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Science News

Evaporation Prevention Using Molecular Blankets 223

Makarand writes "According to this article in the New Scientist, a Canadian company is testing a technology to reduce water evaporation from reservoirs by spreading an ultra-thin blanket of organic molecules on the surface to block the escape of water molecules into the air. Trials conducted in India and Morocco showed between 30 and 45 per cent reduction in evaporation using this method. However, the long term ecological effects of reducing evaporation in lakes or reservoirs is not yet clear as evaporation prevention can increase water temperatures and affect the exchange rates of gases such as oxygen, nitrogen and carbon dioxide."
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Evaporation Prevention Using Molecular Blankets

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  • Algae population ? (Score:3, Interesting)

    by Anonymous Coward on Sunday November 02, 2003 @01:38AM (#7369737)

    won't this increase the algae population ?

    the problem with water is distribution not evaporation
  • see with this level of molecular technology, we can easily tap into the.. hey! whats that over there?

    I rally shouldn't post after reading PA.
    • DAMN!

      Am I the only one to see this from the other side?

      Conversation 50 years ago:
      Scientist1 : Nice theory, that uranium fusion and plutonium fission, but where could we possibly test it?
      Scientist2 : I dunno, somewhere real far away.
      S1 : Japan?
      S2 : Hmm it could get ugly if it works ...
      S1 : Bah, I say we go for it.

      Conversation Today :
      S1 : Nice theory, spreading a thin layer of carbon tetrachloride over a lake to keep water from evaporating. What could go wrong?
      S2 : Umm I dunno, that's a pretty delicate ec
  • by Anonymous Coward on Sunday November 02, 2003 @01:42AM (#7369749)
    Scientists working to stop evaporation accidentally unleash it on the world's ocean. This causes weather around the world to go crazy, and only a group of scientists doing something bizarre can fix it.
  • Hey... (Score:5, Funny)

    by hazman ( 642790 ) on Sunday November 02, 2003 @01:42AM (#7369751)
    That's not a environment destroying oil spill, its a high tech water evaporation prevention film.
    • [...] its a high tech water evaporation prevention film.
      Melting 1-decanol with either calcium hydroxide or gypsum (adding sulfuric acid in the latter case) to obtain a fine powder which is distributable using dusting machines isn't what I'd call high tech but a way to re-market bulk and waste chemicals.

    • oil spill,

      Actually, we kind of want some evaporation from salt water, where the oil supertankers ply.

      It's the fresh water we want to keep around.

  • by Anonymous Coward on Sunday November 02, 2003 @01:43AM (#7369754)

    same result, you get a nice film on the surface and damages the local ecology plus you can get it from your local gas station

    how about spending money on better infrastructure or de-salination plants first ? then you wouldnt need to stop evaporation, remember 80% of the globe is covered with H2O so evaporation is not the problem

    • "same result, you get a nice film on the surface and damages the local ecology plus you can get it from your local gas station"

      Except that heavy hydrocarbons aren't something you want to drink (or breathe, for that matter). Or would you mind of I add a little 92 octane to your drinking water? The idea of this film is to prevent evaporation and only evaporation, with negligible effects on the human body upon ingestion and (as a secondary goal) having as small a footprint on the local ecosystem as possibl
      • "Ignoring drought for the moment (like you seem to be doing), even without RTFA I can tell you that these tests were conducted in Morocco. Morocco as in "middle of the freakin' Sahara" Morocco. "80% of the surface" is all well and good until you recall that the distribution is far from homogeneous."

        yes I'm sure this is really going to help the rainfall in morocco which is already critically low.
  • Why do we have to control evaporation on large bodies of water already ?
  • Weather too (Score:5, Insightful)

    by BWJones ( 18351 ) on Sunday November 02, 2003 @01:44AM (#7369760) Homepage Journal
    However, the long term ecological effects of reducing evaporation in lakes or reservoirs is not yet clear as evaporation prevention can increase water temperatures and affect the exchange rates of gases such as oxygen, nitrogen and carbon dioxide."

    Don't forget possible changes to the weather. For instance, there are a number of areas whose climate and micro-climate are influenced by nearby bodies of water.

