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Researchers develop method of desalination that could save millions of lives: 'A paradigm shift is essential to sustain human life'

On a large scale, desalination is a promising method to provide abundant fresh water.

On a large scale, desalination is a promising method to provide abundant fresh water.

Photo Credit: Australian National University

Australian researchers have announced a breakthrough in desalination science that has the potential to provide millions of people with clean water.

The experts from the Australian National University are perfecting an alternative to creating fresh water from seawater that's more cost-efficient and uses less energy than reverse osmosis and other common methods

It's a twist on a concept first recorded in science books in the 1850s, according to a university lab report

"We're going back to the thermal desalination method but applying a principle that has never been used before, where the driving force and energy behind the process is heat," lead chief investigator Dr. Juan Felipe Torres said in the university summary. 

It works by using relatively low heat from sunlight or residual warmth created by industrial machines or air conditioners to heat channels, as the university report explained. When salty water is moved through a narrow channel, salt ions collect on the colder side. To maximize the impact, the researchers heated the top side to about 140 degrees Fahrenheit. The lower side was cooler, around 68 degrees. 

Holding true to Swiss scientist Charles Soret's findings in the middle of the 19th century, salt moved to the bottom. 

"Our mission became to find a way to fast-track the diffusion process," Torres said in the report. "The key was reducing the channel height from 30 centimeters [nearly a foot] to one millimeter [less than 0.04 inches] and adding multiple channels." 

As the water passed through the collection of channels, the lower salty water was removed, knocking salinity down about 3% with each pass, according to the summary.  

The larger channels required 53 days to reach a "steady state." The new approach cut the diffusion process to minutes. 

"Our research shows that after repeated cycles, seawater salinity can be reduced from 30,000 parts per million to less than 500," doctorate student and first author Shuqi Xu said

Importantly, the water can remain in liquid form, a big advantage over techniques that require vaporization. 

The results could be life-saving. Nature reports that worldwide water demand has spiked 600% in the last century. About 300 million people in over 150 countries rely on desalination for clean water, according to information from the World Bank. 

However, the supply is lacking despite the tech, as UNICEF stated in a 2023 report that 600 million children around the planet are in need of "safely managed drinking water." Poor sanitation is sullying a lot of water, evidenced by the 400,000 kids under age five who die each year from a dirty supply, per the report. 

The good news is that you can take action to save water at home with some simple tricks. A quick adjustment to your toilet tank can save liters of water a day while still working well, as one example. Tightening up your water waste around the house can save thousands of gallons, as well as lower your utility bill. 

On a large scale, desalination is a promising method to provide abundant fresh water. The experts in Australia are working to prove their concept with a plant in drought-hit Tonga in the South Pacific, according to Tech Xplore. 

They hope to have a commercial unit finalized within eight years. 

"A paradigm shift is essential to sustain human life over the next century," Torres said in the lab report. 

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