This conference at ASU asks: How can we tap into the water reserves floating in the air?

Thursday marks the kickoff of the third annual International Atmospheric Water Harvesting Summit, hosted at Arizona State University.

Atmospheric water harvesting is an intriguing new frontier in water science. The idea is relatively simple: in addition to harvesting from rivers and recycling groundwater, what if we could tap into the water reserves floating in the air around us?

Research into atmospheric water harvesting is still in its early stages.

The Show spoke with one of the presenters at this year’s summit: Carl Abadam, a Ph.D. student at the University of New Mexico.

Abadam said the first challenge is figuring out how to extract water from the air.

University of New Mexico

/

Handout

Full conversation

CARL ABADAM: There are different types of technologies for atmospheric water harvesting. We have fog nets, there are these things called desiccant-based technologies, which essentially absorbs water vapor out of the air, and condensation-based technologies. So think of like a glass of cold, iced water, where water will condense on the side on a hot sunny day.

That's essentially what atmospheric water harvesting is doing, trying to utilize the reservoir of water vapor in the air. There's approximately 13 trillion liters of water vapor estimated in the atmosphere, which is essentially six times the total combined amount of water in all of Earth's rivers. If we could tap even just a small percentage, not even a full percentage of that reservoir, it could really serve a lot of people around the world.

SAM DINGMAN: So can I ask you, and I apologize if this is a really basic question, but you, you described fog nets. And if this were to be broadly implemented, what would this look like? What is a fog net?

A literal net that you would put up in a place where there's a lot of fog and then somebody would come by and take the net down and?

ABADAM: Yeah, so fog nets are more suitable for really think of like high in the mountains or where there's a lot of condensation. There are lots of different devices all the way from the laboratory bench scale, from like little tiny devices different researchers are fabricating, all the way to like really giant, industrial-sized atmospheric water harvesters meant for like HVAC.

Just I think the last conference, there was a marketed atmospheric water generator meant to be put in your home, like in your kitchen, collecting water around your home and that you could drink. So there are currently a huge range of what these devices look like.

DINGMAN: And how much does water that is collected this way need to be treated before it's potable?

ABADAM: It really depends. And we have research going on that looks at the water quality based off of where you sample. So we have one site that's an urban site, characterized by high vehicle traffic, you, you might be able to capture, how does the exhaust smoke affect your water quality?

And the other side of town, we have an industrial site. This is where heavy manufacturing goes on. There's agricultural farming going on here. And so you could imagine that the different characteristics and air quality between, you know, an urban commercial district versus a more rural industrial district, and how the different air qualities between the two might impact water quality. And from our research, we found that there is a statistically significant difference between water qualities.

DINGMAN: If you think about traditional water sources, you need things like pipes and distribution infrastructure.

Is part of the promise of atmospheric water harvesting? The idea that not only, as you pointed out, is it this massive resource that we could tap into even if we were only able to get a small amount of it, but is it also cheaper to capture and distribute?

ABADAM: Cheaper depends on what you're comparing against. We've also done research in our group, techno-economic analysis by Natalie Gayoso. She looked specifically at the cost per liter for different harvesting environments. So in an arid region, a temperate region, and in a tropical region.

And she found out that the cost of doing atmospheric water harvesting in those certain regions could actually outperform the cost of bottled water in certain cases, to speak, on the pipes and the distribution network.

I think that's also one of the main draws of atmospheric water harvesting, is that you don't need to be on a municipal grid. Essentially, the idea would be you set up one of these devices, you don't need essentially that distribution network.

DINGMAN: But also, I would imagine in parts of the country or the world where access to major urban infrastructure isn't available, this could be a meaningful alternative to get people safe water to drink.

ABADAM: Absolutely. Absolutely.

DINGMAN: So are you aware of any municipalities here in the U.S. or around the world where these experiments are going on?

Like, are there people in the world currently who are drinking atmospherically harvested water?

ABADAM: I'm not sure about the drinking yet because I think there's still a lot of questions that need to be answered regarding, like, water quality and also maybe pre- and post-treatment of this water quality.

But there is a utility that I know of that we work with, and it's the Southern Nevada Water Authority, and they've deployed, I guess they call them atmospheric water generators on top of cooling towers.

Essentially, you may have, you might have seen cooling towers, you know, exhaust water vapor out into the atmosphere for part of their cooling systems. And the idea is if you put an atmospheric water generator on these cooling towers, you can recapture that water instead of just letting it leave into the atmosphere.

And so, so their, their application is really cool because it's not a drinking water application, but more of like a, a process type of industrial application, which is a really cool way to see other uses of atmospheric water harvesting.

DINGMAN: So, last question for you, Carl. Do you think widespread adoption of these technologies is something that's imminent? Or how far off is putting this into practice?

ABADAM: I think there are still a lot of questions that need to be answered, especially if you're taking water out of the atmosphere, are you inevitably drying the atmosphere, right. Are you just changing the weather? And we want to start working with government regulation agencies to start saying, like, are there water rights for the atmosphere?

You know, and is that something. If there is an app, do those measures need to be put in place? And so this is like the Wild West of water right now.