Desalination is the process where salt is removed from seawater or brackish water. People have been trying to remove salt from seawater since around 300 BC. People such as “Aristotle in 1320 BC, Rome’s Pliny the Elder in 70 AD, Greece’s Alexander of Aphrodisias in 200 AD, French Explorer Jean De Lery in Brazil in 1565, and James Cook during his circumnavigation around the world have tried to desalinate seawater .” (Desalination Overview – November 2013) Humans and animals cannot drink salt water, as it would be harmful to their body. Freshwater has less than 1000 ppm (parts per million). Saltwater has between 10,000 – 35, 000 ppm. Ocean water has about 35,000 ppm of salt, which makes it undrinkable. Since the Earth is 70% water and of
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Some of them are reverse osmosis, forward osmosis, low temperature distillation, membrane distillation, pressure retarded osmosis, biomimetic and grapheme membrane, and solar desalination. In the mid 1900’s, commonly used techniques of desalination involved distillation and evaporation. Solar desalination relies on the sun’s energy to create water vapor, which produces condensation of fresh water. Similar to the first part of the water cycle, the sun heats up the water, which creates water vapor. The water vapor rises and creates liquid condensation. This liquid condensation does not contain salt, but fresh water. The salt remains at the bottom of the water. Solar desalination is not used as much as reverse osmosis because you do not produce as much fresh water in a given amount of time. Desalination using reverse osmosis is where “water is pushed through a semipermeable membrane that blocks the passage of dissolved solutes.” (How Reverse Osmosis Works – September 2011) Israel and Australia are two countries that use reverse osmosis desalination plants because they are both near the ocean and are very dry places. In 2002, there were about 12,500 desalination plants around the world in 120 countries. The countries that uses the desalinated water the most are Kuwait, Saudi Arabia, the United Arab Emirates, Qatar, Bahrain, Libya, and Algeria. (water.usgs.gov/edu/drinkseawater-January
Some of them are reverse osmosis, forward osmosis, low temperature distillation, membrane distillation, pressure retarded osmosis, biomimetic and grapheme membrane, and solar desalination. In the mid 1900’s, commonly used techniques of desalination involved distillation and evaporation. Solar desalination relies on the sun’s energy to create water vapor, which produces condensation of fresh water. Similar to the first part of the water cycle, the sun heats up the water, which creates water vapor. The water vapor rises and creates liquid condensation. This liquid condensation does not contain salt, but fresh water. The salt remains at the bottom of the water. Solar desalination is not used as much as reverse osmosis because you do not produce as much fresh water in a given amount of time. Desalination using reverse osmosis is where “water is pushed through a semipermeable membrane that blocks the passage of dissolved solutes.” (How Reverse Osmosis Works – September 2011) Israel and Australia are two countries that use reverse osmosis desalination plants because they are both near the ocean and are very dry places. In 2002, there were about 12,500 desalination plants around the world in 120 countries. The countries that uses the desalinated water the most are Kuwait, Saudi Arabia, the United Arab Emirates, Qatar, Bahrain, Libya, and Algeria. (water.usgs.gov/edu/drinkseawater-January