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Desalination Desalination, desalinization, or desalin- isation refers to any of several processes that remove excess salt and other minerals from water. More generally, desalination may also refer to the removal of salts and miner- als,[1] as in soil desalination.[2][3] Water is desalinated in order to be conver- ted to fresh water suitable for human con- sumption or irrigation. Sometimes the pro- cess produces table salt as a by-product. It is used on many seagoing ships and submar- ines. Most of the modern interest in desalina- tion is focused on developing cost-effective ways of providing fresh water for human use in regions where the availability of fresh wa- ter is limited. Large-scale desalination typically uses ex- tremely large amounts of energy as well as specialized, expensive infrastructure, making it very costly compared to the use of fresh water from rivers or groundwater. The large energy reserves of many Middle Eastern countries, along with their relative water scarcity, have led to extensive construction of desalination in this region. By mid-2007, Middle Eastern desalination accounted for close to 75% of total world capacity.[4] The world’s largest desalination plant is the Jebel Ali Desalination Plant (Phase 2) in the United Arab Emirates. It is a dual-pur- pose facility that uses multi-stage flash distil- lation and is capable of producing 300 million cubic meters of water per year. The largest desalination plant in the Un- ited States is the one at Tampa Bay, Florida, which began desalinating 25 million gallons (US Gal.) (95000 m³) of water per day in December 2007.[5] The Tampa Bay plant runs at around 12% the output of the Jebel Ali Desalination Plants. A January 17, 2008, art- icle in the Wall Street Journal states, "World- wide, 13,080 desalination plants produce more than 12 billion gallons of water a day, according to the International Desalination Association."[6] Water desalination Methods 1. Distillation 1. Multi-stage flash distillation (MSF) 2. Multiple- effect evaporator (MED|ME) 3. Vapor- compression (VC) 2. Ion exchange 3. Membrane processes 1. Electrodialysis reversal (EDR) 2. Reverse osmosis (RO) 3. Nanofiltration (NF) 4. Membrane distillation (MD) 4. Freezing 5. Geothermal desalination 6. Solar humidification (HDH, MEH) 7. Methane hydrate crystallization 8. High grade water recycling 9. RF Induced Hyperthermia 10. Seawater greenhouse Methods As of July 2004, the leading method is Multi- stage flash distillation (85% of production world-wide).[7] The traditional process used in these operations is vacuum distillation—es- sentially the boiling of water at less than at- mospheric pressure and thus a much lower temperature than normal. This is because the From Wikipedia, the free encyclopedia Desalination 1 boiling of a liquid occurs when the vapor pressure equals the ambient pressure and va- por pressure increases with temperature. Thus, because of the reduced temperature, energy is saved. In the last decade, membrane processes have grown very fast, and most new facilities use reverse osmosis technology. Membrane processes use semi-permeable membranes and pressure to separate salts from water. Membrane systems typically use less energy than thermal distillation, which has led to a reduction in overall desalination costs over the past decade. Desalination remains energy intensive, however, and future costs will con- tinue to depend on the price of both energy and desalination technology. Considerations and criticism Co-generation Cogeneration is the process of using excess heat from power production to accomplish another task. In the sense of desalination, co- generation is the production of potable water from seawater or brackish groundwater in an integrated, or "dual-purpose", facility in which a power plant is used as the source of energy for the desalination process. The facil- ity’s energy production may be dedicated en- tirely to the production of potable water (a stand-alone facility), or excess energy may be produced and incorporated into the energy grid (a true cogeneration facility). There are various forms of cogeneration, and theoretic- ally any form of energy production could be used. However, the majority of current and planned cogeneration desalination plants use either fossil fuels or nuclear power as their source of energy. Most plants are located in the Middle East or North Africa, due to their petroleum resources and subsidies. The ad- vantage of dual-purpose facilities is that they can be more efficient in energy consumption, thus making desalination a more viable op- tion for drinking water in areas of scarce wa- ter resources. [8][9] In a December 26, 2007 opinion column in the The Atlanta Journal-Constitution, Nolan Hertel, a professor of nuclear and radiologic- al engineering at Georgia Tech, wrote, "... nuclear reactors can be used... to produce large amounts of potable water. The process is already in use in a number of places around the world, from India to Japan and Russia. Eight nuclear reactors coupled to de- salination plants are operating in Japan alone... nuclear desalination plants could be a source of large amounts of potable water transported by pipelines hundreds of miles inland..." Additionally, the current trend in dual-pur- pose facilities is hybrid configurations, in which the permeate from an RO desalination component is mixed with distillate from thermal desalination. Basically, two or more desalination processes are combined along with power production. Such facilities have already been implemented in Saudi Arabia at Jeddah and Yambu-Medina.