Editing Desalination (section)

==History==
{{See also|Distillation#Desalination by distillation|Distilled water#History}}
Ancient Greek philosopher [[Aristotle]] observed in his work ''[[Meteorology (Aristotle)|Meteorology]]'' that "salt water, when it turns into vapour, becomes sweet and the vapour does not form salt water again when it condenses", and that a fine wax vessel would hold potable water after being submerged long enough in seawater, having acted as a membrane to filter the salt.<ref>Aristotle with E.W. Webster, trans., ''Meteorologica'', in:  Ross, W. D., ed., ''The Works of Aristotle'', vol. 3, (Oxford, England:  Clarendon Press, 1931), Book III, [https://archive.org/stream/workstranslatedi03arisuoft#page/n71/mode/2up §358: 16–18 and §359: 1–5.]</ref> 

At the same time the desalination of seawater was recorded in China. Both the ''Classic of Mountains and Water Seas'' in the [[Period of the Warring States]] and the ''Theory of the Same Year'' in the [[Han dynasty|Eastern Han Dynasty]] mentioned that people found that the bamboo mats used for steaming rice would form a thin outer layer after long use. The as-formed thin film had [[adsorption]] and [[ion exchange]] functions, which could adsorb salt.<ref>{{Cite journal |last1=Zhang |first1=Huachao |last2=Xu |first2=Haoyuan |date=2021-03-01 |title=Investigation and Research on the Status Quo of Informatization Development at Home and Abroad |journal=IOP Conference Series: Earth and Environmental Science |volume=692 |issue=2 |pages=022040 |doi=10.1088/1755-1315/692/2/022040 |bibcode=2021E&ES..692b2040Z |issn=1755-1307|doi-access=free }}</ref>

Numerous examples of experimentation in desalination appeared throughout Antiquity and the [[Middle Ages]],<ref>See:
*Joseph Needham, Ho Ping-Yu, Lu Gwei-Djen, Nathan Sivin, ''Science and Civilisation in China: Volume 5, Chemistry and Chemical Technology'' (Cambridge, England:  Cambridge University Press, 1980), [https://books.google.com/books?id=xrNDwP0pS8sC&pg=PA60 p. 60.]
*[[Alexander of Aphrodisias]] (fl. 200 A.D.) wrote, in his commentary on Aristotle's ''Meteorology'', that if a lid is placed on a boiling pot of seawater, fresh water will condense on the lid.
*In his ''Hexaemeron'', Homily IV, § 7, [[Basil of Caesarea|St. Basil of Caesarea]] (c. 329–379 AD) mentioned that sailors produced fresh water via distillation.  Saint Basil with Sister Agnes Clare Way, trans., ''Saint Basil Exegetic Homilies'' (Washington, DC:  The Catholic University of America Press, 1963), p. 65.  [https://books.google.com/books?id=AWxwDmFvDiwC&pg=PA65 From p. 65:]  "Moreover, it is possible to see the water of the sea boiled by sailors, who, catching the vapors in sponges, relieve their thirst fairly well in times of need."</ref> but desalination became feasible on a large scale only in the modern era.<ref>{{cite web |title=Sample |url=http://www.desware.net/Sample-Chapters/D01/01-003.pdf |website=www.desware.net}}</ref> A good example of this experimentation comes from [[Leonardo da Vinci]] (Florence, 1452), who realized that distilled water could be made cheaply in large quantities by adapting a [[still]] to a cookstove.<ref>J. R. Partington, History of Chemistry, Vol. 2–3, Macmillan, London, 1962.</ref> During the Middle Ages elsewhere in Central Europe, work continued on distillation refinements, although not necessarily directed towards desalination.<ref name="Birkett1984">{{Cite journal |last=Birkett |first=James D. |date=1984-01-01 |title=A brief illustrated history of desalination: From the bible to 1940 |journal=Desalination |language=en |volume=50 |pages=17–52 |doi=10.1016/0011-9164(84)85014-6 |bibcode=1984Desal..50...17B |issn=0011-9164}}</ref>

