[Sludge characteristics in an aerobic granular sludge membrane bioreactor]

Area of Science:

• Environmental Engineering
• Microbiology
• Wastewater Treatment

Context:

• Granular sludge membrane bioreactors (GMBR) are advanced systems for wastewater treatment.
• Alternating anaerobic-aerobic operation is employed to enhance treatment efficiency.
• Understanding sludge characteristics is crucial for optimizing GMBR performance.

Purpose:

• To investigate the relationship between sludge size distribution, surface charge, and settleability in a GMBR.
• To evaluate the long-term performance of GMBR for organics removal and simultaneous nitrification and denitrification (SND).
• To analyze the factors contributing to sludge concentration increase and its impact on bioreactor operation.

Summary:

• The GMBR demonstrated effective organics removal and SND over 120 days.
• Sludge concentration increase was attributed to smaller granular sludge (<0.45 mm) and flocculent sludge (<0.18 mm).
• Sludge surface negative charge increased with smaller sludge particles, correlating inversely with sludge size and positively with SVI, indicating good settleability (60-90 mL/g).

Impact:

• Provides insights into sludge dynamics and surface charge variations in GMBRs.
• Highlights the importance of sludge size distribution and surface properties for effective wastewater treatment.
• Offers valuable data for optimizing GMBR design and operation for enhanced performance and sludge management.