Biological Nitrogen Removal Database
A manually curated data resource for microbial nitrogen removal
Biological Nitrogen Removal Database
A manually curated data resource for microbial nitrogen removal
Influent:Raw wastewater
Comammox System:Partial nitrification?anaerobic ammonium oxidation (anammox) (PN?A) in continuously stirred tank-reactor (CSTR)
reactor:Bench-scale bioreactor with continuously stirred tank-reactor (CSTR)
Medium:Suspended-sludge
Culture taken from:Comammox bioreactor
Microorganism cultured:nan
Respiration:Aerobic
Electron donor:Sodium bicarbonate
Electron acceptor:Ammonium chloride
PH:7.4-8.0
Temperature:30 °C
HRT:12.5 days
NH4–N Influent conc(mg/L):220
NO2–N Influent conc(mg/L):nan
NO3–N Influent conc(mg/L):nan
NH4–N Effluent (mg N/L):69.6?99.9
NO2–N Effluent (mg N/L):81.6
NO3-N Effluent (mg N/L):nan
NH4–N removal rate mg/L/d:24.7
NO2–N removal rate mg/L/d:nan
NO3-N removal rate mg/L/d:12.3
TN Removal rate (mg N/L/d):24.7
Authors:Shao and Wu. 2021
Title:Comammox Nitrospira Species Dominate in an Efficient Partial Nitrification–Anammox Bioreactor for Treating Ammonium at Low Loadings
Pubmed link:None
Full research link:Link
Abstract:Bacteria capable of complete ammonia oxidation (comammox) are widespread and contribute to nitrification in wastewater treatment facilities. However, their roles in partial nitrification–anaerobic ammonium oxidation (anammox) systems remain unclear. In this study, a bench-scale bioreactor with continuous stirring was operated for more than 1000 days with limited oxygen supply to achieve efficient nitrogen removal (70.1 ± 2.7%) at a low ammonium loading of 35.2 mg-N/L/day. High-throughput amplicon sequencing analysis of the comammox ammonia monooxygenase subunit A (amoA) gene revealed seven sequence types from two clusters in clade A of comammox Nitrospira. Quantitative polymerase chain reaction analyses suggested that the comammox species dominated the ammonia-oxidizing community, with an abundance as high as 89.2 ± 7.9% in total prokaryotic amoA copies. Multiple linear regression further revealed the substantial contribution of the comammox Nitrospira to ammonia oxidation in the bioreactor. The investigation with bioreactor and batch experiments consistently showed that activities of comammox Nitrospira were inhibited by free ammonia far more severely than other ammonia-oxidizing microbes. Overall, this study provided new insight into the ecology of comammox Nitrospira under hypoxic conditions and suggested comammox-associated partial nitrification–anammox as a potential method for treating low-strength ammonium-containing wastewater.