Note on Emerging Science

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Air Date: Week of July 3, 2009

A new device can pull drinking water out of humid air. Living on Earth’s Annie Glausser reports.

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YOUNG: It's Living on Earth. I'm Jeff Young.

CURWOOD: And I'm Steve Curwood.

Coming up – today's birders resurrect the past to trace changing migration patterns. But first, this note on emerging science from Annie Glausser.

GLAUSSER: Go for a run during the hot summer months and chances are you'll finish covered in salty, sticky sweat. The driving force behind the drips—humidity.

Instead of griping about the sticky weather, researchers in Germany want to harness it. They've designed a tower-like device that pulls drinking water right out of humid air. The key to its design is hygroscopic brine—a saline solution that dribbles down the tower, much like sweat rolls down our faces. As the salty brine trickles down the tower, it absorbs moisture from the air.

The diluted brine is sucked up into a ground-level tank. The tank, using solar energy, boils the brine so that the fresh water evaporates, condenses, and can be whisked away down a separate channel. The re-concentrated brine is then pumped back to the top of the tower and the cycle repeats.

Because the tower relies on solar cells, the design is completely self-sustaining—an important feature for areas where there's little or no electricity. The device could be especially useful for places where lakes and rivers are scarce yet humidity is high.

Researchers hope that if their demonstration facility is successful, each teaspoon drawn from the air and tucked away in the tower's tank could one day add up to a healthy water supply for communities.

So when the sweat clings to you this summer, just think: in this weather, you could be squeezing out drinking water.

That's this week's note on emerging science. I'm Annie Glausser.

To learn more about the new design, click here.