Using an innovative umbrella-shape membrane module to improve MBR for PN-ANAMMOX process

Area of Science:

• Environmental Engineering
• Biotechnology
• Wastewater Treatment

Background:

• Membrane fouling is a major limitation for membrane bioreactor (MBR) applications.
• The partial nitrification-anaerobic ammonia oxidation (PN-ANAMMOX) process offers efficient nitrogen removal but faces operational challenges.

Purpose of the Study:

• To investigate the efficacy of a novel umbrella-shape membrane module in MBRs for the PN-ANAMMOX process.
• To assess the impact of the module design on membrane fouling and process performance.
• To optimize nitrogen removal efficiency and microbial community stability.

Main Methods:

• Construction and operation of two MBRs utilizing umbrella-shape membrane modules for a two-stage PN-ANAMMOX process.
• Monitoring of nitrogen removal rates, operational stability, and membrane fouling over 105 days.
• Analysis of microbial community composition, including ammonia oxidizing bacteria (AOB) and ANAMMOX bacteria (AnAOB).

Main Results:

• Successful initiation and coupling of PN and ANAMMOX processes within 55 days.
• Achieved a maximum nitrogen loading rate (NLR) of 0.4 kg N·(m³·d)⁻¹ and a total nitrogen removal rate (TNRR) of 75.23%.
• Demonstrated superior membrane fouling resistance, requiring cleaning only once, and high abundances of AOB (73.25%) and AnAOB (57.80%).

Conclusions:

• The umbrella-shape membrane module enhances MBR performance for PN-ANAMMOX processes.
• This design facilitates rapid process start-up, stable operation, and effective nitrogen removal.
• Optimizing membrane module shape is a viable strategy to mitigate membrane fouling and expand MBR applications.