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I Is 80pa a huge pressure?

  1. Mar 14, 2016 #1
    I went to a desalination plant and the guy explaining reverse osmosis says that they force water through the membrane at a huge pressure of 80 pa

    But I was wondering and that is less than 1atm. And it's like an 8kg placed on a 1 square meter space. I thing a 65kg human gives more pressure since the feet is smaller than 1 meter squared.
    What am I missing here
  2. jcsd
  3. Mar 14, 2016 #2


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  4. Mar 14, 2016 #3
    I know that. I'm asking this is 80 pa a lot of pressure? Cause that guy in the plant said so and I asked him if he's sure it's pa and he said " yes 80pa " and said it was a " huge" pressure.
  5. Mar 14, 2016 #4
    The guy at the plant is incorrect. It takes pressure of the order of many hundreds of psi to force the water through a membrane depending on the salinity. 80 Pa is as you noted is pretty low. Think of the order of MPa.
  6. Mar 14, 2016 #5
    Thank you
  7. Mar 14, 2016 #6
    As the link shows, the pressures used are in the range of 80 bar rather than 80 Pa.
    So it may be than someone was confused about units.
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