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Updated: May 2, 2026
08:13
A Novel Bioreactor for High Density Cultivation of Diverse Microbial Communities
Published on: December 25, 2015
16.8K
Integrated fixed-film activated sludge ANITA™Mox process--a new perspective for advanced nitrogen removal
F Veuillet1, S Lacroix1, A Bausseron1
1Veolia Environment Research and Innovation, Chemin de la Digue - BP 76, 78603 Maison-Laffitte Cedex, France
Summary
The integrated fixed-film activated sludge (IFAS) configuration significantly boosts ANITA™Mox performance for nitrogen removal. This method enhances bacterial distribution and substrate accessibility, leading to higher removal rates compared to traditional moving-bed biofilm reactors.
Area of Science:
- Environmental Engineering
- Wastewater Treatment
- Microbial Ecology
Background:
- The ANITA™Mox process utilizes moving-bed biofilm reactor (MBBR) technology for energy- and cost-effective autotrophic nitrogen removal via anammox (anaerobic ammonium oxidation) bacteria.
- Enhancing substrate transport and accessibility within the biofilm is crucial for improving ANITA™Mox performance under various operating conditions, including mainstream and sidestream applications.
Purpose of the Study:
- To evaluate and compare the performance of the ANITA™Mox process in two configurations: integrated fixed-film activated sludge (IFAS) and pure MBBR.
- To characterize the distribution of anammox (AnAOB) and ammonia-oxidizing bacteria (AOB) in both suspended sludge and biofilm using molecular tools.
Main Methods:
- Operation of two laboratory-scale biofilm ANITA™Mox reactors in IFAS and MBBR configurations.
- Quantitative Polymerase Chain Reaction (qPCR) to determine the distribution of AnAOB and AOB populations in suspended sludge and biofilm.
Main Results:
- The IFAS configuration achieved significantly higher nitrogen removal rates (up to 8 gN/m².d), which were 3-4 times greater than those in the pure MBBR mode.
- IFAS mode promoted efficient bacterial distribution, with AnAOB primarily active in the biofilm (96%) and AOB mainly in the suspended phase (93%).
- Higher mixed liquor suspended solids (MLSS) in IFAS enhanced substrate accessibility for AOB in the bulk, leading to increased nitrite production and improved AnAOB activity.
Conclusions:
- The IFAS configuration offers superior performance for the ANITA™Mox process by optimizing bacterial distribution and substrate availability.
- Effective control of MLSS levels in IFAS reactors is key to maximizing nitrogen removal efficiency.
- These findings support the expanded application of the compact and robust ANITA™Mox process for cost-effective nitrogen removal in both sidestream and mainstream wastewater treatment.
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