Characteristics of a Microbial Fuel Cell and of the Anodic Microbial Community Derived from the Activated Sludge of Waste Treatment Facilities

Abstract Technologies based on microbial fuel cells (MFC) have a high potential in wastewater treatment. The present work describes an easy-to-build two-chamber MFC, which yielded the current of 200–250 μA 10–15 days after inoculation with activated sludge and introduction of acetate as a carbon and energy source. The fuel cell exhibited Coulombic efficiency of 15–21% and the maximum specific power of 6.9 mW/m2. The microbial community formed at the anode after two months was enriched with members of the genera Geobacter (15.8%) and Methanosaeta (22.4%). During the following two months, the share of Methanosaeta decreased to 9.9%; it was replaced by members of the phyla Rhodocyclaceae, Competibacteraceae, and Desulfocapsaceae. Direct transfer was the main way of electron transport from the biofilm to the anode.