STRAIN AND FACTOR SELECTION FOR CARBON DIOXIDE FIXATION USING MICROALGAE CULTIVATED IN OIL SANDS PROCESS WATER

Biological fixation of CO2 using microalgae is a potential CO2 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 CO2. Also, the effect of phosphate, nitrate, CO2 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 CO2 uptake rate than Chlorella pyrenoidosa. Moreover, CO2 concentration, light intensity and phosphate concentration proved to have the strongest effects (in that order) on the growth and CO2 uptake rate of Chlorella kessleri.