On the possibility of controlling the dynamics of the development of Chlorella (Chlorella vulgaris) in freshwater areas under the influence of infrared lasers

Intensive agricultural activity leads to pollution and cyanobacterial blooms of freshwater areas, which threatens not only human health, but also the flora and fauna of the aquatic environment. The paper examines the results of studies of the impact of electromagnetic radiation of various wavelengths on the development of Chlorella vulgaris.For this purpose, a grown suspension of Chlorella vulgarisin a nutrient solution was irradiated using EMR of various wavelength ranges: in ultraviolet (UV) with a wavelength of 220 nm and 253 nm, in green (Gr) with a wavelength of 520 nm, in red (R) with a radiation range of 625 nm and in infrared (IR) in the range of 1200–1400 nm. As a result of the experiments, it was found that exposure to UV radiation in both wavelength ranges of 220 nm and 253 nm, as well as under the influence of Gr at a wavelength of 520 nm, did not lead to a change in the concentration of chlorella cells in the tested samples, compared with control samples within 6 days of measurements after irradiation. At the same time, in samples irradiated with R and IR, respectively, at wavelengths of 625 and 1200–1400 nm, an approximately twofold increase in the concentration of chlorella cells in the suspension was observed, compared with the control sample. The authors consider the most promising to be the use of the infrared range of the electromagnetic spectrum when influencing chlorella in order to activate its growth. Meanwhile, when selecting a wavelength in the IR range, it is recommended to take into account the optical transparency windows of the atmosphere above water bodies.