Date:21 April 2017
Our atmosphere is a large water source that’s largely been untapped. But now it could serve as the go-to source for drinking water.
Scientists have developed technology that can extract drinking water from the air under humidity conditions as low as 20 percent while using the power of the sunlight.
Previous water-harvesting technologies have been limited to areas with fog or high-moisture conditions. But an estimated one-third of the world’s population lives in areas with low relative humidity.
In a study published in the journal Science a team of researchers, led by Evelyn Wang from MIT and Omar Yaghi from the University of California, demonstrated how the device collects moisture from the air and turns it into drinkable water. There is no need for solar panels, batteries, or additional energy.
The technology is based on a porous metal-organic framework (MOF-801) composed of organic molecules stitched together with metal atoms. The network of microscopic sponge-like pores trap gases as water vapour. At room temperature the water vapour collects in the pores. As the temperature rises the water escapes.
When heated by the sun, water molecules in the trapped air are released and condensed, essentially extracting the water out of the air.
The device is still in it’s prototype phase and the size of a small tissue box. The researchers demonstrated it could pull 2.8 litres of water from the air over 12 hours in conditions with just 20 to 30 percent humidity. The process of converting low-humidity air into water takes up to two hours.
The team plans to carry out improvements in an effort to scale up the technology and enhance the production of the water within the next two years.
The technology will eventually supply clean drinking water in some of the driest and poorest parts of the globe.