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New Nano Desalinization Method 216 216

lbmouse writes "The Technology Review is reporting that researchers at the Lawrence Livermore National Laboratory have announced a way to use carbon nano-tube technology to reduce the cost of desalination of ocean water by 75 percent over current methods of reverse osmosis. From the article: 'The technology could potentially provide a solution to water shortages both in the United States, where populations are expected to soar in areas with few freshwater sources, and worldwide, where a lack of clean water is a major cause of disease.' The technology may also lead to new ways of eliminating carbon dioxide emitted from power plants."
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New Nano Desalinization Method

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  • Perfect (Score:5, Funny)

    by Who235 (959706) <secretagentx9NO@SPAMcia.com> on Tuesday June 13, 2006 @05:08PM (#15527688)
    Now, as sea levels rise, we can just drink it up.

    Woo-Hoo!
  • by ENOENT (25325) on Tuesday June 13, 2006 @05:09PM (#15527691) Homepage Journal
    Just think of the patent licensing fees they can charge!

    • Re:Wow, 75% cheaper (Score:5, Informative)

      by wealthychef (584778) on Tuesday June 13, 2006 @06:53PM (#15528387)
      LLNL is a national laboratory. This technology will probably be available more broadly than if it was developed by a private company. This sounds like really good news for the world, especially e.g. African nations where potable water is a huge issue.
    • Re:Wow, 75% cheaper (Score:3, Informative)

      by Whibla (210729)
      But what would their patent be for?

      So far what they have is a workable, small scale (no pun intended), test solution to the problem of water filtration. But there is little novel, or unobvious, in what they have done.

      If there is a patent in this it will be in the process used to create commercial quantities of nanotube filters.

      There are of course usually several ways of skinning your animal of choice, so in fact it is probable that there will be several patents sought for nanotube manufacturing processes -
    • Just think of the patent licensing fees they can charge!

      Why shouldn't they be able to patent? This is a novel and useful technology reduced to practice for the first time, and is exactly the kind of thing that patents were designed to cover.

      Don't want to pay royalties? Fine, go back to the previous (and more expensive) method of desalination. If the new method has value, you should expect to compensate the inventors over the lifetime of the patent. After that, it's all yours.

  • by Anonymous Coward
    If your short of drinking water in the US.. stop watering your lawn...
    • How does not watering my lawn from a well affect my drinking water shortage?
      • You have a magic well that's not connected to the same water table that everyone in your area uses? Screw nanotech, patent the magic well! That and some magic beans and you could change the world!

        Hate to break it to you bud, but it's all the same water in the end. There was a paper company that opened up east of here, and on the day that they commenced operations private wells for 50 miles around dried up, and who got hurt? People who had seen no reason to care because their water was totally different from
        • I'm a quarter mile from a body of water that flows a billion gallons a day, sorry about your luck.
    • But, but. How will the lawns be green???
  • ...when can I buy one? This would be an ideal upgrade for an awful lot of people. I have a RO water filter right now, not for desalination but for cleaning up drinking water that's just undrinkable, like the stuff in Marysville, CA. The thing's not all that huge, but it's sizable. (At least the size of an Xbox 360!) :D It would be great to have a tiny portable RO filter.
    • by RingDev (879105) on Tuesday June 13, 2006 @05:37PM (#15527885) Homepage Journal
      Think of the other ramifications, one of the huge problems with cracking hydrogen from water is getting pure enough water to start with. If you can cut the cost of desalination significantly, you can reduce the total cost of hydrogen production.

      -Rick
      • My first thought was much more sinister.

        Steve
  • by i kan reed (749298) on Tuesday June 13, 2006 @05:10PM (#15527698) Homepage Journal
    We'd probably call it vaporware
  • End Our Wet Drought! (Score:3, Interesting)

    by aslate (675607) <planetexpress@gma[ ]com ['il.' in gap]> on Tuesday June 13, 2006 @05:10PM (#15527702) Homepage
    This could solve all the UK's problems with our current drought! An island nation, somehow surrounded by water, it sounds like it could be a great way to give us plenty of water to drink.

