{"id":137,"date":"2022-11-23T21:24:24","date_gmt":"2022-11-23T21:24:24","guid":{"rendered":"https:\/\/terrascope2026.wpengine.com\/?page_id=137"},"modified":"2022-12-01T06:17:35","modified_gmt":"2022-12-01T06:17:35","slug":"solar-distillation","status":"publish","type":"page","link":"https:\/\/terrascope2026.mit.edu\/?page_id=137","title":{"rendered":"Solar Distillation"},"content":{"rendered":"<p><script>\nvar view_footnotes = function() {\n  var footnotes = document.getElementsByClassName(\"footnotes_h\");\n  while(0<footnotes.length) {\n    footnotes[0].classList.add(\"footnotes_v\");\n    footnotes[0].classList.remove(\"footnotes_h\");\n  };\n};\n<\/script><\/p>\n<style>\ndiv.footnotes_h {<br \/>  display: none;<br \/>}<br \/>div.footnotes_v {<br \/>  display: block;<br \/>}<br \/>span.reference {<br \/>  color: #00000081;<br \/>}<br \/>div.document {<br \/>  font-weight: 400;<br \/>}<br \/>div.footnotes_v {<br \/>  counter-reset: footnote_counter;<br \/>}<br \/>div.footnotes_v ol li {<br \/>  counter-increment: footnote_counter;<br \/>}<br \/><\/style>\n<div class=\"document\">\n<p><b>Background<\/b><\/p>\n<p><span style=\"font-weight: 400;\">The Din\u00e9 people have historically been subject to chronic water pollution and contamination, especially as a result of the mining boom in the 1900s for uranium <strong><span class=\"reference\">[1]<\/span><\/strong>. The release of heavy metal-laden tailings, combined with the presence of sulfides and iron oxides that promote dissolution of heavy metals, has resulted in widespread contamination of an already scarce water supply <strong><span class=\"reference\">[1]<\/span><\/strong>. In addition to modern-day contamination, there is a significant reservoir of saline groundwater spanning almost the entire Navajo Nation\u2019s area <strong><span class=\"reference\">[4]<\/span><\/strong>. Due to the salinity of this water, it is considered unusable for domestic and agricultural use.\u00a0<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400;\">One idea to combat water shortages in the Navajo Nation is to treat existing contaminated water in the area. Numerous water treatment methods exist, from reverse osmosis to phytoremediation to ion exchange resins. One possible method that could prove viable in Navajo Nation is the use of solar distillation, a method that draws upon the use of solar energy to separate clean water from contaminants.\u00a0<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><b>What is Solar Distillation?<\/b><\/p>\n<p><span style=\"font-weight: 400;\">Solar distillation works by using the differences in physical properties between water and other substances <strong><span class=\"reference\">[2]<\/span><\/strong>. Water has a boiling point of 100 degrees Celsius (212 degrees Fahrenheit), meaning it is converted into a gaseous form at that temperature <strong><span class=\"reference\">[2]<\/span><\/strong>. However, heavy metals have a drastically higher boiling point, with uranium having a boiling point of 4131 degrees Celsius (7468 degrees Fahrenheit) and arsenic having a boiling point of 613 degrees Celsius (1135 degrees Fahrenheit) <strong><span class=\"reference\">[5]<\/span><\/strong>. As a result, solar energy can be directed to heat contaminated water until it boils, leaving behind contaminants <strong><span class=\"reference\">[2]<\/span><\/strong>. This water vapor can then be cooled and recondensed into liquid, producing clean water <strong><span class=\"reference\">[2]<\/span><\/strong>. The structure of solar distillers can vary, but generally consist of one container to hold contaminated water, some component to capture and direct water vapor, and a second container to store the clean, recondensed water, all of which is ideally made airtight to prevent loss of water <strong><span class=\"reference\">[2]<\/span><\/strong>.