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  for Metal Finishing since 1989
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To remove ferric ammonium ferrocyanide from wastewater

Hello everybody,

I work for a cosmetic company which uses ferric ammonium ferrocyanide in some fromulas. The problem is that the only treatment system we use is a settlement tank which removes most of powder residue before going into sewer. However, I am trying to find a practical way of treating or removing the metal cyanide when it gets to settling tank. We have met compliance with local authority but the concentration of metal cyanide will be increased in some formulas and I am concerned it may exceed permit limit of 1 ppm total cyanide.

I would really appreciate any help anyone reading this can give.

sincerely,

thanks

Padraig O Dalatun
cosmetic manufacturer - Congers, New York, USA
April 3, 2008

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April 4, 2008

That is a strange item to put in cosmetics, since the "CN" word is nearly as frightening as the "cancer " word.
Ferric cyanide is very insoluble, but will dissolve enough to cause problems in acidic water conditions.
You might try filtering the effluent to take out more of the really fine particles as they will show up in the digestion method of analysis.

James Watts
- Navarre, Florida

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If the ferrocyanide is in particulate form, filtration will remove it. If it is dissolved, there are precipitative methods for removing it. I've used such methods on metal finishing waters with great success.

Dave Wichern
Consultant - The Bronx, New York
April 8, 2008

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Filter solids at pH desired
then adjust ph to 5.4 and wait a while, then filter.

Fred Gibbons
- Sarasota, Florida, USA
June 2, 2008