Acclimated cathode

Figure 1.8 Cyclic voltammograms of the anode, acclimated cathode, and nnacclimated cathode. The scan rate was 1 mV s . Reproduced with permission from Ref. [163]. Copyright 2014 WILEY-VCH Verlag GmhH Co. KGaA, Weinheim.

Cheng SA, Kiely P, Logan BE. Pre-acclimation of a wastewater inoculum to cellulose in an aqueous-cathode MEC improves power generation in air-cathode MFCs. Bioresour Technol 2011 102 367-371. 

Metals and metal coatings. The use of various metals and metal coatings on carbon materials has not been well-examined for MFCs. In one study, it was shown that addition of vapor-deposited iron oxide to a carbon paper cathode decreased acclimation time of a reactor but did not affect maximum power Kim et al. 2005). A two-chamber reactor was used, and thus power production was limited by high internal resistance so it is not known if the iron oxide would have resulted in an increase in power production in a reactor with less internal resistance. Over time the iron oxide coating dissolved into solution, leaving only the carbon paper electrode. However, the use of iron to enrich iron-reducing bacteria on the electrode may be a beneficial approach for acclimation of an electrode with exoelectrogenic bacteria. 

There are many challenges remaining to fully exploit the maximum power production possible by MFCs, to find ways to make the systems economical, and to create wastewater treatment systems based on MFC bioreactors. Power densities still need to be increased but this must be done under realistic conditions. For example, work with chemical catholytes such as ferricyanide should be abandoned and the focus should be squarely placed on using oxygen in air at the cathode. Materials, and different methods to treat materials, must be examined that are efficient both in terms of power generation and cost. It is clear that anode treatment can reduce acclimation times and increase power... 

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