[Development of a low-cost single chamber microbial fuel cell type BOD sensor]

Area of Science:

• Environmental Science
• Electrochemistry
• Analytical Chemistry

Context:

• The 5-day biochemical oxygen demand (BOD5) test is standard for measuring biodegradable organics in wastewater but is slow and requires expertise.
• Current BOD5 methods are unsuitable for real-time, on-line wastewater monitoring.

Purpose:

• To develop and validate a microbial fuel cell (MFC)-type sensor as a rapid and reliable alternative to the conventional BOD5 test.
• To optimize MFC sensor parameters, including external resistance, anolyte pH, reaction time, and rinse time.

Summary:

• A mediator-less, single-chamber MFC sensor utilizing MnO2 as a cathode catalyst and a cation exchange membrane was investigated.
• Optimal conditions identified were 12 kΩ external resistance, pH 7.0, 2-hour reaction time, and 2-10 minute rinse time.
• The MFC sensor demonstrated a low detection limit (0.2 mg/L), high precision (0.33%), and strong linear correlation (R² = 0.9992) with BOD concentration.

Impact:

• The MFC-type sensor offers a low-cost, user-friendly, and fast-response method for accurate BOD determination in wastewater.
• This technology is suitable for on-line wastewater quality monitoring, overcoming limitations of traditional BOD5 testing.