Long-Term Low Dissolved Oxygen Operation Decreases N2O Emissions in the Activated Sludge Process

2021 ◽  
Author(s):  
Guoqiang Liu ◽  
Xianwei Wu ◽  
Deyong Li ◽  
Lugao Jiang ◽  
Ju Huang ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Activated Sludge ◽  
N2o Emissions ◽  
Activated Sludge Process ◽  
Low Dissolved Oxygen

Long-Term Effects of Copper Nanoparticles on Wastewater Biological Nutrient Removal and N2O Generation in the Activated Sludge Process

2012 ◽  
Vol 46 (22) ◽  
pp. 12452-12458 ◽  
Author(s):  
Yinguang Chen ◽  
Dongbo Wang ◽  
Xiaoyu Zhu ◽  
Xiong Zheng ◽  
Leiyu Feng
Keyword(s):  
Activated Sludge ◽  
Copper Nanoparticles ◽  
Nutrient Removal ◽  
Biological Nutrient Removal ◽  
Activated Sludge Process ◽  
Long Term Effects

scholarly journals ComammoxNitrospiraare the dominant ammonia oxidizers in a mainstream low dissolved oxygen nitrification reactor

2018 ◽  
Author(s):  
Paul Roots ◽  
Yubo Wang ◽  
Alex F. Rosenthal ◽  
James S. Griffin ◽  
Fabrizio Sabba ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Activated Sludge ◽  
Removal Rate ◽  
Ammonia Removal ◽  
Biological Nutrient Removal ◽  
Ammonia Oxidizing Bacteria ◽  
Ammonia Oxidizers ◽  
Total Abundance ◽  
Low Dissolved Oxygen ◽  
Activated Sludge Processes

AbstractRecent findings show that a subset of bacteria affiliated withNitrospira, a genus known for its importance in nitrite oxidation for biological nutrient removal applications, are capable ofcompleteammoniaoxidation (comammox) to nitrate. Early reports suggested that they were absent or present in low abundance in most activated sludge processes, and thus likely functionally irrelevant. Here we show the accumulation of comammoxNitrospirain a nitrifying sequencing batch reactor operated at low dissolved oxygen (DO) concentrations. Actual mainstream wastewater was used as influent after primary settling and an upstream pre-treatment process for carbon and phosphorus removal. The ammonia removal rate was stable and exceeded that of the treatment plant’s parallel full-scale high DO nitrifying activated sludge reactor. 16S rRNA sequencing showed a steady accumulation ofNitrospirato 53% total abundance and a decline in conventional ammonia oxidizing bacteria to <1% total abundance over 400+ days of operation. After ruling out other known ammonia oxidizers, qPCR confirmed the accumulation of comammoxNitrospirabeginning around day 200, to eventually comprise 94% of all detectedamoAand 4% of total bacteria by day 407. Quantitative fluorescence in-situ hybridization confirmed the increasing trend and high relative abundance ofNitrospira. These results demonstrate that comammox can be metabolically relevant to nitrogen transformation in wastewater treatment, and can even dominate the ammonia oxidizing community. Our results suggest that comammox may be an important functional group in energy efficient nitrification systems designed to operate at low DO levels.

Long term operation at low dissolved oxygen conditions results in Comammox dominated nitrifying community structure

2017 ◽  
Vol 2017 (7) ◽  
pp. 4069-4078
Author(s):  
Leon Downing ◽  
Colin Fitrzgerald ◽  
Mike Young
Keyword(s):  
Community Structure ◽  
Dissolved Oxygen ◽  
Low Dissolved Oxygen ◽  
Term Operation ◽  
Oxygen Conditions
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