Stable aerobic granules in continuous-flow bioreactor with self-forming dynamic membrane

Area of Science:

• Environmental Engineering
• Biotechnology
• Water Treatment

Background:

• Conventional wastewater treatment often struggles with simultaneous removal of carbon, nitrogen, and phosphorus.
• Membrane fouling remains a significant challenge in membrane bioreactors, increasing operational costs and reducing efficiency.

Purpose of the Study:

• To develop and evaluate a novel continuous-flow bioreactor combining aerobic granular sludge and a self-forming dynamic membrane (CGSFDMBR).
• To assess the efficiency of CGSFDMBR in treating septic tank wastewater, focusing on simultaneous nutrient removal and membrane fouling mitigation.

Main Methods:

• Cultivation and characterization of aerobic granular sludge within a continuous-flow bioreactor.
• Implementation of strategies to maintain aerobic granular sludge stability based on settling velocity and particle size.
• Operation of the CGSFDMBR for septic tank wastewater treatment and monitoring of pollutant removal rates and membrane fouling.

Main Results:

• Aerobic granular sludge with small particle size (0.1-1.0mm) and low settling velocity (15-25 m/h) was successfully cultivated.
• The CGSFDMBR demonstrated significantly reduced membrane fouling, requiring cleaning only once in over 45 days.
• High removal rates were achieved: 83.3% for COD, 73.3% for NH(4+)-N, 67.3% for TN, and 60% for TP.

Conclusions:

• The CGSFDMBR is a highly efficient system for simultaneous carbon, nitrogen, and phosphorus removal from wastewater.
• The bioreactor design effectively mitigates membrane fouling, offering a more stable and cost-effective wastewater treatment solution.
• This novel approach presents a promising alternative to conventional bioreactors for advanced wastewater treatment.