Metal finishing Q&As since 1989

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copper sulphate disposal

I am a highschool and for an independent project we had to build a battery that conducted at least 2 volts. One of my electrolytes was copper sulphate [on eBay or Amazon], and for the write-up we have to include disposal methods. How would you dispose of the copper sulphate solution in a rural highschool classroom? thank-you

Stefanie Anne V.
student - Eganville, ON, Canada
2004

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One way to approach the problem is to save it for next years class, since some one will probably have the same project. You have two things to get rid of, copper and acid. You can set up an electroplating rig, a copper cathode (-) and a stainless steel anode (+). Agitation helps a great deal, a spin bar would be great. Hook the anode up to a controllable power source at about + 1 volt DC. Hook the cathode to the negative side. Plate for about one month. Remove the setup and drop in some steel wool [on eBay or Amazon] that has been cleaned to remove the production oils. This will plate out copper to a very low level. Remove the steel wool after a day. Neutralize the acid very carefully with bicarbonate of soda to a neutral point. The steel wool will have reacted with most of the acid. Flush the remaining liquid down the drain with a good bit of water and throw your cathode,anode and rinsed steel wool in a metal recycle trash bin. Not 100% legal, but very very close and very effective for your small amount.

James Watts
- Navarre, Florida
2004