Effect of Ion Selectivity on Current Production in Sewage Microbial Fuel Cell Separators

Abstract

This study compared the performance of two microbial fuel cells (MFCs) equipped with separators of anion or cation exchange membranes (AEMs or CEMs) for sewage wastewater treatment. Under chemostat feeding of sewage wastewater (hydraulic retention time of approximately 7 h and polarization via an external resistance of 1 Ω), the MFCs with AEM (MFCAEM) generated a maximum current that was 4–5 times greater than that generated by the MFC with CEM (MFCCEM). The high current in the MFCAEM was attributed to the approximately neutral pH of its cathode, in contrast to the extremely high pH of the MFCCEM cathode. Due to the elimination of the pH imbalance, the cathode resistance for the MFCAEM (13–19 Ω·m2) was lower than that for the MFCCEM (41–44 Ω·m2). The membrane resistance measured as the Cl- mobility of AEMs for the MFCAEM operated for 35, 583, and 768 days showed an increase with operation time and depth, and this increase contributed minimally to the cathode resistance of the MFCAEM. These results indicate the advantage of the AEM over the CEM for air-cathode MFCs. The membrane resistance may increase when the AEM is applied in large-scale MFCs on a meter scale for extended periods.

Optimizing low-voltage boosting for an air-cathode microbial fuel cell with an anion exchange membrane in a 246 L wastewater treatment reactor

“…The membrane resistance depended on the operation time or depth, and the effect on the cathode reaction was negligible. 29…”

“…The boosted electricity has been used as a power source for light-emitting diodes (LEDs), 25 a sensing and data transmission system, 23 and pumps, 22 as well as for charging a mobile phone battery. 27 Here, we examined the applicability of two different DC/ DC converters, viz., LTC3105 and ADP5090, to boost a tubular air-cathode MFC using an anion exchange membrane (AEM) as the separator, 3,28 which is superior to an MFC with a cation exchange membrane in terms of power recovery 29 and has been successfully scaled up to 226 L. 30 First, the connection of 1-12 MFC units was evaluated based on the electricity produced and electric density; thereafter, the MFCs were boosted using two DC/DC converters and the secondary use of the electricity was evaluated.…”

Investigating the Sulfonated Chitosan/Polyvinylidene Fluoride-Based Proton Exchange Membrane with fSiO2 as Filler in Microbial Fuel Cells

“…The separator/membrane is one of the most noticeable components in MFC, and the membrane also determines MFC performance [ 24 , 25 , 26 , 27 ]. In MFC, the prominent role of the membrane is to conduct the ion transport from the anode to the cathode to complete the reaction process, prohibiting the substrate cross-over and contact between the anode and cathode electrodes.…”

Simultaneous removal of organic matter and nitrogen compounds by partitioned aeration in a 226 L-scale microbial fuel cell

“…Further improvement of the anode results in a comparatively higher cathode resistance and separator membrane resistance. 11 Although MFCs have progressed, the primary goal of MFC wastewater treatment is to provide good quality effluent to meet discharge standards.…”