Dimension effect of anammox granule: Potential vs performance

Area of Science:

• Environmental Microbiology
• Wastewater Treatment Engineering

Background:

• Anammox granules are crucial for anammox sludge bed reactors.
• Understanding granule dimension effects is key to optimizing nitrogen removal.

Purpose of the Study:

• To investigate the impact of anammox granule size on specific anammox activity (SAA).
• To correlate granule size with bacterial community, cell viability, and mass transfer efficiency.

Main Methods:

• Batch cultivation of anammox granules categorized by volume surface mean diameter (VMD).
• Bacterial community analysis using Q-PCR and flow cytometry.
• Measurement of specific anammox activity (SAA).

Main Results:

• Anammox granules with a VMD of 2.17 mm exhibited maximum SAA (399.6 ± 37.6 mg-N/(g-VSS·d)).
• Candidatus Kuenenia was the predominant AnAOB genus.
• Viable AnAOB cell counts increased with granule size, enhancing removal potential.
• Mass transfer efficiency decreased with increasing granule size, limiting performance.

Conclusions:

• Optimal anammox granule size results from a balance between nitrogen removal potential and mass transfer efficiency.
• Findings provide insights for optimizing anammox processes and nitrogen removal capacity.