Metal finishing Q&As since 1989

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Which is best method to separate the chromium sediment from the treated effluent?

Hi,

We are doing chromium plating for auto-ancillaries. We ourself treat the effluent and dispose it.
In this, right now we heat the treated effluent using solar evaporation method to vaporize the water content and the dried sediment will be disposed. As this practice consumes lot of space as well as time, we would like to go for force heating like electrical heating to vaporize the water content. Otherwise we can go for filter system to filter the sediments.
But can you tell me which method will be appropriate. What we feel is that in vaporizing method the fumes/vapor may contain chromium particles.

So can you please suggest me which will be better system whether vaporizing or filtering?

V. Ranga Bhuvana Balaji
Process Designer - India
2007

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If you are treating your effluent, and this treatment includes reduction of the hexavalent chromium, I think you have little worry. There may be residual sulfites in the dried residue that could cause allergic reactions in sensitive individuals.

If by "treatment", you mean simple pH adjustment, then there's a real potential for airborne particulates bearing hexavalent chromium being generated. The inhalation of these can have serious consequences for human health.

Dave Wichern
Consultant - The Bronx, New York
2007