India and some regions of Africa may soon be a testing ground for a new public urinal that can generate enough electricity to light the cubicle's LED tubes, say scientists.
The cubicle uses a device created by researchers at the University of the West of England (UWE) that can transform urine into electricity with the help of bacterial metabolism.
A test cubicle was installed this year at Glastonbury, UK's largest music festival, but the final aim is to improve sanitation facilities in developing world countries or in areas where there is limited electricity generation, such as refugee camps, researchers said.
"The technology in the prototype is based on microbial fuel cells (MFC), which, like batteries, has an anode and a cathode," said Irene Merino, a researcher on the team.
The cells are installed inside a container which collects the urine, currently only from male users due to the design of the urinals.
Inside, bacteria colonise the anode electrode and act as a catalyst, decomposing the organic material in the urine.
This decomposition releases both protons, which travel from the anode to the cathode across a semipermeable membrane, and electrons, which travel through an external electrical circuit.
To complete the cycle, an oxygen reduction reaction also takes place in the cathode. The process generates enough energy to power light bulbs or LED tubes.
"Our project is aimed at developing countries, with a view to improving or incorporating sanitary facilities. In addition to producing electricity, the system reduces chemical oxygen demand (COD); in other words, it also serves to treat the urine," Merino said.
At present, the researchers have carried out two field tests - one at the university campus, with limited numbers of participants, and another at Glastonbury festival, where last year it was tested by around a thousand users per day.
In both experiments, the electricity generated was used to illuminate the interior of the cubicle where the urinal was installed.
The university campus prototype contained 288 MFC cells and generated an average of 75 milliwatts, whereas the Glastonbury prototype included 432 cells and generated 300 mW.
The researchers are now planning to test these urinals in India or in some regions of Africa.
Specifically, at refugee camps, in communities, at schools and in public toilets that lack lighting.
"The ultimate purpose is to get electricity to light the toilets, and possibly also the outside area, in impoverished regions, which may help improve the safety of women and children, in countries where they have to use communal toilet facilities outside their homes," said Ioannis Ieropoulos, the Director of the Bristol BioEnergy Centre at UWE.
The research was published in the journal Environmental Science: Water Research and Technology.
