Assessment of the Potential of Using Microalgae from the Genus Desmodesmus for the Bioremediation of Water Polluted with TiO2 Nanoparticles

Abstract

The increasing demand for products manufactured using nanotechnology contributes to a major increase in the synthesis of nanoscale materials and their inflow into the aquatic environment. TiO₂ nanoparticles as micropollutants in the aquatic environment directly affect many living organisms with generally negative effects. Microalgae have proven efficacy in bioremediation, which makes them a potential agent for the bioremediation of nanoparticles from wastewater. Evaluation of the capacity of microalgae from the genus Desmodesmus for the bioaccumulation of TiO₂ nanoparticles is carried out and the degree of resistance of microalgae cells to the action of environmentally relevant concentrations of these nanoparticles is determined. Spherical TiO₂ nanoparticles with a size of 30–40 nm are used. It is found by flow cytometry that TiO₂ nanoparticles at concentrations of 10, 100, and 1000 μg/L have no significant effect on the viability of microalgae cells and level of oxidative stress. Nanoparticles at a concentration of 1000 µg/L increase the concentration of photosynthetic pigments by 18–33% by day 13 of the experiment. Desmodesmus sp. appears to be a culture relatively resistant to nanoparticles; the increased bioaccumulation of titanium by microalgae cells in the experimental groups is detected by ICP-MS. All this indicates the significant potential of Desmodesmus sp. for the removal of nanostructured pollutants from the aquatic environment.