Carbon dioxide fixation of freshwater microalgae growth on natural water medium

•This study presented the algae growth of “self-designed” bio-functions of nature.•We showed the potential of CO2 fixation by algae using natural water medium.•We focused on the bio-fixation of algae to utilize the atmospheric air CO2 directly.•The study presented the extremely high CO2 uptake rate and consumption efficiency.

This study was undertaken as an effort to develop the knowledge that could provide information and clue regarding the algae niche in the natural environment. We utilized natural water medium to mimic natural water body in laboratory to grow algae, to understand the algae niche in the ecosystems and to demonstrate the potential of algal CO2 bio-fixation. The continuously long-term operation in the laboratory demonstrated the impressed algal function as in nature. The study showed that natural water resource had sufficient nutrients for microalgae growth. We also found evidences to prove that 100% carbon source came from the atmospheric CO2 absorption to reach the extremely high CO2 consumption efficiency. This study illustrated that the growth conditions of algal niche in the natural CO2 absorption processes is helpful in understanding the algae ecology in water bodies and is also valuable for future global warming and energy crisis issues.