Large-Scale Cultivation of Spirulina for Biological CO2 Mitigation in Open Raceway Ponds Using Purified CO2 From a Coal Chemical Flue Gas

Baohua Zhu; Han Shen; Yun Li; Qiuke Liu; Guiyong Jin; Jichang Han; Yan Zhao; Kehou Pan

doi:10.3389/fbioe.2019.00441

Large-Scale Cultivation of Spirulina for Biological CO₂ Mitigation in Open Raceway Ponds Using Purified CO₂ From a Coal Chemical Flue Gas

Front Bioeng Biotechnol. 2020 Jan 9:7:441. doi: 10.3389/fbioe.2019.00441. eCollection 2019.

Authors

Baohua Zhu¹, Han Shen¹, Yun Li¹, Qiuke Liu¹, Guiyong Jin¹, Jichang Han², Yan Zhao², Kehou Pan^{1

3}

Affiliations

¹ Key Laboratory of Mariculture (Ocean University of China), Ministry of Education, Qingdao, China.
² College of Marine Life Sciences, Ocean University of China, Qingdao, China.
³ Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.

Abstract

In order to select excellent strains with high CO₂ fixation capability on a large scale, nine Spirulina species were cultivated in columnar photobioreactors with the addition of 10% CO₂. The two species selected (208 and 220) were optimized for pH value, total dissolved inorganic carbon (DIC), and phosphorus content with intermittent CO₂ addition in 4 m² indoor raceway ponds. On the basis of biomass accumulation and CO₂ fixation rate in the present study, the optimum pH, DIC, and phosphate concentration were 9.5, 0.1 mol L^-1, and 200 mg L^-1 for both strains, respectively. Lastly, the two strains selected were semi-continuously cultivated successfully for CO₂ mitigation in 605 m² raceway ponds aerated with food-grade CO₂ purified from a coal chemical flue gas on a large scale. The daily average biomass dry weight of the two stains reached up to 18.7 and 13.2 g m^-2 d^-1, respectively, suggesting the two Spirulina strains can be utilized for mass production.

Keywords: CO2 mitigation; Spirulina sp.; coal chemical flue gas; large-scale cultivation; process optimization.