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Evaporation Prevention Using Molecular Blankets

Posted by CowboyNeal on from the natural-cycle-alteration dept.

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."

3 of 223 comments (clear)

  1. Hey... by hazman · · Score: 5, Funny

    That's not a environment destroying oil spill, its a high tech water evaporation prevention film.

  2. 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.

    --
    Some drink at the fountain of knowledge. Others just gargle.
  3. Old hat by njh · · Score: 5, Informative

    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.