Desalination

Desalination means any process that removes the excess salt and other minerals from water in order to obtain fresh water suitable for animal consumption or irrigation. Most desalination is by distillation. Some is by reverse osmosis or other methods.

The main purpose is to make water for people to use. The salt is usually carried away as brine but in some places the solid salt is extracted. 

Desalination  of brackish water is done in the United States in order to meet treaty obligations for river water entering Mexico. Several Middle Eastern countries have energy reserves so great that they use desalinated water for agriculture. Saudi Arabia's desalination plants account for about 24% of total world capacity. The world's largest desalination plant is the Jebel Ali Desalination Plant (Phase 2) in UAE. It uses multi-stage flash distillation, dual-purpose and it is capable of producing 300 million cubic meters of water per year.

Methods
Distillation 
Multi-stage flash (MSF)
Multiple-effect (MED|ME)
Vapor compression (VC)
Evaporation/condensation
Membrane processes
Electrodialysis reversal (EDR)
Reverse osmosis (RO)
Nanofiltration (NF)
Forward osmosis (FO)
Membrane distillation (MD)
Cold (freezing)
thermal
Solar humidification 
Methane hydrate crystallisation
High grade water recycling

The traditional process used in these operations is vacuum distillation — essentially the boiling of water at less than atmospheric pressure, and thus a much lower temperature than normal. Due to the reduced temperature, energy is saved.

References

 Other websites 
 Middle East Desalination Research Centre 
 Encyclopedia of Desalination and water and Water Resources
 Global Water Intelligence - monthly newsletter featuring 'Desal Project Tracker'
 Water Desalination Report - weekly newsletter on international desal 
 International Desalination Association
 Desalination & Water Reuse - Official magazine of the International Desalination Association 
 European Desalination Society
 IAEA - Nuclear Desalination 
 German Desalination Society - DME
 Geothermal Desalination 
 SDSU (San Diego State University) Center for Information Technology and Infrastructure (CITI) International Consortium of Advanced Technologies and Security 
 "Desalination Journal" and Desalination Directory of the European Desalination Society
Desalination by humidification and dehumidification of air: state of the art 
 Zonnewater - optimized solar thermal desalination (distillation) 
 SOLAR TOWER Project - Clean Electricity Generation for Desalination.
 Solar Desalination using the MEH-Method
 Article: Water issues prompt new look at desalination 
 Desalination bibliography Library of Congress
 Water-Technology
Water Desalination Worldewide, Market, Technologies and Companies
Cheap Drinking Water from the Ocean - Carbon nanotube-based membranes will dramatically cut the cost of desalination
BBC2 Newsnight Film: Israel build the world's largest desalination plant 
Solar thermal-driven desalination plants based on membrane distillation 
Encyclopedia of Water Sciences, Engineering and Technology Resources 

Category:Water