Desalination and Tsunamis
By Euijin Choi, Melanie Elliott & Kaitlin Haines
Is desalination suitable to sustain life
after a tsunami?
Yes, it is. In fact, apart from the destruction it leaves behind,
Tsunamis are perfect for desalination. This is because the
Tsunami leaves behind tonnes of sea water – the main
component of desalination. It would be quite simple to
extract the salt and turn it into fresh water. When the salty
water from the ground has been collected it can be
transported to a desalination plant and turned into clean,
fresh water which can be used to give access to clean
water for many people and animals.
Is desalination suitable to sustain life
after a tsunami? (continued)
When the salt water has been removed from the
ground, life can go back to normal. The only
downside to desalination is that there is a large
amount of energy - 600 kilowatts - needed to
make one litre of water, which is not very
sustainable or energy efficient. If you were to use the
sun in desalination, it would supply roughly half a
kilowatt of energy per square metre, which is a
small contribution, but worthwhile.
What are tsunamis?
Tsunamis are ocean waves caused by large earthquakes, volcanoes and
landslides that occur near or under the ocean. Tsunami waves are unlike typical
ocean waves generated by wind and storms. When tsunamis approach shore they
behave like a very fast moving tide that extends far inland.
When they hit land, tsunami cause massive destruction and can hit speeds of up
to 200 kilometres an hour! Most tsunamis do not break like the curling, windgenerated waves popular with surfers, and they can continue for hours!.
Tsunami Survival Kit
Being prepared!!!
• Pack plenty of water
•First Aid Kit
•Food (cans of baked beans etc)
•Can opener
•Torch / batteries
•matches
•Blankets/warm clothes
What is “Desalination”?
Desalination is the process of removing salts from seawater to render it
suitable for drinking. Water is desalinated in order to be converted to
fresh water for human consumption or to supply land with water. It
goes through large plants and is heated so the water evaporates and
the water and salts are separated. The water is then cooled and
transported to towns/cities.
There are several ways to do it, however, all the methods are very
expensive. If you used a vacuum, you would also save energy and
heat, because it would lower the boiling point - which would help to be
sustainable in the long run! Afterwards, the excess salt is either turned
into salt and salt products or returned to the sea.
The desalination process
Is it possible to desalinate sea water
sustainably?
Yes it is, in a way, but not truly. The only way to make
desalination more sustainable is to simplify the method
and turn it into evaporation or something similar. But you
could also replace the heat with natural solar heat, from the
sun.
Unfortunately the desalination process relies on heat and so
you can’t truly sustainably desalinate; only simplify and
make easier! You could use natural wave energy to create
energy that would heat the water, but even then, it still
takes a lot of energy and is not real sustainability.
Our Proposal
A desalination plant that is near a source of energy (the sun),
which is energy and water efficient (as much as possible).
•It will gather water from the sea and then transport it in a
system of pipes (with a little bit of heat trapped inside) to a
building that gets a majority of sun during the day.
•The water will then be heated by the sun – in a room that has
windows for walls and is facing the sun.
• The remaining salt will be collected in bags by workers to be
used elsewhere.
•The water will then be cooled from water vapour
back to liquid in the “freezing room”
The Proposal (continued)
• The freezing room will be a room with no windows; facing
away from the sun.
• The water will collect in tubes on the ground and will then be
transported to houses around the district.
• When the water has been used it will then go back to the
plant and to a special room where the water will be filtered
clean.
• It will then be recirculated around the district again and
again, using and gathering no new water since the start.
But if need be there could be more water transported to fit
needs. There will be no desalination during the night as there
would be no sun!
Bibliography
• http://en.wikipedia.org/wiki/Desalination
•http://www.kidzone.ws/WATER
•http://www.fema.gov/kids/tsunami.htm
•http://www.edwardsaquifer.net/desalination.html
•World Book 2009
•Teachers :]
•YouTube presentations