Beautiful, isn't it? It's also synthetic, made through joyous electro-chemistry. Not that there's anything wrong with that, especially for our good German friends at Fraunhofer. A group of scientists there have been growing diamonds, not to try to pawn off in Antwerp or anything, but rather to coat electrodes, and ultimately use them to clean up sewage.
Let me explain. Without diamondes, electrodes can clean dirty water. When they're placed in water and a current is turned on between them, the charge produces oxidants like ozone and hydroxyl radicals. Those oxidants neutralize substances in water that contain carbon, including solvents, bacteria and pesticides.
But the challenge is that you need just the right strength of electrical current to produce just the right kind of oxidants. A current that's too strong will create other oxidants that can't be used to neutralize the nasties.
Enter the diamond. Well, really a micro-layer of synthetic diamond, that can be grown on the electrodes. The diamond layer hinders the formation of the oxidants you don't want, and gives you more of the hydroxyl radicals, which "can destroy any pollutant in water by oxidizing it," says research Lothar Schaefer of the Fraunhofer Institute for Surface Engineering and Thin Films IST in Braunschweig.
And all that's left behind are some salts and carbon dioxide.
"The big advantage of the method is that no additional chemicals have to be added into the water," Schaefer wrote me in an email. "The oxidants are produced by the water itself. You just need electrical power and you can easily control the current between the diamond-coated electrodes."
There are, of course, drawbacks. If you scaled this up, you'd need a high amount of electrical energy, which could get expensive. What's more, the diamond-coated electrons can't treat suspended solids in the water.
On the other hand, says Schaefer, you could bring electricity use down by powering the Fraunhofer system with solar energy. And, he notes, it can be easily integrated into existing water treatment systems that employ filtration or biological means of killing water-borne nasties.
This is, by the way, only one of the ways Fraunhofer's trying to find new ways to clean our water.
(Photo: Steve Jurvetson)
Tags: Water
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