Performance evaluation of membrane bioreactor coupled with self-forming dynamic membrane

Area of Science:

• Environmental Engineering
• Water Treatment Technologies
• Membrane Science

Background:

• Membrane bioreactors (MBRs) are crucial for wastewater treatment but suffer from membrane fouling.
• Conventional MBRs (C-MBRs) experience significant fouling, primarily due to cake layer resistance, limiting operational efficiency.
• Effective fouling mitigation strategies are essential for sustainable and cost-effective MBR operation.

Purpose of the Study:

• To evaluate the fouling reduction efficacy of a modified membrane bioreactor (M-MBR) compared to a C-MBR.
• To investigate the impact of a self-forming dynamic membrane (SFDM) integrated into the M-MBR system.
• To quantify the reduction in cake layer and pore blocking resistance in the M-MBR.

Main Methods:

• A modified membrane bioreactor (M-MBR) was developed by incorporating a self-forming dynamic membrane (SFDM) on nylon cloth filters preceding a flat sheet membrane.
• Coarse (125 μm) and fine (37 μm) nylon cloth filters were used to form the SFDM.
• The fouling characteristics, including cake layer resistance (R_C) and pore blocking resistance (R_P), were compared between C-MBR and M-MBR.

Main Results:

• The C-MBR exhibited frequent fouling, with cake layer resistance (R_C) accounting for 83.98% of total resistance (R_T).
• In the M-MBR, R_C was reduced to 67.86% of R_T, and pore blocking resistance (R_P) was significantly lowered to 1.31% of R_T.
• The M-MBR demonstrated prolonged operational stability, reaching 8.6 KPa over 150 days (0.057 KPa/day), indicating substantial fouling reduction.

Conclusions:

• The integration of an SFDM in the M-MBR effectively mitigates membrane fouling.
• The modification significantly reduces both cake layer and pore blocking resistance, enhancing MBR performance.
• The M-MBR offers a promising approach for sustainable wastewater treatment with improved operational longevity.