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New Process For Nanoscale Filtration Holds Promise of Cheap, Clean Water

Soulskill posted about a year ago | from the fighting-the-evil-oceans dept.

News 116

New submitter Spinnakker writes "Lockheed Martin, traditionally known for its development of military systems and aircraft, has developed a process for perforating graphene (carbon sheets only one atom thick) that could potentially reduce the energy required for desalination by two orders of magnitude. The process tailors the hole size to the molecules being separated. In the case of desalination, one would create holes in the graphene large enough to allow water to pass but small enough to block the salt molecules. The advantage to using graphene comes from how extremely thin the material is compared to traditional filters. The thinner the filter, the less energy is required to facilitate reverse osmosis."

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Holy moly (4, Insightful)

i kan reed (749298) | about a year ago | (#43185647)

I remember when this theoretical technology was proposed about a year ago, and figured it would be a decade before they could actually do it.
Cheap desalinization and filtration would mean an end to one of the biggest world health problems(safe drinking water), and could improve world-wide standards of living dramatically.

Re:Holy moly (3, Funny)

fustakrakich (1673220) | about a year ago | (#43185723)

It's very hard to keep prices up and maintain austerity measures if fresh, clean water becomes more abundant. Desalination seems like such a waste when we can collect, harvest, and distribute rain water. But low profit margins will keep that from happening. Making war and stealing other peoples' water is the market solution.

Re:Holy moly (1)

alen (225700) | about a year ago | (#43185841)

we already do collect rain water

upstate NY the rain falls into lakes and rivers and then into the NYC water system

i don't think its feasible collecting rain water straight from the sky though

Re:Holy moly (4, Informative)

Ol Biscuitbarrel (1859702) | about a year ago | (#43186069)

i don't think its feasible collecting rain water straight from the sky though

Sure it is, people have been doing it for millenia: Brief Outline of the History of Rainwater Catchment Technologies [ernet.in]

Archaeologists found a sophisticatedrainwatercollection and storage system on the island of Crete while working on the reconstruction of the Palace of Knossos (1700 B.C.). However, with the development of building construction based on new materials such as lime and burnt clay bricks, new construction techniques like arches and domes developed. The ancient Romans became masters inrainwaterharvesting and the construction ofreservoirs. It was this new technique of building closed cisterns, and at the same time the urbanization within the Roman Empire around the Mediterranean, which resulted in the development of arainwatercatchment culture at all those places where water resources were limited. This is why oldrainwatercisterns are to be found on the islands of Capri and Malta and at places of historical interest in Spain and Turkey, in the Lebanon and on the island of Sicily.

Plenty of research is being conducted on modern approaches to rainwater harvesting. In the developed world these often come into conflict with environmental regulations regarding water quality, and in general there's a surfeit of water from other sources that is ran through central filtration facilities so no great press is on to tap rainwater as a major source. It's something popular with people who are interested in green tech and the like.

Re:Holy moly (2)

fazookus (770354) | about a year ago | (#43186335)

The problem with rainwater harvesting that most of the worlds potable water already comes from rainwater... in anything approaching a largish scale you're going to be in conflict with river basins and the like and grabbing rain destined for forests, farm animals and crops.. The advantage of desalination is that you let nature harvest the rainwater and concentrate it for you and then just process that.

Re:Holy moly (1)

rohan972 (880586) | about a year ago | (#43186949)

Most water people use ends up in the drain, being treated and returned to the system. Bringing in desalinated water doesn't preserve the natural water levels in that area it adds to it. Desalination and centralized distribution also has infrastructure and energy costs that local rain harvesting doesn't and then there's the problem of what to do with the salt.

Re:Holy moly (1)

Anonymous Coward | about a year ago | (#43186113)

we already do collect rain water

gp never said we didn't

We do use rain water (1)

Anonymous Coward | about a year ago | (#43188027)

Here in Australia most of the households use rain water, I'm not even connected to the town water (and I'n not a threehugger...).
The idea initially sounded weird (I'm from Europe), but it works fine and the quality is excellent, without fluoride and other craps.

Re:Holy moly (1)

Anonymous Coward | about a year ago | (#43185857)

I bet you are a lot of fun at parties:

"The punch is probably poisoned".

"You are just contributing to Big Liquor".

"I bet none of these girls really like me. They're just after my money"

"Did you know that Halliburton owns Frito Lays?"

Re:Holy moly (1)

reboot246 (623534) | about a year ago | (#43188771)

Making war and stealing other peoples' water is the market solution.