The first major land-based desalination plant may have been installed under emergency conditions on an island off the coast of [[Tunisia]] in 1560.<ref name="Birkett1984" /><ref name="NebbiaMenozzi1966">{{Cite journal |last1=Nebbia |first1=G. |last2=Menozzi |first2=G.N. |date=1966 |title=Aspetti storici della dissalazione |journal=Acqua Ind. |volume=41–42 |pages=3–20}}</ref> It is believed that a garrison of 700 Spanish soldiers was besieged by the Turkish army and that, during the siege, the captain in charge fabricated a [[still]] capable of producing 40 barrels of fresh water per day, though details of the device have not been reported.<ref name="NebbiaMenozzi1966" />

Before the [[Industrial Revolution]], desalination was primarily of concern to oceangoing ships, which otherwise needed to keep on board supplies of fresh water. Sir [[Richard Hawkins]] (1562–1622), who made extensive travels in the [[South Seas]], reported that he had been able to supply his men with fresh water by means of shipboard distillation.<ref>{{Cite journal |last=Haarhoff |first=Johannes |date=2009-02-01 |title=The Distillation of Seawater on Ships in the 17th and 18th Centuries |journal=Heat Transfer Engineering |volume=30 |issue=3 |pages=237–250 |bibcode=2009HTrEn..30..237H |doi=10.1080/01457630701266413 |issn=0145-7632 |s2cid=121765890}}</ref> Additionally, during the early 1600s, several prominent figures of the era such as [[Francis Bacon]] and [[Walter Raleigh]] published reports on desalination.<ref name="NebbiaMenozzi1966" /><ref>{{Cite journal |last=Baker |first=M.N. |date=1981 |title=Quest for Pure Water |journal=Am. Water Works Assoc. 2nd Ed. |volume=1}}</ref> These reports and others,<ref>{{citation |last=Cleveland |first=J. |title=Universal Magazine |date=1754 |pages=44}}</ref> set the climate for the first patent dispute concerning desalination apparatus. The two first patents regarding water desalination were approved in 1675 and 1683 (patents No. 184<ref>W. Walcot, Purifying Water, Britain No. 184, 1675</ref> and No. 226,<ref>R. Fitzgerald et al, Purifying Salt Water, Britain No. 226, 1683.</ref> published by [[William Walcot]] and Robert Fitzgerald (and others), respectively). Nevertheless, neither of the two inventions entered service as a consequence of scale-up difficulties.<ref name="Birkett1984" /> No significant improvements to the basic seawater distillation process were made during the 150 years from the mid-1600s until 1800.

When the frigate ''[[Protector (1779 frigate)|Protector]]'' was sold to Denmark in the 1780s (as the ship ''Hussaren'') its still was studied and recorded in great detail.<ref>{{Cite web |title=Enkel Søgning |url=http://www.orlogsbasen.dk/visskib.asp?skib=Hussaren&la=1 |website=www.orlogsbasen.dk}}</ref> In the United States, [[Thomas Jefferson]] catalogued heat-based methods going back to the 1500s, and formulated practical advice that was publicized to all U.S. ships on the reverse side of sailing clearance permits.<ref>{{cite web |author=Thomas Jefferson |date=21 November 1791 |title=Report on Desalination of Sea Water |url=https://founders.archives.gov/documents/Jefferson/01-22-02-0296}}</ref><ref>{{Cite web |title=Desalination of Sea Water {{pipe}} Thomas Jefferson's Monticello |url=https://www.monticello.org/site/research-and-collections/desalination-sea-water |website=www.monticello.org}}</ref>

Beginning about 1800, things started changing as a consequence of the appearance of the [[steam engine]] and the so-called [[Steam power during the Industrial Revolution|age of steam]].<ref name="Birkett1984" /> Knowledge of the thermodynamics of steam processes<ref>{{Cite book |last=Lyle |first=Oliver |url={{google books|plainurl=yes|id=dtgTngEACAAJ}} |title=The Efficient Use of Steam: Written for the Fuel Efficiency Committee of the Ministry of Fuel and Power |date=1956 |publisher=H.M. Stationery Office |language=en}}</ref> and the need for a pure water source for its use in boilers<ref>{{Cite book |last=Fraser-Macdonald |first=A. |url={{google books|plainurl=yes|id=yJxBAAAAIAAJ}} |title=Our Ocean Railways: Or, The Rise, Progress, and Development of Ocean Steam Navigation |date=1893 |publisher=Chapman and Hall, Limited |language=en}}</ref> generated a positive effect regarding distilling systems. Additionally, the spread of [[European colonialism]] induced a need for freshwater in remote parts of the world, thus creating the appropriate climate for water desalination.<ref name="Birkett1984" />