    Although Thames Water fixing all the leaks could also be a huge help...
    • Eh. Probably wouldn't change anything. For example, the Metropolitan Detroit area has relatively easy access to the fresh water in Lake Huron, Lake Michigan (because of the nature of the Huron-Mighican connection), and Lake Erie -- the third, fourth, and tenth largest freshwater lakes in the world. And yet, have a dry summer, and places wind up on water restriction -- because the infrastructure can't handle the increase in demand during a drought. Building infrastructure that delivers 95% of the time is
  • by CrystalFalcon (233559) * on Tuesday June 13, 2006 @05:11PM (#15527707) Homepage
    - Do you realize what this would mean to the starving nations of the planet?

    - WOW! They'd have enough salt to last forever!
  • by karvind (833059) <karvind AT gmail DOT com> on Tuesday June 13, 2006 @05:16PM (#15527749) Journal
    Does anyone have any idea why the small pores have higher flow rate through them ? My classical fluid dynamics class beats me here. Should be something to do with quantum effects at that scale, but can't guess it. Quantization in electronic states makes sense to me, but don't know what it is doing to 'flow dynamics'.


    Cool work nevertheless. I wish they could do something with silicon nanowires as silicon is the second most abundant element on earth.

    • by w33t (978574)
      perhaps it has something to do with nanotubes being akin to (or perhaps actual) metamaterials. In that case it would seem that they posses some electromagnetic properties that greatly alter their interaction with certain materials.

      Perhaps this increased flow is an indication that nanotubes are also very resitant to atmospheric wear (which would be a boon to using them for large-scale structures). Or perhaps it's an indication that they wear down at an accelerated pace.

      All I know is that it is so awesome tha
    • capillary action. I'm guessing since they didn't declare it that they are good researchers - don't say it's so until you know it's so.

      Water is an incredible molecule. It's affinity for weak bonding at boundary layers is legendary and might prove to be what is occurring here as well. Think about the edge of the water in your glass - it curves upward. You get the two edges together and it races up the glass.

      That's my hypothesis anyway.

    • by kebes (861706) on Tuesday June 13, 2006 @05:34PM (#15527865) Journal
      I'm reading the original Science article now (sorry, only available to subscribers, although the Science summary [sciencemag.org] may be available to the general public).

      The reason that the gas and liquid transport through nanotubes is so much higher than you might expect is due to the smoothness of the inside walls. The classic hydrodynamic equations have some amount of surface roughness inherently built into them. If you just naively scale them down to nano-dimensions, you'll predict very high resistance to fluid flow. However carbon nanotubes have "perfect" inside walls, that are atomically flat. This allows the water molecules (or gas, or whatever travelling inside them) to travel without "getting caught" or "bumping" into defects. In essence the atomic smoothness of the walls brings us into a whole new (nano) hydrodynamic regime.

      This effect was predicted by computer simulations previously, but now has been actually observed in real samples. Very impressive.
    • Does anyone have any idea why the small pores have higher flow rate through them ?

      Laminar flow + less friction is a possibility.
  • This could help in purifying water that will be separated into hydrogen for use in fuel cells etc. A reduction in purification costs is one step closer. I know, I know, there are lots of other challenges, but its a baby step.

    Where are these US water shortages? Broadband in the US may suck but I wasn't aware of any water rationing.

    Also, this micro fluid dynamics intrigues me. Increased flow rate at reduced diameters. Very cool. Sounds like a possible research field for the old PhD.

    • north carolina for most of last year if i recall correctly (i dont live there, just what a friend told me)
      • i do live in north carolina. we were 6" or more below normal for rainfall for the year. if it wasn't for end of year wetness, it would have been more. local governments restricted lawn watering, car washing, and some industrial applications in an effort to conserve. a lot of the creeks and rivers were at their lowest point in years.

        interestingly, parts of florida are very dry right now. they've been having wildfires and have had to shut down i-95 more than once due to smoke and other hazards. some were ho

    • by Surt (22457) on Tuesday June 13, 2006 @05:34PM (#15527861) Homepage Journal
      Out of curiosity, why would it be important to purify the water before separation into hydrogen/oxygen? Most of the methods I'm familiar with don't particularly care if the water is pure, the waste rate from impurities is meaningless, and cleaning just means occasional sludge removal.
      • by rossifer (581396) on Tuesday June 13, 2006 @08:01PM (#15528748) Journal
        Out of curiosity, why would it be important to purify the water before separation into hydrogen/oxygen?

