Sludge Derived Carbon Modified Anode in Microbial Fuel Cell for Performance Improvement and Microbial Community...

Area of Science:

• Environmental Science
• Materials Science
• Electrochemistry

Background:

• Activated sludge presents a significant waste management challenge.
• Conversion of sludge into value-added materials like sludge carbon (SC) is gaining traction.
• Microbial fuel cells (MFCs) offer a sustainable energy generation technology.

Purpose of the Study:

• To investigate the impact of sludge carbon (SC) pyrolyzed at various temperatures on microbial fuel cell (MFC) anode performance.
• To elucidate the mechanisms behind SC's influence on anode efficiency.
• To develop a cost-effective method for producing high-performance MFC anodes from waste sludge.

Main Methods:

• Activated sludge was pyrolyzed at 600, 800, 1000, and 1200 °C to produce sludge carbon (SC).
• SC was incorporated into carbon cloth (CC) electrodes (SC/CC) for MFC anode fabrication.
• Electrochemical performance, including power density and current density, was evaluated.
• Microbial activity, community structure, and biofilm formation on the anodes were analyzed.

Main Results:

• The SC/CC anode pyrolyzed at 1000 °C (SC1000/CC) achieved a maximum areal power density of 2.165 ± 0.021 W·m⁻² and current density of 5.985 ± 0.015 A·m⁻².
• These performance metrics were 3.017- and 2.992-fold higher, respectively, compared to the bare CC anode.
• SC addition enhanced microbial activity, optimized microbial community structure, and promoted c-type cytochrome expression, facilitating electroactive biofilm formation.

Conclusions:

• Sludge carbon pyrolyzed at 1000 °C significantly boosts MFC anode performance.
• SC acts as a beneficial additive, improving microbial electrochemical activity and biofilm development.
• This research presents a sustainable approach for converting waste activated sludge into high-performance, low-cost MFC anodes.