Actually, very few wars have been fought over water.
"Scientists at International Water Management Institute and Oregon State University have recently found that water conflicts are in the minority of issues concerning water use with hundreds of treaties in place guiding benevolent use of water resources between nations. Water conflicts tend to arise as an outcome of other social issues."

Re:Holy moly (2)

the eric conspiracy (20178) | about a year ago | (#43185751)

The problem with existing home RO is that the pressure available is low resulting in a lot of wasted water. Efficiency is maybe 15%. This may be a big help in that regard.

The other limitation with membranes is they are not sufficient for sterilization. Holes in the membranes plus the lack of residual action means additional treatment is needed downstream of the filter. This is not likely to address that issue.

Re:Holy moly (0)

Anonymous Coward | about a year ago | (#43185799)

What kind of bacteria smaller than a NaCl molecule in size are you worrying about ?

Re:Holy moly (1)

The_Wilschon (782534) | about a year ago | (#43185809)

Which viruses or bacteria are you worried about that are smaller than salt ions?

Re:Holy moly (0)

Anonymous Coward | about a year ago | (#43185907)

Ones that are smaller than the HOLES in the MEMBRANES that he mentioned (which will almost certainly arise).

I'm not too worried about it, actually. If the output water tests cleaner than tap water, that's enough.

Re:Holy moly (1)

Zeromous (668365) | about a year ago | (#43186045)

It would have to be a hole through several layers of membrane, but yes a mild standard treatment afterwards may be more than enough. This is hardly the expensive part of desalinization.

Re:Holy moly (0)

Anonymous Coward | about a year ago | (#43186243)

If there aren't any holes in the membrane, how does the water get through?

Re:Holy moly (1)

The_Wilschon (782534) | about a year ago | (#43186265)

If the HOLES in the MEMBRANES are large enough to allow viruses and bacteria through, then they're large enough to allow salt ions through in much greater numbers, and then the membrane would not be doing it's job of desalination. I'm sure that this is not difficult to understand.

Re:Holy moly (4, Informative)

the eric conspiracy (20178) | about a year ago | (#43186817)

Holes in membranes are a fact of life. The reason they aren't crucial for desalinization is that you don't need ion free water for it to be potable. In fact it's common to add ions back in after desalination because pure water is much more corrosive than typical drinking water.

Disease organisms are a different issue altogether.

Post treatment growth of micro-organisms is a fact of life. Some sort of treatment with a residual action is absolutely needed. Usually this is chlorine or chlorine compounds. Maybe in a home system you can get away without it but certainly not in a municipal water system.

This isn't new knowledge folks. People have been doing this for decades.

http://www.fwrj.com/techarticles/1109%20fwrj_tech1.pdf [fwrj.com]

Re:Holy moly (2)

Xenna (37238) | about a year ago | (#43189175)

But surely the biggest use of this technology is not for drinking water but for irrigation? Turning the desert into arable land...

Re:Holy moly (3, Informative)

Zeromous (668365) | about a year ago | (#43185861)

No bacteria would pass though due to size, so coagulation not necessary. Chlorination also not necessary.

So what does that leave, purification of certain compounds which happen to be smaller than H2O? (likely a mild chemical treatment process judging by other filtration techniques.) Since this is a desalination filter process seems safe to assume anything above Ng on the perdioc table would not pass through ( I am not a chemist by trade so please correct me if I am wrong). This leaves H He Li Be Bo C N O Fl Ne to be worried about from a chemical standpoint after filtration.

So what really is left after passing through graphene?

Re:Holy moly (1)

Zeromous (668365) | about a year ago | (#43185875)

Ach, anything above Ne* I mean (Boron just B, also Flourine is just F). Told you I wasn't a chemist, but not bad from memory.

Re:Holy moly (0)

Anonymous Coward | about a year ago | (#43187437)

Fluorine. There's no flour in duogh.

Re:Holy moly (1)

Anonymous Coward | about a year ago | (#43186281)

In practice, a fraction of the living bacteria can and do pass through RO membranes through minor imperfections, or bypass the membrane entirely through tiny leaks in surrounding seals. Thus, complete RO systems may include additional water treatment stages that use ultraviolet light or ozone to prevent microbiological contamination.

wikipedia

Re:Holy moly (0)

Anonymous Coward | about a year ago | (#43187543)

This is not true with graphene. This is the entire point of the carbon structure.