        Well, if there's salt in the water and you attempt electrolysis, you'll get chlorine gas and NaOH in solution. It's actually the modern process for producing sodium lye (aptly named the chlor-alkali process). Once you run out of chloride ions to convert to chlorine, then you start to produce hydrogen gas, but now you've got some high pH liquid in your reaction vessel, and you probably have other reactions going on that you didn't intend...

        Regards,
        Ross
    • I know, I know, there are lots of other challenges, but its a baby step.


      Yup. Now the only major hurdle is the fact that hydrogen production is endothermic.


    • The entire area on top of the Oglalla aquifer depends on unsustainable mining of the aquifer's water. If that ran out or got managed responsibly you'd see the underlying shortage shine through.

      Would you consider a water war to be a form of rationing? Research the history of Los Angeles.

      Famous saying, sometimes attributed to Mark Twain, sometimes to Texas tradition: "Whiskey is for drinking. Water is for fighting over"
    • I live in the Mojave Desert (Southern California part), and while we are not yet facing water rationing, we are probably not too far away from it; especially considering the number of people leaving Los Angeles and the surrounding area to the desert. Much of Southern California's water is fed to it via the California Aqueduct [wikipedia.org]. The areas the Aquaduct draw from are being drained at an alarming rate. Also, our local water table is overtapped and the water we pull from the Colorado River's watershed (e.g. Mo
      • [...] and the water we pull from the Colorado River's watershed (e.g. Mojave River) is slowly causing a problem for those downstream from us

        I think you're confused. The Mojave certainly doesn't flow into the Colorado, although it's possible (but unknown if) it did during the last ice age.

        However, it's good to find that I'm not the only /.er living in the Mojave Desert.
  • by w33t (978574) on Tuesday June 13, 2006 @05:17PM (#15527754) Homepage
    I've heard it said that materials science is the slowest science - and it's almost certainly true. It is taking forever to get consumer products from carbon nanotubes (with a few exceptions [blogs.com]).

    But all the uses found for a new material and all the new applications discovered - in many respects it certaily seems to be the most fruitful science (at least in the engineering and day-to-day sense).
  • I was wondering how I was going to get all that salt out of my iPod.
  • nano (Score:2, Funny)

    by uberjoe (726765)
    When I first read the headline I was wondering how iPods got salty in the first place.

  • I wonder how it compares to Condensation?

    The way that isn't mentioned in the article is to use a warm climate, moderately warm salt water, and relatively cold salt water to get the warmer water to condense from the air into a collection well. A half filled tank of warm water with cold water lines running over the water reservior will cause fresh water to condense on the lines, where it can then be collected.

    If you compare this to the initial costs of replacing nano-tube filters, I bet it is competitive, if
    • This new method should only require pumps. From your description of condensation it requires temprature differentials. That will require power input as well as the pumps.

      It may be more efficient (and cheaper) by simply being, well, simpler.
      • No, I've seen the gp post's system described (I think). You pump the cold water up from the ocean deeps and run it through pipes in a collection area, and the humidity in the air (and any sea air in a warm area will be humid) condenses on the outside of the pipes, producing fresh water. All you need are pumps. What's better is that the system is not primarily interested in producing fresh water, but electricity -- good ol' ocean thermal energy conversion.

