Affinity of Microbial Fuel Cell Biofilm for the Anodic Potential

Abstract

In analogy to the well established dependency of microbial reactions on the redox potential of the terminal electron acceptor, the dependency of the microbial activity in a highly active microbial fuel cell on the potential of the electron-accepting electrode (anode) in a microbial fuel cell (MFC) is investigated. An acetate-fed, pH-controlled MFC was operated for over 200 days to establish a highly active MFC anodic biofilm using ferricyanide as the catholyte and granular graphite as electrode material. From the Coulombic efficiency of 83% of the MFC the microbial activity could be recorded by online monitoring of the current. Our results suggest that (1) in analogy to the Michaelis-Menten kinetics a half-saturation anodic potential (here termed k(AP) value) could be established at which the microbial metabolic rate reached half its maximum rate. This k(AP) value was about -455 mV (vs Ag/AgCl) for our acetate-driven MFC and independent of the oxidation capacity of the cathodic half-cell; (2) a critical AP (here termed AP(crit)) of about -420 mV (vs Ag/AgCl) was established that characterizes the bacterial saturation by the electron-accepting system. This critical potential appeared to characterize the maximum power output of the MFC. This information would be useful for modeling and optimization of microbial fuel cells and the relative comparison of different microbial consortia at the anode.

Ammonium as a sustainable proton shuttle in bioelectrochemical systems

“…Experimental runs were performed in a two-chamber bioelectrochemical cell made of transparent Perspex as described in (Cheng et al, 2008). The two chambers were physically separated by a cation exchange membrane (CMI-7000, Membrane International Inc.) with a surface area of 168 cm 2 and were identical in volume and dimension (350 mL (14 cm x 12.5 cm x 2 cm)).…”

“…2.0 g L -1 . It was mixed with a synthetic wastewater (10 %, v/v) as described in Cheng et al (2008). Initially, 50 mM potassium ferricyanide K 3 Fe(CN) 6 (Sigma-Aldrich, Inc., Purity ca.…”

Optimizing Treatment Performance of Microbial Fuel Cells by Reactor Staging

“…So, the proposition can be proved if it can be shown that Moving S f (S f +S 0 )/2(K S,m + 2S f ) to the right-hand side, removing the denominators, and rearranging gives Equation 24 can be further simplified to …”

In-line deoxygenation for organic carbon detections in seawater using a marine microbial fuel cell-biosensor

“…For maximum power production, the anodic potential of a MFC is negative and the cathode potential positive (Cheng et al, 2008). In this study, the MFC is not used for obtaining electricity output but to be used as a biosensor to detect low levels of AOC by using a potentiostat which typically keeps the cathode more negative than the anode.…”

“…AOC is one of the main food sources for bacteria to proliferate and hence it is more appropriate to be used as an indicator of the relative biofouling potential of feed-water (Jeong et al, 2013). Other attempts at AOC tests such as biochemical oxygen demand BOD 5 (Bourgeois et al A typical MFC-biosensor consists of an anodic chamber (anaerobic) and a cathodic chamber separated by a cation exchange membrane. The active anodophilic bacteria oxidise organic carbon in the anodic chamber and generate electrons and protons.…”