\u00a0<\/span><\/p>\n<p><img fetchpriority=\"high\" decoding=\"async\" class=\"wp-image-144 aligncenter\" src=\"https:\/\/terrascope2026.wpengine.com\/wp-content\/uploads\/2022\/11\/Screenshot-2022-11-23-171207.png\" alt=\"A diagram of a basin-type solar still.\" width=\"618\" height=\"287\" srcset=\"https:\/\/terrascope2026.mit.edu\/wp-content\/uploads\/2022\/11\/Screenshot-2022-11-23-171207.png 1240w, https:\/\/terrascope2026.mit.edu\/wp-content\/uploads\/2022\/11\/Screenshot-2022-11-23-171207-300x139.png 300w, https:\/\/terrascope2026.mit.edu\/wp-content\/uploads\/2022\/11\/Screenshot-2022-11-23-171207-1024x476.png 1024w, https:\/\/terrascope2026.mit.edu\/wp-content\/uploads\/2022\/11\/Screenshot-2022-11-23-171207-768x357.png 768w, https:\/\/terrascope2026.mit.edu\/wp-content\/uploads\/2022\/11\/Screenshot-2022-11-23-171207-320x149.png 320w, https:\/\/terrascope2026.mit.edu\/wp-content\/uploads\/2022\/11\/Screenshot-2022-11-23-171207-480x223.png 480w, https:\/\/terrascope2026.mit.edu\/wp-content\/uploads\/2022\/11\/Screenshot-2022-11-23-171207-800x372.png 800w, https:\/\/terrascope2026.mit.edu\/wp-content\/uploads\/2022\/11\/Screenshot-2022-11-23-171207-1200x557.png 1200w\" sizes=\"(max-width: 618px) 100vw, 618px\" \/><\/p>\n<p style=\"text-align: center;\"><span style=\"font-weight: 400;\">Figure 1: Basin-type still example <strong><span class=\"reference\">[7]<\/span><\/strong><\/span><\/p>\n<p><img decoding=\"async\" class=\"wp-image-147 aligncenter\" src=\"https:\/\/terrascope2026.wpengine.com\/wp-content\/uploads\/2022\/11\/Screenshot-2022-11-23-171414.png\" alt=\"A diagram of a wick-type solar still.\" width=\"532\" height=\"327\" srcset=\"https:\/\/terrascope2026.mit.edu\/wp-content\/uploads\/2022\/11\/Screenshot-2022-11-23-171414.png 1102w, https:\/\/terrascope2026.mit.edu\/wp-content\/uploads\/2022\/11\/Screenshot-2022-11-23-171414-300x184.png 300w, https:\/\/terrascope2026.mit.edu\/wp-content\/uploads\/2022\/11\/Screenshot-2022-11-23-171414-1024x629.png 1024w, https:\/\/terrascope2026.mit.edu\/wp-content\/uploads\/2022\/11\/Screenshot-2022-11-23-171414-768x472.png 768w, https:\/\/terrascope2026.mit.edu\/wp-content\/uploads\/2022\/11\/Screenshot-2022-11-23-171414-320x197.png 320w, https:\/\/terrascope2026.mit.edu\/wp-content\/uploads\/2022\/11\/Screenshot-2022-11-23-171414-480x295.png 480w, https:\/\/terrascope2026.mit.edu\/wp-content\/uploads\/2022\/11\/Screenshot-2022-11-23-171414-800x491.png 800w\" sizes=\"(max-width: 532px) 100vw, 532px\" \/><\/p>\n<p style=\"text-align: center;\"><span style=\"font-weight: 400;\">Figure 2: Wick-type solar still <strong><span class=\"reference\">[7]<\/span><\/strong><\/span><\/p>\n<p>&nbsp;<\/p>\n<p><b>Evaluation of Solar Distillation<\/b><\/p>\n<p><span style=\"font-weight: 400;\">This method is well suited for Navajo Nation\u2019s climate, considering that the area is considered a desert with limited water input and is currently experiencing a megadrought <strong><span class=\"reference\">[3]<\/span><\/strong>. One similar project, centered on solar desalination, has been piloted in 2018 by the University of Arizona. The group focused on ways to source and purify water from a saline aquifer that encompasses a majority of the Navajo Nation, testing desalination via thermal energy inputs, membrane\/nanofiltration, and solar-powered electrochemistry <strong><span class=\"reference\">[3]<\/span><\/strong>.\u00a0 Their results showed that using sunlight for thermal energy to evaporate and recondense water was most effective at removing contaminants, with almost zero waste produced <strong><span class=\"reference\">[3]<\/span><\/strong>.