        The problem is that there aren't huge numbers of s
    • by Latent Heat (558884) on Tuesday June 13, 2006 @07:15PM (#15528499)
      It takes about 1000 BTU's to evaporate a pound of water, and about 1000 BTU's are given up when that water condenses. Assuming 140,000 BTU (don't know if it is the high or low heating value, which also depends on water condensation from the H2O of combustion) for a gallon of Diesel fuel, a gallon of Diesel can evaporate 140 pounds or about 18 gallons of water. For people making maple syrup by direct evaporation (requires 30-40 to 1 concentration), it takes about two gallons of Diesel to make a gallon of maple syrup (an appetizing thought when you pour that syrup on your pancakes).

      That ocean water scheme is taking much lower grade heat, thermodynamically, than the energy in Diesel fuel, but it still requires 1000 BTU's of heat per pound of water (8000 BTU's per gallon). That is a lot of heat to take out of the environment, and a lot of heat to transfer.

      Another way for more efficient desalination is to recycle that 1000 BTU/lb -- use 1000 BTU to evaporate a pound of water to purify it and then condense that water vapor to get back that heat to evaporate more water. Trouble is that water condenses at the same temperature it evaporates, and you need at least a small temperature differential to get heat to flow downhill.

      There are two approaches to recycling the heat. One approach is multi-effect distillation. You evaporate at a higher temperature and pressure, and then condense at that same temperature, which you use to evaporate other water at a lower temperature and pressure in a vacuum chamber. You have a cascade of evaporators at successively lower pressures and keep reusing the same heat. This method was developed by Norbert Rillieux, the Louisiana son of a French engineer and an American former slave, and is widely used in food preparation -- sugar from cane or beets, orange juice concentrate, and so on.

      The second approach is vapor compression. You boil at one temperature, but you condense at a higher temperature by compressing the vapor to a higher pressure using something akin to an automotive supercharger driven by an electric motor, and that way the heat from condensing at a slightly higher temperature and pressure is recovered by the evaporator. This requires only a single "effect" on account of the vapor pump instead of the multi-effect cascade into successively lower pressure chambers, but it needs the electric motor and vapor pump, and you need to move a lot of heat at low temperature differentials across large surface area plate heat exchangers.

      Reverse osmosis is a pure mechanical process that doesn't require exchange of the 1000 BTUs per pound of water, but the osmosis membrane offers resistance to pumping in excess of the natural osmotic pressure (the pressure differential required to overcome the salinity differential, the PV work representing the true thermodynamic cost of desalinating the water, which is much less than the 1000 BTU's per pound). By the way, it is always more cost effective to desalinate slightly-salty (brackish) water from marshes or irrigation runoff or other sources than going for the highly-salty sea water on account of the energy inherent in the dissolved salt as reflected in the higher osmotic pressure).

      • For people making maple syrup by direct evaporation (requires 30-40 to 1 concentration), it takes about two gallons of Diesel to make a gallon of maple syrup (an appetizing thought when you pour that syrup on your pancakes).

        I never understood why anybody would use direct evaporation for that entire process. It's naturally cold where sugar maples grow, and a signifigant portion of the concentration process could be done just by letting the sap freeze and removing the (almost pure) water ice from the vessel.
  • Cheap Drinking Water from the Ocean

    Carbon nanotube-based membranes will dramatically cut the cost of desalination.

    A water desalination system using carbon nanotube-based membranes could significantly reduce the cost of purifying water from the ocean. The technology could potentially provide a solution to water shortages both in the United States, where populations are expected to soar in areas with few freshwater sources, and worldwide, where a lack of clean water is a major cause of disease.

    The new membran
  • by smannell (157236)
    The article doesn't say how much waste water would be needed to de-salinize a given volume of H20, but if the water flows through with considerably less force than a traditional RO unit maybe there will be less waste water. This could be more important than the energy savings. A good comercial RO filter produces roughly 1 gallon of waste water for every gallon of potable water, and most home units produce two or more.
    • Yes, bcause we have no where to dump salt water...

      'Waste water' concerns of desalinization, sheesh.

