Scalable microbial fuel cell (MFC) stack for continuous real wastewater treatment.

Area of Science:

• Environmental Science
• Electrochemistry
• Biotechnology

Background:

• Microbial fuel cells (MFCs) offer a sustainable approach to wastewater treatment and energy harvesting.
• Scalable and cost-effective MFC designs are crucial for practical applications.

Purpose of the Study:

• To investigate the performance of a tubular air-cathode MFC stack for simultaneous real wastewater treatment and bioelectricity generation.
• To evaluate the impact of series and parallel circuit configurations on MFC stack performance.

Main Methods:

• Construction of a scalable tubular air-cathode MFC stack using non-precious metal (non-Pt) components.
• Operation under continuous flow mode with swine wastewater at two organic loading rates (ORLs): 1.2 and 4.9 kg COD/m³d.
• Comparison of MFC stack performance in series and parallel circuit configurations.

Main Results:

• The parallel stack configuration maintained high power output, while the series configuration experienced energy loss due to substrate cross-conduction.
• At 1.2 kg COD/m³d, the parallel stack achieved 83.8% COD removal and 90.8% NH₄⁺-N removal.
• At 4.9 kg COD/m³d, the parallel stack achieved 77.1% COD removal and 80.7% NH₄⁺-N removal, demonstrating continuous electricity production.

Conclusions:

• The developed MFC stack is a scalable and cost-effective technology for simultaneous real wastewater treatment and bioelectricity generation.
• The parallel circuit configuration is superior for maintaining power output in MFC stacks.
• The MFC stack system effectively removes organic matter and nutrients from swine wastewater while generating usable energy.