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Considering the complexity associated with bioelectrochemical processes, the performance of a microbial fuel cell (MFC) is governed by input operating parameters. For scaled-up applications, a MFC system needs to be modeled from engineering perspectives in terms of optimum operating conditions to get higher performance and energy recovery. Several conceptual numerical models to advanced computational simulation approaches have been developed to represent simple-form of a complex MFC system. Application of mathematical and computation models are explored to establish the relationship between operating input-variables and power output. The present review discusses about the complexity of system, modeling strategies used and reality of such modeling for scaling-up applications of MFCs. Additionally, the selection of an appropriate mathematical model reduces the computational duration and provides better understanding of the system process. It also explores the possibility and progress towards commercialization of MFCs and thus the need of development of model-based optimization and process-control approaches., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Two different saline sediments were used to inoculate potentiostatically controlled reactors (a type of microbial bioelectrochemical system, BES) operated in saline conditions (35 gNaCl l(-1)). Reactors were fed with acetate or a mixture of acetate and butyrate at two pH values: 7.0 or 5.5. Electroactive biofilm formation lag-phase, maximum current density production and coulombic efficiency were used to evaluate the overall performance of reactors. High current densities up to 8.5 A m(-2) were obtained using well-defined planar graphite electrodes. Additionally, biofilm microbial communities were characterized by CE-SSCP and 454 pyrosequencing. As a result of this procedure, two anode-respiring bacteria (ARB) always dominated the anodic biofilms: Geoalkalibacter subterraneus and/or Desulfuromonas acetoxidans. This suggests that a strong electrochemically driven selection process imposed by the applied potential occurs in the BES system. Moreover, the emergence of Glk. subterraneus in anodic biofilms significantly contributes to broaden the spectrum of high current producing microorganisms electrochemically isolated from environmental samples., (Copyright © 2015 Elsevier B.V. All rights reserved.)

A biofilm-based 4 L two chamber microbial electrolysis cell (MEC) was continuously fed with acetate under saline conditions (35 g/L NaCl) for more than 100 days. The MEC produced a biogas highly enriched in H2 (≥90%). Both current (10.6 ± 0.2 A/m(2)Anode or 199.1 ± 4.0 A/m(3)MEC) and H2 production (201.1 ± 7.5 LH2/m(2)Cathode·d or 0.9 ± 0.0 m(3)H2/m(3)MEC·d) rates were highly significant when considering the saline operating conditions. A microbial analysis revealed an important enrichment in the anodic biofilm with five main bacterial groups: 44% Proteobacteria, 32% Bacteroidetes, 18% Firmicutes and 5% Spirochaetes and 1% Actinobacteria. Of special interest is the emergence within the Proteobacteria phylum of the recently described halophilic anode-respiring bacteria Geoalkalibacter (unk. species), with a relative abundance up to 14%. These results provide for the first time a noteworthy alternative for the treatment of saline effluents and continuous production of H2., (Copyright © 2015 Elsevier Ltd. All rights reserved.)