A single-chamber microbial fuel cell as a biosensor for wastewaters

Area of Science:

• Environmental Science
• Biotechnology
• Electrochemistry

Background:

• The 5-day biochemical oxygen demand (BOD5) test is a standard method for assessing water quality but has significant limitations.
• Its unsuitability for process control and real-time monitoring hinders efficient wastewater management.

Purpose of the Study:

• To evaluate a single-chamber microbial fuel cell (SCMFC) as a biosensor for biochemical oxygen demand (BOD).
• To assess the biosensor's performance metrics including measurement range, response time, reproducibility, and operational stability.

Main Methods:

• A single-chamber microbial fuel cell (SCMFC) with an air cathode was designed and tested as a biosensor.
• Performance was analyzed using artificial and real wastewater, with modifications to reduce anolyte volume.
• Outputs were correlated with standard chemical oxygen demand (COD) and BOD measurements.

Main Results:

• The SCMFC biosensor demonstrated a linear response to BOD concentration up to 350 mg/L with artificial wastewater.
• High reproducibility and operational stability exceeding 7 months were observed.
• Reducing anolyte volume improved response time to 40 minutes, aligning with hydraulic retention time (HRT).
• Real wastewater analysis showed a strong correlation between COD and current output, validating its practical application.

Conclusions:

• The SCMFC biosensor provides a viable, rapid, and stable alternative to traditional BOD testing.
• Its effectiveness in real-time monitoring and process control for wastewater treatment is confirmed.
• The system's performance indicates significant potential for environmental monitoring applications.