Large-scale switchable potentiostatically controlled/microbial fuel cell bioelectrochemical wastewater treatment...

Area of Science:

• Environmental Engineering
• Microbiology
• Electrochemistry

Background:

• Wastewater treatment is energy-intensive, with oxygen delivery consuming significant energy.
• Microbial communities on electrodes can facilitate electron exchange for wastewater treatment.
• Existing methods lack sustainable and failure-free bioelectrochemical solutions.

Purpose of the Study:

• To develop a switchable dual-mode bioelectrochemical wastewater treatment system.
• To evaluate the system's efficiency in chemical oxygen demand (COD) removal.
• To assess the long-term stability and microbial community dynamics.

Main Methods:

• Enrichment of microbial communities on polarized anodes and cathodes.
• Switching between self-powered microbial fuel cell (SP-MFC) and potentiostatically controlled (PC) modes.
• Laboratory-scale (260 L) and pilot-scale (1200 L) system evaluation.

Main Results:

• PC and SP-MFC modes showed improved COD removal (41.6 ± 3.5 and 38.4 ± 3.1 mg L⁻¹ d⁻¹) compared to control (28.8 ± 2.1 mg L⁻¹ d⁻¹).
• The laboratory system operated continuously for one year without interruption.
• Specific enrichment of active microbial communities was observed on PC anodes.

Conclusions:

• The combined PC and SP-MFC system offers a sustainable and failure-free approach to wastewater treatment.
• This dual-mode system enhances COD removal efficiency.
• The technology demonstrates potential for scalable and robust bioelectrochemical wastewater treatment.