(published on 10/22/2007)
(published on 10/22/2007)
(published on 10/22/2007)
(published on 11/26/2007)
(published on 04/27/2011)
(published on 06/08/2012)
(published on 05/07/2013)
Yes, it should work well for that.
Mike W
(published on 05/19/2013)
It sounds like you've done just the tests needed to show that these spots are from some residue. De-ionized water has usually been run through an ion-exchange resin that pulls out most anions and cations. They're replaced with H+ and OH-, which recombine to form water. That can still leave traces of other gunk, and I guess that's what you're seeing. Sorry I can't be more specific. Perhaps with distilled water or reverse-osmosis purified water you'd not get those residues.
Mike W.
(published on 06/07/2013)
In the lab when we wanted de-ionized water on demand, we'd usually use columns of de-ionizing resin, available commercially. The output is not 100% de-ionized, but then nothing really is. Occasionally you have to replace the columns. Alternatives are old-fashioned stills (not very convenient or energy efficient) or reverse-osmosis systems. Industrial users seem to generally prefer the exchange resins, I suppose for price reasons. You can monitor the output with a conductivity meter. Depending on how pure you really need the water to be, you may be able to use one as cheap as under $200.
The Wikipedia article on this topic looks pretty good to me: .
Mike W.
(published on 11/25/2013)
Thanks for the info. I have one small quibble. For the combined resin+reverse osmosis method, wouldn't it make sense to use the resin first? That way whatever organic gunk it gave off would be removed in the second stage.
Mike W.
(published on 12/26/2014)