Scientists Can Pull Drinking Water From Air With Food Scraps

One in four people worldwide lacks access to clean drinking water, according to the 2023 United Nations (UN) World Water Development Report. This means that around two billion individuals do not have a safe source of potable water. And, as the UN report indicates, this issue is anticipated to worsen significantly in the coming decades due to climate change and population growth.

As scientists globally explore innovative methods to enhance access to water, a team of researchers from the University of Texas at Austin has developed a groundbreaking solution: extracting water from thin air. And they’re utilizing food scraps to do it. 

In February, the researchers published a new study in the peer-reviewed scientific journal Advanced Materials, showcasing their method for extracting water from the air, known as “atmospheric water harvesting.” 

Atmospheric water harvesting, the researchers explain in their published findings, “offers a promising pathway to alleviate global water scarcity, highlighting the need for environmentally responsible sorbent materials.” (Per the United States Environmental Protection Agency (EPA), sorbent materials “are insoluble materials or mixtures of materials used to recover liquids through the mechanism of absorption, or adsorption, or both.”)

This new research presents a “universal strategy” that transforms natural polysaccharides — also known as complex carbohydrates found in plants and animals — into effective hydrogel sorbents, which are polymers capable of absorbing water.

To do this, the team created “molecularly functionalized biomass hydrogels,” made out of everything from food scraps to seashells that have the ability to absorb massive amounts of water relative to their weight.

Here’s where the clean source of water comes in: According to the researchers’ field tests, they extracted 3.75 gallons of clean water per kilogram of sorbent daily after gently heating the product to release the water. The research paper details that they were able to extract 95% of all the water they captured.

“With this breakthrough, we’ve created a universal molecular engineering strategy that allows diverse natural materials to be transformed into high-efficiency sorbents,” Guihua Yu, a professor of materials science and mechanical engineering at the Texas Materials Institute at UT Austin, says in a statement. “This opens up an entirely new way to think about sustainable water collection, marking a big step towards practical water harvesting systems for households and small community scale.”

The team adds that this also allows for the conversion of virtually any biomass into a system designed to harvest water from the air, turning waste into a powerful solution for sustainability. As UT Austin’s statement clarifies, unlike synthetic sorbents, this hydrogel requires minimal energy to release water — and it is biodegradable.

The team shares that it is already working on ways to scale production of the product, including self-sustaining irrigation systems and emergency drinking water devices. 

“At the end of the day, clean water access should be simple, sustainable, and scalable,” says Weixin Guan, a senior doctoral student and the study’s lead researcher. “This material gives us a way to tap into nature’s most abundant resources and make water from air — anytime, anywhere.”