Controlling ratio of carbon dioxide to hydrogen to improve hydrogen utilization rate and denitrification rate of hydrogenotrophic autotrophic denitrification through homoacetogenesis-heterotrophic denitrification pathway

Hydrogenotrophic denitrification was the most environmental-friendly denitrification method for organic-free influent, but the low mass transfer efficiency of hydrogen and large pH fluctuations limited its application. In this study, controlling CO2/H2 ratio was used to enhance hydrogenotrophic denitrification. By controlling the high CO2/H2 ratio, the dominant hydrogenotrophic autotrophic denitrification pathway was transformed into the homoacetogenesis - heterotrophic denitrification pathway, thereby obtaining more stable pH, higher hydrogen utilization and denitrification rate.