    • as long as the molecular shield stays put, this really shouldn't affect much. these are reservoirs we're talking about, typically a man-made body of water. whatever changes to the environment that happen will be changes back to the environment that was there before the man-made reservoir was added.
      • Reservoirs are made from rivers. I can't back this up with hard data, but I'd bet the slowing of water to form deep reservoirs has already slowed evaperation quite a lot, since a swirling river should have a very high evap. rate due to surface agitation. This will just make it worse.

        Cleary I just pulled that out of my ass, but it makes at least a little sense :-)
        • the reservoirs around here (portland, oregon) are all man-made, cement holes. :)
        • Actually, conversion to resivoirs generally increases evaporative loss, at least as far as people have been able to tell.
        • Re:Weather too (Score:3, Insightful)

          by WhiteBandit ( 185659 )
          Well it was a good try :)

          A big part of evaporation is surface area. The more surface area exposed to the sun and heat, the greater amount of water you will have leaving the system.

          In fact, slowing a river down doesn't help this either, as there is no water to replenish what evaporates. Perfect examples of this are: Mono Lake, Owens Lake, and the Aral Sea.
    • Re:Weather too (Score:4, Interesting)

      by pipingguy ( 566974 ) on Sunday November 02, 2003 @02:39AM (#7369937)
      Don't forget possible changes to the weather. For instance, there are a number of areas whose climate and micro-climate are influenced by nearby bodies of water.

      Were you envisioning covering the Great Lakes with this stuff?

      I'd be willing to test the product in my toilet based on the assumption that it'd reduce the atomized crap on my toothbrush due to flushing. [straightdope.com]
      • Re:Weather too (Score:5, Insightful)

        by TheLink ( 130905 ) on Sunday November 02, 2003 @02:56AM (#7369990) Journal
        While the film reduces evaporation, I doubt it reduces aerosolization significantly.

        Still, as long as its your crap or someone close to you (family) it shouldn't matter that much in most cases.

        Coz either the germs are yours or you're going to get them from other routes anyway. e.g. if you and your family are healthy, then small amount of aerosolized germs are unlikely to kill you - your immune systems already know how to deal with em. However your germs may kill/sicken strangers, and theirs might do the same to you.
        • Not only that, but over-clean households have the ironic effect of reducing the strength of our immune systems. Dirt is actually good for us, we're evolved to handle it, even if now and then we tend to die from its extremes.

          Bleaching one's bathroom and kitchen probably does more harm than good.

          Related note: use of antibiotics in childhood have now been confirmed as a cause of allergies and asthma in later life. We actually _need_ exposure to those bugs if we're to remain healthy.

          The toilet aerosol and
        • You mean I should stop letting strangers use my toothbrush?
    • But you're American... Surely you're not suggesting you care about the environment of other countries? Nah....
    • Or, you could close the lid before flushing and keep the toothbrush on the opposite side of the sink. Say, that gives me an idea - put a sensor in the toilet seat so it flushes whenever you put the seat down, unless you hold down the override button. (There'd still be a manual flusher.) This way, no crappy toothbrushes, no females complaining about the seat being up, and no females leaving the seat in the middle.
  • If it also slows down the rate that water can give off heat energy as well as slow the evaporation rate, this would be great for extending the usable season for outdoor pools.

    If this prevents evaporation, does it also increase the surface tension of the water? That could make diving into a treated lake a painful proposition.
    • by Anonymous Coward
      these sort of products have been available for swimming pools for a fair while now afaik

      eg

      http://www.adirect-energy-source.com/pool/poolco ve r/liquid-blanket/liquid-blanket.htm

      and http://www.flexiblesolutions.com/products/heatsavr /
    • by Jodaxia ( 312456 )
      Actually creating monolayers of organic molecules reduces the surface tension of water.

      Water with its strong tendency to hydrogen bond has a greater surface tension than that of an eight carbon simple alcohol. These alcohols form monolayers by hydrogen bonding with the water molecules. The hydrophobicity of their carbon chained tails creates an excess surface concentration, which at a great enough concentration forms a monolayer.

    • I've already seen stuff in the store which claims to do this. It's called "Liquid solar blanket" or some such thing.

