London, June 19: Researchers have developed a system which can generate electricity from urine -- enough to charge a mobile phone -- and also kill bacteria harmful to humans, an advance that could be harnessed to treat wastewater.
In this process, wastewater flows through a series of cells filled with electroactive microbes that attack and destroy pathogens.
The researchers believe that the microbial fuel cell (MFC) technology could one day be used in developing countries in areas lacking sanitation or installed in homes to help clean waste before it flows into the municipal sewerage network, thereby reducing the burden on water companies to treat effluent.
It was necessary to establish the technology could tackle pathogens in order for it to be considered for use in the developing world, said lead researcher Ioannis Ieropoulos, Professor at University of the West of England, Bristol.
"We were really excited with the results -- it shows we have a stable biological system in which we can treat waste, generate electricity and stop harmful organisms making it through to the sewerage network," he said.
In this system, the organic content of the urine is consumed by microbes inside the fuel cells, breaking it down and creating energy.
For the pathogen experiment, the bacterium Salmonella enteritidis was added to urine flowing through the system, then checked at the end of the process to identify if bacteria numbers had been reduced.
Results, published in the journal PLOS ONE, revealed pathogen numbers had dropped significantly, beyond minimum requirements used by the sanitation sector.
The researchers said other pathogens, including viruses, are now being tested and there are plans for experiments which will establish if the MFC system can eliminate pathogens completely.
The system could be beneficial to the wastewater industry because MFC systems fitted in homes could result in wastewater being cleaner when it reaches the sewerage system, Ieropoulos said.