      • Just dump it in the sea, just not too much in one spot, the water we use will eventualy wash down the river or rain out of the sky returning things to its normal tonicity. Right now we digging out a shit pile of salt from the ground deposited by prehistoric ocean evaperation, switching to desalination salt should help us achieve natrium-neutrality and make the eco-whackoes happy.
  • Energy (Score:3, Informative)

    by Lord Satri (609291) <alexandrelerouxNO@SPAMgmail.com> on Tuesday June 13, 2006 @05:25PM (#15527806) Homepage Journal
    The challenge is not about methods to desalinize (there's plenty of methods [wikipedia.org]), it's about finding a method which requires very little energy (and thus money) that it becomes advantageous to proceed to desalinization in the first place...
  • Orchid fractals (Score:5, Interesting)

    by LiquidCoooled (634315) on Tuesday June 13, 2006 @05:26PM (#15527816) Homepage Journal
    I once read something about a class of fractals called >orchids [crowddynamics.com].
    They are the result of monitoring crowd flow dynamics and producing the formulas.

    They too noticed that for a large crowd (concert, football match) crowd flow speed INCREASES with a number of small gates rather than one large gate, hence one by one through the turnstyles actually makes the process quicker.

    This appears to be a similar unintuitive process.

    Anyway, I know it wasn't totally on topic I just thought I would share.
    • Similarly for heavy traffic - if you reduce the speed limit during peak traffic times, the ovrall flow of traffic is greater. I guess its because of less wave effects, where you end up stopping and starting all the time.

      a lot of things are un-intuitive, but correct.
  • by ZSpade (812879) on Tuesday June 13, 2006 @05:29PM (#15527831) Homepage
    I wonder if it will also sterilize any water passed through it, as carbon nano tubes seem to evoke cell death upon contact. This is one area where that could actually prove to be a benefit rather than a set-back.

    Just being able to desalinize water cheaply is a pretty damn big breakthrough though, I know Los Angeles could use it with all the draughts they have. I mean how ironic is it that they'll have a 7 year drought and water shortages, and yet be right on the coast of the largest body of water in the world?
    • Well, given that the article claims pore widths allowing only seven water molecules to pass through at a time, one can probably conclude that it would also serve to sterilize (since most pathogens in the water would almost certainly be bigger than that).
    • by Derek Pomery (2028) on Tuesday June 13, 2006 @06:25PM (#15528193)
      Recent analysis of the test used,the methylthiazol tetrazolium (MTT) test shows that the test may have been screwed up by the fact that the MTT was binding to the nanotubes. Using a different toxicity test, NO toxicity was found.
      Based on this, carbon nanotubes should probably be considered cleared of causing cell death for now.
      Inconvenient for your filter, but a boon for many many other applications.
    • L.A. did (in the 70's) have some of the best desalination plants in the world.
      The it was deemed to expensive(even though the largest portion of the expense had all ready been sunk) to run. Since them it has been stripped for parts and rendered useless.
      ANother issue were (concerned citizens*) screwed up a good thing.

      Concerned enough to be busy bodies, not concerned enough to look at what was going on, and make an attempt to understand the purpose of the plants.
        gah.
    • Just being able to desalinize water cheaply is a pretty damn big breakthrough though, I know Los Angeles could use it with all the draughts they have.

      Los Angeles isn't having water problems because it lacks water - but because it has too many people living in what is essentially a desert.
      • Los Angeles isn't having water problems because it lacks water - but because it has too many people living in what is essentially a desert.

        Well, actually it's more because everyone in L.A. INSISTS on having lush grass, tropical trees, etc., despite the limited water. If it wasn't used for irrigation, the current supplies would be plenty.

        There's nothing wrong with the desert, per se.
  • This is all well and good, but does the process increase the efficacy of removing the chlorides in sea water? This because 99.999% is not good enough: if you spray that on your farm - in a few years the evaporating water has left the remaining salts (Chlorides) behind and will have sterilised the soil so that nothing can grow in it.

    This would be a major concern in areas where desertification is already rampant.

