A microbial fuel cell, able to generate electricity through the cleaning of domestic wastewater, has undergone significant modifications that will make it markedly cheaper.

Environmental engineers at the Penn State University, who first developed the tool, have removed the polymeric proton exchange membrane (PEM), and have substituted carbon paper for the electrodes.

The new system consists of carbon paper that contains a small amount of platinum, placed on opposite ends of a small plastic tube. Platinum wire completes the circuit. The carbon paper allows oxygen to react at the cathode, so obviating the need to bubble air into the water at the cathode.

The modification is hoped to yield a major financial benefit, as the Penn State project leader Dr Bruce Logan explained to ANI.

"By eliminating the PEM, which was one of the most expensive components, we bring the cost down significantly. Substituting carbon paper for graphite rods further reduces the cost," he said.

"I'm optimistic that MFCs may be able to help reduce the 25 billion dollars annual cost of wastewater treatment in the US and provide access to sanitation technologies to countries throughout the world," Logan said.