\u00a0<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400;\">Additionally, there are a wide variety of possible setups. The most basic type simply allows the sun to shine directly into a vessel of contaminated water, and allows the water vapor to condense and collect in a second container <strong><span class=\"reference\">[2]<\/span><\/strong>. More complex versions utilize wicks and cloths to transport water within the containers more efficiently <strong><span class=\"reference\">[2]<\/span><\/strong>. The primary maintenance would be cleaning out the components regularly and checking to ensure the containers remain airtight <strong><span class=\"reference\">[2]<\/span><span class=\"reference\">[3]<\/span><\/strong>. Additionally, most solar still designs have an average operating cost of $0.0135 to $0.23 per liter of clean water, meaning that this is implementable, even in resource limited areas <strong><span class=\"reference\">[8]<\/span><\/strong>.\u00a0<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400;\">Students can make use of the versatility and wide possible range of setups of solar distillation to tackle the engineering challenge of making their solar still. Using materials available to them, students of all ages and grade levels can develop their own designs for a solar still. Then, they can evaluate the efficiency based on the yield of clean water after a set time and the changes in water quality before and after distillation. Based on the feedback, they learn how to improve their designs and can understand how to directly implement this method to source clean water in their own daily lives.\u00a0<\/span><\/p>\n<p><img decoding=\"async\" class=\" wp-image-148 aligncenter\" src=\"https:\/\/terrascope2026.wpengine.com\/wp-content\/uploads\/2022\/11\/Screenshot-2022-11-23-171741.png\" alt=\"Basin type solar still, adapted as classroom project\" width=\"475\" height=\"315\" srcset=\"https:\/\/terrascope2026.mit.edu\/wp-content\/uploads\/2022\/11\/Screenshot-2022-11-23-171741.png 696w, https:\/\/terrascope2026.mit.edu\/wp-content\/uploads\/2022\/11\/Screenshot-2022-11-23-171741-300x199.png 300w, https:\/\/terrascope2026.mit.edu\/wp-content\/uploads\/2022\/11\/Screenshot-2022-11-23-171741-320x212.png 320w, https:\/\/terrascope2026.mit.edu\/wp-content\/uploads\/2022\/11\/Screenshot-2022-11-23-171741-480x319.png 480w\" sizes=\"(max-width: 475px) 100vw, 475px\" \/><\/p>\n<p style=\"text-align: center;\"><span style=\"font-weight: 400;\">Figure 3: Basin type solar still example, adapted as classroom project <strong><span class=\"reference\">[9]<\/span><\/strong><\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400;\"><strong>Comparison of common solar distillation setups: <span class=\"reference\">[5]<\/span><span class=\"reference\">[6]<\/span><span class=\"reference\">[7]<\/span><\/strong><\/span><\/p>\n<p>&nbsp;<\/p>\n<table>\n<tbody>\n<tr>\n<td><span style=\"font-weight: 400;\">Type<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Description<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Pros:<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Cons:<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">Single Basin Stills<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Basin with an optionally reflective bottom and sloped clear top cover to allow sunlight in, filled with contaminated water. Water vapor condenses on top cover and drains down into a conduit for collection.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Classroom alternative: One large bowl, partially filled with contaminated water. Smaller, clean bowl nested inside the large bowl. Cover with Saran Wrap and weigh down so that the lowest point hangs over the small bowl, allowing the condensed water vapor to drip into the smaller bowl for collection (see figure 3).