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  for Metal Finishing since 1989
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Chromium Testing for Science Fair

I am planning to do a Science Fair project regarding chromium testing. Chromium has been detected in our area, and I want to test to see whether it is Cr+3, or Cr+6. If their is a procedure, or kit to test for Chromium deposits please tell me.

Amy M
- Canada
2000

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2000

Yes, there are test kits available from Hach [Loveland, CO] and LaMotte Chemical [Chestertown, MD], and the NAMF has/had a booklet evaluating them called "The Performance of Analytical Test Kits on Metal Finishing Wastewater Samples" by Frank Altmayer and John Ruf (1987).

One potential problem though is that some materials may be undesirable even in concentrations low enough that they are difficult to test with simple kits. Another problem may be materials that interfere with your test and give you an unrealistically low or high reading.

An interesting thing about chromium wastewater is that the color indicates whether the dissolved chromium is hexavalent or trivalent, even down into the part-per-million range. Barring interferences, hexavalent chromium is honey colored to maple syrup colored;trivalent chromium is a faint green or bluish-green color.

Good luck.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey