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[no dialogue]
>> Cartic: Good evening friends!
Our group topic is water desalination.
My name is Cartic.
>> Rah Fandinda: My name is Rah Fandinda.
>> Frecomgrande: My name is Frecomgrande.
>> Sean Wiggins: My name is Sean Wiggins.
>> Cartic: Water desalination, the
word desalination itself says that conversion of salt
water into normal water by taking away the
salt and other minerals from the salt water.
It is a really important process nowadays.
Almost, as we know that 2/3 of the Earth is covered with
seawater, so if we just convert seawater into normal water
we can eliminate the concept of drought in the
parts of the world, and moreover it produces very less fish.
The by-product fits this process produced is
salt, it is also consumed by human beings.
Salt is implemented in countries like Australia and New Zealand.
Now let me give you a sample of an
easier process of how desalination is done.
Let us [unclear dialogue] a container
with salt water, as you all know that water boiling point is
somewhat slower than salt, so if we just hit the salt water
thereby the water just evaporate first and this evaporated
water is cool and [unclear dialogue].
Then by separating the salt as well as water and leaving
the salt and other minerals as by-product.
This is how the simple desalination process is done.
♪ ♪ [music playing--no dialogue] ♪
>> male Speaker: The water planet, third from the
Sun and the only planet in the solar
system where water exist in liquid form.
In fact three quarters of the earth
surface is covered with it.
Yet millions of people struggles to
find enough water to survive.
With the world's population and growing by about ninety
million people a year, the supply of
useable water just isn't keeping up.
Useable is the key.
The overall amount of water on the planet
never changes; it is only the distribution of it that varies.
As a liquid on the surface or below it, as a vapor in clouds
or as a solid in high altitude and in the higher latitudes.
Making sure we have enough water in useable form and getting it
where it's needed is what water management is all about.
Conservation is one method, using
less water whenever possible.
Building dams, reservoirs and aqueducts...
Cleaning up polluted water and recycling
water, especially for irrigation.
Desalination or de-salting is another method of
increasing the supply of useable water.
To most people desalination means desalting
seawater, unlocking the oceans vast liquid treasurers.
De-salting seawater requires a lot of energy and
has not been the top priority in the United States.
It has been widely used in the Mid-East where the
abundance of oil means inexpensive energy, but there's
another use for desalination, which is more practical and has
just as much potential.
By removing salts, minerals, and other contaminates
it can raise the quality of inland water
supplies to use as drinking water or irrigation.
>> Sean Wiggins: Okay well that's just a little
bit about desalination.
Now we will be talking about the positives and negatives of
this technology, to do so we would have class
involvement and to do that we will
be playing the popcorn game.
I'm not sure if any of you guys ever done that?
What it is you read a couple of notes from the
slide and then you pass it and popcorn to the next person.
I would like to start with Bruce, here you go popcorn.
>> Bruce: Positives of this Technology A
typical American uses 80 to 100 gallons of
water a day, according to the U.S. Geological Survey.
The entire country consumes about 323 billion
gallons per day of surface water and another 84.5
billion gallons of ground water.
The price difference will undoubtedly narrow, especially
in regions that could experience more intense
droughts due to climate change.
Water use has been growing twice as fast as
population growth, causing more and
more communities to suffer water shortages.
The demand for freshwater supplies will drive prices
higher, making desalination increasingly attractive.
>>Sean Wiggins: One of the main points
we would like for you to take from this slide
is the fact that water is going scarce as the population
grow, so sooner or later it is going to be a major issue.
Popcorn...
>> Dr. Wahby: Large amounts of energy are
needed to generate the high pressure
that forces the water through the filter.
Current methods require about 14 kilowatt- hours of energy to
produce 1,000 gallons of desalinated seawater.
>> Rah Fandinda: Actually, these have more
negative effects, when we compare
the cause to the effects.
The constriction process also takes a lot of
time inconvenience and also the effects on the environment.
It has main effects on the aquatic animals.
One of the major points of this desalination process is
excluding; which effects aquatics animals and also leads
to loss of many aquatic habitants.
Moreover, one of the other graphical disadvantage
of desalination is that it also uses the underground water.
These are the main side effects of desalination process.
>> Sean Wiggins: You can popcorn; you
chose who you want to speak next.
>> male Speaker: Multi-Stage Slash Distillation
(MSF) is a water desalination process that distills seawater
by flashing a portion of the water into steam in multiple
stages of what are essentially countercurrent heat exchangers.
Multi-stage flash distillation plants produce
85% of all desalinated water in the world.
>> Frecomgrande: As you have seen in the video
the water corporative and created a steam,
again it comes in the form of [unclear dialogue].
This is the process and 85 percent
of the water is purified in this way.
>>male Speaker: Reverse Osmosis (RO) is
a membrane-technology filtration method that removes
many types of large molecules and ions from solutions by
applying pressure to the solution when it is on one side
of a selective membrane.
Large reverse osmosis and multistage
flash desalination plants are used in the Middle East,
especially South Arabia.
>> Sean Wiggins: Next person.
This is just a video we had that was showing the
whole process of, but we already have kind
of gone through that I'll speak and then we'll go next.
Vacuum Distillation is a method of distillation
whereby the pressure above the liquid
mixture to be distilled is reduced to less than its vapor
pressure causing evaporation of the most volatile liquids.
This distillation methods works on the vapor pressure of a
liquid exceeds the ambient pressure.
This is the most general form where you boil the water
and like we said before since the water's boiling point
is before the salts the water evaporated and leaving
excess salt and separating the water from the salt.
>> Dr. Wahby: Only got three more minutes.
>>Sean Wiggins: Oh, we only have three more
minutes, okay we'll speed it up.
We will give you all a few things about the implementation
of this technology.
There's actually a lot of implementation
around the world.
Arizona has an implementation where they constructed
a plant, which feeds the rivers, used to clean
the rivers and some of the water sources out there.
It is not so much for drinking, it just to keep the water
levels clean and those states in the surrounding states.
China also has a major desalination plant, which
combines desalination and coal with a coal-fired power
plant designed to alleviate critical water shortages.
>>Frecomgrande: We are implementation this
technology because water is used day by day and to make this
water for the demands of the people and the demand of
the population; this technology is very useful and
it used in various countries.
According to the research, different kinds of
implementation are added into this technology like sheets
of graphene that is used in filtration process.
One atom-thick form of the element of carbon, which stays
in this filtration process, is also used in this process.
Using these kinds of materials in this filtration
process makes the implementation of this
process very cheap and very effective.
>>Sean Wiggins: That was a video; from the slide
you can see the graphene, which is used
to separate those two products and that is our slide.
[audience clapping]
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