Utilization of simulated flue gas for cultivation of Scenedesmus dimorphus

Effects of flue gas components on growth of Scenedesmus dimorphus were investigated and two methods were carried out to eliminate the inhibitory effects of flue gas on microalgae. S. dimorphus could tolerate CO2 concentrations of 10–20% and NO concentrations of 100–500 ppm, while the maximum SO2 concentration tolerated by S. dimorphus was 100 ppm. Addition of CaCO3 during sparging with simulated flue gas (15% CO2, 400 ppm SO2, 300 ppm NO, balance N2) maintained the pH at about 7.0 and the algal cells grew well (3.20 g L−1). By intermittent sparging with flue gas controlled by pH feedback, the maximum biomass concentration and highest CO2 utilization efficiency were 3.63 g L−1 and 75.61%, respectively. These results indicated that S. dimorphus could tolerate high concentrations of CO2 and NO, and the methods of CaCO3 addition and intermittent sparging have great potential to overcome the inhibition of flue gas on microalgae.