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Water + Salt + Energy = Clean!

Posted by ryuzaki0 on from the don't-know-that-I'd-drink-it dept.

codesmith.ca writes "CTV News is reporting about a device built at the Russian Institute for Medical Engineering that can convert standard water and salt into an antimicrobial solution. Apparently it's works on almost anything (virii, bacteria, cysts...) and it's safe for human consumption to boot. I can't find a site for the institute, but there are articles around. This one is fairly detailed, but hard to reach. Here's the Google cache. Here's one about a paper shows it's not exactly super-new technology." Any chemist care to comment on what sounds to be too good to be true?

4 of 368 comments (clear)

  1. A more balanced description by jbuhler · · Score: 5, Informative

    Here's a report summary I found on the technology from the Foundation for Water Research. It's not all that and a bag of chips.

    http://www.fwr.org/wrcsa/832100.htm

  2. It's plain simple ... by Anonymous Coward · · Score: 5, Informative

    No rocket science here, don't understand why something as simple as the electrolysis of brine makes in on Slashdot ...

    Freshman chemistry tells you:
    NaCl -> Na+ + Cl-
    H2O -> H+ + HO- (actually H3O+ instead of H+ but that's details)

    Then, you add some electricity and you get:

    At cathode (- electrode), H+ -> H2 (bubbles out) which means a lot of Na+ and HO- are left floating around - thus, per Google cached article in the original post: "The catholyte is a powerful alkaline solution used for [...]" -- not surprising at all, as you can see ...

    Then, at anode (+ electrode) you've got HO- and Cl- ... as expected, Cl- -> Cl2 ... but the trick here is that the formed chlorine reacts with water and even better with the NaOH that diffuses from the cathode to form ... bleach (hypochlorite that is) !
    Cl2 + NaOH -> NaCl + NaClO
    Now what does the article say? ... "The anolyte has powerful bactericidal characteristics and is effective in the control of harmful organisms like bacteria, viruses, cysts, and germs."

    Damn that highschool chem :-)

    END-OF-CHEM-LESSON

  3. Science News had an article on this... by wowbagger · · Score: 5, Informative

    The reaction isn't, as some have said:

    NaCl + 2H20 + electricity -> Na + Cl + 2H2 + O2

    Rather, you get a hypochlorous acid ion, an a sodium hydroxide ion. In effect, the reverse of mixing hypochlorous acid and lye.

    However, you get it in VERY dilute quantities, nowhere near what you'd need to damage human skin. But if you are an itty bitty microbe, the oxidizing effect is deadly.

    Really, this is just a "bleach on demand" sort of thing.

    --
    www.eFax.com are spammers
  4. Trivial details... by chazR · · Score: 5, Informative
    Bruce is right. This is snake oil. Flummery. Rubbish.Tosh. Garbage. Bollocks.


    Unfortunately, some of the things Bruce has stated are not entirely accurate. The general facts are correct. but some bits need modification.


    Hydrogen is reactive. It's only 'highly' reactive if you haven't played with really reactive stuff, like fluorine, chlorine and, er, oxygen. Potasium is fun too.. (I have only seen Cesium once. That's quite enough).

    Skin only catches fire if you get it very hot. An uncontrolled fire in a pure oxygen atmosphere is more likely to vaporize the skin; then the fat underneath will start to burn. Pure oxygen at reasonable (3atm) pressure will not cause spontaneous combustion of people. But if a fire starts in that environment, then you won't be able to put it out. The fire in Apollo 1 was not spontaneous. It was started by an electrical fault. The three astronauts suffocated in flame. Not nice.

    You can happily mix hydrogen and oxygen in a 2:1 ratio. You can pressurize the mixture to astonishing levels. If there's a lot less oxygen, you can breathe the mixture for days at a time (google for "deep hydrogen diving"). If you make a spark, then you'll understand just how reactive oxygen is. The lesson learnt will be very short, and terminally instructive.

    But hydrogen and oxygen are not hypergolic. Ask a rocket scientist. Even the Space Shuttle needs a match to get it going.

    Sodium is a disinfectant. In the same way that a raging forest fire is disinfectant. Kids! treating your grazed knees with sodium metal may sting! Also, your parent's lawyers will have to contend with a stupidity counter-claim.

    Oxidizing agents and reducing agents are defined by their ability to grab or release electrons.

    If you want to understand this stuff, find somebody who knows what "Gibb's free energy" is about. Then, get them to explain it to me...