[10] A typical aircraft carrier in the U.S. milit- ary uses nuclear power to desalinate 400,000 gallons (US Gal.) of water per day. [11] Economics A number of factors determine the capital and operating costs for desalination: capacity and type of facility, location, feed water, labor, energy, financing and concentrate dis- posal. Desalination stills now control pres- sure, temperature and brine concentrations to optimize the water extraction efficiency. Nuclear-powered desalination might be eco- nomical on a large scale. [12] But, critics will point to the high costs of desalination technologies, especially for de- veloping countries, the impracticability and cost of transporting or piping massive amounts of desalinated seawater throughout the interiors of large countries, and the byproduct of concentrated seawater, which some environmentalists have claimed "is a major cause of marine pollution when dumped back into the oceans at high temper- atures"[13] While noting that costs are falling, and generally positive about the technology for affluent areas that are proximate to oceans, one study argues that "Desalinated water may be a solution for some water-stress re- gions, but not for places that are poor, deep in the interior of a continent, or at high eleva- tion. Unfortunately, that includes some of the places with biggest water problems." and "Indeed, one needs to lift the water by 2000 m, or transport it over more than 1600 km to get transport costs equal to the desalination costs. Thus, it may be more economical to From Wikipedia, the free encyclopedia Desalination 2 transport fresh water from somewhere else than to desalinate it. In places far from the sea, like New Delhi, or in high places, like Mexico City, high transport costs would add to the high desalination costs. Desalinated water is also expensive in places that are both somewhat far from the sea and some- what high, such as Riyadh and Harare. In places close to the ocean, the dominant cost is desalination, not transport; the process would therefore be less expensive in places like Beijing, Bangkok, Zaragoza, Phoenix, and, of course, coastal cities like Tripoli."[14] After being desalinized at Jubail, Saudi Ara- bia, water is pumped 200 miles (320 km) in- land though a pipeline to the capital city of Riyadh. [15] For cities on the coast, desalina- tion is being increasingly viewed as an un- tapped and unlimited water source. Nevertheless, desalination does not take into account recycling water and broken in- frastructure. Water is reused in Fountain Val- ley, CA, Fairfax, VA, El Paso, TX and Scotts- dale, AZ. This process is an alternative to de- salination that requires 50% less energy due to the significantly lower salt content and produces new water at 30% less cost to the consumer than desalinated sea water without the damage to marine life and ecosystems common to desalination plants. Israel is now desalinating water at a cost of US$0.53 per cubic meter.[16] Singapore is desalinating water for US$0.49 per cubic meter.[17] Many large coastal cities in de- veloped countries are considering the feasib- ility of seawater desalination, due to its cost effectiveness compared with other water sup- ply options, which can include mandatory in- stallation of rainwater tanks or stormwater harvesting infrastructure. Studies have shown that the desalination option is more cost-effective than large-scale recycled water for drinking, and more cost-effective in Sydney than the vastly expensive option of mandatory installation of rainwater tanks or stormwater harvesting infrastructure. The city of Perth has been successfully operating a reverse osmosis seawater desalination plant since 2006, and the West Australian government has announced that a second plant will be built to service the city’s needs. Desalination plants are being built in Aus- tralia’s largest city, Sydney, and at Wonthaggi, Victoria in the near future.