A multi-electrode continuous flow microbial fuel cell with separator electrode assembly design.

Area of Science:

• Electrochemistry
• Environmental Engineering
• Biotechnology

Background:

• Scaling up microbial fuel cells (MFCs) necessitates compact, multi-electrode reactor designs.
• Optimizing electrode spacing and separator materials is crucial for MFC performance.

Purpose of the Study:

• To design and evaluate a scalable single-chamber MFC using a separator electrode assembly (SEA).
• To assess the MFC's performance in fed-batch and continuous flow operations for power generation and wastewater treatment.

Main Methods:

• A 130 mL single-chamber MFC with graphite fiber brush anodes and an air cathode was constructed.
• A separator electrode assembly (SEA) was employed to minimize electrode spacing.
• Performance was evaluated using textile and glass fiber separators in fed-batch and continuous flow modes, monitoring voltage, power density, chemical oxygen demand (COD) removal, and coulombic efficiency (CE).

Main Results:

• The MFC with a textile separator achieved a maximum voltage of 0.65 V and power density of 975 mW/m², with >90% COD removal and 53% CE in fed-batch mode.
• In continuous flow (8h HRT), the MFC maintained 0.21 V and 85% CE.
• Internal resistance was low (33 Ω total, 2 Ω solution resistance).

Conclusions:

• The SEA-based MFC design is scalable and effective for stable power generation and efficient wastewater treatment.
• Textile separators prevent short-circuiting, outperforming glass fiber separators.
• The MFC demonstrates potential for practical application in continuous flow wastewater treatment systems.