      I haven't tried it myself yet, well my dad hasn't, he's the pool owner *grins*
  • This should be fun (Score:3, Insightful)

    by Anonymous Coward on Sunday November 02, 2003 @01:45AM (#7369763)
    Just wait until they make a version that replicates.. so you can pour 1 cup in a lake and in a few days it covers the lake....

    Then wait until someone pours a cup of this into the oceans.

    Then wait when it stops raining and we all die.

    YAY
  • Is this Really New?? (Score:3, Interesting)

    by RMacolyte ( 645561 ) on Sunday November 02, 2003 @01:46AM (#7369767)
    What's the difference between this "new" system for evaporation prevention and the Liquid Solar Blankets sold in Pool Supply stores? This tech has been used for years!! Course this company has probably jacked up the pricing since this is supposedly "new" once again...
  • by goombah99 ( 560566 ) on Sunday November 02, 2003 @01:47AM (#7369772)
    No natural body of water has wter on the surface. its all coated by oily or other hydrophobic molecules lighter than water. I guess I dont understand what they are proposing to do differently. do their molecules cross link to each other forming an actual blanket that is kinetically impermeable at natural temperatures.

    I would think that if water cant get out kinetically then air and nitrogen cant get in. so you can kiss all fish and algea goodbye.

    • >>No natural body of water has wter on the surface. its all coated by oily or other hydrophobic molecules lighter than water.

      Either you've never left New Jersey, or you're living on a different planet to the rest of us. Possibly both.
  • other uses (Score:3, Interesting)

    by distro stu ( 719158 ) on Sunday November 02, 2003 @01:49AM (#7369784)
    I'm sure they could use this in the Ural Sea (or whats left of it). Could animals drink through it? If they could I can imagine this being very useful for the thirsty animals during dry seasons in Africa's national parks.
  • Need more research (Score:5, Insightful)

    by whereiswaldo ( 459052 ) on Sunday November 02, 2003 @01:49AM (#7369786) Journal
    However, the long term ecological effects of reducing evaporation in lakes or reservoirs is not yet clear as evaporation prevention can increase water temperatures and affect the exchange rates of gases such as oxygen, nitrogen and carbon dioxide.

    This seems like a pretty critical area of the research. If the water becomes stagnant and full of algae or dead fish, what good is it?

    This could have unforeseen effects on the local ecosystem.

    Unforseen? Maybe if you have your eyes and ears taped shut? Forgive me for being cynical, but it seems so many scientists are out for a little fame and don't see the big pictures.

    • Oh, you just aerate.

      The federal contracts will be worth billions.

      • Forgive me for being cynical, but it seems so many scientists are out for a little fame and don't see the big pictures.
      Well, the way I look at it, at least the question has been raised. That's a very important step, and is certainly _not_ indicative of the search for glory at the price of environment.

      I would distrust a project more, if it listed only positive effects, rather than positive and possible negative. Now that is cynicism.
      • in my experience, most scientists are much, much more interested in being right, it's an ego thing.
        • by Daniel Dvorkin ( 106857 ) * on Sunday November 02, 2003 @03:58AM (#7370120) Homepage Journal
          in my experience, most scientists are much, much more interested in being right, it's an ego thing.
          And your experience is?

          I'm sorry, I have to ask this. Working in biotech as I do, I deal with scientists on a daily basis. (I'd like to call myself one, but honesty won't allow me to do so until I get my PhD.) In my experience, they're human like anyone else -- and like anyone else, of course they'd prefer to be right than wrong; but the nature of the profession is that it ultimately rewards those who check their data carefully and accurately forecast the consequences of their actions, and punishes those who don't.

          The idea that scientists are egotists who refuse to acknowledge their failings is a vile stereotype, with no more basis in fact than the idea that they're cold and unfeeling, or sexless geeks, or unable to appreciate art and culture, or ... well, you get the idea. So you'll understand if I have my doubts that such a slur comes from someone with much real experience of science and scientists at all. If I'm wrong, please let me know.
          • My experience is 15 years in research and development of various diagnostic analyzers. Just because it is not nice, doesn't mean it's wrong. In fact it doesn't mean it doesn't apply to me! It's hard to work on something for a long time with out coming to believe it's the most wonderful thing on earth. And marketing pressures tend to send products out before they are quite ready or sometimes when they should have at all.
            • Okay, fair enough. Like I said, I don't deny that scientists can fall victim to the right-at-all-costs failing -- what bothers me is the implication that it's a failing of scientists in particular. It's a human failing -- and at least in science, as in few other areas of human endeavor, there is a definite standard for determining whether someone is right or wrong.

