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CARBON NANOTUBES AND THE DESALINTION OF WATER
Joseph Nicolosi (jdn27)
combination of mechanical and chemical filtration makes the
process very promising for the desalination of water. The
biggest benefit of using carbon nanotubes is the fact that they
can be up to 30% cheaper than the current desalination
processes. This due to the fact that it saves a significant
amount of energy because the process of running the water
through the nanotube filtration device is almost frictionless
and because the water only has to be run through one
filtration device. The desalination techniques currently being
used require a dual set up; one for removing salt and one for
removing pollutants. This drives up operating costs and
energy consumption, which turns off many countries. [2] A
major obstacle hindering expanded use of carbon nanotube
desalinization is that the cost to build a plant is very high.
Recently in California, it was projected that a nanotube
desalination plant can cost up to a billion dollars to start up.
This is a huge initial investment but since the technology is
very durable and may be worth it in the long run. For
example, one plant can provide over 50 million gallons of
drinking water per day. If plants are built commercially, they
can have a significant positive impact on the depleting global
drinking water supply. [3]
INTRODUCTION
Carbon nanotubes are a very import invention that
could hold the key for cheaper desalination of water. The
lack of potable water is a growing worldwide issue that
requires attention sooner rather than later. With global
warming, this issue is only getting worse and the already
depleted water supplies are running out. The need for water is
at an all-time high. It is estimated that by 2025 that about 1.8
billion people will lack water. The desalination of seawater is
the most logical solution considering 71% of the earth is
covered in salt water. The only problem is that the current
desalination processes are very expensive. On average, it
would cost five to seven dollars a month per person to
produce desalinized water using current desalinization
processes. While this might not seem expensive, in a country
as big as the United States that would cost an additional two
billion dollars per month. Given the fact that most countries
that are in need of water are not wealthy, this cost is
prohibitive. The main reason that current desalinization is
expensive is because of the high energy costs associated with
operating the desalination plant. This is where the invention
of carbon nanotubes could greatly help the desalination
process. By using carbon nanotubes, energy costs can be
reduced by almost 30 percent. This makes desalination a lot
more cost efficient and practical.
WHY CARBON NANORUBES ARE
IMPORTANT
This topic is compelling to me because I want to
become an engineer to invent things that will aid people in
need. The need for clean water is undeniable and the situation
is getting worse each day. Right now there are approximately
840,000 people that die each year because they do not have
drinking water. [4] This statistic will likely get worse unless
something is done to address the diminishing supply of
potable water. I believe access to clean drinking water is a
human right that everyone should have and that clean water
is taken for granted in more privileged countries like the
United States. This is a very serious worldwide issue as
evidenced by the fact that one in ten people don’t have access
to clean drinking water. However, most of the countries that
do not have clean drinking water are poor and can not afford
the current methods of desalination and therefore are in need
of a cheaper alternative. So far carbon nanotubes appear to be
the most viable potential solution. With lower operating costs
as compared to existing desalinization techniques, carbon
nanotube desalinization seems practical and should be
implemented. This is the kind of invention that makes me
want to become an engineer. My goal is to help others and to
make contributions that will aid in making the world a better
place. Discoveries like this keep me motivated to learn more
and better myself academically. If you could help almost
900,000 people a year with one innovation, then why
wouldn’t you pursue bringing that innovation to the masses.
CARBON NANOTUBES
Carbon tubes are made up a complex arrangement
of carbon atoms that are bonded together by a series of
covalent bonds [1]. This allows the structure to be extremely
durable as well as extremely lightweight. Although the
concept of using carbon nanotubes as a desalination device is
new, the technology of nanotubes has been around for some
time. They were first invented in 1991 by a professor at Rice
University with the intended use to be in aerospace. In space
they were used effectively as a water filtration device since
there is an absence of gravity and traditional filtration devices
don’t work. All of the generic filters require the water to
flow through them to provide mechanical filtration, but since
carbon possesses the chemical properties to attract and trap
different elements, the use of nanotubes proved to be an
effective alternative means of chemical filtration in space.
This use was the genesis of using carbon nanotubes for
desalination. For applications on earth, the aerospace design
was changed to allow water to flow through the nanotubes
which acted as a filter for both salt and other pollutants. This
process worked by arranging the samples of carbon into
vertical layers and running the salt water through them. The
pores of the nanotubes where so small that they let minimal
amounts of salt through the filter. Since they were made of
carbon, the nanotubes also possessed the ability to attract and
trap pollutants because of their chemical properties. This
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[4]Can Engineered Carbon Nanotubes Help to Avert Our
Water Crisis?” Can Engineered Carbon Nanotubes Help to
Avert Our Water Crisis? Phys.org, 17 Mar. 2015. Web. 05
Oct. 2015.
[5]Gethard, Ken. “Water Desalination Using CarbonNanotube-Enhanced Membrane Distillation.” ACS Applied
Materials & Interfaces (ACS Publications). Applied
Materials and Interface, 28 Dec. 2011. Web. 05 Oct. 2015
Aside from being interested in the potential benefits
that carbon nanotubes can bring, I picked this topic because I
was always fascinated with how carbon elements can be
fused together to create lightweight but extremely durable
bonds. This process has been used in many other fields such
as aerospace and the medical field with great success. This
invention is so versatile and has many practical implications.
That is why when I learned that carbon nanotubes were being
tested for the desalination of water I was immediately
interested in understanding more about this topic. I am
amazed by how the element carbon can have such a profound
effect on such a broad spectrum of topics.
ACKNOWLEDGEMNETS
I would like that my roommate for giving me
helpful insight on my topic. With his help I was
able to narrow down my topic and write a better
paper. I would also like to thank the Liberians for
being very helpful in assisting me in my research.
WHY SHOULD ENGINEERS FOCUS
ON NANOTUBES
I believe engineers should focus on carbon
nanotubes because the overall goal of an engineer is to
improve the quality of life by solving problems. Addressing
the global water shortage through this innovative technique
would certainly accomplish that objective. Given that less
than one percent of the earth’s water is suitable for drinking
there is already a limited natural water supply. Global
warming is contributing to accelerating the depletion of that
supply by affecting many of our natural water sources such
as glaciers and snowcaps. Since temperatures are rising each
year, it seems to be only a matter of time before we run out of
the earth’s diminishing natural water supply. Accordingly,
the need for viable alternative desalinization options has
become more important and engineers need to focus on this
issue before this problem becomes more wide spread. Right
now this issue only affects smaller impoverished countries
but larger countries will still start feeling the need to change
how they supply water as well. Engineers, by researching
the use of carbon nanotubes, have the ability address this
issue and offer viable solutions. Currently, using carbon
nanotubes seems to be the cheapest and most reliable means
of desalination of salt water but more research and
development is needed prior to broad commercial use. If
engineers where able to make a breakthrough in this field, the
aid to people worldwide would be immeasurable.
REFERCENCES
[1] Corry, Ben. “Energy & Environmental Science.” Water
and Ions through Carbon Nanotubes. Royal Society of
Chemistry, 4 Jan. 2011. Web. 05 Oct. 2015.
[2]”Designing Carbon Nanotube Membranes for Efficient
Water Desalination.” – The Journal of Physical Chemistry B
(ACS Publications). The Journal of Physical Chemistry, 27
Dec. 2010. Web. 05 Oct. 2015.
[3] Pan, Likun, and Yanping Zhang. “Electrosorptive
Desalination by Carbon Nanotubes.” Water Research. By
Haibo Li. 30th ed. Vol. 42. N.p.: n.p., n.d. 4923-928. Print.
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