Operational conditions for successful partial nitrification in a sequencing batch reactor (SBR) based on process
Xiaoguang Liu1, Mingu Kim2, George Nakhla1,2
1a Department of Civil and Environmental Engineering , University of Western Ontario , London , Canada.
Environmental Technology
|July 8, 2016
Summary
This study analyzed factors influencing partial nitrification in sequencing batch reactors (SBRs). Optimal dissolved oxygen (DO) and ammonia levels were identified for stable partial nitrification, with kinetic models accurately predicting performance.
Area of Science:
- Environmental Engineering
- Biotechnology
- Wastewater Treatment
Background:
- Partial nitrification is a key step in nitrogen removal from wastewater.
- Optimizing partial nitrification is crucial for efficient and cost-effective wastewater treatment.
- Sequencing Batch Reactors (SBRs) offer flexibility in managing nitrification processes.
Purpose of the Study:
- To investigate the impact of dissolved oxygen (DO) and influent ammonia concentration on partial nitrification performance in an SBR.
- To evaluate the stability and efficiency of partial nitrification under varying operational conditions.
- To determine kinetic parameters and validate a kinetic model for predicting SBR performance.
Main Methods:
- Conducted a 4-month operational study of a sequencing batch reactor (SBR).
- Manipulated dissolved oxygen (DO) levels and influent ammonia concentrations as key operating variables.
- Utilized batch tests and model simulations to determine kinetic parameters.
- Employed intermittent aeration strategies to manage the nitrification process.
Main Results:
- Achieved stable partial nitrification under two distinct conditions: (1) 190 mg N/L ammonia with 0.6-3.0 mg/L DO, and (2) 100 mg N/L ammonia with 0.15-2.0 mg/L DO.
- Observed no suppression of nitrite-oxidizing bacteria growth at 90 mg N/L ammonia and 0.6-3.0 mg/L DO.
- Kinetic parameters were successfully determined and estimated.
- The developed kinetic model demonstrated a strong ability to predict SBR performance.
Conclusions:
- Dissolved oxygen and influent ammonia concentration are critical factors controlling partial nitrification in SBRs.
- Specific DO and ammonia ranges, coupled with intermittent aeration, can ensure stable partial nitrification while preserving nitrite-oxidizing bacteria activity.
- Kinetic modeling provides a reliable tool for understanding and predicting the performance of partial nitrification in SBR systems.
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