Researchers from multiple US universities have successfully demonstrated a new method for harvesting water from the air using adsorbent fins. As climate change continues to worsen the water shortage, millions of people will probably have trouble getting access to clean water. Traditionally, water supplies have relied on local water bodies, but technological advancements now enable extracting water directly from the air.
Estimates indicate that the Earth’s atmosphere holds trillions of liters of fresh water in the form of water vapor. Finding an effective way to turn this vapor into liquid water for local usage is difficult, especially in arid locations with insufficient conventional techniques.
Scientists from the Georgia Institute of Technology, the Massachusetts Institute of Technology, and the University of Tennessee Knoxville have created a unique humidity harvester for these arid areas. Dry locations need specific materials to capture and convert water vapor, unlike areas that frequently see fog or dew, which condenses more easily.
Prior attempts to harvest humidity in arid regions have used materials like metal-organic frameworks and hydrogels that respond to temperature. As they can absorb moisture even at low humidity levels, crystalline aluminosilicates, or zeolites, have shown promise among them. The extraction process requires only the application of heat, which is simple.
The researchers from the United States highlighted that a minimal and effective setup is necessary for real-world implementation. Combining this system with something that produces heat as a byproduct would be the most economical and environmentally beneficial way to implement it.
The researchers designed their water harvester with a unique fin design to meet this problem. They constructed the fin structure by sandwiching thin copper sheets between copper foam treated with zeolite. Mounted on a copper base plate, the device—which had ten tiny fins spaced no more than two millimetres apart—was tested in a desert-like environment with a relative humidity of only 10%.
The fins became saturated with water within an hour. The team successfully harvested the water by raising the temperature to 363 degrees Fahrenheit (183 degrees Celsius). In environments with 30 percent relative humidity, extrapolations suggest that the device could collect up to 1.3 liters of water per day, five times more than similarly built devices.
This technology can revolutionize water harvesting in arid regions. The researchers propose integrating the device into existing infrastructure, such as buildings or vehicles that produce waste heat, to maximize efficiency and cost-effectiveness. This system could accelerate water harvesting, providing a much-needed solution to water scarcity in some of the world’s most challenging environments.
The research findings, published in the ACS Energy Letters, demonstrate the potential of adsorbent fin technology in mitigating the world’s water scarcity.