              What company do you work for? It's quite possible that I've used some of your analyzers. I'll let you know if they don't work. ;)
              • It is a human failing! And I believe the smarter you are the more susceptible you to that sort of thing. I've seen good scientists react quite differently to challenges to it. Some find not understanding a problem with a product a personal affront and put amazing efforts and time into their resolution. Unfortunately others, having expending what resources they had, lost all vestiges of ethics and responsibility. I must emphasize these people are good people, I'd be glad for my kids to be in school with th
    • ...it seems so many scientists are out for a little fame and don't see the big pictures.

      It's not scientists. It's companies that seek to capitalize on the fruits of science that you're looking to blame. Real scientists seek to understand the big picture. Companies look for new ways to make money.
  • by atgrim ( 103715 ) <vinrod&speakeasy,net> on Sunday November 02, 2003 @01:50AM (#7369791) Homepage
    Call me silly... but, isn't water evaporation part of the cycle of weather? Take out one part and the machine doesn't work. I hope that this "technology" is not used on a large scale. The implications concerning local weather patterns could be devastating.
  • I say Saran Wrap. What's the big difference?
  • this is a BAD idea (Score:4, Insightful)

    by c4ffeine ( 705293 ) <(moc.liamg) (ta) (enieff4c)> on Sunday November 02, 2003 @01:51AM (#7369798)
    Last time I checked, something called "rain" is made possible by evaporation from lakes, resiorvoirs, etc. Wouldn't preventing evaporation prevent rain? Rain happens to be a great way to irrigate fields, and is very good for our environment...
    • Tell you what... if your rain fall rate gets too low, you can have as much of ours as you want, we here in WA have plenty to go around.
    • It's still a good idea. Rain clouds have no problem forming over the middle of a barren desert, and they also used to form before the days of reservoirs.

      Generally, rain clouds develop from humid air, not because they happen to be over lakes. So reducing the evaporation from reservoirs or lakes by 45% won't necessarily change weather patterns. Even lake effect snow storms (found in cities next to the Great Lakes and the Great Salt Lake) should be ok, since I believe its the warm air of the lakes, and
    • If anything, this would help restore ecological balance in the areas around resivoirs. The resivoirs I've seen are human created, not natural. This actually causes an increase in humidity and perhaps rainfall in the areas around them.
      Decreasing the evaporation would bring things more in line with the "natural" state of the area.
    • Exactly. Man-made reservoirs have been the major source of evaporation for at least the last couple billion years or so.
    • Take the size of the worlds resovoirs.

      Take the size of the worlds oceans.

      Which is bigger
    • Actually, most rain comes from the oceans evaperating, not resevoirs behind dams, or lakes used for drinking water. This would have a barely noticiable effect on the weather. Its meant to preserve drinking water.

      This might have a small effect on very local weather, but it might have a big effect on anything living in the resorvoir due to the temperature going up, and the lack oxegenation at the surface.

  • Nice idea (Score:4, Insightful)

    by helix400 ( 558178 ) on Sunday November 02, 2003 @01:53AM (#7369801) Journal
    This would be great for those of us in the intermountain west.

    Our reservoirs lose tons of water over the long hot dry days of summer. Add that to the 5 year drought we're in....and it'd help enormously. Of course, that would probably mean boats and jetskis would be off limits during that time, but having water is more important that having fun.
    • Re:Nice idea (Score:2, Informative)

      by helix400 ( 558178 )
      Heh, next time I'll read the article before commenting.

      Boating would be ok. Since this "blanket" isn't one physical object, but a collection of molecules...boaters could rip a path through the water, and these molecules would close off the exposed water. Wow, looks like the only hangup now is possible ecological issuegs.
    • Re:Nice idea (Score:3, Insightful)

      by YrWrstNtmr ( 564987 )
      This would be great for those of us in the intermountain west.
      Our reservoirs lose tons of water over the long hot dry days of summer. Add that to the 5 year drought we're in....and it'd help enormously.


