Editing Distilled water

{{Short description|Water purified by condensing it from steam}}
[[File:Aqua-distillata.jpg|thumb|Bottle for distilled water in the [[Royal Palace of Madrid#Royal Pharmacy|Real Farmacia]] in Madrid]]

'''Distilled water''' is water that has been purified by boiling it into [[water vapor|vapor]] then condensing it back into liquid in a separate container. Impurities in the original water that do not boil below or near the [[properties of water|boiling point of water]] remain in the original container.

==History==
{{See also|Distillation#Desalination by distillation|Desalination#History}}
[[Drinking water]] has been distilled from [[seawater]] since at least about AD 200, when the process was clearly described by [[Alexander of Aphrodisias]].<ref name=Taylor>{{Cite journal| doi = 10.1080/00033794500201451 | issn = 0003-3790 | volume = 5 | issue = 3 | page = 186 | last = Taylor | first = F. Sherwood | author-link = F. Sherwood Taylor | title = The Evolution of the Still | journal = Annals of Science | year = 1945}}</ref> Its history predates this, as a passage in [[Aristotle]]'s ''[[Meteorologica]]'' refers to the distillation of water.<ref name="Meteorology">{{cite web |author=Aristotle |title=Meteorology – Book II |url=https://ebooks.adelaide.edu.au/a/aristotle/meteorology/book2.html |url-status=dead |archive-url=https://web.archive.org/web/20100426031024/http://ebooks.adelaide.edu.au/a/aristotle/meteorology/book2.html |archive-date=2010-04-26 |access-date=2010-06-14 |publisher=The University of Adelaide |at=II.3, 358b16 |format=PDF}}</ref> Captain Israel Williams of the [[Friendship of Salem#Friendship .281797.29|''Friendship'' (1797)]] improvised a way to distill water, which he described in his journal.<ref>{{cite book|chapter-url=https://archive.org/stream/cu31924028839152/cu31924028839152_djvu.txt|title=The old shipmasters of Salem|last=Trow|first=Charles Edward|publisher=G.P. Putnam's Sons|year=1905|location=New York and London|pages=178ff|chapter=Chapter XVI|oclc=4669778|quote=Short of Fresh Water Causes Alarm — Captain Williams's Invention to Make Salt Water Fresh — His 'Still' Described by him}}</ref>

==Applications==
In chemical and biological laboratories, as well as in industry, in some appliances, [[DI water|deionized water]] or [[Reverse osmosis|reverse osmosis water]] can be used instead of distilled water as a cheaper alternative.
If exceptionally high-purity water is required, [[Purified water#Double distillation|double distilled water]] is used.

In general, non-purified water could cause or interfere with chemical reactions as well as leave mineral deposits after boiling away. One method of removing impurities from water and other fluids is [[distillation]].

For example, [[ions]] commonly found in tap water would drastically reduce lifespans of [[lead–acid batteries]] used in cars and trucks. These ions are not acceptable in automotive cooling systems because they corrode internal engine components and deplete typical [[antifreeze]] anti-corrosion additives.<ref>[https://web.archive.org/web/20100701012047/http://www.hazardouswaste.utah.gov/SWBranch/Adobe/P2Factsheets/AntifreezeRecyclingFactSheet.pdf Pollution Prevention Fact Sheet Antifreeze Recycling & Disposal]. Utah Department of Environmental Quality, US</ref>

Any non-volatile or mineral components in water are left behind when the water evaporates or boils away. Water escaping as steam, for example from a boiler of heating system or steam engine, leaves behind any dissolved materials leading to mineral deposits known as [[Glossary of boiler terms#S|boiler scale]].
[[File:Steam water distiller.JPG|thumb|A boiling water distiller. Boiling tank on top and holding tank on the bottom.]]

