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Making Saltwater Drinkable With Graphene
An anonymous reader writes "Graphene once again proves that it is quite possibly the most miraculous material known to man, this time by making saltwater drinkable. The process was developed by a group of MIT researchers who realized that graphene allowed for the creation of an incredibly precise sieve. Basically, the regular atomic structure of graphene means that you can create holes of any size, for example the size of a single molecule of water. Using this process scientist can desalinate saltwater 1,000 times faster than the Reverse Osmosis technique."
If they've found a way to desalinate water with much less energy, practically, that's huge.
Bruce Perens.
Surely it won't last forever, but the membrane lifetime could be extended by using normal filters to retain impurities, and let the graphene deal with pure saline water. Maybe the graphene filter can be cleaned a couple of times and be reutilized.
All of those would be larger molecules than H20, don't you think? This is a pretty cool discovery/invention.
The cesspool just got a check and balance.
I agree,getting salt out is fine, but, fishy smell, fish pee, industrial pollution (mercury 'n'such ).
Err, no one does that... Seriously. Fishy smell? Fish pee? wtf??
Mercury is not toxic much anyway, unless it is in organic forms.
But then on the plus side, if Uranium cost were > $350/lb, it would be economical to mine Uranium from sea water. It doesn't mean this concentration is toxic for you.
Where I live, most of the water is from a lake, with fish pee and moose pee all mixed in together. haha
Water Molecule: 275 pico-meters
Ecoli Bacteria: 0.6 micro-meters (109,000x larger)
Rhinovirus: 30 nm (110x larger)
Figure 8 on Page 6 of the actual paper shows what they're measuring. They're comparing filter materials by Salt rejection % vs Water permeability measured in L/cm2/day/MPa. That unit incorporates all the energy-efficeny goodness you want in a filter without looking at what pump technology is actually used to provide the energy input. It says that more filtered water (L) per square centimeter of filter (/cm2) per day (/day) per MegaPascal of pressure (/MPa, the energy input) is more good. Assuming any particular pump technology would give you a number for MPa/MJ that you could apply, but it doesn't help you understadn the performance of the filter itself. The figure for improvement vs existing technology they actually give is 2-3 orders of magnitude (100-1000x) so TFS is taking the optimistic side.
The bottom line is that this has a huge potential but is still a ways from practical application.
Keep in mind that this process is regarding desalinization, not water purification. I'm sure if graphene solves the problems of desalinization, it will work wonders with purification, but there are adequate water purification systems located in most places, but water desalinization is a massively expensive procedure in comparison.
A robust and cost effective desalinization system is literally one of the biggest necessities we're going to need in the next century, as average rainfall levels continue to fall all over the U.S.
I know it may be impractical but I see giant desalinization inlets from the ocean leading to a network of irrigation and river systems for the West coast.
My kingdom for a donkey!