Re:Holy moly (0)

Anonymous Coward | about a year ago | (#43186733)

No bacteria would pass though due to size, so coagulation not necessary. Chlorination also not necessary.

Based on water treatment design standards and safe drinking water regulations in the US you would still have to do all of the treatment you do now you could just swap the RO membranes for these new membranes.

You can't feed raw water into membranes. They would foul quickly so typical design has them following clarification, roughing filters, micro filters, and then a final RO stage. After this you add Chlorine (normally but you could add chloramine) to maintain a residual in the pipes.

Re:Holy moly (4, Informative)

Anonymous Coward | about a year ago | (#43187061)

what does that leave, purification of certain compounds which happen to be smaller than H2O. ... This leaves H He Li Be Bo C N O Fl Ne

He & Ne aren't a problem - 1) they're a gas, and He, at least, is sparingly soluble in water, so it'll all bubble off. 2) They're as inert as they get, so wouldn't make much of a difference even if they were in the water.

C N O - Aren't found as mono-atomic atoms. Will always be in larger molecules, which for the most part are larger than water.

H Li Be B F - Found as monoatomic species, but only as ions. With ions you always get a shell of hydration around them, and it's a significant amount of work to strip that away. Effectively, you don't have a Li+ on its own, you have a Li+(H2O)x complex, which by necessity will be bigger than a single water molecule

The only thing you'd be worried about are small, neutral molecules. Something like methane might be a problem, but if you have methane in your source water, you probably know it, and will have some other pre-treatment to deal with it specially.

Re:Holy moly (0)

Anonymous Coward | about a year ago | (#43187585)

This is awesome stuff!

Re:Holy moly (1)

budgenator (254554) | about a year ago | (#43187799)

The only times methane in the water is a problem is when you burp while smoking or when the glass gets knocked out of your hand due to a gas bubble going through the water tap.

Re:Holy moly (0)

Anonymous Coward | about a year ago | (#43187531)

Sorry to be pedantic but Nitrogen is N and not Ng... Just saying

Re:Holy moly (1)

iggymanz (596061) | about a year ago | (#43186049)

downstream treatment can be very simple though, appropriate filter, heating to high enough temp for appropriate time but without boiling, etc.

Re:Holy moly (1)

pchimp (767649) | about a year ago | (#43186333)

As others have mentioned, with pores of this size (even with the defects or 'holes' in the membrane) the bigger problem is biofouling -- bacteria, organisms, proteins... any kind of macromolecular junk may quickly clog the pores. Nevertheless, this is exciting news; affordable desalination is sure to be a critical technology sooner than we like.

Re:Holy moly (1)

rtb61 (674572) | about a year ago | (#43189143)

Downstream is truly the wrong word. The highest cost of desalination is, everywhere you want to use the water is going to be 'upstream' from it source. Most fresh water is used downstream from it's source less or no expensive pumping. Getting that water uphill is the real cost, pumping tons and tons of it, many kilometres inland and many hundreds of even thousands of metres uphill is the real cost problem. Cheap energy produces cheap water and low cost nuclear is still the best interim goal to producing lots and lots of potable water where it is required at a low price (fresh is a really a bad word to use with regards to water quality).

Re:Holy moly (0)

Anonymous Coward | about a year ago | (#43186075)

I remember when this theoretical technology was proposed about a year ago, and figured it would be a decade before they could actually do it. Cheap desalinization and filtration would mean an end to one of the biggest world health problems(safe drinking water), and could improve world-wide standards of living dramatically.

Last I heard, graphene was extremely expensive and difficult to make in quantity. It's nice they figured out how to put the right size whole in it, but unless someone comes up with a way to mass produce graphene, we're still a decade away, like every advance we can't make today.

Re:Holy moly (4, Informative)

interkin3tic (1469267) | about a year ago | (#43186185)

Yes, but we still need to figure out the other half of the problem of desalination, which is what to do with the high-salt brine. If you get 50% efficiency, as much water as you get out, you'll get out wastewater with 200% salt in it. In large volumes, you obviously can't store it or evaporate it off fast enough. Dumping it into the ocean will kill anything near the exhaust. And then there's still the problem of piping the water to cities.

It makes more sense to use this to filter out municipal waste water and re-use it for drinking water. It's right there where you need it, it's got less junk to get out than seawater, and there is less byproduct. The only problem with that is people don't like the idea of drinking their own sewage, even if it has been filtered well.

