availability as an electron acceptor and the electron flux through the circuit. We evaluated
the effects of R ext on MFCs using acetate or glucose. The average current densities (I)
ranged from 40.5 mA/m2 (9,800 Ω) to 284.5 mA/m2 (150 Ω) for acetate-fed MFCs (acetate-
fed reactors [ARs]), with a corresponding anode potential (E an) range of− 188 to− 4 mV
(versus a standard hydrogen electrode [SHE]). For glucose-fed MFCs (glucose-fed reactors …