Stackable and submergible microbial fuel cell modules for wastewater treatment

Area of Science:

• Environmental Engineering
• Electrochemistry
• Wastewater Treatment

Background:

• Microbial fuel cells (MFCs) offer a sustainable approach to wastewater treatment and energy generation.
• Optimizing MFC design and operational parameters is crucial for enhancing performance.

Purpose of the Study:

• To fabricate and evaluate a stackable and submergible microbial fuel cell (SS-MFC) system.
• To compare the performance of anion exchange membrane-membrane electrode assemblies (A-MEAs) and cation exchange membrane-MEAs (C-MEAs) within the SS-MFC system.
• To investigate the impact of organic concentration and hydraulic retention time (HRT) on SS-MFC performance.

Main Methods:

• Fabrication of a 30 L SS-MFC system with three modules, each containing A-MEA and C-MEA.
• Operation in batch and continuous modes with varying organic loads (50–1000 mg/L) and HRTs (3.4–7.2 h).
• Monitoring of voltage, current density, and power density to assess system performance.

Main Results:

• The SS-MFC system consistently produced stable voltage.
• C-MEAs exhibited higher average maximum power density (3.16 W/m³) compared to A-MEAs (2.82 W/m³).
• Current density increased with organic concentration following Monod kinetics; C-MEA power density increased with HRT, while A-MEA power density decreased.

Conclusions:

• The SS-MFC system is a viable technology for stable electricity generation during wastewater treatment.
• C-MEAs demonstrate superior power generation capabilities over A-MEAs in this configuration.
• The SS-MFC modules show promise for integration into existing wastewater treatment infrastructure.