Not to be a wet graphene blanket: this is a very good thing, you're absolutely right that it will improve the standard of living worldwide if it pans out, and we do need better filtration technology. Just that we shouldn't forget the ecological concerns.

Re:Holy moly (1)

Anonymous Coward | about a year ago | (#43186567)

1. put it back into the ocean
2. put it back into the ocean?
3. how about try to read the above again.

How difficult is it to actually think these days? You don't dump it with 2x salt contents. You dump it at 5% higher salt content or 1% higher salt content or whatever. Make a long pipe 2km long and dump it there.

What's the problem?

And please don't say "how you can do that when process outlet is 200+% salt content of input".

But if you really don't want to dump it back in, you can

  1. make sea salt from it
  2. use it for industrial purposes that don't care about salt (fracking and conventional oil/gas production would come to mind)

It makes more sense to use this to filter out municipal waste water and re-use it for drinking water. It's right there where you need it, it's got less junk to get out than seawater, and there is less byproduct. The only problem with that is people don't like the idea of drinking their own sewage, even if it has been filtered well.

1. there are placed that do that but waste water has more bacteria
2. sea water is more consistent

Re:Holy moly (0)

Anonymous Coward | about a year ago | (#43186803)

what to do with the high-salt brine.

Bacon.

Re:Holy moly (0)

Anonymous Coward | about a year ago | (#43186819)

Or dehydrate fully and use the salt as a "molten salt battery" to store solar heat.

Re:Holy moly (0)

Tailhook (98486) | about a year ago | (#43186895)

we shouldn't forget the ecological concerns.

Like that's going to happen.

We could flood the planet with the bodily fluids of armchair ecologists bitching about stuff using their Chinese computer hardware.

Re:Holy moly (0)

Anonymous Coward | about a year ago | (#43187165)

We (humans) spend a LOT of time taking all manner of things out of the ground and leaving large holes behind (salt mines, iron mines, large cavities left from oil drilling, etc). Is there a downside to putting salt brine into those giant voids? Would the ground filter the moisture from the brine, putting more water into aquifers and leaving behind salt deposits?

I'm asking out of total ignorance - can someone answer?

Re:Holy moly (2)

budgenator (254554) | about a year ago | (#43187841)

The salt doesn't filter out, many places the underground aquifers are saline, we have a local pickle factory that has a brine well.

Re:Holy moly (1)

kqc7011 (525426) | about a year ago | (#43187387)

You just keep diluting it with seawater until it reaches the level of salinity that is acceptable. Maybe even start the dilution at the outflow of a sewage treatment plant, where treated, fresh water is introduced into the ocean. That way you stop killing organisms that cannot handle the freshwater. About every city that has it sewage plant outflows going into a ocean creates dead zones.

Re:Holy moly (1)

MangoCats (2757129) | about a year ago | (#43187939)

Ummmm.... the ocean is big, really big, and whatever water a major city needs is a small consideration compared to evaporation. You could tap a supply for all of south Florida from a single point and still dilute it to harmless levels just by mixing your 200% brine solution with 10 parts of straight seawater before discharge. I suspect industrial scale desalination would discharge much more dilute brine than 200%, unless they were attempting to also harvest sea salts, anyway...

Re:Holy moly (1)

radtea (464814) | about a year ago | (#43186251)

I remember when this theoretical technology was proposed about a year ago, and figured it would be a decade before they could actually do it.

It would be fascinating to troll through the /. archives and find out what fraction of things that were predicted to come to market in timescale X actually did so. XKCD aside, I don't think this question has ever been properly addressed.

Waterworld (1)

Anonymous Coward | about a year ago | (#43185719)

How soon before I can pee into a Mr. Coffee and get iced tea?

captcha: profound

Re:Waterworld (1)

Anonymous Coward | about a year ago | (#43185963)

> How soon before I can pee into a Mr. Coffee and get iced tea?

You could do that for McDonalds right now. Booya!

Q: What's the difference between roast beef and pea soup?
A: Anybody can roast beef!

Re:Waterworld (4, Funny)

onkelonkel (560274) | about a year ago | (#43186067)

You can pee into a glass mug and get Coors Light.

Re:Waterworld (0)

Anonymous Coward | about a year ago | (#43186401)

Q: How do you turn a German beer into an American beer?
A: Drink it.

Re:Waterworld (1)

rrohbeck (944847) | about a year ago | (#43189193)

I thought you run it through a horse.

expensive filter will get gummed up in no time (0)

Anonymous Coward | about a year ago | (#43185765)

so that means each hole will be permanently gummed up with a single molecule? how many molecules of salt (etc) are there in a liter of water? how many holes? and how expensive are these graphene filters?