In parallel with the development and improvement of systems using steam ([[multiple-effect evaporator]]s), these type of devices quickly demonstrated their desalination potential.<ref name="Birkett1984" /> In 1852, [[wikisource:Normandy, Alphonse René Le Mire de|Alphonse René le Mire de Normandy]] was issued a British patent for a vertical tube seawater distilling unit that, thanks to its simplicity of design and ease of construction, gained popularity for shipboard use.<ref name="Birkett1984" /> Land-based units did not significantly appear until the latter half of the nineteenth century.<ref name="Birkett2010">{{Cite book |last=Birkett |first=James D. |url= |title=History, Development and Management of Water Resources |date=2010-05-15 |publisher=EOLSS Publishers |isbn=978-1-84826-419-9 |volume=I |page=381 |language=en |chapter=History of Desalination Before Large-Scale Use |chapter-url={{google books|plainurl=yes|id=8bfODAAAQBAJ|page=381}}}}</ref> In the 1860s, the US Army purchased three Normandy evaporators, each rated at 7000 gallons/day and installed them on the islands of [[Key West]] and [[Dry Tortugas]].<ref name="Birkett1984" /><ref name="Birkett2010" /><ref>{{cite journal|last=Birkett |first=J. D. |title=The 1861 de Normandy desalting unit at Key West |journal=International Desalination & Water Reuse Quarterly |volume=7|issue=3|pages=53–57}}</ref> Another land-based plant was installed at [[Suakin]] during the 1880s that provided freshwater to the British troops there. It consisted of six-effect distillers with a capacity of 350 tons/day.<ref name="Birkett1984" /><ref name="Birkett2010" />

After World War II, many technologies were developed or improved such as Multi Effect Flash desalination (MEF) and Multi Stage Flash desalination (MSF). Another notable technology is freeze-thaw desalination.<ref>{{Cite journal |last1=Mao |first1=Shudi |last2=Onggowarsito |first2=Casey |last3=Feng |first3=An |last4=Zhang |first4=Stella |last5=Fu |first5=Qiang |last6=Nghiem |first6=Long D. |date=2023 |title=A cryogel solar vapor generator with rapid water replenishment and high intermediate water content for seawater desalination |url=http://dx.doi.org/10.1039/d2ta08317e |journal=Journal of Materials Chemistry A |volume=11 |issue=2 |pages=858–867 |doi=10.1039/d2ta08317e |issn=2050-7488}}</ref> Freeze-thaw desalination, (cryo-desalination or FD), excludes dissolved minerals from saline water through crystallization.<ref>{{Cite journal |last1=Zambrano |first1=A. |last2=Ruiz |first2=Y. |last3=Hernández |first3=E. |last4=Raventós |first4=M. |last5=Moreno |first5=F.L. |date=June 2018 |title=Freeze desalination by the integration of falling film and block freeze-concentration techniques |url=http://dx.doi.org/10.1016/j.desal.2018.02.015 |journal=Desalination |volume=436 |pages=56–62 |doi=10.1016/j.desal.2018.02.015 |bibcode=2018Desal.436...56Z |hdl=2117/116164 |issn=0011-9164|hdl-access=free }}</ref>

The Office of Saline Water was created in the [[United States Department of the Interior]] in 1955 in accordance with the Saline Water Conversion Act of 1952.<ref name="Transcript" /><ref name="Records">{{cite web |date=August 15, 2016 |title=Records of the office of Saline Water |url=https://www.archives.gov/research/guide-fed-records/groups/380.html}}</ref> This act was motivated by a water shortage in California and inland western United States. The Department of the Interior allocated resources including research grants, expert personnel, patent data, and land for experiments to further advancements.<ref>{{Cite web |title=Saline Water Act |url=https://uscode.house.gov/statviewer.htm?volume=66&page=328 |access-date=2024-01-20 |website=uscode.house.gov}}</ref> 

