Electrically enhanced MBR system for total nutrient removal in remote northern applications

Area of Science:

• Environmental Engineering
• Water Treatment Technologies
• Biotechnology

Background:

• Decentralized wastewater treatment is crucial for remote, sparsely populated communities in cold climates like northern Canada.
• Conventional Membrane Bioreactors (MBRs) offer advanced treatment but face challenges with membrane fouling.
• Electro-technologies are effective in water treatment but rarely combined with MBRs.

Purpose of the Study:

• To design and evaluate a novel electrically enhanced membrane bioreactor (EMBR) system.
• To improve nutrient removal efficiency and reduce membrane fouling in decentralized wastewater treatment.
• To assess EMBR performance in cold conditions with real sewage.

Main Methods:

• Comparison of an EMBR with a control MBR using identical submerged hollow fiber membranes.
• Operation with synthetic feed at room temperature (20°C) for 4 months.
• Operation with real sewage at 10°C for 2 months.

Main Results:

• EMBR showed significantly slower transmembrane pressure (TMP) increase and doubled cleaning intervals.
• Dissolved organic matter (COD/TOC) and extracellular polymeric substances (EPS) reduced by 30-51% and 26-46% respectively in EMBR.
• EMBR achieved >90% phosphorus removal, compared to 47-61% in MBR, while both removed >99% ammonium-N and >95% COD.
• EMBR's advantages in fouling reduction and phosphorus removal were more pronounced at 10°C with real sewage.

Conclusions:

• The EMBR system effectively reduces membrane fouling and enhances nutrient removal, particularly phosphorus.
• The technology demonstrates suitability for cold climates and remote applications due to improved performance and reduced maintenance.
• EMBR offers a promising solution for decentralized domestic wastewater treatment in challenging environments.