Water Harvesting from Air Could Help Deal with Water Crisis in Some Regions: MIT

Water Harvesting from Air Could Help Deal with Water Crisis in Some Regions

Water Harvesting from air sounds like a difficult idea to implement but a research team from MIT and UC Berkeley has successfully developed a prototype water harvester which can collect water from air with as low at 20-30 percent humidity. The technique can help in dealing with water crisis in many regions across the world and research team added that water harvested with this technique is pure and drinkable. The research team has presented a device based on porous metal-organic framework-801 [Zr6O4(OH)4(fumarate)6] which is powered by natural sunlight.

The research team informed that their harvesting device can collect nearly 2.8 liters of water per kilogram of porous metal-organic framework (MOF) at low humidity level of 20 percent. MOFs are compounds created by combination of organic molecules and specific metals. Researchers have created nearly 20,000 different MOFs using different organic molecules and metals. MOFs find applications in many fields of science and have been helpful in carrying out innovative projects.

For the current project, UC Berkeley and MIT researchers created a specific MOF that binds to water. The research team created a water collecting device using this MOF. Mechanical engineer Evelyn Wang of MIT and his students have worked hard on creating water harvester that runs on solar power. It is quite difficult to collect water in case of dry air (with humidity of less than 40 percent) and the device created by researchers works well in 20-30 percent humidity as well.

Senior researcher associated with the project, Professor Omar Yaghi, said, “The research team envisions a future where water is supplied off-grid, where you have a device at home running on ambient solar for delivering water that satisfies the needs of a household."

There are other compounds that can suck water from the air, zeolites for example, but Wang says it takes a significant amount of energy to get these materials to release the water.

Wang and her colleagues tested the prototype of their MOF-based device on the roof of a building at MIT, and it worked great.

Nearly 4 billion people across the world face acute water scarcity for at least once in a month. Water scarcity problem is even worse in some developing countries with hot climate. Such devices that require no energy source, can be very effective in dealing with water scarcity.