Letter 6022

Removal of copper from electroplating waste 

.

To:Tom Pullizzi

Hi,

I am a student from Singapore Polytechnic and is currently doing a final year school project on "Removal of copper from electroplating wastewater".

However, my group members and I found that the presence of gluconate in the wastewater affect the efficiency of copper removal.

Hence, the following are some questions which we would like to ask you:

1) The chemistry of gluconate.

2) Is EDTA able to chelate Cu and separate it from gluconate?

3) Are there any chemical means of reducing gluconate.

4) Physical separation methods besides electrodialysis.

5) In your letter #3907, you mentioned that gluconate complexes with iron when ferric chloride is added. So will gluconate complex better with iron or Cu.

Your help is invaluable to our project.

Thank you --From ChuChu, Sylvia, Jade.

ChuChu Leo
- Singapore

Gluconate is a wonderful chelator of many metals. That is why it's used in many alkaline tanks. EDTA is a stronger chelator, so that is no help to your problem.

To the best of my knowledge, most anything that you add to bust the gluconate will cause you other problems, with a net negative cost effect.

Keep the gluconate-bearing rinses/dumps away from the copper-bearing rinses/dumps is probably the most cost effective, even tho it requires a second treatment line, or at least separate storage tank and the trouble of shutting down the other treatment to do the copper treatment. This could be cost effective by easier treatment of the other rinses.

James Watts
- FL

Post a question on a different subject.

 

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