\u00a0<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Costs of less than $0.01\/L of clean water produced<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Simplest and cheapest to build<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Easily customizable for size\/water volume, sun angle<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Less effective at cold temperatures<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Produces highly concentrated brine\/contaminated water that is difficult to evaporate<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">Wick Stills<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Similar to basin stills, but blackened cloth or another wicking material is added within the basin, either covering the bottom and\/ or distributed to form banks subdividing the basin.\u00a0<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Higher efficiency\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Increases absorption of heat<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Highly saline\/contaminated waters can be treated with less energy<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Still low cost, approx. $0.05\/L of clean water<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Wicks will need regular replacement.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Wicks will have be discarded safely\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">if water is contaminated with heavy metals or other toxins<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">Diffusion Stills<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Uses closely spaced vertical partitions in the basin and a set of wicks to maximize evaporation and condensation of water<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Highest efficiency\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Produces the least brine\/highly contaminated water<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Requires most materials<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Wicks will need regular replacement<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Wicks need to be discarded safely if use with contaminated water<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Most difficult to clean up<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>&nbsp;<\/p>\n<p><span style=\"text-decoration: underline;\"><strong>Works Cited:<\/strong><\/span><\/p>\n<div class=\"document\">\n<div class=\"footnotes\">\n<div class=\"footnotes_h\">\n<p><span style=\"font-weight: 400;\"><strong>[1]<\/strong> Ingram, J. C., Jones, L., Credo, J., and; Rock, T. (2020, March 20). Uranium and arsenic unregulated water issues on Navajo Lands. Journal of vacuum science &amp;; technology. A, Vacuum, surfaces, and films : an official journal of the American Vacuum Society. Retrieved November 30, 2022, from <\/span><a href=\"https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC7083651\/\"><span style=\"font-weight: 400;\">https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC7083651\/<\/span><\/a><\/p>\n<p><span style=\"font-weight: 400;\"><strong>[2]<\/strong> Hancock, N. (2021, September 29). Solar water distillation. Safe Drinking Water Foundation. Retrieved November 30, 2022, from <\/span><a href=\"https:\/\/www.safewater.org\/fact-sheets-1\/2016\/12\/8\/solar-water-distillation\"><span style=\"font-weight: 400;\">https:\/\/www.safewater.org\/fact-sheets-1\/2016\/12\/8\/solar-water-distillation<\/span><\/a><\/p>\n<p><span style=\"font-weight: 400;\"><strong>[3]<\/strong> Navajo Nation Climate Change Program. (2021). Water: Navajo nation climate change program: Window rock. Navajo Nation Climate Change Program . Retrieved November 30, 2022, from <\/span><a href=\"https:\/\/www.navajoclimatechange.org\/copy-of-feral-horses\"><span style=\"font-weight: 400;\">https:\/\/www.navajoclimatechange.org\/copy-of-feral-horses<\/span><\/a><\/p>\n<p><span style=\"font-weight: 400;\"><strong>[4]<\/strong> Peon-Anaya, R., &amp;amp; Yazzie, C. B. (2019, November 11). Solar desalination in action at the Navajo Nation. N-Gen. Retrieved November 30, 2022, from <\/span><a href=\"https:\/\/nextgensd.com\/solar-desalination\/\"><span style=\"font-weight: 400;\">https:\/\/nextgensd.com\/solar-desalination\/<\/span><\/a><\/p>\n<p><span