SCIENCE
Researchers at the University of Waterloo in Ontario, Canada have designed an energy-efficient device that produces drinking water from seawater using an evaporation process driven largely by the sun.
Roughly 2.2 billion people worldwide don’t have access to clean water. Desalination is critical for many coastal and island nations to provide access to fresh water.
Current desalination systems pump seawater through membranes to separate salt from water, but this is energy-intensive, and salt often accumulates on the device’s surface, obstructing water flow and reducing efficiency. As a result, these systems require frequent maintenance and can’t operate continuously.
To solve the problem, researchers drew inspiration from the natural water cycle to create a device that mirrors how trees transport water from roots to leaves. The new technology can continuously desalinate water without needing major maintenance.
“Our inspiration comes from observing how nature sustains itself and the way water evaporates and condenses in the environment,” says Dr Michael Tam, a professor in Waterloo’s Department of Chemical Engineering. “The system we’ve engineered induces water to evaporate, transports it to the surface, and condenses it in a closed cycle, effectively preventing the accumulation of salt that reduces the efficiency of the device.”
The device is also solar-powered and can convert about 93% of the sun into energy, five times better than current desalination systems. It can also produce about 20 litres of fresh water per square metre, the same amount the World Health Organisation recommends each person needs every day for basic drinking and hygiene.
“This new device is not only efficient but also portable, making it ideal for use in remote regions where access to fresh water is limited,” says Dr Yuning Li, also a professor in the Department of Chemical Engineering.
The team next plan to build a prototype of their device that can be deployed at sea to test the technology on a larger scale.
ABOVE A mockup of the solar desalination system
PHOTO University of Waterloo
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