Low-volume humidifiers such as [[cigar]] [[humidor]]s can use distilled water to avoid mineral deposits.<ref>{{Cite web|date=2020-06-19|title=Distilled water {{!}} Empire City Auto Parts|url=https://empirecityautoparts.com/products/parts/distilled-water/|access-date=2021-09-22|language=en-US}}</ref>

Certain biological applications require controlled impurities, especially in experiments. For example, distilling water to be added to an [[aquarium]] would remove known and unknown non-volatile contaminants. Living things require specific minerals; adding distilled water to an ecosystem, such as an aquarium, would reduce the concentration of these minerals. Fish and other living things that have evolved to survive in lakes and oceans should be expected to thrive at mineral ranges found in their original habitat.<ref>{{cite web |url=http://www.dfg.ca.gov/caep/r3/docs/basic-aquarium-set-up.pdf |title=Basic Aquarium System Set-Up Trout-in-the-Classroom |access-date=2015-01-03 |url-status=dead |archive-url=https://web.archive.org/web/20150923214044/http://www.dfg.ca.gov/caep/r3/docs/basic-aquarium-set-up.pdf|publisher=Department of Fish and Game |archive-date=2015-09-23 }}</ref>

Controlled impurities as well as equipment reliability are critically important in medical applications where, for example, distilled water is used in [[continuous positive airway pressure]] (CPAP) machines to humidify air for breathing. Distilled water will not leave contaminants behind when the humidifier in the CPAP machine evaporates the water.<ref>{{cite web|title=Distilled Water And CPAP Usage|url=http://www.cpap.com/cpap-faq/Humidifiers.html#why-do-i-need-to-use-distilled-water-with-in-my-humidifier-chamber|publisher=cpap.com|url-status=live|archive-url=https://web.archive.org/web/20140705042850/http://www.cpap.com/cpap-faq/Humidifiers.html#why-do-i-need-to-use-distilled-water-with-in-my-humidifier-chamber|archive-date=2014-07-05}}</ref><ref>{{cite web|url=http://www.cpap.com/cpap-faq/Humidifiers.html#why-do-i-need-to-use-distilled-water-with-in-my-humidifier-chamber|title=CPAP Humidifier Frequently Asked Questions - CPAP.com|work=cpap.com|url-status=live|archive-url=https://web.archive.org/web/20140705042850/http://www.cpap.com/cpap-faq/Humidifiers.html#why-do-i-need-to-use-distilled-water-with-in-my-humidifier-chamber|archive-date=2014-07-05}}</ref>

It is also possible for brewers to blend distilled water with hard water to mimic the soft waters of [[Plzeň]].<ref>{{cite web|url=http://www.howtobrew.com/section3/chapter15-1.html|title=How to Brew – By John Palmer – Reading a Water Report|work=howtobrew.com|url-status=live|archive-url=https://web.archive.org/web/20091005195150/http://www.howtobrew.com/section3/chapter15-1.html|archive-date=2009-10-05}}</ref>

Another application was to increase the density of the air to assist early airplane jet engines during takeoff in 'hot and high' atmospheric conditions, as was used on the early [[Boeing 707]].<ref>''Down the Susquehanna to the Chesapeake'' by John H. Brubaker, Jack Brubaker – page 163</ref>

===Use in steam irons===
Distilled water can be used in [[Ironing|steam irons]] for pressing clothes to minimize the build-up of limescale in hard water areas shortening the lifespan of steam irons. Some steam irons have built in filters to remove minerals from the water meaning standard tap water can be used.

==Equipment to distill water==
[[File:Double Distilled Water Unit.jpg|thumb|Typical laboratory distillation unit]]

Until World War II, distilling seawater to produce [[fresh water]] was time-consuming and expensive in fuel. The saying was: "It takes one gallon of fuel to make one gallon of fresh water."{{citation needed|date=August 2018}} Shortly before the war, Dr. R.&nbsp;V. Kleinschmidt developed a compression still, which became known as the Kleinschmidt still, for extracting fresh water from seawater or contaminated water. By compressing the steam produced by boiling water, {{convert|175|gal|abbr=on}} of fresh water could be extracted from seawater for every gallon ({{convert|1|gal|disp=out}}) of fuel used. During World War II this equipment became standard on Allied ships and on trailer mounts for armies. This method was in widespread use in ships and portable water distilling units<ref>{{cite book |url=https://books.google.com/books?id=2yADAAAAMBAJ&q=popular+science+February+1946&pg=PA89 |title=Popular Science |author=Bonnier Corporation |date=February 1946}}</ref> during the latter half of the century. Modern vessels now use [[Flash evaporation|flash-type evaporators]] to boil seawater, heating the water to between {{convert|70|and|80|C}} and evaporating the water in a vacuum; this is then collected as condensation before being stored.

