Desalinating the Earth's Ocean for Energy Efficient Drinking Water (Video)
Water is one of Earth's most precious resources. It covers our planet, providing the basis for life for billions of organisms. Now, scientists are working on a more efficient way to desalinate the ocean for drinking water--one nanoliter at a time.
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With current methods of desalination, a membrane is needed to separate the salt from water. Yet this new method, called electrochemically mediated seawater desalination, overcomes many of the issues associated with current techniques. It is dramatically simple and consumes less energy.
So how does it work exactly? The researchers apply a small voltage to a plastic chip filled with seawater. The chip contains a microchannel with two branches. At the junction of this channel, an embedded electrode neutralizes some of the chloride ions in seawater to create an "ion depletion zone." This increases the local electric field, which then redirects salts into one branch. The desalinated water then flows through the other branch.
"The availability of water for drinking and crop irrigation is one of the most basic requirements for maintaining and improving health," said Richard Crooks, one of the researchers, in a news release. "Seawater desalination is one way to address this need, but most current methods for desalinating water rely on expensive and easily contaminated membranes. The membrane-free method we've developed still needs to be refined and scaled up, but if we can succeed at that, then one day it might be possible to provide fresh water on a massive scale using a simple, even portable, system."
Scaling up could certainly be an issue, though. Right now, the microchannels are merely the size of a human hair and produce a miniscule 40 nanoliters of desalted water per minute. In order to actually make this system practical, it would have to produce liters of water per day. If the researchers can succeed, though, it could mean the difference for communities across the globe.
"People are dying because of a lack of freshwater," said Tony Frudakis, founder and CEO of Okeanos Technologies, in a news release. "And they'll continue to do so until there is some kind of breakthrough, and that is what we are hoping our technology will represent."
The findings are published in the journal Angewandte Chemie International Edition.
Want to learn more? Check out the video below, courtesy of YouTube.