Have
you ever wondered what happens to all the liters of water you flush
daily down the toilet? Every day, probably without even being aware
of it, you use liters and liters of water to brush your teeth, do
the dishes, water the plants, take a shower, do the laundry, cook,
and a longer list of other activities. Now, can you imagine a day
without this precious resource? Just ONE. I bet you can't. The truth
is that billions of people in this world don't have access to this
resource to satisfy their BASIC needs. Yet, in cultures like ours*
we tend to use water as if it was infinite, but it is not. Because
of this, in Ideals Matter we wanted to explore deeper into the world
of water after we use it.
We started our adventure by watching a
documentary (Crapshoot:
The gamble with our wastes) that showed us the origin of the
water systems that we currently use in most of “developed”
cities around the world. It was astonishing to discover that these
systems were invented in times when needs were different. It seems
acceptable to think of these systems as the solution to many of the
disease problems caused by dirty water running down the streets of
cities when they were created. However, it looks like we didn't
think of what the consequences of adopting the same system would
have been in a world with billions of people before copying and
spreading it all around. We didn't even care for making it better!
The result is that (luckily!) we are not seeing the tons and tons of
dirt we produce everyday. No. Worse yet: we are eating it! Read
further to see how come this happens and what can we all do to help
reduce this and other problems caused by flushing things down to our
toilets...
Video made by Ave Kris Lend
To
continue with the adventure, after all the questions that arouse
while watching the documentary, we decided to set one of our trips of
the summer to the water treatment plant of Tallinn. The plant, which
is located in the Paljassaare peninsula, one of the districts of the
Estonian capital, receives the sewage water that once belonged to the
lake Ülemiste. This lake, which is located to the southeast of the
city, provides its citizens with 90% of the water that is consumed.
Paljassaare Wastewater Treatment Plant
The
sewage water then goes through eight stages before it is released
into the sea, where it will go back to its natural cycle. These
stages involve mechanical, chemical and biological processes. Let’s
take a closer look at these stages:
Wastewater being pumped into the plant
to start the treatment process
Removing
solid: the first stage, which is
one of the mechanical ones, is aimed to remove trash that is
visible and floating on the water, like bags, bottles and others of
the kind. It can be shocking to see how many things we throw into
the water. And that’s only the part that is visible. You probably
know the smell of it. Unbearable. Many things can go through your
mind while standing on this spot looking at this brownish, black
liquid mixture of filth that was once crystal clear water.
Grit
removal: in this second stage, also mechanical, smaller solid
particles are removed using primary sedimentation basins. This
particles, result in a mass called sludge which is extracted for a
parallel treatment. This mass deserves us to take a pause and give
some further explanation.
Mechanical process where visible solid waste is removed
What
is sludge?
It
is a scary word. Why? The documentary mentioned above and Wikipedia
have helped us a bit with this definition. Sludge is basically a word
used to name the undefinable. It is a mixture of solids - stop here
for a second and think of all the solid things that go down the
kitchen sink after cooking a meal, the ones resulted from doing the
laundry, your mouth, the toilet or the industrial processes- and
water. When treated, it is then used with agricultural purposes. To
put it in simpler words: we eat our own crap...and chemicals...and
metals...and much more.
You
have an idea now...let’s go on with the next stage:
Removing
phosphorus: this is the first chemical stage of the process, in
which coagulants are added to the water to extract the phosphorus.
This component is a chemical usually found in soap, detergents,
shampoos, toothpaste, and other cleaning and cosmetic products.
The
problem with phosphorus...
is
that it stimulates the growth of algae. And when there’s too much
algae, the oxygen of natural bodies of water, such as rivers, lakes
and seas, is depleted making it harder for other water creatures to
survive. In a water treatment process, even with the wonderful aim of
purifying the water we have made dirty, it is impossible to remove
100% of the things we dump into it and this only means we are not
only eating our filth, we are leaving some of it into our water, the
water we eventually consume again.
Nitrogen
removal: For the biological treatment the wastewater is
conducted to the aeration tanks where the vital activity of various
bacteria helps to remove nitrogen and biologically decomposing
substances from the water. To ensure a living environment suitable
for the bacteria and to make their work more efficient, air and
additional carbon in the form of methanol are injected.
More
solid removals: just like in stage number two, the water goes
again into sedimentation basis, this time into a secondary phase,
where activated sludge is removed. The first sludge (from the second
stage) is called primary sludge, which is mainly excrement. The
second sludge is a culture of bacteria that is used in previous
stages to remove contaminants.
First sedimentation basin. In here the grid removal takes place
Water
is returned to the sea:
although the process of purifying the water is finished in this
stage in which water is pumped back into the sea, the activity in a
water treatment plant does not end here.
Sludge
treatment: the sludge that was removed in the previous stages is
treated in the plant sending it into digesters, where anaerobic
bacteria will do a decomposition process. From this stage there are
two final by-products: one is a biogas that is then reused in the
plant to continue with the cycle, and the other one is the digested
sludge. The latter is dried and mixed with peat and is later sold as
mass for cultivation.
| 
| Sludge is later dried and mixed with peat
to be is for cultivation | Sludge is later dried and mixed with peat
to be is for cultivation |
To
finish the story of our adventure we want to remind you that, even if
we visited a local water treatment plant, we are sure that what we
saw there is probably not very different from what happens in your
city, whichever it is. As we mentioned above, the water system we
adopted has existed for centuries and has been transferred from one
society to another. And although there are probably differences from
one another, we believe the reality, and most importantly, the
problems that these systems represent, are applicable to all of us.
Because
of this, it is important to remember that, even if the whole process
is made with the great objective of offering us clean water, we do
have to consider the dangerous consequences of polluting our water in
the first place. Because of this, we encourage you to become more
attentive on the way you use the water at home and pay special
attention to the substances you pour in it. We recommend you to
dispose them in alternative ways and find products to clean your
house and yourself that contain none or the lowest amount of
chemicals that’s possible. This way, you will not only avoid
polluting the water, but you will also be taking care of yourself by
reducing the amount of chemicals your body is exposed to.
*If
you have access to this article, published only on the Internet, you
can figure out for yourself what we mean by ours.
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