style=\"font-weight: 400;\"><strong>[5]<\/strong> Ahmed, S. T. (2003, March 6). Study of single-effect solar still with an internal condenser. Science Direct. Retrieved November 30, 2022, from <\/span><a href=\"https:\/\/www.sciencedirect.com\/science\/article\/pii\/0741983X88900616\"><span style=\"font-weight: 400;\">https:\/\/www.sciencedirect.com\/science\/article\/pii\/0741983X88900616<\/span><\/a><\/p>\n<p><span style=\"font-weight: 400;\"><strong>[6]<\/strong> Velliangiri, M., Shanmugasundaram, K., Sengottain, S., Balasundaram, J., &amp;amp; Chandrasekaran, J. (2013, April). Wick Type Solar Stills: A Review. ResearchGate. Retrieved November 30, 2022, from <\/span><a href=\"https:\/\/www.researchgate.net\/publication\/271564213_Wick_type_solar_stills_A_review\"><span style=\"font-weight: 400;\">https:\/\/www.researchgate.net\/publication\/271564213_Wick_type_solar_stills_A_review<\/span><\/a><\/p>\n<p><span style=\"font-weight: 400;\"><strong>[7]<\/strong> Manchanda, H., &amp;amp; Kumar, M. (2015, November 11). A comprehensive decade review and analysis on designs and performance parameters of passive solar still. SpringerOpen. Retrieved November 30, 2022, from <\/span><a href=\"https:\/\/jrenewables.springeropen.com\/articles\/10.1186\/s40807-015-0019-8#Sec2\"><span style=\"font-weight: 400;\">https:\/\/jrenewables.springeropen.com\/articles\/10.1186\/s40807-015-0019-8#Sec2<\/span><\/a><\/p>\n<p><span style=\"font-weight: 400;\"><strong>[8]<\/strong> Abdullah, A. S., Alarjani, A., Abou Al-sood, M. M., Omara, Z. M., Kabeel, A. E., &amp;amp; Essa, F. A. (2019, December 6). Rotating-wick solar still with mended evaporation technics: Experimental approach. Science Direct. Retrieved November 30, 2022, from <\/span><a href=\"https:\/\/www.sciencedirect.com\/science\/article\/pii\/S1110016819301395\"><span style=\"font-weight: 400;\">https:\/\/www.sciencedirect.com\/science\/article\/pii\/S1110016819301395<\/span><\/a><\/p>\n<p><span style=\"font-weight: 400;\"><strong>[9]<\/strong> Brower, D. (2021, February 23). How to distill water using a pot and stove. Earth Water Alliance. Retrieved November 30, 2022, from <\/span><a href=\"https:\/\/www.earthwateralliance.org\/distill-water-using-pot-stove\/\"><span style=\"font-weight: 400;\">https:\/\/www.earthwateralliance.org\/distill-water-using-pot-stove\/<\/span><\/a><\/p>\n<\/div>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Background The Din\u00e9 people have historically been subject to chronic water pollution and contamination, especially as a result of the mining boom in the 1900s for uranium [1]. The release of heavy metal-laden tailings, combined with the presence of sulfides and iron oxides that promote dissolution of heavy metals, has resulted in widespread contamination of &hellip; <\/p>\n<p class=\"link-more\"><a href=\"https:\/\/terrascope2026.mit.edu\/?page_id=137\" class=\"more-link\">Read more<span class=\"screen-reader-text\"> &#8220;Solar Distillation&#8221;<\/span><\/a><\/p>\n","protected":false},"author":17,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-137","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/terrascope2026.mit.edu\/index.php?rest_route=\/wp\/v2\/pages\/137","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/terrascope2026.mit.edu\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/terrascope2026.mit.edu\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/terrascope2026.mit.edu\/index.php?rest_route=\/wp\/v2\/users\/17"}],"replies":[{"embeddable":true,"href":"https:\/\/terrascope2026.mit.edu\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=137"}],"version-history":[{"count":0,"href":"https:\/\/terrascope2026.mit.edu\/index.php?rest_route=\/wp\/v2\/pages\/137\/revisions"}],"wp:attachment":[{"href":"https:\/\/terrascope2026.mit.edu\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=137"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}