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Published on: October 15, 2015
Settleability and kinetics of a nitrifying sludge in a sequencing batch reactor
1Universidad Autónoma Metropolitana-Iztapalapa, Div. CBS, Departamento de Biotecnología, Av. San Rafael Atlixco 186, Col. Vicentina, CP 09340, México D.F. actx@xanum.uam.mx
Canadian Journal of Microbiology
|January 13, 2005
Summary
Nitrifying sludge in sequencing batch reactors (SBRs) achieved high ammonium removal efficiency. However, nitrite oxidizing bacteria activity declined over time, impacting nitrification performance.
Area of Science:
- Environmental Microbiology
- Wastewater Treatment Engineering
- Bioreactor Technology
Background:
- Nitrifying sludge is crucial for converting ammonia to nitrate in wastewater treatment.
- Sequencing batch reactors (SBRs) offer flexibility in managing nitrification processes.
- Understanding sludge physiology and kinetics is key to optimizing treatment efficiency.
Purpose of the Study:
- To investigate the physiological characteristics and long-term stability of nitrifying sludge in an SBR.
- To evaluate the impact of operational time on the activity of ammonia and nitrite oxidizing bacteria.
- To determine the kinetic parameters governing nitrification under pseudo steady-state conditions.
Main Methods:
- Operation of a sequencing batch reactor (SBR) with nitrifying sludge.
- Monitoring of ammonium removal efficiency and nitrogen conversion rates.
- Analysis of biomass production, sludge settling properties, and exopolymeric substances.
- Kinetic analysis of ammonia and nitrite oxidizing bacteria activity over extended operation.
Main Results:
- Achieved high ammonium removal efficiency (99% +/- 1%) and nitrate conversion (98% +/- 2%).
- Demonstrated negligible biomass production and good sludge settling properties.
- Observed a decrease in nitrite oxidizing bacteria activity and an increase in nitrite accumulation after 22 cycles.
- Ammonia oxidizing bacteria exhibited greater stability throughout the 4-month study period.
Conclusions:
- Nitrifying sludge in SBRs can achieve efficient ammonium removal.
- Longer operation times can lead to a decline in nitrite oxidizing bacteria activity, affecting overall nitrification.
- Ammonia oxidizing bacteria demonstrate superior stability compared to nitrite oxidizing bacteria in SBRs.
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