The ecological toilet of the future: Tove Larsen at TEDxLausanne

The ecological toilet of the future: Tove Larsen at TEDxLausanne


Translator: Hiroko Kawano
Reviewer: Alejandra Buchelli Just imagine you desperately need to go to the toilet, but we have closed down
all the toilets in this building. It sounds like a nightmare, but some people will never wake up
from this nightmare. My colleague just came home
the other day and said, “Wow.” Now he had seen it, an informal settlement
with no single toilet. People have to do
what they have to do in the open. If you are woman
this means you’ll have to do it at night. But it’s not only informal settlements. More than a third of the world population is still waiting for a safe toilet. And the costs are immense. One-and-a-half million children
die every year from diarrhea. With safe toilets and good hygiene, most of those children
would not have to die. Why is this so difficult? Well, we all pretend that we don’t know
what ends up in a toilet. I grew up on a Danish pig farm
so cannot pretend that I don’t know. (Laughter) I became an environmental engineer because I got fascinated
by wastewater treatment plants when I was 16. That’s wastewater treatment plants. But it’s whole general solution of flush toilets, sewers,
wastewater treatment plants but that doesn’t function in this area
in an informal setting. That’s clear. Just try to plant a sewer network there
and to build it. But it’s not only informal settlements. There are many more problems with our standard solution
to urban hygiene. I was fascinated at 16,
but in the meantime many people including myself
have realized that that will not be the solution to the problems of wastewater treatment
in the 21st century. One of the main problems with the system
apart from such areas is water scarcity. A sewer only functioned
with plenty of water. If we look at the global map
of water scarcity, we see two things: One, it’s bad;
Two, it will get worse. So we better come up
with some alternatives to our standard solution. But it’s not only water
which is the problem. In many places
there is water and there are sewers, but there are no treatment plants. Then it many looks like this. This is from Maryland, in the US. Too many nutrients
have killed these fish. And untreated wastewater being discharged
directly into the surface waters is contributing to this problem. It’s a problem which increases with population growth
and with climate change. Just listen through radio
in the next year’s. It’s mostly a problem of the North. We have sewers bringing wastewater
directly into the surface waters, but the South will become the part, too. At my institution we started to look for alternatives
to conventional water treatment some fifteen years ago. Like many others at the same time we came up with
the idea of source separation. This just means that the simple sources
of domestic wastewater are kept apart. There are three mainstreams: A small amount of feces, but responsible for most of the pathogens
leading to diarrhea; Urine containing most of the nutrients, leading to the fish death
in a very small amount of water; And grey water which is
just the rest without toilet waste. We can treat these simple streams
much better than in combined wastewater. And we can extract resources: from feces we can extract energy
and also some fertilizer; and from urine we can extract nutrients, which is just another word for fertilizer; grey water, it is not very polluted, so we can extract water from it. At my institution at Eawag, you run a large project
on urine source separation, which we call NOMIX Technology. We interviewed hundreds of people who work together with toilet producers. We develop technology
for nutrients recovery. And we checked it for whether we could reuse it
in agriculture. It was a long project,
it was a large project. And after 6 years of research,
we convinced, ‘yes, source separation
is a good answer to the global problems
of wastewater management’. At my institution,
they installed NOMIX toilets. It’s just a normal flush toilet,
but in the front urine is separated and this fertilizer has been produced
from these installations. In the last years have been
an increasing awareness of the scale of the sanitation crisis
in developing countries. The Bill & Melinda Gates Foundation recently started a sanitation program, and Eawag has got two projects
within this project. Both of these projects are based partially on our experience
with NOMIX technology and partially on the huge experience
in the Eawag department on sanitation in developing countries, Sandaek. The first project is called Luna. It means harvest in pseudo. A colleague runs this together
with the Durban and water services. And the idea is to collect
urine from a large number of toilets. We have two goals. Protect the water resource of Durban, which is endangered from these toilets, and produce much needed fertilizer
for urban agriculture. Our Durban colleagues are optimizing the collection of urine
from these small toilet buildings, which are used in the areas of Durban
where there are no sewers. The toilet, the urine diverting dry toilet
used in this buildings is the huge improvements of sanitation
as compared to pit-latrines. It’s the same principle:
urine in the front; and feces in the back, but it’s dry. But from the users point of view, there are still room for improvement. (Laughter) In the second project,
where I’m personally more involved, we are responding to the Gates’
reinvent the toilet challenge. And we want to come up with such toilets
with the attractive and which can be imbedded within a system
of transport and resource recovery and replicated in a large number
of informal settlements. The core is still
a sort of urine diverting dry toilet. But when urine and feces
have been diverted, we can flush the toilets,
and of course, wash the hands. The water used
for hand washing and flushing is collected behind the toilet, treated,
and recycled back to use again. Feces and urine is brought
to nearby resource recovery plants, where fertilizer and perhaps even some
energy surplus energy is produced. It looks amazingly simple. But there are, of course,
a few challenges. The toilet recycling, water recycling,
resource recovery plant, and we also have to adapt all this
to a social economic reality. Fortunately, we have a super team. So I’ll be sure to tell you what this team
intends to do with all this: Our design partner
from XXX, Austria plants to design the toilets as a pierce of the
furniture including all the technology. This can even be installed
in an existing toilet building. The water recovery, we depend on already-existing technology. This is a gravity-driven
membrane filtration developed by Eawag colleagues for drinking water production
in developing countries. it functions totally without energy,
and without maintenance. We are going to adopt this to the much
more to the stronger wastewater from our installation and in principle
we know how to do this. The difficulty is to do this without more energy than
what people can produce themselves. For instance with this foot pump,
which we saw on the last picture. I’m not ready to talk
about the resource recovery plant because, in this project, we are not developing technology for this. We’re just evaluating existing technology. This technology, for instance, prepare the urine for being distilled,
and turned into fertilizer. It’s placed at our own institution. And chances are good that one day
it will also be in your institution. But that going into technology allows me to turn
to the socio-economic embedment. We’re doing our reality checks
in Kampala, in corporation with colleagues
in the local university. There are two main challenges: One of them is to organize the transport from one toilet
to the resource recovery plants: The other is to set up
an overall business plan. Fortunately for the last task, we have support
from a business administrator from another department at Eawag. Even in this small project,
there are a plenty of challenges. Nevertheless we are convinced
that source separation will help solve the major problems
of urban water managements [not only] in developing
but also in industrialized countries. Our colleagues in Durban they are now installing
flush NOMIX toilets in their own facilities. With the idea
of spreading this technology also into the middle-class
area of Durban. And it would be unthinkable
to plan this new living lap without source separation of wastewater. And we are certainly
involved in the planning of this extramental guesthouse where scientists and industry
will work together on the building technology of tomorrow, including NOMIX toilets, including source separation
of wastewater, and including some of the reactors, which we develop for Durban
at the moment which we have in our own office buildings and which we’ll also use
in the informal settlements. I would be very proud
if I could tell my grandchildren that I had been involved
in the development of the toilet that the a use everyday at at time when source separation
was still considered revolutionary. Thank you. (Applause)

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