Guenter

Are you trying to say that the bacteria were "eating" the metals? That
would surprise me very much as copper and lead both have marked
bactericidal properties (tin somewhat less so). Or were they attacking
the shredded epoxy, to leave the metals, in which case I would have
thought that gravimetric separation would be easier and more efficient?

Even if, by some miracle, the bacteria were destroying the metals, it
would make the problem worse. Instead of a relatively inert solid metal,
you would have an easily degraded organism which could rapidly release
its metal content to the environment.

??????????

Brian

Guenter Grossmann wrote:
>
> Regarding the recycling of lead and tin we had an interesting project with the institute of Biology at the University of Zurich. The folks there where growing bacteria that enabled a selective extraction of copper, tin and lead from shreddered PCB's. It worked quite well. The problem was that the surface of the solder fraction was too small. This resulted in a low efficiency of the process. Unfortunately, we didn't get any more founding to continue the work.
>
> Guenter
>
> Guenter Grossmann
>
> Swiss Federal Institute for Materials Testing and Research EMPA
> Centre for Reliability
> 8600 Duebendorf
> Switzerland
>
> Phone: xx41 1 823 4279
> Fax :      xx41 1823 4054
> mail:     [log in to unmask]
>
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