Effect of light supply on CO₂ capture from atmosphere by Chlorella vulgaris and Pseudokirchneriella subcapitata

• Published in: Mitigation and adaptation strategies for global change 2014-10, Vol.19 (7), p.1109-1117
• Main Authors: Pires, J. C. M, Gonçalves, A. L, Martins, F. G, Alvim-Ferraz, M. C. M, Simões, M
• Format: Article
• Language: English
• Subjects: Algae; Alternative energy sources; Atmosphere; Atmospheric Sciences; Bacteria; Bioenergetics; Biomass; Carbon dioxide; Carbon dioxide fixation; Carbon dioxide removal; Carbon sequestration; Chlorella vulgaris; Climate change; Climate Change Management and Policy; Earth and Environmental Science; Earth Sciences; Emissions control; energy efficiency; Environmental Management; Geoengineering; Greenhouse gases; Growth rate; Light; light intensity; Membrane separation; Microalgae; Microorganisms; Original Article; Photooxidation; Photosynthesis; plants (botany); Selenastrum capricornutum; Solar energy
• ISSN: 1381-2386; 1573-1596
• DOI: 10.1007/s11027-013-9463-1

Carbon dioxide (CO₂) is one of the primary greenhouse gases that contribute to climate change. Consequently, emission reduction technologies will be needed to reduce CO₂ atmospheric concentration. Microalgae may have an important role in this context. They are photosynthetic microorganisms that are able to fix atmospheric CO₂ using solar energy with efficiency ten times higher than terrestrial plants. The objectives of this study were: (i) to analyse the effect of light supply on the growth of Chlorella vulgaris and Pseudokirchneriella subcapitata; (ii) to assess the atmospheric CO₂ capture by these microalgae; and (iii) to determine the parameters of the Monod model that describe the influence of irradiance on the growth of the selected microalgae. Both microalgae presented higher growth rates with high irradiance values and discontinuous light supply. The continuous supply of light at the highest irradiance value was not beneficial for C. vulgaris due to photooxidation. Additionally, C. vulgaris achieved the highest CO₂ fixation rate with the value of 0.305 g-CO₂ L⁻¹ d⁻¹. The parameters of the Monod model demonstrated that C. vulgaris can achieve higher specific growth rates (and higher CO₂ fixation rates) if cultivated under higher irradiances than the studied values. The presented results showed that microalgal culture is a promising strategy for CO₂ capture from atmosphere.