Maintaining a source of freshwater is difficult if you live in a desert.
Desalination is one solution, but it requires a supply of brine from which to remove the salt, which necessitates your desert to be near the sea.
Even in inland deserts, moisture as water vapor is frequently present in the air. The issue is extracting these vapors efficiently and cost-effectively.
And that is what two groups of researchers, one from the University of Connecticut and the other from the University of California, Berkeley, sought to accomplish.
Moreover, a third of the world's population lives in drylands, which have severe water problems.
The University of Texas at Austin's scientists and engineers have devised a solution that might assist residents in these places have access to safe drinking water.
Low-cost gel film
NASA via Getty Images
The researchers created a low-cost gel sheet comprised of available ingredients that can draw water from the air in even the driest of conditions.
The ingredients used to assist this reaction are only $2 per kilogram, and one kilogram may create more than 6 liters of water each day in locations with less than 15% relative humidity, and 13 liters in situations with up to 30% relative humidity.
The study built on prior discoveries by the team, such as the capacity to extract water from the atmosphere and use that technology to construct self-watering soil.
These systems, however, were developed for rather high-humidity settings.
According to Guihua Yu, a materials science and mechanical engineering professor in the Cockrell School of Engineering's Walker Department of Mechanical Engineering, "This new study is about practical solutions that people may utilize to access water in the hottest, driest regions on Earth," as per ScienceDaily.
This might enable millions of people who do not have constant access to drinking water to have simple, easy-to-use water-generation equipment at home.
Other attempts to extract water from arid air are often energy-intensive and yield little.
Although 6 liters may not seem like much, the researchers believed that optimizing thicker films, absorbent beds, or arrays might significantly enhance the quantity of water they release.
According to the researchers, the reaction itself is simple, which lessens the hurdles of scaling it up and attaining broad utilization.
Adsorption is a process that attaches water molecules from the air with less than 100% relative humidity to the surface of a solid substance, as per The Economist.
The molecules are kept in place by electrostatic connections known as Van der Waals forces, which bind them to the molecules of the relevant surface.
To gather a large amount of water in this manner, a substance with two qualities is required.
The first is a huge surface area. The alternative option is a Van der Waals reaction.
Metal-organic frameworks have been used to create experimental traps that use this idea. These are porous molecular networks that allow air to move through them.
Because of their porosity, they have a large surface area.
Furthermore, once absorbed, the water must be released. This entails warming the adsorptive substance-using the heat given by the sun once it has risen.
Metal-organic frameworks provide concern in this case.
They do not heat up properly since they prefer to reflect sunlight rather than absorb it. To address this, engineers included solid "foams" of copper into the system.
These absorb heat from the sun and transport it to portions of the neighboring metal-organic framework where absorbed water must be released.
This worked, but adding additional foams raised the expense of already expensive technology.
Both factions want to avoid these complexities in different ways. Berkeley researchers lead by Omar Yaghi published their findings last year.
They proposed replacing the zirconium-based metal-organic framework with an aluminum-based framework.
Aluminium is not only less expensive than zirconium, but it is also better at binding to and then releasing water, helping the trap operate more smoothly.
Furthermore, Dr. Yaghi discovered that by putting graphite into the powder from which the framework is made to make it black and so heat-absorbing, he may eliminate the requirement for copper foam.
