Homebrew PCBs

Well im sure you are correct but either way in the world of sewerage that
is what the issue is with diaposing used ferric chloride.
On Mar 10, 2013 11:31 PM, "Todd F. Carney / K7TFC" <k7tfc@...> wrote:

> **
>
>
> Neither iron nor copper are actually "heavy." Atomic number is part of the
> definition. Fe (iron): 26 / Ni (nickel): 28 / Cu (copper): 29 / Zn (zinc):
> 30. Each of these needed by all life (in the proper quantities, of course).
>
> Now, these buggers *are* heavy: Hg (mercury): 80 and Pb (lead): 82. Useful
> but nasty metals.
>
> Sorry for the quibble. Heavy metals is commonly used to mean "toxic metal
> compounds." That's okay. I need coffee. I'll feel better.
>
> 73,
>
> Todd
> ----------------------------------------------------------
> K7TFC / Medford, Oregon, USA / CN82ni / UTC-8
> ----------------------------------------------------------
> QRP (CW & SSB) / EmComm / SOTA / Homebrew / Design
>
> On Sun, Mar 10, 2013 at 11:30 AM, Charlie Taylor <scubadogct@...
> >wrote:
>
> > in my opinon the preasence of ferric is not the issue. It is tje heavy
> > metals that is the peoblem.
> > On Mar 10, 2013 1:03 PM, "Dave Sage" <davesage12@...> wrote:
> >
> > > **
> > >
> > >
> > > Perhaps someone with some knowledge on public works and sewage
> treatment
> > > can
> > > clarify this for me.
> > >
> > > I guess it must be the copper in the ferric chloride etchant that we
> > > dispose
> > > of that is the problem - is that correct? Is there actually copper per
> se
> > > any more after the reaction of etching?
> > >
> > > I'm pretty sure somewhere in the sewage treatment process, after gross
> > > solids are removed, the water in the sewage system is sent to settling
> > > ponds. While in the ponds ferric chloride is added to act as a
> flocculent
> > > i.e. an agent that causes solids to gather together in clumps for easy
> > > removal. If this is the case, would it make any difference if there
> were
> > > some ferric chloride in the system to begin with (from flushing etchant
> > > down
> > > the drain)?
> > >
> > > [Non-text portions of this message have been removed]
> > >
> > >
> > >
> >
> >
> > [Non-text portions of this message have been removed]
> >
> >
> >
> > ------------------------------------
> >
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> Photos:
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> >
> >
> >
> >
>
> [Non-text portions of this message have been removed]
>
>  
>


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