[18] The Perth desalination plant is powered partially by renewable energy from the Emu Downs Wind Farm[19]. The Sydney plant will be powered entirely from renewable sources[20], thereby eliminating harmful greenhouse gas emissions to the environ- ment, a common argument used against sea- water desalination due to the energy require- ments of the technology. The purchase or production of renewable energy to power de- salination plants naturally adds to the capital and/or operating costs of desalination. However, recent experience in Perth and Sydney indicates that the additional cost is acceptable to communities, as a city may then augment its water supply without doing environmental harm to the atmosphere. The Queensland state government recently an- nounced that the Gold Coast desalination plant will be powered entirely from renew- able sources, bringing its environmental foot- print down, in line with the other major plants that will be operating around the same time, in Perth and Sydney. In December 2007 the South Australian Government announced that it would build a seawater desalination plant for the city of Adelaide, Australia located at Port Stanvac. The desalination plant is to be funded by rais- ing water rates to achieve full cost recovery. [1] [2] An online, unscientific poll showed that nearly 60% of votes cast were in favor of raising water rates to pay for desalination. [3] A January 17, 2008 article in the Wall. St. Journal states, "In November, Connecticut- based Poseidon Resources Corp. won a key regulatory approval to build a [US]$300 million water-desalination plant in Carlsbad, north of San Diego. The facility would be the largest in the Western Hemisphere, produ- cing 50 million [U.S.] gallons [190,000 m³] of drinking water a day, enough to supply about 100,000 homes... Improved technology has cut the cost of desalination in half in the past decade, making it more competitive... Pos- eidon plans to sell the water for about [US]$950 per acre-foot [1200 m³]. That com- pares with an average [US]$700 an acre-foot [1200 m³] that local agencies now pay for wa- ter." [4] $1,000 per acre-foot works out to $3.06 for 1,000 gallons, which is the unit of water measurement that residential water users are accustomed to being billed in. [5]. While this regulatory hurdle was met, Pos- eidon Resources is not able to break ground until the final approval of a mitigation project for the damage done to marine life through From Wikipedia, the free encyclopedia Desalination 3 the intake pipe, as is required by California law. Poseidon Resources has made progress in Carlsbad, CA despite its unsuccessful at- tempt to complete construction of Tampa Bay Desal, a desalination plant in Tampa Bay, FL in 2001. The Board of Directors of Tampa Bay Water were forced to buy Tampa Bay Desal from Poseidon Resources in 2001 to prevent a third failure of the project. Tampa Bay Water faced with 5 years of engineering problems and operation at 20% capacity due to marine life and growth captured and stuck to reverse osmosis filters prior to fully utiliz- ing this facility in 2007. [21] According to a May 9, 2008 article in Forbes, a San Leandro, California company called Energy Recovery Inc. has been desa- linizing water for US$0.46 per cubic meter. [22] According to a June 5, 2008 article in Globe and Mail, a Jordanian born chemical engineering Ph.D. student at the University of Ottawa named Mohammed Rasool Qtaisha has invented a new desalination technology that is alleged to be between 600% and 700% more efficient than current technology. Ac- cording to the article, General Electric is looking into similar technology, and the U.S. National Science Foundation announced a grant to the University of Michigan to study it as well. Because the patents were still be- ing worked out, the article was very vague about the details of this alleged technology. [23] While desalinating 1,000 gallons of water can cost as much as $3, the same amount of bottled water costs $7,945. [24] Environmental One of the main environmental considera- tions of ocean water desalination plants is the impact of the open ocean water intakes, especially when co-located with power plants. Many proposed ocean desalination plants initial plans relied on these intakes despite perpetuating ongoing impacts on marine life. In the United States, due to a re- cent court ruling under the Clean Water Act these intakes are no longer viable without re- ducing mortality, by ninety percent, of the life in the ocean; the plankton, fish eggs and fish larvae.[25] There are alternatives includ- ing beach wells that eliminate this concern, but require more energy and higher costs while limiting output.