The process of desalinization occurs when salts dissolved in sea water or brackish water are removed.
Ocean water is, on average, 34 parts per thousand salt. In seas, the salt content varies considerably. While the salt content of the North Sea is rather
low, seas completely surrounded by land such as the Red Sea tend to have much higher salt contents. In those areas, water evaporates at high rates, leaving the salt behind.
Industries produce salt for their use through commercial desalinization. To do this, they can use either distillation or reverse osmosis.
The distillation process involves boiling salt water to separate water vapor from the salt. Then, the water vapor is condensed to form drinkable liquid water.
Reverse osmosis forces sea water through a reverse osmosis membrane. Some fresh water gets through, but the salt water does not. The salt water is put back into the ocean, and the fresh water is used for consumption.
Desalination can be a very expensive process. If drinking water is the intended result, the price is often much higher than that from fresh water sources. The high price comes from the need to use energy in the process. Three kilowatt hours are
needed to produce just one gallon of desalinated water.
Despite its relatively high costs, desalination is used in areas of the world without fresh water supplies, such as Saudi Arabia, Kuwait, and North Africa. Together, those areas produce 2/3 of the world's desalinated water.
Desalination is important because it could help to solve severe water problems. The UN's World Health Organization estimates that poor drinking water kills 25
million people every year.