As long a we're on the topic of metallic poisoning ... I will shortly be
doing some treatment of aluminum using chromate conversion coatings.
When I am done I will be left with just a few ounces of hexavalent
chromium in a few gallons of water, and I really do not know what I will
do with the stuff.

I live way out in the country and do not want it polluting my soil,
septic system, or groundwater.  It is a very long drive to any sort of
hazardous waste disposal site.

In years long past I know I have spilled/dumped ChromiumVI salts on the
ground from other hobby project of mine.  And during my university years
I know I had my hands in the stuff for day at a time when I used it to
create positive transparencies from negative film in the photo lab (and
haven't grown any extra limbs yet) so I suspect that the danger of this
stuff blown way out of proportion.

I had a chemist fishing buddy who could always answer these questions
for me, but he has passed on.  There must be some chemical one can use
to in effect "neutralize" the toxic nature of ChromiumVI and convert it
to rather harmless ChromiumII (or whatever). Anybody know of what might
be used to promote this reducing(oxidizing???) reaction?

Robin Berglund




A web search led me to this patent. Ascorbic acid reduces chromium 6
to chromium 3 under mild conditions. Buy a pound of cheap vitamin C
powder on the internet.

http://www.freepatentsonline.com/6221002.html

Al Rees