Microbial fuel cell scale-up options: Performance evaluation of membrane (c-MFC) and membrane-less (s-MFC) systems under different feeding regimes

Walter, Xavier Alexis; Madrid, Elena; Gajda, Iwona; Greenman, John; Ieropoulos, Ioannis

Abstract

In recent years, bioelectrochemical systems have advanced towards upscaling applications and tested during field trials, primarily for wastewater treatment. Amongst reported trials, two designs of urine-fed microbial fuel cells (MFCs) were tested successfully on a pilot scale as autonomous sanitation systems for decentralised area. These designs, known as ceramic MFCs (c-MFCs) and self-stratifying MFCs (s-MFC), have never been calibrated under similar conditions. Here, the most advanced versions of both designs were assembled and tested under similar feeding conditions. The performance and efficiency were evaluated under different hydraulic retention times (HRT), through chemical oxygen demand measures and polarisation experiments. Results show that c-MFCs displayed constant performance independently from the HRT (32.2 ± 3.9 W m−3) whilst displaying high energy conversion efficiency at longer HRT (NERCOD = 2.092 ± 0.119 KWh.KgCOD−1, at 24h HRT). The s-MFC showed a correlation between performance and HRT. The highest performance was reached under short HRT (69.7 ± 0.4 W m−3 at 3h HRT), but the energy conversion efficiency was constant independently from the HRT (0.338 ± 0.029 KWh.KgCOD−1). The c-MFCs and s-MFCs similarly showed the highest volumetric efficiency under long HRT (65h) with NERV of 0.747 ± 0.010 KWh.m−3 and 0.825 ± 0.086 KWh.m−3, respectively. Overall, c-MFCs seems more appropriate for longer HRT and s-MFCs for shorter HRT.

• Journal Article Type: Article
• Acceptance Date: Dec 4, 2021
• Online Publication Date: Dec 15, 2021
• Publication Date: Feb 1, 2022
• Deposit Date: Mar 14, 2023
• Publicly Available Date: Mar 14, 2023
• Journal: Journal of Power Sources
• Print ISSN: 0378-7753
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 520
• Pages: 230875
• DOI: https://doi.org/10.1016/j.jpowsour.2021.230875
• Keywords: Electrical and Electronic Engineering; Physical and Theoretical Chemistry; Energy Engineering and Power Technology; Renewable Energy, Sustainability and the Environment
• Public URL: https://uwe-repository.worktribe.com/output/10389337
• Publisher URL: https://doi.org/10.1016/j.jpowsour.2021.230875