[26] Other environmental concerns include air pollution and greenhouse gas emissions from the power plants that provide electricity and/or thermal energy to the desalination plants. Regardless of the method used, there is al- ways a highly concentrated waste product consisting of everything that was removed from the created fresh water. This is some- times referred to as brine, which is also a common term for the byproduct of recycled water schemes that is often disposed of in the ocean. These concentrates are classified by the United States Environmental Protec- tion Agency as industrial wastes. With coastal facilities, it may be possible to return it to the sea without harm if this concentrate does not exceed the normal ocean salinity gradients to which osmoregulators are accus- tomed. Reverse osmosis, for instance, may require the disposal of waste water with sa- linity twice that of normal seawater. The benthic community cannot accommodate such an extreme change in salinity and many filter-feeding animals would be destroyed when the water is returned to the ocean. This presents an increasing problem further in- land, where one needs to avoid ruining exist- ing fresh water supplies such as ponds, rivers and aquifers. As such, proper disposal of con- centrate needs to be investigated during the design phases. To limit the environmental impact of re- turning the brine to the ocean, it can be di- luted with another stream of water entering the ocean, such as the outfall of a waste wa- ter treatment plant or power plant. While seawater power plant cooling water outfalls are not freshwater like waste water treat- ment plant outfalls, the salinity of the brine will still be reduced. If the power plant is me- dium to large sized and the desalination plant is not enormous, the flow of the power plant’s cooling water is likely to be at least several times larger than that of the desalina- tion plant. Another method to reduce the in- crease in salinity is to spread the brine over a very large area so that there is only a slight increase in salinity. For example, once the pipeline containing the brine reaches the sea floor, it can split off into many branches, each one releasing the brine gradually along its length through small holes. This method can be used in combination with the joining of the brine with power plant or waste water plant outfalls. From Wikipedia, the free encyclopedia Desalination 4 The concentrated seawater has the poten- tial to harm ecosystems, especially marine environments in regions with low turbidity and high evaporation that already have elev- ated salinity. Examples of such locations are the Persian Gulf, the Red Sea and, in particu- lar, coral lagoons of atolls and other tropical islands around the world. Because the brine is denser than the surrounding sea water due to the higher solute concentration, discharge into water bodies means that the ecosystems on the bed of the water body are most at risk because the brine sinks and remains there long enough to damage the ecosystems. Careful re-introduction can minimize this problem. For example, for the desalination plant and ocean outlet structures to be built in Sydney from late 2007, the water authority states that the ocean outlets will be placed in locations at the seabed that will maximize the dispersal of the concentrated seawater, such that it will be indistinguishable from normal seawater between 50 meters and 75 meters from the outlet points. Sydney is fortunate to have typical oceanographic conditions off the coast that allow for such rapid dilution of the concentrated byproduct, thereby minimizing harm to the environment. In Perth, Australia, in 2007, the Kwinana Desalination Plant was opened. The water is sucked in from the ocean at only 0.1 meter per second, which is slow enough to let fish escape. The plant provides nearly 140,000 m³ of clean water per day. [6] Desalination compared to other water supply options Increased water conservation and water use efficiency remain the most cost effective pri- ority for supplying water.[27] While compar- ing ocean water desalination to waste water reclamation for drinking water shows desal- ination as the first option, using reclamation for irrigation and industrial use provides mul- tiple benefits.[28] Urban runoff and storm wa- ter capture also provide multiple benefits in treating, restoring and recharging groundwa- ter.[29] An emerging alternative to desaliniza- tion in the State of California and other areas in the American southwest is the commercial importation of bulk water either by very large crude carriers converted to water carriers or pipelines. The idea is presently politically un- popular in Canada where governments have been scrambling to impose trade barriers to bulk water exports as a result of a claim filed in 1999 under Chapter 11 of the NAFTA by Sun Belt Water Inc. a company established in 1990 in Santa Barbara, California, to address pressing local needs due to a severe drought in that area. Sun Belt maintains a web site where documents relating to the dispute are posted online at Company website. Experimental techniques and other developments In the past many novel desalination tech- niques have been researched with varying degrees of success. Some, such as Forward osmosis are still on the drawing board now while others have attracted research funding. For example, to offset the energy