Strain and factor selection for carbon dioxide fixation using microalgae cultivated in oil sands process water

Biological fixation of CO 2 using microalgae is a potential CO 2 reduction strategy which can be applied to the oil sands operations in Alberta. These operations also produce large amounts of oil sands process water (OSPW), which can act as a growth medium for the microalgae. In this study, three different microalgae: Botryococcus braunii , Chlorella pyrenoidosa and Chlorella kessleri were investigated for their ability to grow in OSPW, and to uptake CO 2 . Also, the effect of phosphate, nitrate, CO 2 concentrations and light intensity were studied using a fractional two‐level and a full two‐level factorial design. These investigations eliminated Botryococcus braunii as it cannot grow in OSPW, and demonstrated that Chlorella kessleri has a higher CO 2 uptake rate than Chlorella pyrenoidosa . Moreover, CO 2 concentration, light intensity and phosphate concentration proved to have the strongest effects (in that order) on the growth and CO 2 uptake rate of Chlorella kessleri .