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Evaporation Prevention Using Molecular Blankets

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."

18 of 223 comments (clear)

  1. Just pour oil/petroleum in the lake by Anonymous Coward · · Score: 3, Insightful


    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

  2. Weather too by BWJones · · Score: 4, Insightful

    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.

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    1. Re:Weather too by TheLink · · Score: 4, Insightful

      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.

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    2. Re:Weather too by WhiteBandit · · Score: 2, Insightful

      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.

  3. This should be fun by Anonymous Coward · · Score: 3, Insightful

    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

  4. doesn't this happen naturally? by goombah99 · · Score: 5, Insightful
    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.

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  5. Need more research by whereiswaldo · · Score: 4, Insightful

    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.

    1. Re:Need more research by Daniel+Dvorkin · · Score: 4, Insightful
      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.
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  6. Can anyone say "Breaking the Cycle"? by atgrim · · Score: 4, Insightful

    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.

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  7. this is a BAD idea by c4ffeine · · Score: 4, Insightful

    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...

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    1. Re:this is a BAD idea by gerardrj · · Score: 3, Insightful

      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.

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  8. Nice idea by helix400 · · Score: 3, Insightful

    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.

    1. Re:Nice idea by YrWrstNtmr · · Score: 2, Insightful

      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..."

  9. Maybe not so many dead fish by Sir+Holo · · Score: 3, Insightful


    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.)

  10. Everything gets run through the green filter? by TheNarrator · · Score: 4, Insightful

    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.

    1. Re:Everything gets run through the green filter? by greenstork · · Score: 3, Insightful

      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.

    2. Re:Everything gets run through the green filter? by pherthyl · · Score: 3, Insightful

      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 claim that every activity is the same. "Oh hey, well because of our oil tanker crash we polluted 1000 km^2 of ocean but.. uh.. thats like 0.000001% of the earth so who cares right?"
      Sheeesh, get a clue.

  11. Re:One step at a time! by carcass · · Score: 2, Insightful
    The answer is not to require water saving measures through legislation but to make people respect the water they have through prices. It's the perfect incentive for people to consider just how important water is to them.

    I work in the water treatment business, and I've visited water treatment plants all over North America. The thing that is common to all water supplies is that the customers think they have some sort of a "right" to unlimited clean water without sacrifice. They grumble and complain and write woefully misinformed letters to their newspapers when the local water company attempts to raise rates to cover infrastructure improvements or cost-of-living salary increases.

    What people don't see is that treating water to make it drinkable costs money. If you could see the way water infrastructure in the U.S. and Canada is degrading and how the water industry (especially production and distribution companies) are being forced to ignore staffing and capital improvement needs just because their customers vote for the government to force low rates, you'd understand.

    If water prices were allowed to fluctuate more realistically, people wouldn't waste so much of it. Really, in the U.S. and Canada, people pay over US$1.00 for a silly little bottle of water that isn't even guaranteed to have as good quality as tapwater, and then they balk at rate increases of a few pennies per thousand gallons!

    If water prices more accurately reflected the true costs of production and distribution, people would think twice about watering their desert lawns. They'd go out and buy water saving appliances on their own, since it would directly translate into savings on their next water bill.

    The only thing compulsory water conservation accomplishes is building a bloated bureaucracy of bill checkers, house inspectors and intrusions into the private lives of citizens. Realistic water rates encourage conservation, reduce the load on local governments who have to redirect resources from fire departments, roads, etc., to enforcement of water use regulations, and above all, give consumers more respect for the vital natural resource they've been pouring down the drain ever since Roman times.