Researchers Find a New Way to Make Water From Thin Air

(THIS ARTICLE IS COURTESY OF KQED NEWS SITE)

Researchers Find a New Way to Make Water From Thin Air

A prototype MOF-based water-collection device is set up for testing on the roof of a building on the MIT campus.
A prototype MOF-based water-collection device is set up for testing on the roof of a building on the MIT campus. (Courtesy Evelyn Yang, MIT)

Researchers have come up with a new way to extract water from thin air. Literally.

This isn’t the first technology that can turn water vapor in the atmosphere into liquid water that people can drink, but researchers from the Massachusetts Institute of Technology and UC Berkeley say their approach uses less power and works in drier environments.

The new approach makes use of a substance called a MOF, a metal-organic framework. As the name suggests, these are materials made of metals mixed with organic compounds. Powders made from MOFs are very porous, so researchers have proposed using them to store hydrogen or methane fuels or to capture carbon dioxide.

MIT’s Evelyn Wang and her Berkeley colleague Omar Yaghi decided to try using MOFs to capture water. MOF powders can not only suck up liquid water, they can also absorb water vapor.

And there’s plenty of water vapor in the atmosphere. Even in the driest place on the planet there are tons of water molecules floating overhead.

The researchers built a small prototype water collector that contains a thin layer of MOF powder. The powder absorbs water vapor until it is saturated.

“Once you achieve that maximum amount,” Wang says, “you apply some type of heat to the system to release that water.”

And when the water is released, it collects in the bottom of the prototype.

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. Not so with a MOF device. “The amount of energy required is very low,” she says.

In the prototype, the heat needed to drive the water out of the MOF comes from ambient sunlight — no external power supply is needed.

Even in Chile's Atacama Desert, the driest place on Earth, there are water molecules floating overhead.
Even in Chile’s Atacama Desert, the driest place on Earth, there are water molecules floating overhead. (MARTIN BERNETTI/AFP/Getty Images)

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

But it’s just a prototype. It used only a fraction of an ounce of the MOF powder. “So the amount of water that we’ve shown is also pretty small,” says Wang.

According to Wang’s calculations, a full-size system using about 2 pounds of MOF powder could deliver close to three quarts of water per day.

And she expects scaling up the prototype won’t be all that expensive. Although MOFs are a relatively new material, “there are companies that already make various MOFS at very large bulk scales,” she says.

There are many steps before a mass-produced MOF-based water collector becomes a reality. It hasn’t been shown, for example, that the water released by the MOF powder is free of contaminants.

But it’s conceivable that someday if you’re visiting Death Valley, one of the driest places in the United States, you’ll be able to wet your whistle with a device based on Wang and Yaghi’s concept.

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Folks: Please Pray For The People In S.W. Columbia, Northern Ecuador And Northern Peru

(THIS ARTICLE IS COURTESY OF THE BBC AND REUTERS NEWS AGENCIES AND GETTY IMAGES)

Colombia landslide: Rescue teams race to reach survivors

Media caption The landslide struck in the early hours of Saturday

Rescuers are digging through mud and debris in the hunt for those missing after devastating mudslides in Colombia left more than 200 dead.

About 1,100 soldiers and police are involved in the relief effort.

Heavy rain flooded the city of Mocoa in the country’s south-west with mud and rocks burying whole neighbourhoods and forcing residents to flee their homes.

An army statement said there were at least 400 injured and 200 still missing in the capital of Putumayo province.

The exact death toll is hard to confirm with the rescue operation is still under way.

Some local media estimate up to 300 people have been killed, while the Colombian Red Cross has a total hovering above 200.

The Red Cross said it was working to help family members contact each other.

Video footage from the city showed residents crying over a list of missing children, along with their ages, pinned to a family welfare centre.

“We have lost a baby, who has gone missing,” one resident told reporters. “A little baby, we can’t find him anywhere.”

Media caption Dimitri O’Donnell: “The biggest hurdle… is trying to get access to Mocoa”

President Juan Manuel Santos declared a state of emergency in the region and flew in to oversee the rescue effort.

“We will do everything possible to help,” he said. “It breaks my heart.”

Lorries and trucks were thrown into the side of buildings by the force of the waterImage copyrightAFP / GETTY IMAGES
Image captionLorries and trucks were thrown into the side of buildings by the force of the water

A senior UN official in Colombia, Martin Santiago, blamed climate change, saying it had caused “tremendous results in terms of intensity, frequency and magnitude of these natural effects” in the region.

Others said deforestation has also played a role. “When the basins are deforested, they break down. It is as if we remove the protection for avoiding landslides,” said Adriana Soto, a Colombian conservationist and former environment minister.

The Colombian Air Force is bringing supplies to the area as the search operation continues.

With no running water in Mocoa, one resident told El Tiempo newspaper that they had been collecting rainwater. Power lines are also out across the area.

Tweet from @JuanManSantos, in Spanish: We guarantee health care in Mocoa. [The air force] moved 19 patients to Neiva, 20 will be evacuated in coming hoursImage copyright TWITTER/@JUANMANSANTOS
Image caption Colombia’s president said he would guarantee assistance to the victims

Photos posted to social media by the air force showed some patients being evacuated by air.

“Our heroes will remain in the tragedy zone until the emergency is over,” the army’s statement said.

Colombia’s director of the National Disaster Risk Management Unit told the AFP news agency that a third of the region’s expected monthly rain fell during one night.

Media caption President Juan Manuel Santos has declared a state of emergency

Although rainfall is abundant in the area, this downpour was unusually heavy and caused rivers to burst their banks.

The overflow then picked up mud and debris, creating a cascade.

Video footage of the aftermath showed currents so strong that abandoned lorries were propelled through the flooded streets.

Soldiers have been deployed to help local familiesImage copyright EPA
Image caption Soldiers have been deployed to help local families

Local resident Mario Usale, 42, told Reuters he was searching for his father-in-law.

“My mother-in-law was also missing, but we found her alive 2km (1.25 miles) away. She has head injuries, but she was conscious,” he said.

Rescuers seek people among the rubble left by mudslides following heavy rains in Mocoa, Putumayo department, southern Colombia on April 1, 2017.Image copyright AFP
Image caption Rescue workers searched among the rubble and fallen trees
A family wait outside their home damaged by mudslides following heavy rains in Mocoa, Putumayo department, southern Colombia on April 1, 2017Image copyright AFP
Image caption The debris totally destroyed many homes and submerged vehicles

Landslides have struck the region several times in recent months.

In November, nine people died in the town of El Tambo, about 140km (90 miles) from Mocoa, during a landslide that followed heavy rain.

A map showing Colombia and the locations of Mocoa, El Tambo, and Medellin - with neighbouring Ecuador and Peru also marked

Less than a month before that, another landslide killed several people near Medellin, almost 500km (300 miles) to the north.

And in neighbouring Peru, more than 90 people have died since the start of the year because of unusually heavy rainfall, which also caused landslides and flash floods.

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