      After all your local bodies of water have been treated, you can change that to:
      "... the 15 year drought we're in..."
  • by gerardrj ( 207690 ) * on Sunday November 02, 2003 @02:00AM (#7369827) Journal
    ...by spreading an ultra-thin blanket of organic molecules on the surface to block the escape of water molecules...

    Are they trying to place a positive ecological spin on oil spils/slicks? Oil is organic, and it does prevent the evaporation of the underlying water.
    I recall seeing/reading elsewhere that a few millileters is enough to create a minute slick over several square kilometers.
    • Are they trying to place a positive ecological spin on oil spils/slicks?

      They don't need to put a positive spin on that! If you watched fox news, you'd know that "Oil slicks found to keep seals young, supple..."

      Or, at least, I thought it was fox news...
  • Old hat (Score:5, Informative)

    by njh ( 24312 ) on Sunday November 02, 2003 @02:03AM (#7369838) Homepage
    We studied this in school. They use large alcohols as the skin (as covered in this article). The point is that it's usually distribution rather than storage that is the problem. (In Melbourne.au the annual evaporation rate is 3m - on a shallow 30m deep dam this means that it would take 10 years to evaporate the water away, assuming none is added. I have some old papers here from the 60s by the then Melbourne Metropolitan Board of Works about this idea.

    If you are having problems keeping water due to evaporation then you need to choose a better dam site.

    More interesting is a proposal to store stormwater underground. Firstly, the land area and evaporation issues disappear (to be replaced by similar issues :) but more importantly, the water is actually cleaned by the action of anerobic bacteria on the water.
  • How is this different than having suntan lotion come off in the pool?

    Isn't there alot of data on that?

    Geez! What are these researchers thinking about.

    Then next thing you know, Exxon will be dumping oil from their tankers to mitigate "global evaporation".
  • by pipingguy ( 566974 ) on Sunday November 02, 2003 @02:30AM (#7369913)

    Flexible Solutions [flexiblesolutions.com]

    This might also be useful for refineries/chemical plants, etc. that maintain large atmospheric pressure reservoirs of dihydrogen monoxide for fire-fighting purposes.
  • by Shoten ( 260439 ) on Sunday November 02, 2003 @02:30AM (#7369914)
    Ah, just what I need for my new swimming pool...on Arrakis!
  • by Sir Holo ( 531007 ) * on Sunday November 02, 2003 @03:02AM (#7370000)

    My first thought was the same as yours -- oil on water and asphyxiating fish. But that might not be the case.

    They claim that their technique produces a monolayer on the surface. That's a layer one molecule thick. This would easily be disturbed by the slightest motion or breeze. The tiniest ripple would create local openings. In fact, this is probably why their reduction in water loss is so small -- only tens of percent. Lots of water gets out. This implies that lots of gases could also get in. (i.e., gas exchange with the atmosphere would perhaps be inhibited by tens of percent amount.)
  • Did they say what kind of thermal conductivity this layer would have? If it was low, then try this on for size:

    While having this layer of molecules on the surface, rig up an array of thermoelectric modules (Peltier elements) to conduct the heat that would be trapped on the water and use it to generate enough electricity to be able to drive the water pumps or whatever. I don't know how feasable this would be though since from what I hear the efficiency isn't the greatest in the world...

    No beowulf cluster
  • Okay, this sounds to me like vapor ware.

    Ok, sorry, had to...but really, doesn't this sound like the setup for a sci-fi world saving movie where the original cause of the disaster was something incredibly stupid a scientist (the one equipping the rescuers) did?

    "You bred the aliens on Earth?"
    "Doctor! You designed the Neutronomiconimeter Canon!?!"
    "My god! Humans spread the oil on the ocean, causing the sea monsters to attack from Atlantis!?!"
  • by TheNarrator ( 200498 ) on Sunday November 02, 2003 @03:38AM (#7370073)
    It's kind of annoying that these days, when any new technology arrives, it is subject to a ridiculously paranoid environmentalism filter. Resevoir water is about .0001% of all water on the planet and people are worried about gas exchange and the temperature of it! Enough to deprive populations in the developing world of clean drinking water? I was suprised that the cost of the system wasn't mentioned in the header, only the environmental impact.
    • You're right, we should probably just implement new technologies without even considering the environmental consequences. Who needs the environment anyway, it's just the air we breathe and the water we drink, not really important. Blind acceptance of technology is a much wiser option.
    • The percentage of FRESH water that goes through a reservoir at some point is much higher. (I don't know the percentage but I highly doubt your 0.0001% figure is from anywhere but your ass).
      Turns out, the drinking water for almost all larger cities is from reservoirs somewhere. Then there's the reservoirs for power generation. This is a significant percentage of major rivers. Rivers that many species depend on for survival.

