Examination of microbial fuel cell start-up times with domestic wastewater and additional amendments

Rapid startup of microbial fuel cells (MFCs) and other bioreactors is desirable when treating wastewaters. The startup time with unamended wastewater (118h) was similar to that obtained by adding acetate or fumarate (110-115h), and less than that with glucose (181h) or Fe(III) (353h). Initial current production took longer when phosphate buffer was added, with startup times increasing with concentration from 149h (25mM) to 251h (50mM) and 526h (100mM). Microbial communities that developed in the reactors contained Betaproteobacteria, Acetoanaerobium noterae, and Chlorobium sp. Anode biomass densities ranged from 200 to 600μg/cm² for all amendments except Fe(Sh{cyrillic}) (1650μg/cm²). Wastewater produced 91mW/m², with the other MFCs producing 50mW/m² (fumarate) to 103mW/m² (Fe(III)) when amendments were removed. These experiments show that wastewater alone is sufficient to acclimate the reactor without the need for additional chemical amendments.