Nitrogen Removal through Heterotrophic Nitrification and Aerobic Denitrification by Heterotrophic Nitrifier of Bacillus sp. LY

A set of batch assays was used to assess the characteristics of ammonium oxidation, nitrite and nitrate reduction by heterotrophic nitrifier of
Bacillus
sp. LY.
Bacillus
sp. LY is not only a heterotrophic nitrifier, but is also an aerobic denitrifier, and shows a surprising ability of aerobic nitrification- denitrification for nitrogen removal. C/N 15 and 30degC were the optimal conditions for aerobic nitrogen removal. Maximum removal efficiency of NH
₄

⁺
-N and TN was 100% and 78.9% respectively when the medium initially contained 40 mg/l of NH
₄

⁺
- N at C/N 15. The nitrogen conversion during the process was also analyzed. The production of N
₂
O and N
₂
confirmed its aerobic nitrogen removal capability. This is important as the potential for single step nitrogen removal in wastewater treatment by heterotrophic nitrification-aerobic denitrification.