New research promises a potential new technology for sustainable harvesting of drinking water\u2014from air.The atmosphere contains an estimated 13,000 trillion litres of water\u2014equivalent to nearly 10 per cent of all fresh water present in lakes worldwide\u2014that has remained untapped.<\/p>\n
Now, a team of researchers in the US, including two of Indian origin, have developed a device that extracts potable water from ambient air using only sunlight as the energy source.<\/p>\n
The solar-powered water harvester works even when relative humidity (RH) is as low as 20 per cent, the level common in arid areas and deserts of the world, the researchers report.<\/p>\n
\u201cThis is a major breakthrough in the long-standing challenge of harvesting water from the air at low humidity,\u201d Omar Yaghi, chemistry professor at the University of California-Berkeley and one of the corresponding authors, told Nature India.<\/p>\n
\u201cThe key development in our demonstration is that we used only ambient sunlight, with no electricity needed,\u201d Yaghi said. \u201cThis is a major improvement over most other air-water harvesting devices which require energy input and therefore are economically not viable.\u201d<\/p>\n
\u201cI believe this device will work well in most areas of India,\u201d Yaghi said. Largescale use of this device \u201ccan change the landscape of water utilisation in India, where sunlight is abundant\u201d, added co-author Sameer Rao, a post-doctoral associate at the Massachusetts Institute of Technology (MIT).<\/p>\n
The heart of the new device\u2014constructed at MIT\u2014is a metal-organic framework (MOF) that belongs to a class of unique materials exhibiting extremely high porosity that Yaghi\u2019s team had pioneered in the 1990s at Berkeley.<\/p>\n
\u201cThey have high affinity to water molecules to pull them out of ambient air, but do not hold on to them too tightly so that water can be concentrated and released with a slight temperature change (induced by sunlight),\u201d Yaghi said. The adsorbed (as a thin film) water thus released is then stored by the device in a condenser.<\/p>\n
The adsorption-desorption experiments performed in a RH-controlled chamber in the laboratory found the device was able to pull 2.8 litres of water from the air over a 12-hour period at RH levels as low as 20 per cent using one kilogram of MOF. Rooftop tests at MIT confirmed that the device works equally well outdoors.<\/p>\n
The scientists found the experimental data to be in \u201cgood agreement\u201d with a theoretical framework they had developed.<\/p>\n
Yaghi said the daily quantity of harvested water can be scaled up by finding better MOF materials \u201cwith enhanced sorption capacity and high intra-crystalline diffusivity\u201d that could absorb more water. The current MOF can absorb only 20 per cent of its weight in water.<\/p>\n
An official statement released about the solar water harvester said that while Yaghi and his team at Berkeley are at work improving their MOFs, Evelyn Wang, the other corresponding author who led the team at MIT, \u201ccontinues to improve the harvesting system to produce more water\u201d.<\/p>\n
It quoted Wang as saying: \u201cWe wanted to demonstrate that if you are cut off somewhere in the desert, you could survive because of this device.\u201d<\/p>\n
Its developers hope their device, when commercialised, could help every household obtain the drinking water it needs out of the air using only the power of the sun.<\/p>\n
\u201cThe social impact of this in India would be far-reaching,\u201d said Rao.<\/p>\n
\u201cIt would enable greater success for government\u2019s grassroot level programmes seeking to increase literacy and education of women and children in villages\u201d because they would be freed from the everyday job of fetching water for cooking and drinking.<\/p>\n
How much would the solar water harvester cost?<\/strong><\/p>\n \u201cWe have made the significant first step by building the demonstration model combining chemistry and engineering to show how it works,\u201d Yaghi said, adding: \u201cThe economic aspects as well as the production of these materials and devices are the obvious next step.\u201d<\/p>\n IANS<\/strong><\/p>\n Picture source: Alamy Image<\/strong><\/p>\n Picture used for illustrative purposes alone<\/strong><\/p>\n <\/p>\n","protected":false},"excerpt":{"rendered":" New research promises a potential new technology for sustainable harvesting of drinking water\u2014from air.<\/p>\n","protected":false},"author":7,"featured_media":3920,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[31,49],"tags":[],"_links":{"self":[{"href":"https:\/\/kt10.khaleejtimes.ae\/index.php\/wp-json\/wp\/v2\/posts\/3919"}],"collection":[{"href":"https:\/\/kt10.khaleejtimes.ae\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kt10.khaleejtimes.ae\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kt10.khaleejtimes.ae\/index.php\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/kt10.khaleejtimes.ae\/index.php\/wp-json\/wp\/v2\/comments?post=3919"}],"version-history":[{"count":1,"href":"https:\/\/kt10.khaleejtimes.ae\/index.php\/wp-json\/wp\/v2\/posts\/3919\/revisions"}],"predecessor-version":[{"id":3921,"href":"https:\/\/kt10.khaleejtimes.ae\/index.php\/wp-json\/wp\/v2\/posts\/3919\/revisions\/3921"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/kt10.khaleejtimes.ae\/index.php\/wp-json\/wp\/v2\/media\/3920"}],"wp:attachment":[{"href":"https:\/\/kt10.khaleejtimes.ae\/index.php\/wp-json\/wp\/v2\/media?parent=3919"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kt10.khaleejtimes.ae\/index.php\/wp-json\/wp\/v2\/categories?post=3919"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kt10.khaleejtimes.ae\/index.php\/wp-json\/wp\/v2\/tags?post=3919"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}