Lowering the applied potential during successive scratching/re-inoculation improves the performance of microbial anodes for microbial fuel cells

Stephanie F. Ketep (1) , Alain Bergel (2) , Marie Bertrand-Huleux (3, 4) , Wafa Achouak (3, 4) , Eric Fourest (1)

1 CTP - Centre Technique du Papier
2 LGC - Laboratoire de Génie Chimique
3 CEA-DES (ex-DEN) - CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire)
4 BVME - Biologie végétale et microbiologie environnementale - UMR7265

Microbial anodes were formed under polarisation at -0.2 V/SCE on smooth graphite plate electrodes with paper mill effluents. Primary, secondary and tertiary biofilms were formed by a successive scratching and re-inoculation procedure. The secondary and tertiary biofilms formed while decreasing the polarisation potential allowed the anodes to provide current density of 6 A/m² at -0.4 V/SCE. In contrast, applying -0.4 V/SCE initially to form the primary biofilms did not lead to the production of current. Consequently, the scratching/re-inoculation procedure combined with progressive lowering of the applied potential revealed an efficient new procedure that gave efficient microbial anodes able to work at low potential. The observed progressive pH drift to alkaline values above 9 explained the open circuit potentials as low as -0.6 V/SCE. The remarkable performance of the electrode at alkaline pH was attributed to the presence of Desulfuromonas acetexigens as the single dominant species in the tertiary microbial anodes.

Mots clés: Pulp mill effluent; Electroactive biofilm; Imposed potential; Alkaline pH; Microbial fuel cell (MFC)

Domaines: Génie chimique; Biologie végétale; Génie des procédés

Stephanie F. Ketep, Alain Bergel, Marie Bertrand-Huleux, Wafa Achouak, Eric Fourest. Lowering the applied potential during successive scratching/re-inoculation improves the performance of microbial anodes for microbial fuel cells. Bioresource Technology, 2013, vol. 127, pp. 448-455. ⟨10.1016/j.biortech.2012.09.008⟩. ⟨hal-00877380⟩