US scientists based at Pennsylvania State University have developed an innovative device, which utilises a platinum electrode, to generate electricity from domestic wastewater and thereby turn it into a valuable resource.

Key to the microbial fuel cell is the bacteria contained in the wastewater which eats other organic matter, Nature magazine reports.

As the bugs oxidise their food they strip electrons from the organic matter, which are then harnessed to generate an electric current.

Bruce Logan, who leads the research team, explained that the device is just 6.5 cm wide and 15 cm long with eight graphite rods as negative electrodes and a platinum, plastic and carbon tube as the positive electrode.

When wastewater is pumped through the chamber, bacteria stick to the graphite rods and channel electrons into them as they eat organic material. The electrons travel through wires to the platinum rod, completing the circuit.

Mr Logan said that power generation levels were constantly being improved and that a reasonably-sized device would be able to power light bulbs for example.

He stated: 'We believe we can increase power generation to levels of about 1000 mW per square metre.'

As a by-product, the fuel cell cleans the waste water, thereby making sewage treatment cheaper.