Swiss Researchers invent a new Toilet

There are 2.6 billion people in the world who have no access to a decent toilet. An interdisciplinary team of Swiss aquatic researchers and designers from Austria won with their invention as part of the 'Re-invent the Toilet' competition, sponsored by the Bill and Melinda Gates Foundation a special recognition award. The new toilet model will provide a sanitary solution that ensures human dignity and hygiene, while also being environment-friendly and economically feasible. All for less than five Cents per day and person.

 22 universities and research facilities submitted proposals to the Bill and Melinda Gates Foundation in 2011 for the 'Re-Invent the Toilet Challenge' (RTTC). Goal of the competition: invent the toilet of the future! Prerequisites: the new toilet should need no sewer and no outside energy source, should be part of a recycling and treatment system for wastes and should cost no more than five cents per day and person. By the end of 2011, eight teams were still in the running, among them such renowned institutes as the Massachusetts Institute of Technology in Boston and the California Institute of Technology. They all presented their projects yesterday in Seattle (USA). The team from the Swiss Federal Institute of Aquatic Science and Technology Eawag and the Austrian design firm EOOS in Vienna is among the best. Their 'Diversion' toilet was highlighted with the Special Recognition Award for outstanding design of a toilet user interface.

 The Toilet is also a small Waterworks

Project leadership lay in the hands of process engineer Tove Larsen. For years her work at Eawag has been concerned with the separation of urine and faeces. 'It was obvious that separation technology should also be part of the competition model,' says Larsen, 'only thus can the valuable raw materials and the water in urine and faeces be recovered efficiently.' A separating toilet acceptable in every culture and to every user does not yet exist; it must therefore be developed and designed. The result: a modern squatting toilet. The special features of the 'Diversion' model are not only separation of urine and a clever seal against odours but, more important, the use of very little water, about 1 to 1.5 litre per individual use. 'This is absolutely decisive for cleaning the toilet, hand washing and the anal hygiene with water practised by Muslims and Hindus,' says Larsen. The new separation toilet needs no connection to a water supply. Every time a user operates a foot pedal, water flows into the small water reservoir and already used water is pumped upwards behind the toilet. Cleansed by means of a membrane filter, the used water is also guaranteed free of germs, thanks to electrolysis by a solar powered electrode.

Illustrations in print-quality resolution and legends may be downloaded from  www.eawag.ch

media Illustrations in print-quality resolution and legends may be downloaded here.