Regular articleMitigation of inhibition effect of acid gases in flue gas using trona buffer for autotrophic growth of Nannochloris sp

- Trona was used as a buffer chemical along with CO2(g) to supply inorganic carbon.
- The method provides high DIC concentration for enhanced autotrophic growth.
- The method does not inhibit autotrophic growth under high purity CO2(g).
- The method alleviates the inhibition effect of acid gases on autotrophic growth.
- The method can be used after wet flue gas desulfurization of coal power plants.

In this study, trona buffer was used to mitigate the previously reported inhibition effect of CO2, SO2, NO, and HCl gases in combustion flue gases for the growth of Nannochloris sp. Culture medium with trona buffer after absorbing CO2(g) contains high dissolved inorganic carbon (DIC) concentration that can help maximize the growth and alleviate the inhibition effect as long as the pH of the medium is controlled at an optimum pH (pH ∼7-8) window for the growth of Nannochloris sp. A supply of high purity CO2(g) did not inhibit the growth. The acid gaseous constituents including SO2, NO, and HCl gases did not significantly reduce the growth as compared to the results previously reported. This study suggests that trona buffer can be effectively used for microalgae cultivation as biological CO2 remediation when it is considered being integrated into a coal-fired power plant after wet flue gas desulfurization system.