Homebrew PCBs

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@rogers.com> 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]
>
>  
>


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