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.
A Business Model for one's Business
For Tove Larsen, it is not only the new technology in the
toilet that is decisive. 'It is important that our
toilet is part of a total sanitation system that can be
managed by the local people - cost-covering or even with a
profit.' A major concern of the Eawag-EOOS team has
thus been the research and development of a logistic
concept for transport that is applicable to conditions in
informal settlements in low and middle income countries. A
modular system of self-sealing faeces containers and urine
barrels, along with a transport vehicle, makes the
collecting tour as efficient and hygienic as the toilet
itself. Finally, the researchers have already worked out
how urine and faeces can be processed in semi-central
treatment plants into saleable products like fertilizer
and biogas. A complete business model has thus been
developed for the 'Diversion' toilet, a type of
contracting: a local entrepreneur rents the toilets to the
users, manages the collecting tours, runs the treatment and
processing plants and finally sells the products.
The Challenge is yet to come
The prize money of 40'000 USD awarded by the Bill and Melinda
Gates Foundation is payment and praise alike for the research
team. But the engineers, technicians, social scientists and
designers can't rest on their laurels. Up to now they
have shown that their system can function. Now real
prototypes of their toilet have to be built and tested.
That's the challenge until the end of 2013. It will be
some years yet before the 'Diversion' toilet, the
collecting vehicle and the processing plants can be put into
widespread use all over the world. For Larsen however it is
already clear that: 'Whether our system can really become
established depends on the quality of our business model. No
system that depends permanently on subsidies can function ov
er the long term.' Illustrations in print-quality
resolution and legends may be downloaded from www.eawag.ch
> media
Further information: Eawag media officer
Links:
Project page: www.eawag.ch/rttc
Media release Gatesfoundation:
http://www.gatesfoundation.org/press-releases/Pages/Bill-Gates-Names-Winners-of-the-Reinvent-the-Toilet-Challenge-120814.aspx
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