require- ments of desalination, the U.S. Government is working to develop practical solar desalination. As an example of newer theoretical ap- proaches for desalination, focusing specific- ally on maximizing energy efficiency and cost effectiveness, Passarell Process may be considered. Other approaches involve the use of geo- thermal energy. From an environmental and economic point of view, in most locations geothermal desalination can be preferable to using fossil groundwater or surface water for human needs, as in many regions the avail- able surface and groundwater resources already have long been under severe stress. Recent research in the U.S. indicates that nanotube membranes may prove to be ex- tremely effective for water filtration and may produce a viable water desalination process that would require substantially less energy than reverse osmosis.[30] On June 23, 2008 it was reported that Siemens Water Technologies had developed a new technology that desalinizes one cubic meter of water while using only 1.5 kWh of energy, which, according to the report, is one half the energy that other processes use. [31] According to MSNBC, a report by Lux Re- search estimated that the worldwide desalin- ated water supply will triple between 2008 and 2020. [32] From Wikipedia, the free encyclopedia Desalination 5 Existing Facilities Tampa Bay Water Desalination Project The Tampa Bay Water Desalination project was originally a private venture led by Pos- eidon Resources. This project was delayed by the bankruptcy of Poseidon Resources suc- cessive partners in the venture, Stone & Webster, then Covanta (formerly Ogden) and its principal subcontractor Hydranautics. Po- seidon’s relationship with Stone & Webster through S & W Water LLC ended in June 2000 when Stone & Webster declared bank- ruptcy and Poseidon Resources purchased Stone & Webster’s stake in S & W Water LLC. Poseidon Resources partnered with Covanta and Hydranautics in 2001, changing the consortium name to Tampa Bay Desal. Through the inability of Covanta to complete construction bonding of the project, the Tampa Bay Water agency was forced to pur- chase the project from Poseidon on May 15, 2002 and underwrite the project financing under its own credit rating. Tampa Bay Water then contracted with Covanta Tampa Construction, who produced a project that did not meet required performance tests, and Covanta Tampa Construction filed bank- ruptcy in October 2003 to prevent losing the contract with Tampa Bay Water, which resul- ted in nearly 6 months of litigation between Covanta Tampa Construction and Tampa Bay Water. The plant was not fully operational until 2007. [33] El Paso (Texas) Desalination Plant Brackish groundwater has been treated at the El Paso Plant since around 2004. Produ- cing 27.5 million gallons of fresh water daily (about 25% of total freshwater deliveries) by reverse osmosis, it is a crucial contribution to water supplies in this water-stressed city. [34] References [1] "Desalination" (definition), The American Heritage Science Dictionary, Houghton Mifflin Company, via dictionary.com. Retrieved on 2007-08-19. [2] "Australia Aids China In Water Management Project." People’s Daily Online, 2001-08-03, via english.people.com.cn. Retrieved on 2007-08-19. [3] There exist a new solution with the HelioTech products. HelioTech company ltd. Takashi, Kume, Amaya Takao, and Mitsuno Tooru. "The Effect of Soil Desalinization in the Hetao Irrigation District, Inner Mongolia, China." Transactions of the Japanese Society of Irrigation, Drainage and Reclamation Engineering, No. 223, pp. 133-139, 2003, abstract via sciencelinks.jp. Retrieved on 2007-08-19. [4] Fischetti, Mark (September 2007), "Fresh from the Sea", Scientific American (Scientific American, Inc.) 297 (3): 118–119, http://www.sciam.com/ article.cfm?id=fresh-from-the-sea, retrieved on 2008-08-03 Note: only the first two paragraphs are available on-line for no charge. [5] Applause, At Last, For Desalination Plant, The Tampa Tribune, December 22, 2007 [6] Kathryn Kranhold, Water, Water, Everywhere..., The Wall Street Journal, January 17, 2008 [7] Source: water-technology.net [8] Hamed, Osman A. (2005). “Overview of hybrid desalination systems – current status and future prospects.” Desalination, 186, 207-214. [9] Misra, B.M., J. Kupitz. (2004). “The role of nuclear desalination in meeting potable water needs in water scarce areas in the next decades.” Desalination, 166, 1-9. [10]Ludwig, Heinz. (2004). “Hybrid systems in seawater desalination – practical design aspects, present status and development perspectives.” Desalination, 164, 1-18. [11]How Aircraft Carriers Work [12] "Nuclear Desalination: UIC Nuclear Issues Briefing Paper #74," Uranium Information Centre Ltd., Melbourne, Australia, October 2006. Retrieved on 2007-08-20. [13]Barlow, Maude, and Tony Clarke, "Who Owns Water?" The Nation, 2002-09-02, via thenation.com. Retrieved on 2007-08-20. [14]Zhoua, Yuan, and Richard S.J. Tolb. "Evaluating the costs of desalination and water transport." (Working paper). Via a From Wikipedia, the free encyclopedia Desalination 6 Hamburg University website. 