    I have no idea what the accepatble level is, but it needs to be damn low before you can irrigate w
    • by RelliK (4466)
      huh? your fresh water contains waaay more than 0.001% salt (as well as other minerals)
      • your fresh water contains waaay more than 0.001% salt (as well as other minerals)
        First rain water is esentialy distilled water so it washes out the salt accumilation in the soil; where irrigation is the only source it will build chlorides. What the Mesopotamian's called irrigated crop lands, the Iraqis call salt marshes
    • This because 99.999% is not good enough: if you spray that on your farm - in a few years the evaporating water has left the remaining salts (Chlorides) behind and will have sterilised the soil so that nothing can grow in it.

      Well, 0.001% is awfully low. Still, even if there are unacceptable ammounts of salt left-over, farmers will just have to add some calcium to the water to counteract it, and possibly some magnesium and potassium as well.
  • by johansalk (818687) on Tuesday June 13, 2006 @06:01PM (#15528036)
    Just as current wars are fought over oil, wide predictions are that future ones will be fought over access to water resources.
  • by PatTheGreat (956344) on Tuesday June 13, 2006 @06:03PM (#15528048) Homepage
    This article raises two thoughts in my wonderful little head.

    1) Why do they bother calling it "reverse osmosis?" From a quick review of high school biology, I have come to realize "reverse osmosis" really means "pumping through a filter."

    2) I saw this other method in Discover that I really liked. Basically, it proposes using deep water and methane to flash-freeze water. All you need to do is to pump methane into water of the right depth, and it instantly freezes into that flammable ice mining rigs love to dig up and play with, without like, refrigerating it. Anyways, as it freezes, all the salt gets pushed out and it floats to the top, so all you have to do is melt the ice and reuse the methane. It appealed to the recycler in me, and it seems to me some tubes and plumbing would be easier than nanotubes, eh?

  • If these doohickeys have pores that are so small, how prone are they to clogging? Lots of things work just fine in the clean laboratory but dang it, just don't work in the real world, where there is rumored to be dust. It sounds like these things could get clogged by anything bigger than a few water molecules, which includes an awful lot of things out there.
  • I don't think nano [nano-editor.org] needs to be desalinized; it's pretty good the way it is. It could use syntax highlighting though...
  • Awesome! Now we can replace the polar ice caps with polar salt caps!
  • If it can trap green house gasses too, I'd love to have a pair of underwear made of this stuff so I can fart all day long and not bother anyone.
  • by owlstead (636356) on Tuesday June 13, 2006 @06:33PM (#15528241)
    What I never understand with these kind of filters is where the waste ends up. There is quite a lot of salt in the water, so these filters should clog pretty quickly, and just rinsing them every minute does not seem to be very practical. Does anyone know how this works?
  • by Morinaga (857587) on Tuesday June 13, 2006 @06:50PM (#15528366)
    In quick succession we have stories from MIT and other Labs have discovered new and exiting uses for nanotechnology. They all seem to "discover" a scientific breakthrough. I'm just as excited about this as the next guy but from what I've read none of these discoveries have working prototypes of the technologies they espouse as the next great thing. Seems to me these are all working theories at best.

    I really am looking forward to batteries lasting 100x longer, nanopaper and this latest discovery. I just have absolutely no read on how far we are out on practical implementations of this technology.

  • The technology could potentially provide a solution to water shortages both in the United States, where populations are expected to soar in areas with few freshwater sources

    I thought the southwest, particularly Nevada, New Mexico and Arizona, was where the population is going to boom and there are water shortages. Don't these areas have water shortages PERIOD, as opposed to just shortages of FRESH water?
  • As far as I can gather they mean the same thing ... removing water from salt. Does having two similar sounding words to describe the exact same thing add any value to the English language? Why not use just one of the words(somebody choose) and eliminate the other to reduce dictionary clutter?

    It reminds me of the contention between regardless and irregardless. Yeah, I hate irregardless too.

  • Drink your pee (Score:3, Insightful)

    by CrimeaRiver (744268) on Wednesday June 14, 2006 @06:18AM (#15530856)
    Could this be used to filter water from urine? That might come in handy in survival situations, or in closed environments such as habitable space modules. Or simply for weirdo geeks.

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