Influent:Synthetic wastewater simulating municipal wastewater
Comammox System:Intermittently aerated SBR
reactor:Sequencing batch reactor
Medium:Suspended-sludge
Culture taken from:Seeding sludge was taken from a full-scale municipal WWTP
Microorganism cultured:nan
Respiration:Aerobic
Electron donor:Polyhydroxyalkanoates
Electron acceptor:Ammonium, nitrite
PH:7.6-8.2
Temperature:25?C
HRT:8 h and 20 days
NH4–N Influent conc(mg/L):50
NO2–N Influent conc(mg/L):50.0
NO3–N Influent conc(mg/L):nan
NH4–N Effluent (mg N/L):25
NO2–N Effluent (mg N/L):16.0
NO3-N Effluent (mg N/L):4
NH4–N removal rate mg/L/d:27.31
NO2–N removal rate mg/L/d:3.6
NO3-N removal rate mg/L/d:nan
TN Removal rate (mg N/L/d):nan
Authors:Liu et al., 2021
Title:Minimization of N2O Emission through Intermittent Aeration in a Sequencing Batch Reactor (SBR): Main Behavior and Mechanism
Pubmed link:None
Full research link:Link
Abstract:To explore the main behavior and mechanism of minimizing nitrous oxide (N2O) emission through intermittent aeration during wastewater treatment, two lab-scale sequencing batch reactors operated at intermittently aerated mode (SBR1), and continuously aerated mode (SBR2) were established. Compared with SBR2, the intermittently aerated SBR1 reached not only a higher total nitrogen removal efficiency (averaged 93.5%) but also a lower N2O-emission factor (0.01–0.53% of influent ammonia), in which short-cut nitrification and denitrification were promoted. Moreover, less accumulation and consumption of polyhydroxyalkanoates, a potential endogenous carbon source promoting N2O emission, were observed in SBR1. Batch experiments revealed that nitrifier denitrification was the major pathway generating N2O while heterotrophic denitrification played as a sink of N2O, and SBR1 embraced a larger N2O-mitigating capability. Finally, quantitative polymerase chain reaction results suggested that the abundant complete ammonia oxidizer (comammox) elevated in the intermittently aerated environment played a potential role in avoiding N2O generation during wastewater treatment. This work provides an in-depth insight into the utilization of proper management of intermittent aeration to control N2O emission from wastewater treatment plants.