Catalytic CO2 fixation in microalgae Arthrospira platensis using direct flue gas

• Published in: Environmental challenges (Amsterdam, Netherlands) Vol. 20; p. 101213
• Main Authors: Farhad, Noshin, Karimi, Javad, Hafizi, Ali
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2025; Elsevier
• Subjects: Arthrospira platensis; Biological CO2 fixation; Carbon dioxide; Microalgae; Photocatalyst; Sodium hydrogen carbonate; Biological CO2 fixation; Sodium hydrogen carbonate; Microalgae; Arthrospira platensis; Photocatalyst; Carbon dioxide
• ISSN: 2667-0100; 2667-0100
• DOI: 10.1016/j.envc.2025.101213

Greenhouse gas (GHG) emissions, particularly CO2, pose a significant threat to climate regulation and the sustainability of human habitats. Effective CO2 control mechanisms are essential for addressing these challenges. This study investigated the potential of Arthrospira platensis microalgae for biological CO2 sequestration from industrial emissions. The primary objective is to optimized A. platensis for CO2 absorption and stabilization, while simultaneously producing valuable by-products for industrial applications. The study was employed a mixotrophic culture approach, manipulating the growth medium with sodium hydrogen carbonate, direct CO2 gas injection, and anatase TiO2 as a catalyst. Analyses included measurements of dry weight, pigment content, pH levels, and CO2 flux. The results revealed that sodium hydrogen carbonate effectively replaced dissolved CO2 gas, allowing biological stabilization without the need for baking soda. Furthermore, sunlight utilization promoted the production of high-value by-products such as phycocyanin and fatty acids. This study underscores the potential of A. platensis to enhance carbon sequestration under mixotrophic conditions. It presents a sustainable strategy to CO2 mitigation while generating industrially valuable compounds, thereby contributing to both environmental and economic objectives.