      So yes, it does have to be run through the "green" filter. Otherwise you can clai
    • A tiny percentage, but closer to us. The water I'm most worried about is the .000000000000000000000000000001% that's in my body--don't be messing with any green filters there!
    • Many people are legitimately concerned about the negative impact on the reservoir. It will become a catastrophic mini ecosystem that might foul the water, making that reservoir temporarily useless.

      I agree though that we have nothing fear for the sake of the weather and global environment.

  • From the referenced article: "... saving the water costs less than half the price of replacing it..."

    That means that the water-saving layer is VERY expensive, if it is only two molecules thick.
  • > spreading an ultra-thin blanket of organic molecules on the surface to block the escape of water molecules

    Mmm..... Organic molecules.....

  • Prior art ? (Score:2, Funny)

    by Anonymous Coward
    by spreading an ultra-thin blanket of organic molecules on the surface

    Isn't this an Oil Slick, some complanies have been doing it for years.

    Oops ultra-thin obviously, given oil prices and shortages, they cant afford the old style heavy slicks any more.
  • The interested reader might want to have a look at the US patents of Robert Neville O'Brien, the founder of Flexible Solutions:
    • PAT. NO. 6,303,133
    • PAT. NO. 6,558,705
  • by Dynamoo ( 527749 ) on Sunday November 02, 2003 @07:30AM (#7370429) Homepage
    This is *exactly* the basis for the plot in J G Ballard's bleak vision of the future, "The Drought" where the oceans become covered in a thin molecular film which prevents evaporation of the seas, and hence no rain.

    In the book the film is caused by pollution, but it is almost impossible to disperse and remains resistant to the waves and man-made attempts to break up the film. In the end, humanity ends up clinging to life by the edges of the ocean, each person with their own solar-powered desalination plant.

    A sobering thought if you've read the book. Imaging what whould happen if this stuff got loose?

  • I thought they called that "algae"?
  • by whovian ( 107062 ) on Sunday November 02, 2003 @08:55AM (#7370520)
    As I recall correctly, this is not a new idea, but perhaps its implementation is. I had a professor who described this concept in the classroom over 10 years ago.

    People wanting more info should STF(ree)W for Irving Langmuir or Langmuir-Blodgett monolayers, e.g.,

    http://www.woodrow.org/teachers/chemistry/ institutes/1992/Langmuir.html

    The crowning achievement of any chemist's career must be the honor of winning a Nobel Prize. This accomplishment was realized by Irving Langmuir in 1932. Langmuir was fascinated with surface chemistry and it was for his efforts in this area that he became the first non-academic chemist to receive the Nobel Prize. Along with Dr. Katherine B. Blodgett, he studied thin films and how substances are adsorbed on surfaces. Through their efforts, surface chemistry became a full-fledged scientific discipline. In addition to their interest in these surfaces, they also wanted to know more about interfaces, where phases come together. The studies led to clarification of the true nature of surface adsorption and established the existence of monolayers. Monolayers are surface films a single atom or molecule thick which have peculiar, two-dimensional qualities. Thin layers on surfaces such as living membranes are important in the action of enzymes, toxins, antitoxins and other biological substances. Again turning to the practical, this discovery led to the possibility of measuring molecular sizes of viruses and toxins, a significant step forward in the eyes of biologists. Langmuir developed experimental techniques for the study of proteins. The studies on monolayers also led to the development of almost perfectly transparent glass, made by placing a thin film of a flourine compound on the surface.

  • Didn't we already try this with the Exxon-Valdez?
  • Will good old corn oil do the same? I used to use it to insulate capacitors made with salt water - it prevented the ring of corona around the pickle jars. I suppose it may reduce evaporation too.

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