Field study on attached cultivation of Arthrospira (Spirulina) with carbon dioxide as carbon source

Microalga is considered as a promising candidate for CO₂ bio-sequestration. Biofilm attached cultivation is a newly developed technology with many advantages over conventional aqua-suspended methods. In this research, the field performance of this technology was investigated with a 10 m² pilot system under greenhouse condition by cultivating Arthrospira (Spirulina) platensis with CO₂ as carbon source. The system run continuously for two months without contamination bloom. Averaged biomass productivity was 38.3 g m^-2 d^-1 with protein content over 60% and overall CO₂ usage efficiency of 75.1%. Construction cost for the pilot system was over US$200 per m² which was much higher than that of open pond. However, there was a great reduction space in future large-scale application if the most expensive materials were substituted with cheaper ones. These results indicated the attached cultivation was a promising technology for industrialized application of microalga in CCUS (carbon capture, utilization and storage).