals from Technogenically Contaminated Treated Waters

The extraction of mineral resources in the mining industry, such as quarry development, processing of non-ferrous metals, and the formation of waste dumps, presents significant environmental challenges. These processes generate acid mine drainage contaminated with heavy metals, which have substantial adverse effects on the environment.
For this study, we selected industrial wastewater generated by the mining and processing operations of the "RMG Group" in Bolnisi district, Georgia. The research aimed to identify a modern method to remove residual heavy metals (Cu, Zn, Fe, Cd, Mn, Se) from chemically treated wastewater through phytomigration. The chosen method for this purpose was phytoremediation.
During the research, laboratory analyses were conducted on water samples collected from the Mashavera River—the recipient of treated wastewater—during the years 2022-2024. The heavy metal concentrations in these samples were compared with those obtained from studies conducted in 2018-2020. Despite the influence of climate change and the operation of a small hydroelectric power plant in the discharge section (resulting in decreased river discharge), the results showed that the average concentration of heavy metals decreased by 18.89% in 2022-2024 compared to 2018-2021.
For phytoremediation studies in 2024, wetlands impacted by industrial pollution near the mining quarry were selected. From these sites, plant species from five genera were identified. In wetland N1, located 2,928 meters (direct distance) from the quarry, four plant genera were collected. In wetland N2, situated 2,620 meters from the quarry near the tailings pond base, three plant genera were identified. For control samples, wetland N3 in Upper Karabulakhi, located 25,260 meters from the quarry, provided two plant genera. Based on research and analysis, the species selected for phytoremediation studies were: (1) Typha latifolia L. and (2) Arundo L. It is noteworthy that plants in the anthropogenic wetland near the tailings pond continued to grow despite the highly toxic and polluted environment, where the pH was as low as 3.42 and heavy metal concentrations were elevated.
The research is ongoing, and the findings from analyses of plant samples (roots, stems, leaves, and flowers) provide valuable information for the future development of the study.
If satisfactory results are achieved from pilot experiments on the phytoremediation of residual heavy metals from wastewater, the research will lay the groundwork for improving water quality in both surface and groundwater systems.
Furthermore, the green technological outcomes of this research could be highly beneficial for addressing similar environmental challenges in other industrial enterprises. Discovering new potential for aquaculture species may also lead to the development of cost-effective and profitable phytotechnologies for mining operations in the future.