Enhanced Carbon Dioxide Fixation and Bio-Oil Production of a Microalgal Consortium

In this study, a microalgal consortium was cultivated with different CO2 supplements: ambient air (0.03% CO2), 10 and 30% (v/v) CO2. It was found that the growth rate of the cultures supplemented with 30% CO2 was the highest among the others. The biomass and lipid productivity for the microalgal consortium with 30% CO2 were 21.1 and 4.8 mgL(-1) day(-1) (27.6% of dry weight, dw). The ability of CO2 fixation under 30% CO2 supplementation was found to be 0.0271 g CO2 L-1 day(-1), which is higher than in the ambient air supplementation. Then, the microalgal consortium was cultivated with exhaust gas (19% CO2) from a power generator supplied by biogas from chicken manure. It was found that the growth of the microalgae supplemented with exhaust gas was higher than in the ambient air. The biomass and lipid productivity for the microalgal consortium with exhaust gas were 25.82 and 5.2 mg L-1 day(-1) (16.96% of dw) and the most dominant algal species observed were Acutodesmus (Scenedesmus) sp., A. dimorphus (Turpin) Tsarenko and Scenedesmus obliquus (Turpin) Kutzing, respectively. Moreover, it could be revealed that the ability of CO2 fixation under supplementations with exhaust gas increased 1.3-fold compared with ambient air. Therefore, the microalgal consortium has high potential for both CO2 reduction and bio-oil production, simultaneously.