Re:expensive filter will get gummed up in no time (5, Funny)

fustakrakich (1673220) | about a year ago | (#43185781)

...how many holes?

Enough to fill the Albert Hall

Re:expensive filter will get gummed up in no time (0)

Anonymous Coward | about a year ago | (#43186341)

Oh boy.

Re:expensive filter will get gummed up in no time (1)

Chris Mattern (191822) | about a year ago | (#43186343)

So they had to count them all, then.

Re:expensive filter will get gummed up in no time (1)

k3vlar (979024) | about a year ago | (#43186463)

Well, at least now they know how many holes it takes.

Re:expensive filter will get gummed up in no time (1)

Anonymous Coward | about a year ago | (#43185813)

so that means each hole will be permanently gummed up with a single molecule? how many molecules of salt (etc) are there in a liter of water? how many holes? and how expensive are these graphene filters?

You back flush the filter like most desalt plants. The patent shows them using gravity as the pressure source and the only real power being the flush and filling the gravity feed tanks.

Wait a moment (2)

H3lldr0p (40304) | about a year ago | (#43185831)

I thought part of the problem with current desalination techniques was that it removed all of the salts making us have to go back and re-add a bunch of phosphates and whatnot that are found in fresh water sources and are somewhat expected/required by our and plant's biological functions. That is, we were making the water too pure to be used without additional processing. This sounds like that taken the next level, so how much more efficient can it really be if the process requires even more post-processing to make it usable?

Re:Wait a moment (3, Interesting)

asm2750 (1124425) | about a year ago | (#43187861)

The issue with normal filtration is you need to replace the filter media after so many gallons. The issue with normal desalination is you need a lot of energy to purify the water.

Yes you need to re-add minerals when you use this new filter for watering plants and properly hydrating the human body, but think about it. With this invention you get a filter that will pretty much last forever with no degradation as long as it is maintained properly, and you can get fresh water from the sea and toxic sources without having to use up a ton of energy and money. In the end this idea is win-win, just make sure to include the trace minerals before drinking.

Re:Wait a moment (1)

soundguy (415780) | about a year ago | (#43189243)

So you're saying ... plants crave electrolytes?

Again? (1)

rosencreuz (1393933) | about a year ago | (#43185845)

Very similar article [slashdot.org] was published half a year ago. Is there something new now?

Re:Again? (3, Insightful)

Anonymous Coward | about a year ago | (#43185903)

Very similar article [slashdot.org] was published half a year ago. Is there something new now?

It's gone from "A group of MIT researchers" to "Lockheed Martin", the latter of which could actually make it commercially available.

Current technology is already efficient (4, Interesting)

drmaxx (692834) | about a year ago | (#43185849)

Considering that the theoretical minimal energy requirement for seawater desalination is approx. 0.75 kWh/m3 and current RO technology can be as low as 1.5 to 2 kWh/m3 (+ an other 2 kWh/m3 to pretreat the seawater) then I am really wondering how they will gain two orders of magnitude less energy? Can anybody enlighten us about that?

Re:Current technology is already efficient (1)

GodfatherofSoul (174979) | about a year ago | (#43185949)

Where's that energy currently coming from? I know nothing about desalination, but maybe better filters allow for purely gravity-fed tanks rather than some pressurized or multi-passed treatment system?

Re:Current technology is already efficient (2)

Thud457 (234763) | about a year ago | (#43186273)

Where's that energy currently coming from?

Casimir forces.

Re:Current technology is already efficient (1)

demonlapin (527802) | about a year ago | (#43188135)

Unless you're working in Death Valley or the Dead Sea region, gravity-fed tanks are going to have to provide the same energy input. And if you are in one of those places, you'll have to transport it uphill at some point.

Re:Current technology is already efficient (0)

Anonymous Coward | about a year ago | (#43186015)

There is zero prospect of transformational improvement in energy efficiency of sea-water desalination (because existing desalination membranes already are reasonably close to the thermodynamic limits to efficiency).

It is thermodynamically feasible, however, to substantially reduce the area of membrane required. The press release is culpably deficient in conveying this crucial distinction.

How much would smaller membranes reduce the overall cost of sea-water desalination? A plausible answer is: appreciably but not transformationally.

Re:Current technology is already efficient (1)

Zeromous (668365) | about a year ago | (#43186063)

>The press release is culpably deficient in conveying this crucial distinction.

