Topic
Desalination refers to the processes of removing salts and minerals from saline water. Desalination of water is carried out by two ways-1) Natural water desalination (The water cycle) and 2) Human Made Desalination Systems. During the hydrologic cycle the water that evaporates from the ocean leaves the salt content behind because salt does not evaporate. The water cycle helps in filtering saline sea water thereby creating fresh water for the irrigation of plants and crops. Human made desalination systems include thermal desalination and membrane desalination. Membrane desalination includes techniques like reverse osmosis and electro-dialysis.
Why is it important?
Importance of desalination- The earth is a planet with abundant water. The problem lies in the fact that most of the water (around 97 %) is in the oceans which have an average salt content of 35,000 ppm by weight and drinking this water regularly can be fatal. The rest of the water that is not in the oceans (around 3%) is not easily available for our use. Thus we need to use methods like desalination to produce fresh water for irrigation and human consumption. Desalination projects can be found in around 150 countries today. As world population increases, the demand for clean water will increase and desalination will become an important part of water supply in the 21st century.
Reference
Desalination. (n.d.). Retrieved March 4, 2015, from http://en.wikipedia.org/wiki/Desalination
Thoughts of a Lapsed Physicist. (n.d.). Retrieved March 4, 2015, from http://www.lapsedphysicist.org
Find Curriculum. (n.d.). Retrieved March 4, 2015, from https://www.teachengineering.org