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A Novel Bioreactor for High Density Cultivation of Diverse Microbial Communities
Published on: December 25, 2015
Model-based study of nitrite accumulation with OUR control in two continuous nitrifying activated sludge
Irene Jubany1, Juan Antonio Baeza, Javier Lafuente
1Department d'Enginyeria Química, Escola d'Enginyeria, Universitat Autònoma de Barcelona, Bellaterra 8193, Spain.
Summary
This study demonstrates a control strategy for stable partial nitrification using ammonium oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB). Configuration A, with multiple reactors, achieved stable partial nitrification even under challenging environmental conditions.
Area of Science:
- Environmental microbiology
- Wastewater treatment technologies
- Biochemical engineering
Background:
- Partial nitrification is crucial for nitrogen removal in wastewater treatment.
- Ammonium oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) have different sensitivities to environmental factors.
- Controlling conditions like pH, temperature, dissolved oxygen, free ammonia, and free nitrous acid is key to achieving stable partial nitrification.
Purpose of the Study:
- To theoretically investigate a control strategy for stable partial nitrification.
- To evaluate the effectiveness of controlling oxygen uptake rate (OUR) by manipulating influent flow rate and other environmental parameters.
- To compare two different reactor configurations for achieving partial nitrification.
Main Methods:
- Simulated two configurations: Configuration A (three continuous stirred-tank reactors in series) and Configuration B (a single reactor).
- Developed a control system manipulating influent flow rate, temperature, pH, and dissolved oxygen to control OUR.
- Assessed the stability of partial nitrification under various conditions.
Main Results:
- The developed control system successfully achieved partial nitrification in both configurations.
- Configuration A demonstrated superior performance, enabling stable partial nitrification even under suboptimal conditions (15°C, pH 8.3, 3 mg O(2)/L DO).
- Partial nitrification was achieved despite theoretically unfavorable environmental parameters.
Conclusions:
- A control strategy based on OUR manipulation is effective for achieving stable partial nitrification.
- Multi-reactor configurations (like Configuration A) offer enhanced stability and performance for partial nitrification processes.
- The findings suggest the potential for robust nitrogen removal in wastewater treatment even under challenging operational conditions.
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