[[Solar still]]s can be relatively simple to design and build, with very cheap materials.<ref>{{cite web |url=http://www.thefarm.org/charities/i4at/surv/sstill.htm |title=Solar Water Distiller |access-date=2009-09-03 |url-status=dead |archive-url=https://web.archive.org/web/20090819050013/http://www.thefarm.org/charities/i4at/surv/sstill.htm |archive-date=2009-08-19 |publisher=thefarm.org}}</ref>

Distilling water with commercial equipment will almost completely remove all dissolved minerals such as calcium, magnesium, sodium, fluoride, potassium, iron, and zinc leaving a TDS of <1PPM, and reduce its electrical conductivity to <2 μS/cm. Typical tap water has electrical conductivity in the range of 200–800 μS/cm. The pH of distilled water is always slightly lower than 7 (neutral) because distilled water will absorb small amounts of carbon dioxide gas from the atmosphere which forms traces of carbonic acid and lowers the pH of distilled water to around 5.8 pH (very weakly acidic).<ref>{{Cite journal |title=The pH of water from various sources: an overview for recommendation for patients with atopic dermatitis |journal=Asia Pacific Allergy| year=2013 |language=en-GB|doi=10.5415/apallergy.2013.3.3.155| last1=Kulthanan | first1=Kanokvalai | last2=Nuchkull | first2=Piyavadee | last3=Varothai | first3=Supenya | volume=3 | issue=3 |pages=155–160 |pmid=23956962 | pmc=3736366 }}

{{Citation | year=2022 | title=Distilled Water pH | url=https://www.golyath.co.uk/blog/distilled-water-ph/ | access-date=22 February 2023}}

</ref>

== Drinking distilled water ==
{{Further|Water purification#Additional treatment options}}
Bottled distilled water can usually be found in supermarkets or pharmacies, and home water distillers are available as well. Water purification, such as distillation, is especially important in regions where water resources or tap water is not suitable for ingesting without boiling or chemical treatment.

Municipal water supplies almost always contain trace components at levels which are regulated to be safe for consumption.<ref>{{cite web |url=http://water.epa.gov/drink/contaminants/index.cfm |title=Drinking Water Contaminants |work=water.epa.gov |year=2011 |access-date=October 25, 2011 |url-status=live |archive-url=https://web.archive.org/web/20150202094944/http://water.epa.gov/drink/contaminants/index.cfm |archive-date=February 2, 2015 }}</ref> Some other components such as trace levels of [[aluminium]] may result from the treatment process. [[Fluoride]] and other ions are not removed through conventional water filter treatments. However, distillation eliminates most impurities.<ref>{{cite journal |last=Anjaneyulu |first=L. |author2=Kumar, E. Arun |author3=Sankannavar, Ravi |author4= Rao, K. Kesava |title=Defluoridation of Drinking Water and Rainwater Harvesting Using a Solar Still |journal=Industrial & Engineering Chemistry Research |date=13 June 2012 |volume=51 |issue=23 |pages=8040–8048 |doi=10.1021/ie201692q}}</ref>

Distilled water is also used for drinking water in arid seaside areas lacking sufficient freshwater, via [[Desalination#Methods|desalination]] of seawater.<ref name="Kozisek 2005">{{cite web |url=https://iris.who.int/bitstream/handle/10665/43403/9241593989_eng.pdf?sequence=1#page=157 |title=Health risks from drinking demineralised water (application/pdf Object) |first=F. |last=Kozisek |work=who.int |year=2005 |access-date=October 25, 2011 }} (Chapter 12 of the [[World Health Organization]] report ''[https://web.archive.org/web/20071019054840/http://www.who.int/water_sanitation_health/dwq/nutrientsindw/en/ Nutrients in drinking-water]'')</ref>

