IntroductionMicrobial fuel cells (MFCs) are devices that convert biochemi-cal energy into electrical energy with the aid of catalytic microbialreactions. They have received increasing attention due to their abil-ity to simultaneously achieve wastewater treatment and powergeneration [1,2]. The application of a biocathode in the MFC hasallowed the integration of carbon removal at the anode and nitro-gen removal in the cathode [3–5] achieving a removal rate as highas 0.146 kg NO3−-N m−3day−1and an energy output of 8 W m−3[3]. A “loop configuration”, in which the wastewater enters theMFC anode, the effluent is then conveyed to the external aerobicnitrification stage and the wastewater is finally introduced to thecathode for nitrification was used to achieve simultaneous nitrifica-tion and denitrification (SND) in MFC system with a maximal poweroutput of 34.6 W m−3and a maximal removal rate of 0.41 kg NO3−-N m−3day−1[6]. SND at the cathode of MFC and a nitrogen removalefficiency of 94.1 ± 0.9% were obtained when 4.35 ± 0.08 mg L−1dissolved oxygen (DO) and 3.5 ± 0.4 mg L−1acetic acid were presentin the cathode [7].