New Desalination System Turns Seawater Into Drinking Water and Useful Salts - Including Lithium

"Scientists have developed a solar desalination system that turns seawater into drinking water without creating environmentally damaging brine," reports ScienceDaily.

"Special laser-textured metal panels use sunlight to evaporate water while automatically moving salt deposits away from the working surface, preventing clogging. The process was successfully tested with water from three oceans and can recover nearly all salts as solids. Those leftover materials could even become a source of valuable lithium for batteries." (The research team was led by University of Rochest professor Chunlei Guo and published their results in the journal Light: Science & Applications.)

The University of Rochester has made an announcement:


The technology uses solar panels made of black metal etched with femtosecond lasers to make the surface super light-absorbing and superwicking — or extremely attractive to water. The panels have a laser-treated active region that pulls a thin layer of water across the surface, absorbs nearly all solar radiation, distills the water, and deposits the leftover salts and minerals into the panel's untreated sides or "passive" region so that the salt does not clog the active region and disrupt continuous desalination... Guo's team precisely etched the black metal's grooves so the various salts and minerals in ocean water would simply slough off... [I]t extracts nearly 100 percent of the salts in solid form.

This could not only produce an abundant supply of table salt, but it could also be used to extract more precious minerals, including lithium, which is used in the lithium-ion batteries that power electric vehicles and other electronics. In a related paper in the Journal of Materials Chemistry A, Guo and his colleagues show how they can use the same superwicking solar panels to separate lithium from the rest of other salts in desalination. Embedding nanoparticles made of hydrogen titanate in the tiny grooves of the black metal surface isolates the lithium from other salts and minerals...Using water samples from Great Salt Lake, the researchers extracted about 50 percent of the lithium from the salts left behind by the desalination process. Guo says now that the superwicking desalination technology has been demonstrated in proofs of concept on small-scale devices, he sees the technology inherently scalable, capable of improving global access to drinking water and building more sustainable supply chains for precious minerals.
"The National Science Foundation, the Bill & Melinda Gates Foundation, and Worldwide Universities Network supported this research."

Read more of this story at Slashdot.