2004-12-09. Retrieved on 2007-08-20. [15]Desalination is the Solution to Water Shortages, redOrbit, May 2, 2008 [16]Sitbon, Shirli. "French-run water plant launched in Israel," European Jewish Press, via ejpress.org, 2005-12-28. Retrieved on 2007-08-20. [17] "Black & Veatch-Designed Desalination Plant Wins Global Water Distinction," (Press release). Black & Veatch Ltd., via edie.net, 2006-05-04. Retrieved on 2007-08-20. [18] "Sydney desalination plant to double in size," ABC News (Australian Broadcasting Corporation), via abc.net.au, 2007-06-25. Retrieved on 2007-08-20. [19]Australia Turns to Desalination by Michael Sullivan and PX Pressure Exchanger energy recovery devices from Energy Recovery Inc. An Environmentally Green Plant Design. Morning Edition, National Public Radio, June 18, 2007 [20]Fact sheets [21]http://www.tampabaywater.org/ watersupply/tbdesalhistory.aspx [22]Hydro-Alchemy, Forbes, May 9, 2008 [23]Ottawa student may hold secret to Water For All, Globe and Mail, June 5, 2008 [24]The Arid West—Where Water Is Scarce - Desalination—a Growing Watersupply Source, Library Index [25]http://www.desalresponsegroup.org/files/ RiverkeepervEPA1-25-07_decision.pdf [26]untitled [27]Gleick, Peter H., Dana Haasz, Christine Henges-Jeck, Veena Srinivasan, Gary Wolff, Katherine Kao Cushing, and Amardip Mann. (November 2003.) "Waste not, want not: The potential for urban water conservation in California." (Website). Pacific Institute. Retrieved on 2007-09-20. [28]Cooley, Heather, Peter H. Gleick, and Gary Wolff. (June 2006.) "Desalination, With a Grain of Salt – A California Perspective." (Website). Pacific Institute. Retrieved on 2007-09-20. [29]Gleick, Peter H., Heather Cooley, David Groves. (September 2005.) "California water 2030: An efficient future." (Website). Pacific Institute. Retrieved on 2007-09-20. [30]Lawrence Livermore National Laboratory Public Affairs (2006-05-18). Nanotube membranes offer possibility of cheaper desalination. Press release. http://www.llnl.gov/pao/news/ news_releases/2006/NR-06-05-06.html. Retrieved on 2007-09-07. [31]Team wins $4m grant for breakthrough technology in seawater desalination, The Straits Times, June 23, 2008 [32]A Rising Tide for New Desalinated Water Technologies, MSNBC, March. 17, 2009 [33]http://www.tampabaywater.org/ watersupply/tbdesalhistory.aspx [34]http://www.epwu.org/water/ desal_info.html See also • Salinity control • Soil salinity • Soil desalination model • Soil salinity and groundwater model Further reading • Committee on Advancing Desalination Technology, National Research Council. (2008). Desalination: A National Perspective. National Academies Press. External links • SIDEM - French Desalination Society • Global Water Intelligence • DesalData.com - Business Intelligence for the Desalination Sector • Water Desalination Report - The Weekly Newsletter for Desalination and Advanced Water Treatment • GeoNoria Solar Desalination Process • National Academies Press | Desalination: A National Perspective • World Wildlife Fund | Desalination: option or distraction? • International Desalination Association • Desalination & Water Reuse - Official magazine of the International Desalination Association • European Desalination Society • IAEA - Nuclear Desalination • DME - German Desalination Society • Large scale desalination of sea water using solar energy From Wikipedia, the free encyclopedia Desalination 7 • "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 • Sun Belt Water Inc. Company website • Desalination bibliography Library of Congress • Water-Technology • 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 • Water Desalination Free pdf book • Tampa Bay Water Seawater Desalination Reverse Osmosis Desalination Plant on Tampa Bay • Solar thermal-driven desalination plants based on membrane distillation • Encyclopedia of Water Sciences, Engineering and Technology Resources • Report on other byproducts of desalination plants • wind-powered desalinization plant in Perth, Australia, is an example of how technology is insulating rich countries from impacts of climate change, while poor countries remain particularly vulnerable. • The Desal Response Group • Encyclopedia of Desalination and water and Water Resources Retrieved from "http://en.wikipedia.org/wiki/Desalination" Categories: Filters, Water supply, Water desalination This page was last modified on 18 May 2009, at 18:36 (UTC). All text is available under the terms of the GNU Free Documentation License. (See Copyrights for details.) Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a U.S. registered 501(c)(3) tax- deductible nonprofit charity. Privacy policy About Wikipedia Disclaimers From Wikipedia, the free encyclopedia Desalination 8
