Nitrous oxide production from sequencing batch reactor sludge under nitrifying conditions: effect of nitrite concentrations.
Nitrous oxide (N2O), a greenhouse gas which contributes to the destruction of the stratospheric ozone layer, can be emitted from nitrifying processes during wastewater treatment. The pathway of N2O production was studied using a lab-scale nitrifying reactor. Allylthiourea was used to inhibit NH4+ oxidation and provide information on processes that happen under nitrifying condition. Our study confirmed that besides heterotrophic bacteria, ammonium-oxidizing bacteria could perform denitrification processes, during which NO2- was the electron acceptor and NH4+ was the electron donor, with N2 and N2O as final products. The relative contribution of the heterotrophic denitrification process to total N2O emissions varied from 46.1% to 60.4% depending on NO2(-)-N addition. Correspondingly, 21.8% to 51.5% of total N2O emissions can be attributed to nitrifier denitrification. Little N2O is emitted during the NO2- oxidation process.
School of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100022, China.
Youkui
Y
Gong
Shuying
S
Wang
Sai
S
Wang
Yongzhen
Y
Peng
D061249:Batch Cell Culture Techniques / Q000295:instrumentation*; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D009573:Nitrites / Q000378:metabolism*; D009609:Nitrous Oxide / Q000378:metabolism*; D012722:Sewage / Q000382:microbiology*
D009573:Nitrites; D012722:Sewage; D009609:Nitrous Oxide