Re: Cu/Zn dechlorination was: Recycling activated charcoal

[Wright Huntley <jwwiii at pacbell_net>]

LeeH920226 at aol_com wrote:
> In a message dated 2/4/03 1:22:53 PM, jwwiii at pacbell_net writes:
> 
> <<  Can 
> anyone explain exactly what is different about this product and the 
> common Cu-Zn alloy (aka brass) used for plumbing fixtures for centuries? :-) 
> 
> 
> Maybe I can, now that I read more about it. I believe this is a zinc/copper 
> couple not an alloy. There is a lot more information at other sites than the 
> one I cited first. Such as:
> http://www.tbaytel.net/gjgourle/index.htm
> http://www.purewaterforu.com/whatiskdf.html
> http://www.naturalsolutions1.com/rainbal1.htm
> http://www.kdfft.com/

Thanks, Lee. I read most all of them and came to a couple of tentative 
conclusions. Your digging these out is much appreciated by those of us too 
lazy to do it ourselves.

It really is just brass, which they even admit in several places.

[It was discovered when the scientist stirred his Cl solution (with 
indicator) with a brass ball-pen liner and the chlorine vanished. It is 
furnished as fine granules or wire, to make large surface area. Still just 
brass, and you could do most of the testing with off-the-shelf brass 
powder, I bet. They claim to optimize the ratio of Cu to Zn, but that 
might be pretty application dependent.]

Chloramine will need a bit of testing for aquarium use. Apparently it is 
removed best by breaking the chlorine-ammonia bond, but the ammonia is 
free to destroy gills if not removed otherwise (aeration, plants, 
biofilter, etc.). [GAC is particularly poor at removing the ammonia, once 
the chlorine is gone.] According to Spotte, ammonia is about as bad on 
gills as David's report of chlorine in soft water, so... Wish we had a 
decent, cheap ammonia test that was sensitive to a few ppb.

> 
>     The claims about removing chloramine are a little vague. Rates may be 
> slower and may not work under some conditions. Another concern that I have is 
> the inhibiting effects claimed on biological activity, especially focused on 
> microorganisms, but what about fish, daphnia, etc.? What is the fate of the 
> copper and zinc? Is it leached into the effluent gradually? Will the 
> concentration of zinc and copper be harmful?

The latter seems to be covered by their claims that the residual copper 
and zinc are well below EPA standards for potable water. That's a range 
about where the disadvantage (toxicity) switches to an essential for life 
(trace nutrients).

Initial tap pH might have a huge impact, here, and should be tested 
carefully before risking non-throwaway fish. Soft acid water over brass 
might do a real number on your snails, plants and even fish.

I love jumping to conclusions so I did it again. The anti-bacterial 
process sounds like it is mostly confined to the immediate vicinity of the 
brass granules, where EMF and chemical effects from H2O2, etc. are strong. 
I doubt if the outlet water has much bacteria killing property.

>     Someone may have to run an experiment ;-?

A bunch of them, IMHO. The early adopters will need to keep the rest 
posted on results.

As you may read between my lines, I switched from a deep sceptic (e.g., 
snake-oil reference) to really curious. This could be a nice addition to 
our techniques for providing the kind of living conditions that suit our pets.

Their explanations of the chemical processes do not satisfy me at all. 
There is a likelihood that most of the actions are catalytic, for the lack 
of metal loss with huge volumes filtered says that the zinc is *not* being 
carried away as ZnCl2, for example. If it *is* being carried away, their 
claims for meeting EPA potable water standards are suspect.

One problem with a technical subject on the web: It takes serious digging 
to get through the blatant sales BS and get at the truth. That, IMHO, is a 
flaw that will cure itself with time (if not regulated into concrete), but 
until then, "caveat emptor." [BTW, I have some nice local Modesto herbs 
that will make you a dynamo in bed. Send cash. Condit and Peterson both 
endorse them.]

Wright

-- 
Wright Huntley -- 209 521-0557 -- 731 Loletta Ave, Modesto CA 95351

      All K-Mart and Walmart stores to be closed in Iraq.
              They will be replaced by Targets.

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