Graphene Sheets Can Be Turned Into the Best Filters Ever, For Desalination and Much More

Graphene, what's not to like: I haven't had this much fun since Bucky Balls!

This story fits well with an enormous problem lurking just below the radar - continental-scale potable water systems.

To keep a warming, drought plagued world habitable by its 9 billion people, tens of cubic miles of sea water will have to be purified and piped to the interior of continents every day for agriculture and human consumption. This is not something which can be powered with windmills or solar panels. It WILL require nuclear power.

If this worked as well as theory says then forevermore we have no water problems anywhere withing site of the sea. Longer distances of course pumping costs would negate the use but it could dramatically impact near-sea shore farming, etc.

Actually no Bildan, "at low pressures"... windmills, turbines and solar power, this low pressure high yield filtration system is a perfect fit. Nuclear is NOT a requirment, now if you wanted to use the current high pressure low yield method at the ammounts you quote, yes something much more powerful than current "green" power supplies would be needed.

Playing Devil's Advocate since 1978

"The only constant in the universe is change"
-Heraclitus of Ephesus 535 BC - 475 BC

Hmmm, this article kind of points to a grand scale of water filtering the oceans for human need.

Ok....

This means, manufactoring of large scale graphene sheets to filter the water. Eventually these sheets will get gagged up with the things we do not want for the clean water we do want. So what we need to process all these dirty filters and the waste they accumulate.

Someone mention above using nuclear energy for a large scale distilation process. I am not excited about using nuclear energy, but the distilation process does separate the bad from the good with the water.

Since the article began with a grand dream of clean water, how about putting 1000s of solar powered dislation plants, pump the water up to tanks or mountains on land somewhere. Store the water for reserve energy use and use of clean water. Allow the natural waste from the sea be pumped back to the sea in a balance enviromentally friendly way.

Ok, I am done day dreaming now. ;)

Robot, the sheet wouldn't clog up, you are thinking "macro" world. The sheets wouldn't clog up with salt molecules, the water behind the filter would just become more salinated, it would still be salt water just as it was before, just with a higher salt content, the water molecules would still flow though just as they did when the sheet first filtered. Think of it as "reflecting" the salt molecules rather than "filtering".

Playing Devil's Advocate since 1978

"The only constant in the universe is change"
-Heraclitus of Ephesus 535 BC - 475 BC

Most membranes, if thats really what they're going to make them into, don't get thrown away when they're plugged. Instead you flush them by reversing the flow of water at a slightly higher pressure and it clears most of the blockages. If they turn it into a filter though it will need to be replaced.

I'm excited to see what comes of this. Even just for cleaning up contaminated water, as long as the contminant is bigger than the water of course.

@EBL- Nice Highland picture. They're an interesting breed

This really could be a game changer. Not only could you fill things like Lake Mead back up, but you could also reduce the mining done for salt.

Heck, if this is cheap enough to produce (which of course it is not currently), you could irrigate the Sahara desert! Somewhere like that, you really could power it with solar panels.

Build it soon enough and we won't have to worry about the San Francisco airport being under water in 10 years! ;)

While utilizing salt water for drinking water (cheaply) my main worry is what will we do with all of the sea salt? A lot of it could be used as table salt, which is healthier than the sodium chloride we use today. However, places like California may end up filtering out enough salt for the whole US (as they have fresh water shortages as well as energy shortages). Maybe we can find new ways to use the excess sea salt? The main issue I see with the excess salt is salinification of our soils. Pretty much all inland vegetation is intolerant to salt and we may see massive crop die-offs, loss of native species, and other issues arise as we dispose of the sea salt.
I know this is an issue that is far off, but because we would rather do things cheaply than right it's something to think about.

@randy782001 - Most desalintion plants don't dry the sea salt down 100%. They get a stream of "fresh" salt free water and a stream of "brine" which contains the salts and other impurities. That brine solution is pumped back out to sea to remix with the rest of the ocean.

Too bad it can't be used to filter the BS coming out of Congress......but then no force on earth could pressure that enough to filter it.

@gizmowiz- Really? You started off in this thread with such a good comment about the real world applications for this tech and then you had to come back and sully it by dragging politics into it. You just had to be "that guy"? I'm sure if we all wanted to we could go through every story on this site and find some clever way to bring politics into it but thats what sites like Foxnews, CNN, and MSNBC are for.

It's the "molecular sieve" from Arthur C. Clarke's "The Man Who Ploughed the Sea", in Tales from the White Hart. Adjust the pore size to extract dissolved minerals, etc. from seawater.

Could use the natural tidal force as the pump, fresh water shortages are closer then we think, this should be piloted soon.

The main problem here will be mass producing graphene sheets with the right pore size in an economical manner.If that is done,it will indeed be a new day for desalination of seawater.