(772d) Enhanced Autotrophic Growth of Nannochloris Sp. with Buffer Chemicals for Sustainable Carbon Recycle

Kim, J., University of Cincinnati
Lee, J. Y., University of Cincinnati
In this study, a potential ability of buffer chemicals for CO2 gas capture and the resultant solutions were investigated for the autotrophic growth of Nannochloris sp. in a modified Shuisheng-4 culture medium. Sodium-based buffer chemicals used in this study well dissolve in water due to their high solubility and the buffer solutions can be converted to sodium bicarbonate solution after absorbing CO2(g). After absorbing CO2(g), both total inorganic carbon (TIC=HCO3-, CO32-, H2CO3, CO2(aq)) and dissolved inorganic carbon (=DIC=HCO3-+CO2(aq)) in the solution significantly increased and the pH of the solution is equilibrated at pH=8.3 suitable for the growth of Nannochloris sp. As a result, high DIC concentration dramatically increased the autotrophic growth rate of Nannochloris sp. when the Na+ concentration was less than 0.12 M. In addition, Nannochloris sp. was cultivated in the buffer chemicals system using simulated flue gas mixed with CO2, N2, SO2, NO, and HCl gases. As a result, the buffer solutions could suppress the possible inhibition effect of acid gases such as SO2, NO, and HCl on the growth of Nannchloris sp. This study suggests that the sodium-based buffer chemicals can be effectively used for biological CO2 conversion and sustainable carbon recycle with pure CO2 or flue gas from a coal-fired power plant.