Significantly. Less maintenance on membranes, likely more re-usable. Less post filtration treatment. Lighter, smaller, faster, better.

Re:Current technology is already efficient (0)

Anonymous Coward | about a year ago | (#43186057)

not sure where you got your data, but in the article it states:
"It's 500 times thinner than the best filter on the market today and a thousand times stronger," said John Stetson, the engineer who has been working on the idea. "The energy that's required and the pressure that's required to filter salt is approximately 100 times less."

maybe it is because they are considering the pressure as well?

Re:Current technology is already efficient (0)

Anonymous Coward | about a year ago | (#43186209)

Claim "It's 500 times thinner than the best filter on the market today and a thousand times stronger," said John Stetson, the engineer who has been working on the idea. "The energy that's required and the pressure that's required to filter salt is approximately 100 times less."

Read literally, the claimed performance gain is thermodynamically impossible. It is shocking that the Lockheed Martin Corporation would publicly assert such an off-the-wall scientific claim, as though no further clarification/explanation was required.

Re:Current technology is already efficient (1)

Immerman (2627577) | about a year ago | (#43187201)

Possible explanations if they're actually citing laboratory results and not just blowing smoke for PR purposes:
1) Our current theory of filtration efficiency is flawed
2) Our current theory is inapplicable in this case due to some quantum level effects

Not that this is necessarily directly applicable, but a while back I read a study where researchers found that water in a container sealed with a multilayer graphene cover evaporated just as quickly as from an uncovered container - the water vapor molecules just happened to be exactly the right size/shape/energy/whatever to slip right through the graphene "mesh" without resistance. Meanwhile most other gasses were completely blocked. Seems to me that would allow for some apparently thermodynamics-breaking gas separation strategies.

Re:Current technology is already efficient (1)

anorlunda (311253) | about a year ago | (#43187383)

Are you talking about osmosis or reverse osmosis? There is a thermodynamic limit to the osmosis process, but reverse osmosis uses high pressure pumps and wastes lots of energy.

I'm not aware of any thermodynamic limit to reverse osmosis efficiency. Can you provide a link?

Re:Current technology is already efficient (1)

Anonymous Coward | about a year ago | (#43188041)

Salt water has higher entropy than fresh water and salt separately. When separating salt water into salt and fresh water, entropy is therefore being decreased. This must be compensated by work from the outside. The minimal possible work needed is given by the difference in free energy between the initial and final state, independently of the method used to go between these states (the method will only affect how much energy above that minimum will be expended). When the start and end states are at the same pressure and temperature (which is the case for the overall process of desalination, even if the pressure is temporarily higher as a step in the process), the appropriate measure of free energy is Gibbs free energy, which you can read more about here: https://en.wikipedia.org/wiki/Gibbs_free_energy

Lockheed-Martin's claim is thermodynamically bogus (0)

Anonymous Coward | about a year ago | (#43188401)

Reference (establishing that the claims of Lockheed-Martin's press release are thermodynamically bogus):

What Is the Current Energy Efficiency of Desalination and Can It Be Improved?

Conclusion The energy demand for seawater desalination by state-of-the-art reverse osmosis is within a factor of 2 of the theoretical minimum energy for desalination, and is only 25% higher than the practical minimum energy for desalination for an ideal reverse osmosis stage.

@article{Author = {Elimelech M. and Phillip W. A.},Journal = {Science Science},Number = {6043},Pages = {712--717},Title = {The future of seawater desalination: Energy, technology, and the environment},Volume = {333},Year = {2011}}

Re:Current technology is already efficient (0)

Anonymous Coward | about a year ago | (#43187655)

Claim "It's 500 times thinner than the best filter on the market today and a thousand times stronger," said John Stetson, the engineer who has been working on the idea. "The energy that's required and the pressure that's required to filter salt is approximately 100 times less."

Read literally, the claimed performance gain is thermodynamically impossible. It is shocking that the Lockheed Martin Corporation would publicly assert such an off-the-wall scientific claim, as though no further clarification/explanation was required.

Shocking, I tell you! Lockheed Martin engineers are gods!

Re:Current technology is already efficient (0)

Anonymous Coward | about a year ago | (#43187187)

The energy required to force sea water through a conventional micro filter is huge. It requires a lot of force to push the water through the thick filters and the brine out the other end.
100 times less energy it seem possible to just let water flow over a membrane tray and collect fresh water out the bottom.

