Studying microbial fuel cells equipped with heterogeneous ion exchange membranes: Electrochemical performance and microbial community assessment of anodic and membrane-surface biofilms

• Published in: Bioresource technology 2022-09, Vol.360, p.127628-127628, Article 127628
• Main Authors: Szakács, Szabolcs, Koók, László, Nemestóthy, Nándor, Bélafi-Bakó, Katalin, Bakonyi, Péter
• Format: Article
• Language: English
• Subjects: Acetate crossover; Bioelectrochemical system; Cation exchange membrane; Membrane biofouling; Metagenomic analysis; Oxygen transfer
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2022.127628

[Display omitted] •Microbial fuel cells were tested with four ion exchange membranes (IEMs).•Anionic IEMs outperformed cationic ones at low acetate concentration.•Membrane selectivity determines the anodic biofilm microbial composition.•O2 crossover level (10-3–10-4 cm s−1) affects biofilm composition on the membrane. In this study, microbial fuel cells deploying heterogeneous ion exchange membranes were assessed. The behavior of the cells as a function of the membrane applied was evaluated in terms of maximal current density, electron recovery efficiency and energy production rate (up to 427.5 mA, 47.7 % and 660 J m-2h−1, respectively) at different substrate (acetate) feedings (2.15 – 8.6 mM). System performance was characterized in the light of oxygen and acetate crossovers. The effect of membranes (in relation to the oxygen mass transfer coefficient, kO) on the microbial diversity of anodic and membrane-surface biofilms was investigated. Based on the relative abundance of bacterial orders, the two populations could be distinguished and membranes with larger kO tended to promote more the air-tolerant microbes in the biofouling layer. This indicates that membrane kO has a direct effect on membrane foulant microbial composition, and thus, on the expected time-stability of the membrane.