Hrechyshkina S. Potential of pleustophytes for phytoremediation of technogenically polluted water bodies.

The thesis focuses on studying the effectiveness of phytoremediation of industrial water bodies contaminated with metal nanoparticles using pleustophytes, floating aquatic macrophytes. The ability of Pistia stratiotes, Limnobium laevigatum, and Salvinia natans to remove metal nanoparticles from the aquatic environment was investigated, along with the impact of these nanoparticles on plant physiological parameters. The aim was to provide recommendations for phytoremediation using higher aquatic plants to purify industrial wastewater and natural/artificial water bodies contaminated with metal nanoparticles. The research becomes even more relevant due to the ongoing war conflict resulting from the Russian Federation's invasion of Ukraine, which causes catastrophic pollution of natural ecosystems, including water bodies. The obtained research results and recommendations could have high importance in the postwar restoration of polluted water bodies in Ukraine. The work highlights the advantages of phytoremediation as an effective method of water purification, including high efficiency, low implementation cost, and ecological safety. Specifically, attention is drawn to the ability of aquatic plants to absorb various pollutants, including metal nanoparticles, from the aquatic environment. The influence of metal nanoparticles on plant organisms was investigated, including their effects on cellular changes, biological molecule functions, and disruption of regulatory processes. Based on the conducted research, it was established that all studied pleustophytes (Pistia stratiotes, Salvinia natans, and Limnobium laevigatum) demonstrated high efficiency in removing metal nanoparticles (Mn, Cu, Zn, and Ag) from colloidal solutions. However, Pistia stratiotes and Salvinia natans showed higher potential for removing water solutions. Pistia stratiotes showed the best results in removing Mn (94%) and Zn (65%) nanoparticles. Salvinia natans demonstrated high capability in removing Mn (86%) and Cu (69%) nanoparticles, as well as equal performance for Ag (76%) in both species. Thus, these pleustophyte species can be recommended for the purification of water bodies from the mentioned nanoparticles.