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Ammonia reduction in plating wastewater

Hello, I am a waste water tech and I have a waste stream that contains NH₄OH & H₂O₂. I am looking for any ideas on pretreatment before I discharge it to the mainstream waste flow. Currently I am using sodium metabisulfite, but I am concerned about how I can effectively break the ammonia complex and not pickup any other metal precipitates.

Thanks for your replies

James miller
- Phoenix , Arizona
1999

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1999

I assume we're talking about a waste stream from plating. Both peroxide and ammonia can be removed by boiling, although this can be impractical considering rinse water volumes, and the ammonia may need to be recaptured again with a fume scrubber anyway.

My limited experience is that ammonia cannot be effectively disposed of with chemicals. Rather than pretreatment, what may be necessary is post treatment. That is, after you have removed the bulk of the precipitated metals with hydroxide precipitation and clarification, hit the remaining stream with DTC and an organometallic co-precipitant, and filter it. Regards,

Ted Mooney, P.E.
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