Impact of carbon source on nitrous oxide emission from anoxic/oxic biological nitrogen removal process and identification of its emission sources.
Wastewater treatment is an important source of nitrous oxide (N(2)O), which is a strong greenhouse gas and dominate ozone-depleting substance. The purpose of this study was to evaluate the effect of carbon source on N(2)O emission from anoxic/oxic biological nitrogen removal process. The mechanisms of N(2)O emission were also studied. Long-term experiments were operated to evaluate the effect of three different carbon sources (i.e., glucose, sodium acetate, and soluble starch) on N(2)O emission characteristics. And batch experiments, in the presence or absence of specific inhibitors, were carried out to identify the sources of N(2)O emission. The ammonia-oxidizing bacteria (AOB) and denitrifiers community compositions under different circumstances were also analyzed based on which the underlying mechanisms of N(2)O emission were elucidated. The conversion ratios of N(2)O in reactors with glucose, sodium acetate, and soluble starch were 5.3 %, 8.8 %, and 2.8 %, respectively. The primary process responsible for N(2)O emission was nitrifier denitrification by Nitrosomonas-like AOB, while denitrification by heterotrophic denitrifiers acted as the sink. Reactor with sodium acetate showed the highest N(2)O emission, together with the highest nitrogen and phosphate removal ratios. Carbon source has a significant impact on N(2)O emission quantity and relatively minor effect on its production mechanism.
Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 27 Shanda Nanlu, Jinan, 250100 Shandong, People's Republic of China.
Zhen
Z
Hu
Jian
J
Zhang
Shanping
S
Li
Huijun
H
Xie
D000641:Ammonia; D001419:Bacteria / Q000235:genetics*; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology*; D002244:Carbon; D058440:Denitrification; D015180:Electrophoresis, Gel, Two-Dimensional; D005947:Glucose; D009584:Nitrogen; D009606:Nitrosomonas; D009609:Nitrous Oxide / Q000032:analysis*; D010088:Oxidoreductases / Q000235:genetics; D010802:Phylogeny; D019346:Sodium Acetate; D013213:Starch; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*; D062065:Wastewater
D000641:Ammonia; D002244:Carbon; D005947:Glucose; D009584:Nitrogen; D009609:Nitrous Oxide; D010088:Oxidoreductases; D019346:Sodium Acetate; D013213:Starch; D062065:Wastewater; C045582:ammonia monooxygenase