The results of these efforts included the construction of over 200 electrodialysis and distillation plants globally, [[reverse osmosis]] (RO) research, and international cooperation (for example, the First International Water Desalination Symposium and Exposition in 1965).<ref>{{Cite journal |last=Report |first=Committee Progress |date=1966 |title=Saline-Water Conversion |url=https://www.jstor.org/stable/41264584 |journal=Journal (American Water Works Association) |volume=58 |issue=10 |pages=1231–1237 |doi=10.1002/j.1551-8833.1966.tb01688.x |jstor=41264584 |issn=0003-150X}}</ref> The Office of Saline Water merged into the Office of Water Resources Research in 1974.<ref name="Records" />

The first industrial desalination plant in the United States opened in [[Freeport, Texas]] in 1961 after a decade of regional drought.<ref name="Transcript" /> 

By the late 1960s and the early 1970s, RO started to show promising results to replace traditional thermal desalination units. Research took place at state universities in California, at the [[Dow Chemical Company]] and [[DuPont]].<ref>{{cite web |author=David Talbot |date=23 November 2015 |title=Bankrolling the 10 Breakthrough Technologies: Megascale Desalination |url=http://www.ide-tech.com/blog/publication/bankrolling-10-breakthrough-technologies-megascale-desalination/ |url-status=dead |archive-url=https://web.archive.org/web/20161003210024/http://www.ide-tech.com/blog/publication/bankrolling-10-breakthrough-technologies-megascale-desalination/ |archive-date=October 3, 2016 |access-date=October 3, 2016}}</ref> Many studies focus on ways to optimize desalination systems.<ref>{{cite journal |last1=Singleton |first1=M. |last2=et. |first2=al. |date=2011 |title=Optimization of ramified absorber networks doing desalination |journal=Phys. Rev. E |volume=83 |issue=1 |page=016308 |bibcode=2011PhRvE..83a6308S |doi=10.1103/PhysRevE.83.016308 |pmid=21405775 |doi-access=free}}</ref><ref>{{cite journal |last1=Koutroulis |first1=E. |last2=et. |first2=al. |date=2010 |title=Design optimization of desalination systems power-supplied by PV and W/G energy sources |journal=Desalination |volume=258 |issue=1–3 |page=171 |doi=10.1016/j.desal.2010.03.018|bibcode=2010Desal.258..171K }}</ref> The first commercial RO plant, the Coalinga desalination plant, was inaugurated in California in 1965 for [[brackish water]].<ref>{{cite book |last1=Fujiwara |first1=Masatoshi |last2=Aoshima |first2=Yaichi |title=Mechanisms for Long-Term Innovation Technology and Business Development of Reverse Osmosis Membranes |date=2022 |publisher=[[Springer Nature|Springer]] |location=Singapore |isbn=9789811948954 |page=59}}</ref> [[Sidney Loeb|Dr. Sidney Loeb]], in conjunction with staff at [[University of California, Los Angeles|UCLA]], designed a large pilot plant to gather data on RO, but was successful enough to provide freshwater to the residents of Coalinga. This was a milestone in desalination technology, as it proved the feasibility of RO and its advantages compared to existing technologies (efficiency, no phase change required, ambient temperature operation, scalability, and ease of standardization).<ref>{{Cite journal |last=Loeb |first=Sidney |date=1984-01-01 |title=Circumstances leading to the first municipal reverse osmosis desalination plant |url=https://dx.doi.org/10.1016/0011-9164%2884%2985015-8 |journal=Desalination |volume=50 |pages=53–58 |doi=10.1016/0011-9164(84)85015-8 |bibcode=1984Desal..50...53L |issn=0011-9164}}</ref> A few years later, in 1975, the first [[sea water]] reverse osmosis desalination plant came into operation.

