Features of the Microalgae and Cyanobacteria Growth in the Flue Gas Atmosphere with Different CO 2 Concentrations

Nowadays, it is important to create the optimal technology for the absorption of flue gases with high CO 2 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 CO 2 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 CO 2 = 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 CO 2 = 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 CO 2 capture and storage technologies.