Desalination please help *begs*?

Question

Why do we need desalination in the present and near future,

how does it work.

where is it necessary, how many desalination plants are there?

Answer 1

We need it because for some areas the only source of economic fresh water is delaniation of sea water.  Places like the Persian Gulf, or remote islands used by the military.

Most desalination uses Reverse Osmosis.  RO works on reversing the osmitic pressure between fresh water and salty water through a membrane.  It takes some energy to produce the pressure and it is usually done by electricity.

There are many.  In the USA there are RO facilities in Florida, Texas, CA and many coastal communities.  There are serveral hundred large desalination plants in the world that can produce enough fresh water for small to medium size communities.  Also they can easily (with money of course) be scaled larger.  

Answer 2

There are many places in the earth which get more rain water than their actual requirement and causing heavy flooding. But the state like Tamil nadu in India we do not get enough rain water or underground water. We have to barrow the water from other states. There are several quarrels between the states for water sharing. Even the judicial departments are helpless in this issue. Therefore to full fill our water requirement we have to purify the sea water and make it suitable for drinking by desalination. There are also several countries like Singapore and many oil producing countries have to purchase the water from their neighbors. .

Answer 3

We'll need it because water for human consumption and agriculture is increasingly hard to come by in many parts of the world.

Desalination can be relatively simple. If you heat seawater to steam, the salts are left behind. Capture the steam and you have fresh water. There are plants in the Middle East that use this technique. The catch is it requires huge amounts of energy. It becomes a difficult decision. Do you pour your energy into making fresh water or powering homes and factories? A society can't live without water but it can't flourish without power.