Researchers at the University of Texas at Austin have developed a biodegradable, biomass-based hydrogel that efficiently extracts drinking water from the air, providing a scalable, sustainable solution for off-grid communities, emergency relief and agricultural water use.
Researchers at the University of Texas at Austin have developed a new system that can extract potable water from thin air, using discarded food scraps, twigs, shells and other natural materials as key ingredients.
This innovative system, called a "molecularly functionalized biomass hydrogel," converts a variety of natural products into adsorbents - a material that can absorb liquids. By combining these adsorbents with mild heat, researchers can extract gallons of drinking water from the atmosphere, even in arid conditions.
"With this breakthrough, we have created a versatile molecular engineering strategy that can convert a variety of natural materials into highly efficient water absorbers," said Guihua Yu, a professor of materials science, mechanical engineering and the Texas Materials Institute at UT Austin. "This opens up a new way of thinking about sustainable water harvesting and marks a big step toward practical water harvesting systems at the scale of homes and small communities."
In field tests, researchers found that each kilogram of absorbent produced 14.19 liters (3.75 gallons) of clean water per day. Most water-absorbing agents can produce 1 to 5 liters of water per kilogram per day.
The new research is published in Advanced Materials.
Converting biomass into efficient adsorbents
The researchers say this system represents a new way to design adsorbents. While traditional "select-and-combine" approaches require selecting specific materials for specific functions, this versatile molecular strategy can transform almost any biomass into a highly efficient water absorbent.
Unlike existing synthetic water-absorbing agents that use petrochemicals and often require high energy inputs, the UT Austin team's biomass hydrogel is biodegradable, scalable, and requires minimal energy to release water. The secret lies in a two-step molecular engineering process that imparts hygroscopic properties and thermostrictive behavior to any biomass-based polysaccharide such as cellulose, starch or chitosan.
"Ultimately, access to clean water should be simple, sustainable and scalable," said Weixin Guan, a senior doctoral student and lead researcher on the study. "This material gives us a way to make water from the air anytime, anywhere, using nature's most abundant resource."
This latest innovation is part of Professor Yu’s years-long effort to develop solutions for people who lack clean drinking water. He has spent his career developing water-generating hydrogels and adapting them to the most arid conditions. He recently created an injectable water filtration system and applied hydrogel technology to agriculture.
The research team is currently working to scale up production and design real-world commercial device systems, including portable water collectors, self-sustaining irrigation systems and emergency drinking water equipment. From the beginning, researchers have focused on scalability and the ability to translate this research into solutions that can help people around the world.
"The biggest challenge in sustainable water harvesting technology is to develop a solution that can scale effectively while maintaining practicality outside the laboratory," said Yaxuan Zhao, a graduate student researcher in the laboratory. "Because this hydrogel can be made from widely available biomass and requires minimal energy input to operate, it has strong potential for large-scale production and deployment in off-grid communities, emergency relief efforts, and decentralized water systems."
Compiled from /ScitechDaily
DOI:10.1002/adma.202420319