Screening anodic inoculums for microbial fuel cells by quantifying bioelectrogenic activity using tungsten trioxide...

Area of Science:

• Electrochemistry
• Environmental Microbiology
• Materials Science

Background:

• Microbial fuel cells (MFCs) rely on electrogenic bacteria for power generation.
• Assessing inoculum electrogenic activity is crucial for MFC performance prediction.
• Current methods for evaluating electrogenic activity can be time-consuming.

Purpose of the Study:

• To develop a rapid detection method for electrogenic activity in MFC inoculums.
• To utilize electrochromic tungsten trioxide (WO3) quantum rods for colorimetric assessment.
• To establish a correlation between inoculum electrogenic activity and MFC performance.

Main Methods:

• Optimized dosage of WO3 and sludge concentration for absorbance measurements.
• Evaluated seven MFCs with varying inoculum ratios (anaerobic sewage sludge and Shewanella putrefaciens).
• Measured inoculum absorbance after WO3 addition and correlated with MFC current densities and Coulombic efficiency (CE).

Main Results:

• Established a correlation between inoculum absorbance (indicating electrogenic activity) and MFC steady-state current densities/CE.
• Demonstrated that WO3 quantum rods provide a visual blue color change under electric fields.
• Identified optimal WO3 dosage and sludge concentration for reliable absorbance measurements.

Conclusions:

• The developed method allows for rapid selection of high-activity inoculums for MFCs.
• This approach enables prediction of MFC current generation potential before reactor startup.
• The colorimetric detection using WO3 offers a practical tool for MFC research and development.