Re:Current technology is already efficient (0)

Anonymous Coward | about a year ago | (#43188099)

Also consider that RO is hardly used in any desalination plants because it is too expensive and high maintenance. Making the filter membrane out of some obscure material isn't going to help that. Look at http://en.wikipedia.org/wiki/Multi-stage_flash_distillation and http://en.wikipedia.org/wiki/Vapor-compression_desalination

Other applications (0)

Anonymous Coward | about a year ago | (#43185917)

[quote]Lockheed officials see other applications for Perforene as well, from dialysis in healthcare to cleaning chemicals from the water used in hydraulic fracturing, or "fracking," of oil and gas wells[/quote]

This does sound like a miracle discovery. In theory you could filter out poisons and microbes from brackish wells as well.

Re:Other applications (1)

ISoldat53 (977164) | about a year ago | (#43186175)

GoreTex!

WOW! Enormous Consequences (1)

anorlunda (311253) | about a year ago | (#43185991)

If this turns out to be as good as it sounds, the financial and social impacts will be staggering.

Reverse osmosis (1)

macraig (621737) | about a year ago | (#43186117)

I had an under-the-sink reverse osmosis system (Ametek, no longer in business) more than 20 years ago. I bought it for some of the plants I was growing at the time (insectivores, epiphytes, etc.), but then I discovered that *I* liked the taste of pure water myself and my usage doubled. Those damned RO membrane cartridges were quite expensive, and I eventually stopped using it. It would be nice to see the technique revamped with graphene if it can lower the cost in general (since home RO never used electricity anyway).

Re:Reverse osmosis (2)

volmtech (769154) | about a year ago | (#43187409)

A new GE unit cost less than $200. The membrane last 5 years and cost less than $50. The conditioning filters cost $40 and last 6 months. Well worth it.

Re:Reverse osmosis (1)

macraig (621737) | about a year ago | (#43187521)

Even that is considerably cheaper than in years/decades past. Last I checked they were $75 and lasted at most two years.

Re:Reverse osmosis (1)

volmtech (769154) | about a year ago | (#43188165)

I use well water and my first one lasted over five years. Chlorinated water will reduce the life of the membrane.

Trickle Down Defense Contractor... (0)

Anonymous Coward | about a year ago | (#43186207)

So the company that made the F-22, and currently makes the F-35, has just become one of the greenest companies on the planet. Yeah, desalination consumes a lotta tera-watts. It'll be nice to save a few.

Maybe now they can get back to making a few more shovel-ready high-tech airplanes. Oh, wait, we have to crush a few cars first.

Clean water is going to become a huge problem. (3, Informative)

wanfuse123 (2860713) | about a year ago | (#43186211)

We have been polluting the water ever since the industrial age began and draining the water supply at the same time. Aquifers are getting depleted, its going to become an expensive problem. It is good to see this technology finally come about . It should help us bring water to arid lands. They say that with global warming it isn't the heat that is going to affect the plant life but the lack of water supply. It is an expensive proposition however to lay thousands of miles of pipe. But perhaps it will become cheap enough to take and desalinate water and fill up major rivers so that natural distribution can be restored. It would take a lot of energy to do it but with the two orders of magnitude cheaper maybe it would be cost effective? I would also suggest that we stop polluting the water with all the plastics and use it to recycle. We produce 37,000,000 tons of plastic each year that ends up in landfills and in the water. We could convert this into fuel energy. I have done a cost analysis on the energy from plastic recycling [rawcell.com] .

Re:Clean water is going to become a huge problem. (1)

FrankSchwab (675585) | about a year ago | (#43186805)

But perhaps it will become cheap enough to take and desalinate water and fill up major rivers so that natural distribution can be restored. It would take a lot of energy to do it but with the two orders of magnitude cheaper maybe it would be cost effective?

So, as a practical matter, major rivers tend to run downhill - that is, the lowest end of the river tends to be at sea level, and the highest end at a significantly higher altitude (and often thousands of miles away). As they say, "Gravity sucks". So "fill up major rivers" involves, first, the energy necessary to desalinate the water, then you get to build a pipeline to the upper end of the river 1000 miles away, and then you can fill the river.

As an example, New Orleans might not be very happy with the water level necessary at the mouth of the Mississippi to get water back up to, say, the Great Lakes (at roughly 2000' of elevation).

Communities located near the ocean (Which is, frankly, most of the worlds largest cities) could benefit from this techology using Ocean water. Iowa, not so much, but they could use it to purify brackish aquifers, farm runoff, or treated sewage.

