Mitigating external and internal cathode fouling using a polymer bonded separator in microbial fuel cells.

Area of Science:

• Environmental science and engineering
• Electrochemistry
• Biotechnology

Background:

• Microbial fuel cells (MFCs) are promising for wastewater treatment and energy generation.
• Cathode fouling significantly reduces MFC power output and operational lifespan.
• Existing methods struggle to mitigate both bio-fouling and salt precipitation effectively.

Purpose of the Study:

• To develop and evaluate a novel method for mitigating cathode fouling in MFCs.
• To enhance the long-term performance and power density of MFCs treating domestic wastewater.
• To investigate the impact of chemically bonded separators on fouling reduction.

Main Methods:

• Chemically bonding a wipe separator to an activated carbon air cathode using polyvinylidene fluoride (PVDF).
• Operating MFCs with bonded and non-bonded separator cathodes using domestic wastewater.
• Quantifying power density, biomass (protein) accumulation, and salt precipitation.

Main Results:

• Separator-bonded cathodes achieved a maximum power density of 190 ± 30 mW/m² after two months, ~220% higher than controls (60 ± 50 mW/m²).
• Reduced biomass accumulation on the bonded separator surface, indicating mitigation of external bio-fouling.
• Decreased salt precipitation, suggesting reduced internal fouling with bonded separators.

Conclusions:

• Chemical bonding of separators to MFC cathodes effectively mitigates both external bio-fouling and internal salt fouling.
• This approach significantly enhances long-term cathode performance and power production in MFCs.
• The PVDF-bonded separator represents a viable strategy for improving MFCs in real-world wastewater treatment applications.