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Related Experiment Video

Updated: Jun 3, 2026

Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O

Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on ¹⁴NH₄⁺/¹⁵NH₄⁺ Analyses via Sequential Conversion to N₂O

Published on: October 7, 2020

Autotrophic nitrogen removal at low temperature.

J R Vázquez-Padín¹, I Fernández, N Morales

¹Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, Rua Lope Gómez de Marzoa s/n, E-15782, Santiago de Compostela, Spain. jose.vazquez.padin@usc.es

Water Science and Technology : a Journal of the International Association on Water Pollution Research

|March 26, 2011

Summary

The CANON process efficiently removes nitrogen at low temperatures, outperforming a two-unit system. Optimizing dissolved oxygen is crucial for the CANON system

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Area of Science:

Environmental microbiology
Wastewater treatment engineering

Background:

Autotrophic nitrogen removal is essential for wastewater treatment.
Moderately low temperatures pose challenges for microbial nitrogen removal processes.

Purpose of the Study:

To compare the efficiency of two autotrophic nitrogen removal configurations at low temperatures.
To investigate the performance of the CANON process under varying temperature and dissolved oxygen conditions.

Main Methods:

Utilized a two-unit system (SHARON reactor coupled to Anammox SBR) and a single-unit CANON system (granular SBR).
Operated systems at 20°C and 15°C, controlling dissolved oxygen to manage ammonia-oxidizing bacteria activity.

Main Results:

The CANON system achieved a nitrogen removal capacity of 1 g N/(L d) at 20°C, significantly higher than the two-unit system (0.08 g N/(L d)).
At 15°C, the CANON system's nitrogen removal rate decreased to 0.2 g N/(L d).
Controlled ammonia oxidation to prevent nitrite inhibition of Anammox bacteria.

Conclusions:

The single-unit CANON process demonstrates superior nitrogen removal efficiency at moderately low temperatures compared to a two-unit system.
Careful control of dissolved oxygen is critical when decreasing temperature in the CANON system to prevent inhibition of Anammox bacteria.