[Start-up and Performance Optimization of a CANON Pilot Reactor]

Area of Science:

• Environmental Microbiology
• Wastewater Treatment Engineering
• Bioreactor Technology

Context:

• Conventional wastewater treatment struggles with efficient nitrogen removal.
• Completely autotrophic nitrogen removal over nitrite (CANON) processes face challenges with bacterial loss and reactor stability.
• Moving bed biofilm reactors (MBBRs) offer potential for enhanced microbial retention and performance.

Purpose:

• To optimize the completely autotrophic nitrogen removal over nitrite (CANON) process by integrating it with a moving bed biofilm reactor (MBBR) using suspension carriers.
• To investigate the nitrogen removal efficiency, operational stability, and microbial community dynamics of the developed CANON-MBBR system.
• To address bacterial loss issues and enhance overall nitrogen removal performance in autotrophic nitrogen removal systems.

Summary:

• A CANON-MBBR system was established using high-density polyethylene fillers, achieving successful startup and stable operation.
• The system demonstrated significant total nitrogen removal loads, reaching up to 1.15 kg·(m³·d)⁻¹, with a stable removal rate.
• High-throughput sequencing revealed ammonia-oxidizing bacteria (AOB) and anaerobic ammonia-oxidizing bacteria (AnAOB) as dominant species, indicating successful suppression of nitrate-oxidizing bacteria.

Impact:

• The CANON-MBBR system exhibits high nitrogen removal efficiency and stability, offering a promising solution for advanced wastewater treatment.
• The use of suspension carriers effectively mitigates bacterial loss, enhancing the robustness of the autotrophic nitrogen removal process.
• This technology contributes to more sustainable and efficient management of nitrogen pollution in aquatic environments.