High concentration CO2 sequestration by using microalgae in staged cultivation

Abstract

The acclimated fresh water microalga Chlorella vulgaris has the excellent growing capability in the process of staged cultivation (SC). In this study, the alga solutions with low (106/mL) and high (107/m) cell densities showed different abilities of growth with different levels of CO2–air mixture gases[5%, 10%, 15% (v/v)]. The SC process can improve the algal mass productivity rapidly by the aerating increased concentrations of CO2 of mixed gases into the algae solution in a short time. The results showed that the cell density was improved to 1.72 g L−1 within 7 days, showing 3.1, 1.48, and 1.70 times improvement compared to that in the biomass from the culture with separate 5, 10, and 15% CO2–air mixture gases. Besides, there were not the obvious distinctions on the contents of biochemicals (carbohydrate, protein, and lipid) from these algae. This study proved that SC process was an efficient method to improve biomass productivity of Chlorella sp. in a short time with low initial cell density. © 2016 American Institute of Chemical Engineers Environ Prog, 35: 1862–1867, 2016