Modification of submerged membrane bioreactors (MBRS) by inserting baffles: pilot scale study

Area of Science:

• Environmental Engineering
• Water Treatment Technologies
• Bioreactor Design

Background:

• Submerged membrane bioreactors (MBRs) are popular for wastewater treatment but struggle with nitrogen removal due to aerobic conditions.
• Intensive aeration in conventional MBRs limits denitrification, a key process for nitrogen removal.

Purpose of the Study:

• To investigate the performance of a modified submerged membrane bioreactor (MBR) with baffles for enhanced nitrogen removal.
• To assess the effectiveness of creating alternating aerobic/anoxic conditions within the bioreactor.

Main Methods:

• A pilot-scale baffled membrane bioreactor (BMBR) was constructed and operated using real municipal wastewater.
• The BMBR incorporated baffles to facilitate the creation of distinct aerobic and anoxic zones.
• Performance was evaluated based on nitrogen, TOC, and phosphorus removal efficiencies, and trans-membrane pressure (TMP).

Main Results:

• The BMBR achieved over 70% total nitrogen removal without requiring an external carbon source.
• Significant removal of TOC and phosphorus was also observed.
• The increase in trans-membrane pressure difference was minimal, suggesting stable membrane performance.

Conclusions:

• The proposed baffled membrane bioreactor (BMBR) design is a viable modification for enhancing nitrogen removal in submerged MBRs.
• The BMBR effectively facilitates nitrogen removal by creating alternating aerobic/anoxic conditions, leading to improved overall wastewater treatment.
• This approach offers a promising solution for efficient and cost-effective nitrogen management in wastewater treatment plants.