Features of the Microalgae and Cyanobacteria Growth in the Flue Gas Atmosphere with Different CO2 Concentrations

Abstract

Nowadays, it is important to create the optimal technology for the absorption of flue gases with high CO2 content. In this regard, the aim of the investigation is to study the five different microalgae strains (Chlorella vulgaris, Chlorella ellipsoidea, Elliptochoris subsphaerica, Gloeotila pulchra, and Arthrospira platensis) under the influence of flue gases. The cultivation of microalgae was carried out in the atmosphere of flue gases with a gas flow rate of approximately 1 L·min−1 at high CO2 concentrations (3, 6, or 8%—from lower to higher concentrations), under continuous (24 h·d−1) illumination intensity of 200 µmol quanta·m−2·s−1 and a constant temperature of 27 ± 1 °C. The duration of the experiments was 12 days. Chlorella vulgaris and Chlorella ellipsoidea demonstrated the highest biomass growth rate at CO2 = 6% (0.79 and 0.74 g·L−1·d−1, respectively). The lowest growth rate (0.21 g·L−1·d−1) was achieved for Arthrospira platensis at CO2 = 3 and 6%. There was no significant drop in pH in the entire series of experiments. The results of microscopy showed a lack or a minimal number of dead cells in the strains under selected conditions. The obtained results can be used for further development of CO2 capture and storage technologies.