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

•Field performance of attached cultivation for microalga was investigated.•Biomass yield of 38.3 g m−2 d-1 with CO2 usage efficiency of 75.1% were achieved.•Construction costs for building the system were also analyzed.•Attached cultivation was promising technology for application of microalga in CCUS. 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).