Activated Sludge-based Microbial Fuel Cell for Bio-electricity Generation

Abstract

Based on the catalytic properties of electrochemically active organisms, activated-sludge based-microbial fuel cell (MFC) system was designed for the electricity generation. As a microbial energy source, glucose has been exploited as electron provider. During the incubation time of bacterial culture in a mediated-less MFC, the cell voltage and degradation rates of glucose were determined. The results showed that electricity output was increasing due to the increase of glucose concentration. The MFC displayed a maximum power density of 52 mW/m2at stable current density 275 mA/m2and a maximum glucose degradation rate 94.4%. However, the electrical current was dropped when the glucose level in the bacterial culture was higher than 5.0 g/l. This fact was confirmed by studying the glucose concentrations using cyclic voltammetry.Concerning to the extracellular electron transfer mechanism(s), the biofilm formation on the anode was visible by Scanning electron Microscope (SEM). SEM showed the intensive adherence of microbes on anodic electrodes.On the other hand, rates of glucose consumption (degradation) were analyzed, the degradation rate was in accordance with the electrical current.Therefore, the current study demonstrates the applicable use of activated sludge-based microbial fuel cells for bioelectricity generation.