Korea ist ein wasserarmes Land und steht trotz einer jährlichen Niederschlagsmenge von 1.300 mm vor Herausforderungen durch Wasserknappheit. Das Fehlen von Trinkwasser hat lebensbedrohliche Auswirkungen für bestimmte Personen. Laut UNICEF leiden etwa 190 Millionen afrikanische Kinder unter Wassermangel, was täglich zum Tod von 1.000 Kindern unter fünf Jahren führt.
Die Entsalzung von Meerwasser ist energieintensiv und basiert auf fossilen Brennstoffen, was Umweltverschmutzung verursacht. Die Gewinnung von atmosphärischem Wasser gestaltet sich in Regionen mit einer Luftfeuchtigkeit unter 70% aufgrund des hohen Energiebedarfs schwierig.
Ein gemeinsames Team von Forschern unter der Leitung von Prof. Woochul Song von der POSTECH und Prof. Omar M. Yaghi von der UC Berkeley hat mit Hilfe von Sonnenlicht erfolgreich atmosphärisches Wasser in der Death Valley-Wüste gewonnen. Der Durchbruch bietet eine vielversprechende Lösung für die Wasserknappheit und nutzt eine unendliche Wasserquelle, ohne die Umwelt zu verschmutzen. Die Forschungsergebnisse wurden am 6. Juli 2023 in Nature Water veröffentlicht.
Das Team entwickelte einen zylinderförmigen Wasserabscheider auf Basis von metallorganischen Gerüsten (MOFs), die atmosphärischen Wasserdampf absorbieren. Das Gerät verwandelt das aufgenommene Wasser mithilfe von Sonnenlicht in trinkbares Wasser um. Das einzigartige Design maximiert dabei die Nutzung von Sonnenlicht von Sonnenaufgang bis Sonnenuntergang.
Der Abscheider wurde sowohl in Berkeley als auch in der Death Valley-Wüste getestet. Bei den Experimenten gewann das Gerät bis zu 285 g bzw. 210 g Wasser pro Kilogramm MOF, eine Verdopplung im Vergleich zu früheren Abscheidern. Der Abscheider extrahierte Wasser erfolgreich, ohne einen Kohlenstoff-Fußabdruck zu hinterlassen, selbst in extrem trockenen Bedingungen.
Die Praktikabilität der Technologie wurde in wirklich extremen Umgebungen demonstriert und zeigt ihre universelle Anwendbarkeit und das Potenzial zur Bekämpfung von Wasserengpässen und Umweltproblemen. Prof. Woochul Song betonte, dass die Technologie eine zuverlässige Wasserquelle unabhängig von geografischen oder klimatischen Bedingungen darstellt und Nachhaltigkeit verkörpert.
The Impact on Water-Scarce Regions
This revolutionary water harvesting technology has the potential to significantly impact water-scarce regions around the world. Countries like Korea, which face severe water scarcity despite receiving a substantial amount of annual precipitation, can benefit from this breakthrough. With the ability to extract drinkable water from the atmosphere using ambient sunlight, this technology offers a sustainable solution to the scarcity of safe drinking water.
Moreover, the situation in Africa is even more dire, with millions of children suffering from a lack of safe water. This technology could potentially save the lives of thousands of children by providing them with a reliable source of clean water every day. The impact on these regions is enormous and cannot be underestimated.
Overcoming the Limitations of Conventional Methods
Seawater desalination and atmospheric water harvesting are two commonly used methods to combat water scarcity. However, both have their limitations. Seawater desalination requires a significant amount of energy and relies heavily on fossil fuels, leading to environmental pollution. On the other hand, atmospheric water harvesting is not efficient in regions with low humidity, as it requires a substantial amount of energy to extract water from the air.
The breakthrough achieved by the joint team of researchers addresses these limitations by harnessing ambient sunlight to harvest atmospheric water. This not only eliminates the need for fossil fuels but also maximizes the utilization of available resources. The unique design of the cylindrical water harvester, based on metal-organic frameworks (MOFs), ensures the efficient extraction of water even in dry conditions.
The Role of Metal-Organic Frameworks (MOFs)
Metal-organic frameworks (MOFs) play a crucial role in this technology. They are highly porous materials consisting of metal ions or clusters coordinated to organic ligands. MOFs have the ability to absorb and store large amounts of water vapor from the atmosphere, making them ideal for water harvesting.
In the cylindrical water harvester, MOFs are used to absorb atmospheric water vapor. When exposed to ambient sunlight, the absorbed water vapor condenses into liquid water, which can be safely consumed. This process is sustainable, as it does not generate any carbon footprint or harm the environment.
Increase in Water Harvesting Efficiency
The team of researchers conducted experiments in both Berkeley and Death Valley desert to test the efficiency of the water harvester. The results were remarkable, with the harvester able to extract up to 285g and 210g of water per kilogram of MOF, respectively. This represents a twofold increase compared to previous water harvesters.
This significant increase in water harvesting efficiency is a game-changer. It means that even in extremely dry conditions, such as the Death Valley desert, this technology can still extract a substantial amount of water from the atmosphere. It opens up possibilities for its implementation in various regions with different climates and levels of humidity.
A Universal Solution to Water Scarcity
One of the most promising aspects of this technology is its universal applicability. Unlike other methods that are limited by geographical or weather conditions, this breakthrough offers a reliable source of clean water regardless of these factors. This makes it suitable for implementation in any water-scarce region around the world.
The practicality of the technology has been demonstrated through experiments conducted in extreme environments like the Death Valley desert. By successfully extracting water without relying on external energy sources or generating any carbon footprint, this technology showcases its potential to address water scarcity and environmental issues effectively.
As the global water crisis continues to worsen, innovative solutions like this are crucial. This breakthrough in atmospheric water harvesting using ambient sunlight gives hope for a future where water scarcity is no longer a threat to human lives. It is a revolution in sustainable water management and a step towards a more water-secure world.
