“Water will become more valuable
than oil”
“The wars of 21st century will be
fought over water”
“By 2025 half of the world the world
would not have access to adequate water”
These are some sayings and
predictions made by people around the world. The world is running out of clean
water. It is as simple as that. Over the last centuries, the world has been
using more clean water than it can create. It is the same as if you are
emptying a bathtub more than you are filling it, eventually the bathtub will
become empty. Many people see desalination as the solution on the water crisis.
Desalination refers to a process where salt and other minerals are removed from
saline water. And with all the salt water available in the oceans, why is this
not a reality?
First of
all, the desalination process needs a lot of energy, which makes it more
expensive than the other possibilities such as collecting fresh water from
rivers or groundwater, water recycling or water conservation. These other
options are not as sustainable, but they are a lot cheaper and without some of
the other challenges that come with desalination, such as the pollution. All
the left over salt after the desalination becomes concentrated waste stream
called brine, which contains up to twice as much salt as regular salt water.
The brine does also often contain chemicals such as chlorine and other nature
damaging substances. A few years back,
around 5 to 10 kWh were needed to create
one cubic meter of clean water, and even with the technology we have today, it
needs around 2kWh. The technology has improved, and the cost has gone down, but
it is still not compete able with the other options.
Even though
there are some challenges considering desalination, there are also some
advantages, for example the guarantee of clean water in the event of drought.
As stated earlier in this post, there is no lack of water from the ocean. Since
there are so much water in the ocean, taking the water from there will not affect
the habitat of the fishes or animals the way it does when the water is taken
from a smaller lake or smaller rivers. Another advantage is that one of the big
desalinisation plants can supply up to 500 million litres of fresh water each
day.
In my opinion,
desalination can be the solution of the water crisis, but only if the
technology in the desalination field improves. The need of energy to make clean
water has decreased, but there are still the environmental issues that have to
be taken care of. There is a long way to
go until we solve the water problems, but making desalination a cheap and safe
way to get clean water would be a giant leap towards the goal.
Sources: http://everylittledrop.com.au/is-desalination-the-answer-to-global-water-shortages
Picture: http://en.wikipedia.org/wiki/Desalination
That is true, and it is an interesting possibility. According to the documentary we saw it is too expensive and creates too much pollution, but as you state, new inventions might help in those areas. Interesting post, learned a lot from reading it!
SvarSlettHi. In the beginng of the year my class had talked all about oil and how it was so vaulable. We never mention the idea that water would become more valuable than water. Nice post.
SvarSlett