Oxygen-reducing bidirectional microbial electrodes designed in real domestic wastewater

Morgane Hoareau (1) , Benjamin Erable (1) , Olivier Chapleur (2) , Cédric Midoux (2) , Chrystelle Bureau (2) , Anne Goubet (2) , Alain Bergel (1)

1 LGC - Laboratoire de Génie Chimique
2 UR PROSE - Procédés biotechnologiques au service de l'environnement

Microbial electrodes were designed in domestic wastewaters to catalyse the oxidation of organic matter (anode) and the reduction of oxygen (cathode) alternately. The successive aeration phases (cathode) enhanced the anodic efficiency, resulting in current densities of up to 6.4 Am-2 without the addition of any substrate. Using nitrogen during the anodic phases affected the microbial populations and the electrodes showed a lower ability to subsequently turn to O2 reduction than the microbial anodes formed in open-to-air conditions did. No strong difference was observed between internal and external biofilm, both of which showed a very large variety of taxa in terms of abundance as well as variance. They comprised a mix of aerobic and anaerobic species, many of which have already been identified separately in bioelectrochemical systems. Such a large diversity, which had not been observed in aerobic bidirectional bioelectrodes so far, can explain the efficiency and robustness observed here. Keywords: Electroactive biofilm; Bioanode; Microbial snorkel; Microbial Fuel Cell; Microbial population.

Mots clés: Electroactive biofilm; Bioanode; Microbial snorkel; Microbial fuel cell; Microbial population; Microbial snorkel -Microbial Fuel Cell; Microbial population.

Domaines: Génie chimique; Génie des procédés

Morgane Hoareau, Benjamin Erable, Olivier Chapleur, Cédric Midoux, Chrystelle Bureau, et al.. Oxygen-reducing bidirectional microbial electrodes designed in real domestic wastewater. Bioresource Technology, 2021, 326, pp.0. ⟨10.1016/j.biortech.2021.124663⟩. ⟨hal-03129147⟩