==Health effects==
Distillation removes all minerals from water. This results in demineralised water, which has not been proven to be healthier than drinking water. The [[World Health Organization]] investigated the health effects of demineralised water in 1982, and its experiments in humans found that demineralised water increased [[diuresis]] and the elimination of [[electrolyte]]s, with decreased serum potassium concentration.{{Citation needed|date=January 2021}} [[Magnesium]], [[calcium]], and other nutrients in water can help to protect against nutritional deficiency. Recommendations for magnesium have been put at a minimum of 10&nbsp;mg/L with 20–30&nbsp;mg/L optimum; for calcium a 20&nbsp;mg/L minimum and a 40–80&nbsp;mg/L optimum, and a total water hardness (adding magnesium and calcium) of 2–4&nbsp;[[mmol/L]]. At water hardness above 5&nbsp;mmol/L, higher incidence of [[gallstone]]s, [[kidney stone]]s, [[urinary stone]]s, [[arthrosis]], and [[arthropathy|arthropathies]] have been observed.{{Citation needed|date=January 2018}} For fluoride the concentration recommended for dental health is 0.5–1.0&nbsp;mg/L, with a maximum guideline value of 1.5&nbsp;mg/L to avoid [[dental fluorosis]].<ref>{{cite book |title=Nutrients in Drinking Water |isbn=92-4-159398-9 |publisher=World Health Organization |author=Kozisek F. |chapter=Health risks from drinking demineralised water |year=1980 |pages=148–159 |chapter-url=https://www.who.int/water_sanitation_health/dwq/nutrientsindw.pdf |url-status=live |archive-url=https://web.archive.org/web/20160218180835/http://www.who.int/water_sanitation_health/dwq/nutrientsindw.pdf |archive-date=2016-02-18 }}</ref>

Water filtration and distillation devices are becoming increasingly common in households. Municipal water supplies often have minerals added or have trace impurities at levels which are regulated to be safe for consumption. Much of these additional impurities, such as [[volatile organic compounds]], [[fluoride]], and an estimated >75,000 other chemical compounds<ref>{{cite web |url=http://watersystems.walton.com/ |title=Walton International – Home |publisher=Watersystems.walton.com |date=2010-11-05 |access-date=2011-12-11 |url-status=dead |archive-url=https://web.archive.org/web/20140904210320/http://watersystems.walton.com/ |archive-date=2014-09-04 }}</ref> are not removed through conventional filtration; however, distillation and reverse osmosis eliminate nearly all of these impurities.

The drinking of distilled water as a replacement for drinking water has been both advocated and discouraged for health reasons. Distilled water lacks minerals and ions, such as calcium, that play key roles in biological functions, such as in nervous system [[homeostasis]], and are normally found in [[Drinking water|potable water]]. The lack of naturally occurring minerals in distilled water has raised some concerns. The ''Journal of General Internal Medicine'' published a study on the mineral contents of different waters available in the US. The study found that "drinking water sources available to North Americans may contain high levels of [[calcium]], [[magnesium]], and [[sodium]] and may provide clinically important portions of the recommended dietary intake of these minerals". It encouraged people to "check the mineral content of their drinking water, whether tap or bottled, and choose water most appropriate for their needs". Since distilled water is devoid of minerals, mineral intake through diet is needed to maintain good health.<ref>{{cite journal |author1=Azoulay A. |author2=Garzon P. |author3=Eisenberg M. J. |year=2001 |title=Comparison of the mineral content of tap water and bottled waters |journal=J. Gen. Intern. Med. |volume=16 |issue=3 |pages=168–175 |pmid=11318912 |pmc=1495189 |doi=10.1111/j.1525-1497.2001.04189.x}}</ref>

The consumption of [[hard water|"hard" water]] (water with minerals) is associated with beneficial cardiovascular effects. As noted in the ''American Journal of Epidemiology'', consumption of hard drinking water is negatively correlated with atherosclerotic [[heart disease]].<ref>{{Cite news |last=Voors |first=A. W. |date=April 1, 1971 |title=Mineral in the municipal water and atherosclerotic heart death |periodical=American Journal of Epidemiology |volume=93 |issue=4 |pages=259–266 |url=http://aje.oxfordjournals.org/cgi/content/abstract/93/4/259 |pmid=5550342 |url-status=dead |archive-url=https://web.archive.org/web/20071012173117/http://aje.oxfordjournals.org/cgi/content/abstract/93/4/259 |archive-date=October 12, 2007 }}</ref>

==See also==
* [[Atmospheric water generator]]
* [[Deionized water]]
* [[Heavy water]]
* [[Ultrapure water]]

==References==
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{{DEFAULTSORT:Distilled Water}}
[[Category:Distillation]]
[[Category:Drinking water]]
[[Category:Water chemistry]]