Power generation by packed-bed air-cathode microbial fuel cells

- Novel and inexpensive packed-bed air-cathodes were developed for MFCs.
- The cathode was a loose bed of activated carbon granules without a binder.
- Power density was positively related to cathode material specific surface area.
- Granular activated carbon and semi-coke air-cathodes were most cost-effective.
- Oxygen transfer limited performance with thicker air-cathodes.