Catalytic CO2 fixation in microalgae Arthrospira platensis using direct flue gas

Abstract

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.