Re:Clean water is going to become a huge problem. (1)

PraiseBob (1923958) | about a year ago | (#43186973)

Might as well convert the water into mist and throw it into the sky and let the wind move it around. The energy required to pump billions of gallons uphill is significant.

Re:Clean water is going to become a huge problem. (1)

budgenator (254554) | about a year ago | (#43187903)

Lake Huron is 577 ft (176 m) above sealevel, Superior is 600 ft (180 m) not 2000 ft.

Re:Clean water is going to become a huge problem. (1)

MangoCats (2757129) | about a year ago | (#43187955)

I've always though that plastics were a by-product of petroleum fuel - all this cheap plastic furniture is basically cast-off from the fractioning process, sure it could be used as fuel, but why not just sell it cheap to Little Tykes to make disposable backyard junk?

Re:Clean water is going to become a huge problem. (0)

Anonymous Coward | about a year ago | (#43188115)

Add that the WHO actively try to medicate the entire planet with sodium fluoride a lethal poison added to drinking water.

Re:Clean water is going to become a huge problem. (0)

Anonymous Coward | about a year ago | (#43189087)

We've also been using massive amounts of water for industrial uses... dying fabrics for example.

Look up DyeCoo (new process using supercritical carbon dioxide instead of water).

From: http://www.dyecoo.com/pdfs/colourist.pdf

The textile industry is believed to be one of the biggest consumers of water. In conventional textile dyeing, large amounts of water are used both in terms of intake of fresh water and disposal of wastewater. On average, an estimated 100–150 litres of water is needed to process 1 kg of textile material, with some 28 billion kilos of textiles being dyed annually.

Re:Clean water is going to become a huge problem. (1)

SpaghettiPattern (609814) | about a year ago | (#43189323)

It is an expensive proposition however to lay thousands of miles of pipe.

I take it'll be cheaper than to lay thousands of miles of oil pipe.

soon (1)

Anonymous Coward | about a year ago | (#43186419)

so after we've got these water chips, stimpacks, we setup the vaults and wait out the inveitable nuclear winter.
so who'll thinks they'll be a vault dweller? and would you be willing to venture out for a new chip?

Global warming no more (0)

Anonymous Coward | about a year ago | (#43186747)

If true, this technology effectively means the end of global warming and a magnificently richer world. Imagine how much carbon would be trapped on an emerald green Baja California peninsula. Green the the worlds ocean adjacent deserts and global warming becomes yesterdays news.

Re:Global warming no more (1)

JohnRoss1968 (574825) | about a year ago | (#43186935)

??????
Can someone please explain to me what removing the salt from water has to do with global warming?????

Re:Global warming no more (1)

Tailhook (98486) | about a year ago | (#43187203)

Abundant fresh water could mean an increase of vegetation, crops or otherwise. Plants sink carbon from the atmosphere. Atmospheric carbon is supposedly the cause of "global warming" which is supposedly bad.

Cheers! (0)

Anonymous Coward | about a year ago | (#43187301)

This is awesome! As the ocean levels rise from the melting ice caps, maybe we can drink our way to "save the beaches"!

Salt molecules? (2)

sp332 (781207) | about a year ago | (#43187469)

Salt is a crystal formed by ionic bonds, there's no such thing as a salt molecule. They must be making holes small enough for a single sodium ion. Not sure why they need to tailor the holes for each chemical, though. Just make them a bit bigger than water molecules, right? Than I guess a second filter that's a bit smaller, to remove contaminants that are smaller...

Re:Salt molecules? (1)

fljmayer (985663) | about a year ago | (#43188323)

Actually I am wondering why an Na or Cl ion would be smaller than a water molecule with 3 atoms. Are they dragging polarized water molecules with them that would prevent them from passing through holes that are small enough for water? This is bit vague so far.

Re:Salt molecules? (1)

Anonymous Coward | about a year ago | (#43188995)

Actually I am wondering why an Na or Cl ion would be smaller than a water molecule with 3 atoms.

Na: 3 electron shells.
Cl: 3 electron shells.
O: 2 electron shells.
H: 1 electron shell.

and not only that (1)

Anonymous Coward | about a year ago | (#43188223)

Each hole also has a Maxwell's demon standing guard.

This only solves half of the desalination problem (0)

Anonymous Coward | about a year ago | (#43189347)

We still don't have a good solution for what to do with all the brine left behind, and ramping up production to this kind of degree will only make that problem much worse.

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