Beneficial re-use of industrial CO₂ emissions using microalgae: Demonstration assessment and biomass characterization

A novel cyclic flow photobioreactor, designed for the capture and recycle of CO₂ using microalgae, was deployed at a coal-fired power plant. Scenedesmus acutus was cultured continuously for a four-month period, during which a biomass productivity of 0.1–0.2 g L⁻¹ day⁻¹ was observed. Samples taken for DNA sequencing showed a strong correlation between the composition of the culture and environmental conditions. Dry and liquid biomass samples and the industrial fertilizers used for preparation of the nutrient medium were analyzed to determine the presence of heavy metals (As, Cd, Hg, Se) and results were compared with standardized and/or regulated maximum contaminant levels (MCLs) for metals in several possible algae derived products. Concentrations of the metals in dry algae biomass were consistent with the incorporation of metals from the supplied nutrients.