8 MB - University of Toronto Magazine

The criteria for the Gates Foundation challenge focused on
both affordability and appropriateness. Teams had to design
a safe, hygienic toilet that would work for five cents per person
per day and operate off the grid and without connection to a
sewer. The U of T group wanted its design to be just as suitable
for densely populated regions as for rural areas. And they
knew their toilet had to be able to filter, separate, dry and
disinfect human waste in a wide variety of climates, cultures
and circumstances. All eight teams that were invited to
participate – along with some 30 others – presented prototypes
at the Gates Foundation’s campus in Seattle in August. U of T’s
entry placed third, earning the team a US$40,000 prize. It is
expected that the U of T team will receive additional funding
for a second phase to refine and test their invention, but
in mid-August the details for how this will proceed had yet to
be confirmed.
In devising their winning approach, members of U of T’s
team knew they would not be able to rely on access to
water or specialized component parts. And they considered
all existing off-the-grid toilet concepts inappropriate for
the challenge. Composting is too slow to deal with high usage.
Existing incineration systems demand too much power.
And high-tech tools for dealing with organic waste, such as
membrane filters and chemical composting accelerants, are
too expensive and too complicated.
The team looked instead to sand. With their approach,
when someone uses the toilet, liquids and solids are separated
and dealt with individually. The solids are partially dried
and then sanitized through a steady, low-energy smouldering
process rather than energy-intensive incineration. Once
the smouldering is started, it is self-sustaining as long as the
toilet is in regular use.
The liquid side of the operation is more complicated.
Because gastrointestinal bugs are so common, liquid waste
often contains bits of fecal matter that must be further
separated. The engineers found that sand makes a serviceable
filter. Once urine and diarrhea pass through the sand, the
liquid can be neutralized via solar-powered ultraviolet lights.
Of course, the sand itself becomes clogged and contaminated,
and must be cleaned. This led to an elegant solution:
sand also happens to provide ideal airflow for the smouldering
process. Sand dirtied through filtering is cleansed through
smouldering, meaning the same sand can be used repeatedly,
moving back and forth from one function to the other.
Not only is sand inexpensive, but it’s also widely available
around the world, allowing for easy local maintenance.
Once the solid waste has been smouldered, the ash can be
discarded safely.
Not all parts of the team’s toilet can be found in nature.
The separation system requires a moving belt that separates
solids from liquid, and spreads the wet solids so they dry
more quickly. The team has analyzed every component,
seeking inexpensive, common technologies that are familiar
to people in low-income countries. As Cheng emphasizes,
Dilip
Soman
“Jugaad is one of
those untranslatable
Hindi words,
but it essentially
refers to using the
things you have
at hand to come up
with solutions.”
the toilet must rely not only on locally available materials,
but also on local knowledge for installation and repair.
“At the moment, we’re using hardware-store sprockets, but
we’re planning to adapt it to use bicycle sprockets,” says
Fishman. “We’re currently using commercially available belt
material. But we’re planning for that to be lower-cost plastic
or something that could be produced locally.”
Cheng is aware that even the best design is useless if people
don’t adopt it; reinventing the toilet isn’t merely a matter
of, “If we build it, they will go.” Early in the project, the team
conducted field research in Bangladesh. Even simple information
such as the preference for squat toilets over western
sit-down models, or the need for women to have a private
place to change their clothes before and after using the facilities,
prompted the team to refine their prototype.
The consultations yielded a spin-off benefit as well: a second,
simpler, design project. “I came across a group of women
talking about parents getting old or sick and being unable to
use squat toilets – they would sometimes relieve themselves
anywhere and these women would have to clean it up,”
says Cheng. So she assigned students in one of her courses to
develop ‘squatting assistance technology.’
In a matter of weeks, the students came up with a freestanding
frame that’s light enough to be positioned over
a squat loo when needed, and easily moved aside when not.
It is sturdy enough to allow users to support themselves
on it with their arms. “It’s a really neat design,” says Cheng.
The product is aimed at elderly, middle-class Bangladeshis,
but also pregnant women and people with illnesses and
disabilities.
Such a project hints at the much wider range of issues
around the world that might be addressed through frugal
innovation.
Dilip Soman, a professor with the Rotman School of
Management and the director of the India Innovation Institute,
is one of Cheng’s collaborators in a broader effort to study lowcost
innovation and the conditions that enable it to succeed.
India has become a centre of innovation for everything from
biotech to manufacturing, and Soman’s institute supports
research on those success stories, situating them in a global
context. He concurs that making a product inexpensive
is often necessary but rarely sufficient to gain purchase in
photo: John Hryniuk
Autumn 2012 35