As of 2000, more than 2000 plants were operated. The largest are in Saudi Arabia, Israel, and the UAE; and the biggest plant with a volume of 1,401,000 m3/d is in Saudi Arabia (Ras Al Khair).<ref name="AngelakisValipourChooAhmedBabaKumarToorWang2021">{{Cite journal |last1=Angelakis |first1=Andreas N. |last2=Valipour |first2=Mohammad |last3=Choo |first3=Kwang-Ho |last4=Ahmed |first4=Abdelkader T. |last5=Baba |first5=Alper |last6=Kumar |first6=Rohitashw |last7=Toor |first7=Gurpal S. |last8=Wang |first8=Zhiwei |date=2021-08-16 |title=Desalination: From Ancient to Present and Future |journal=Water |volume=13 |issue=16 |pages=2222 |doi=10.3390/w13162222 |doi-access=free |bibcode=2021Water..13.2222A |issn=2073-4441|hdl=11147/11590 |hdl-access=free }}</ref>

This decade also saw progress in integrating renewable energy sources, such as solar and wind power, into desalination systems. Though initially in early stages, these efforts paved the way for more environmentally sustainable desalination practices.<ref>{{Cite journal |last1=Al-Obaidi |first1=Mudhar A. |last2=Alsadaie |first2=Salih |last3=Alsarayreh |first3=Alanood |last4=Sowgath |first4=Md. Tanvir |last5=Mujtaba |first5=Iqbal M. |date=2024-04-11 |title=Integration of Renewable Energy Systems in Desalination |journal=Processes |language=en |volume=12 |issue=4 |pages=770 |doi=10.3390/pr12040770 |doi-access=free |issn=2227-9717}}</ref>

The 2010s and 2020s marked the emergence of next-generation membranes, including graphene-based membranes, aquaporin-inspired biomimetic membranes, ceramic membranes, and nanocomposites. These materials significantly improved water permeability, selectivity, and fouling resistance.<ref>{{Cite journal|url=https://www.nature.com/articles/s41699-024-00462-z|title=Graphene oxide-based membranes for water desalination and purification|first1=Saurabh Kr|last1=Tiwary|first2=Maninderjeet|last2=Singh|first3=Shubham Vasant|last3=Chavan|first4=Alamgir|last4=Karim|date=March 27, 2024|journal=npj 2D Materials and Applications|volume=8|issue=1|pages=1–19|via=www.nature.com|doi=10.1038/s41699-024-00462-z}}</ref>

As of 2021 22,000 plants were in operation<ref name="AngelakisValipourChooAhmedBabaKumarToorWang2021" /> In 2024 the Catalan government installed a floating offshore plant near the port of Barcelona and purchased 12 mobile desalination units for the northern region of the Costa Brava to combat the severe drought.<ref>{{Cite web |date=2024-04-18 |title=Floating desalination unit off Barcelona shore to avoid using water tanker ships |url=https://www.catalannews.com/drought/item/desalination-plant-barcelona-offshore-catalonia-drought |access-date=2024-05-20 |website=www.catalannews.com |language=en}}</ref>

In 2012, cost averaged $0.75 per cubic meter. By 2022, that had declined (before inflation) to $0.41. Desalinated supplies are growing at a 10%+ compound rate, doubling in abundance every seven years.<ref>{{Cite web |last=Zimet |first=Saul |date=2023-09-22 |title=Desalinating Water Is Becoming "Absurdly Cheap" |url=https://humanprogress.org/desalinating-water-is-becoming-absurdly-cheap/ |access-date=2024-07-05 |website=Human Progress |language=en-US}}</ref>

Between 2024 and 2025, Spain has recently announced a €340 million investment to build Africa’s largest desalination plant in Casablanca, demonstrating the growing importance of large-scale desalination infrastructure.<ref>{{Cite web|url=https://www.moroccoworldnews.com/2025/05/197899/spain-commits-e340-million-to-casablanca-desalination-plant/|title=Spain Commits €340 Million to Casablanca Desalination Plant|first=Adil|last=Faouzi|date=May 7, 2025}}</ref>