Anammox cultivation in a closed sponge-bed trickling filter

Area of Science:

• Environmental microbiology
• Wastewater treatment technologies
• Bioreactor engineering

Background:

• Conventional nitrogen removal processes can be energy-intensive.
• Anammox (anaerobic ammonium oxidation) offers a more sustainable alternative.
• Optimizing Anammox bacteria cultivation is crucial for efficient nitrogen removal.

Purpose of the Study:

• To evaluate the feasibility of cultivating Anammox bacteria in lab-scale closed sponge-bed trickling filter (CSTF) reactors.
• To compare the performance of CSTF reactors at different temperatures (20°C and 30°C).
• To assess the long-term nitrogen removal efficiency and conversion rates.

Main Methods:

• Cultivation of Anammox bacteria in two CSTF reactors (CSTF-1 at 20°C, CSTF-2 at 30°C).
• Monitoring of reactor stability and nitrogen removal efficiency over 400 days.
• Analysis of total nitrogen conversion rates.

Main Results:

• Stable conditions were achieved in CSTF-2 by day 66 and CSTF-1 by day 104.
• Maximum total nitrogen removal efficiencies were 82% (CSTF-1) and 84% (CSTF-2).
• After 400 days, efficiencies were 74±5% and 78±4% with conversion rates of 1.52 and 1.60 kg-N/m³(sponge)d, respectively.

Conclusions:

• Anammox bacteria can be successfully cultivated in CSTF reactors.
• Temperature influences the rate of achieving stable conditions, with 30°C showing faster stabilization.
• CSTF technology using Anammox bacteria is a promising option for mainstream nitrogen removal in wastewater post-treatment.