An MEC-MFC-coupled system for biohydrogen production from acetate.

Area of Science:

• Bioelectrochemistry
• Renewable Energy
• Microbial Biotechnology

Background:

• Microbial fuel cells (MFCs) generate electricity from organic matter using bacteria.
• Microbial electrolysis cells (MECs) produce biohydrogen but require external voltage.
• Coupling MECs and MFCs offers a potential solution for self-powered biohydrogen production.

Purpose of the Study:

• To develop and evaluate a coupled MEC-MFC system for efficient biohydrogen production from acetate.
• To investigate the impact of phosphate buffer concentration on system performance.
• To demonstrate the feasibility of using MFC-generated power to drive MEC hydrogen production.

Main Methods:

• Constructed a coupled MEC-MFC system.
• Utilized acetate as the substrate for biohydrogen production.
• Varied phosphate buffer concentration (10 mM to 100 mM).
• Measured hydrogen production rate, recovery, Coulombic efficiency, and yield.

Main Results:

• Achieved hydrogen production from acetate without external power input.
• At 10 mM phosphate buffer: hydrogen production rate of 2.2 mL L⁻¹ d⁻¹, yield of 1.21 mol-H₂ mol-acetate⁻¹.
• At 100 mM phosphate buffer: enhanced performance with a rate of 14.9 mL L⁻¹ d⁻¹ and yield of 1.60 mol-H₂ mol-acetate⁻¹.
• Demonstrated mutual influence between MEC and MFC performance.

Conclusions:

• The coupled MEC-MFC system efficiently produces biohydrogen from acetate, eliminating the need for external electricity.
• Increasing phosphate buffer concentration significantly enhances hydrogen production and yield.
• This integrated system shows promise for waste-to-energy applications and efficient power utilization.