sewage outfalls for urban wastewater with
the idea that the dilution effect of the ocean
will essentially treat the sewage, eliminating
the public health risk and reducing the costs
of sewage treatment. While this practice
may be relatively safe from a public health
perspective, it can never be considered
sustainable from an ecological perspective.
Nutrients in human wastes come from the
food we eat, and are ultimately extracted
from agricultural soils. If those nutrients are
taken from the soil and not returned, soil
fertility will progressively decline increasing
malnutrition and reducing farmer income
around the world.
Modern science has responded to this
dilemma through the production and ap-
plication of synthetic fertilizers, derived
through an energy-intensive nitrogen fixa-
tion process called Haber Bosch. Although
this process has been wildly successful for
increasing agricultural outputs, it is highly
dependent on inexpensive fossil fuels. In
addition, the industrial fixation of nitrogen
and subsequent discharge of that nitrogen
into aquatic ecosystems has significantly
shifted the nutrient balance of global eco-
systems and we are only just beginning to
understand the long-term consequences of
The long-term sustainability of sanitation
technologies is going to require a shift in
thinking. Instead of dealing with the problem
by shunting it to another ecosystem we need
to consider transforming wastes into resources so that they can be recycled into the
ecosystem from which they were extracted.
E4C: Five years from now, what improvements would you like to see in the technology
that you and the people you work with use?
SK: I am hoping that rigorous research initiatives will be able to keep up with implementation in the field of ecological sanitation.
There is tremendous potential for the reuse
of human wastes to positively impact both
human health and the environment, but
there are also great risks involved when
implementation programs are rushed with-
out proper research and development.
My hope for the next five years is that
sanitation professionals will work closely
with academic institutions to ensure that
new technologies are adequately researched
before being brought to scale. This is an issue in Haiti currently as large NGO’s are now
taking an interest in ecological sanitation.
Often, donor timelines require that projects
be implemented on a large scale over a very
short timeline and this can result in large-scale mistakes. Although SOIL is obviously
supportive of ecological sanitation, we also
work to encourage other organizations and
government bodies to take the time to pilot
new technologies in the communities where
they are working before bringing them to
scale to ensure that they are accepted by
the community and safe for people and the
IN THE LAB: Prototyping involved
These cell phones are not technically urine powered
3D-printed fuel cells powered by
synthetic urine. When stacked in
a series, the fuel cells generated
enough power to charge a smart
phone and enable text messaging,
Web browsing and brief calls. TO READ THE FULL STORIES AND MORE, VISIT US AT
RECENT HEADLINES RAISED E YEBROWS AT E4C when Bristol Robotics Laboratory announced
that it had charged a cell phone with urine power. Did anyone else imagine a sari-wrapped Indian
small business owner holding up her dead Nokia and asking, “you want me to do what to this?”
But a closer looks shows that these phones are not exactly urine powered, and the concept they
are based on may have potential. The new device is a microbial fuel cell. It's a urine-powered variant
in which microorganisms feed on compounds in urine and generate electricity. When stacked in a
series, the fuel cells have generated power to charge a smart phone just enough to send text mes-
sages, browse the Web and make a brief call.
As this technology advances, we could see bathrooms in the future that turn our waste into elec-
tricity and clean water. That could have advantages in both developed and developing countries.
“One product that we can be sure of an unending supply is our own urine. By harnessing this power
as urine passes through a cascade of microbial fuel cells, we have managed to charge a Samsung
mobile phone,” Ioannis Ieropoulos from University of the West of England, Bristol, said in a statement.
“We are actually re-using waste to create energy,” Ieropoulos says.
The researchers 3D-printed their fuel cell prototypes and fed them with synthetic urine in the lab. •