Desalination is now 10X more fuel-efficient

[True Earthling]

can also be used for waste water treatment...

Commercial desalination is usually done in one of two ways. The first, known as thermal desalination, involves boiling seawater above 212F, then distilling the vapors. The second, called reverse osmosis, uses hydraulic pressure to force water through a membrane that filters out salt. Both require enormous amounts of energy. McGinnis says he's found a method that's at least 10 times more fuel-efficient.

Water molecules naturally want to flow from fresher solutions to saltier ones. Hence the "reverse" in reverse osmosis: It forces water molecules to go against their tendency. McGinnis's method makes use of forward osmosis. He's developed a "draw solution" that's saltier than seawater. Without need for any energy, the water molecules in seawater flow across a porous membrane and into the draw solution, leaving the sea salt behind. McGinnis's solution is as undrinkable as ocean water, but its salt compounds—"essentially just ammonium, carbon dioxide, and some other secret stuff," he says—vaporize at lower temperatures. McGinnis's solution needs only 122F to burn off salts and leave behind pure water, instead of the much higher temperatures required for thermal desalination.

http://www.businessweek.com/magazine/content/11_12/b4220041560310.htm

[WatsonT]

1. It's a very cool concept

I wish we were putting more money in to it.

[Tesha]

2. There was a fairly large-scale article about this in "New Scientist" magazine a few months back. NT