(343j) Influence of CO2 Concentrations on Chlorella Kessleri Cultivation, Growth, and CO2 Fixation

CO₂ biofixation by microalgae has garnered considerable interest. In this context, culture of Chlorella kessleri one of the microalgae species in batch photobioreactors with varying levels of CO₂ in the air. This study aims to determine Chlorella kessleri's capacity for CO₂ biofixation and biomass growth. The biomass concentration and biomass productivity of Chlorella kessleri cultivated under various CO₂ concentrations at 25⁰C temperature and nitrogen to phosphorus (NP) ratio of 2:1 were investigated. During the culture period, biomass concentration increased progressively for all concentrations of 2%, 6%, and 10% CO₂ examined, whereas the opposite is true for 0% CO₂ concentration. Maximum biomass concentration and productivity were determined to be 607 mg/L and 46 mg/L/d, respectively, at 2% CO₂ concentration in the air. Biofixation of CO₂ is primarily dependent on the species and optimal CO₂ concentration provided to the culture. Maximum CO₂ biofixation rate of 84 mg/L/d was achieved at 2% CO₂ air concentration. In conclusion, the culture of Chlorella kessleri microalgae in photobioreactor is a potential strategy for the simultaneous removal of nutrients and biofixation of carbon dioxide.