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Treatment for Silver Nitrate in wastewater

I use Silver Nitrate for titrations for some of our products. Can someone tell me how to treat the wastewater? Thanks

Randy A. Mattson
- Kent, Washington, USA
2007

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First of two simultaneous responses --

It depends a lot what you're titrating, and what you hope to do with the treated water.

If you're doing chloride titrations with a chromate indicator, adjust the pH to 7, and add ferrous sulfate ⇦this on eBay or Amazon [affil links] to reduce hexavaent chrome. Then, either adjust the pH to 10 - 11 to drop the Ag as the hydroxide, add an excess of salt to drop it as AgCl, or, perhaps, plate the Ag out.

You should be aware that there are often permits required for the discharge and/or treatment of haz waste. Your best bet might be just to drum it up and haul it.

Dave Wichern
Consultant - The Bronx, New York
2007

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Second of two simultaneous responses --

Randy
The purpose of titration is to react all the silver, usually to an insoluble compound like silver chloride.
Unless you do a vast number of titrations and have a minute amount of rinse water, I would be surprised if you could detect any silver getting into the effluent.

Geoff Smith
Hampshire, England
2007

 

Consider decreasing the amount of the titration from macro to micro. You probably can cut your sample size 10 fold by using a higher precision burette. If you want to go really micro, look into Hach's micro burette. A bit of a pain to use, but extremely accurate. If you cut your sample size, you can use a 5 or 10 Ml burette which can be read to a 1/100 of a Ml.

James Watts
- Navarre, Florida
2007

There is no Chromic acid in this titration. I am using an autotitrator. Basically it is silver nitrate, nitric acid and deionized water. Can I let the silver settle, decant the water and adjust the pH to 7.0 and dump the water? The Silver waste will be put into a drum and disposed of accordingly. Thanks for you help in advance.

Randy A. Mattson
- Kent, Washington, USA
2007