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Q&As since 1989


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About emissions

2002

Hello:

I am a university student, I have read the article that you took on the web site and found a huge interested in it since I am search a subject about industry electroplating now and I need some information about it. Would you please kind enough to show me just some general information about those questions below:

1. What emissions are there during the electroplating process?
2. What emissions are harmful? What are the standards?
3. What consequences have the emissions?
4. Which solutions can be found for this problem (end of pipe or integrated)?

Xi Yang
- Deventer, Netherlands

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First of two simultaneous responses -- 2002

1. Process chemicals must be rinsed off, so electroplating generates wastewater with metal, acid, and sometimes cyanide ions. Sludges or filter cake which build up must be recycled or more probably landfilled. Air emissions of acid and hexavalent chromium are a third type of emission. 2. Wastewater which is either acidic or alkaline is a problem. Heavy metals dissolved in the wastewater are a problem. Cyanide, if any, is a problem. 3. Without proper pretreatment, any direct discharge can kill a stream. If the waste is discharged to a public sewer system, the metal in the sewer system's sludge can become too high for surface application as fertilizer. 4.There are all kinds of partial solutions, both integrated and end-of-pipe, including ion exchange, reverse osmosis, electrolytic plate-out, evaporation, and chemical precipitation.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

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Second of two simultaneous responses -- 2002

Hi Xi !

Most of your questions could be answered if you spent some time going through the various finishing.com archives.

But please have a look @ # 17983 This mentions (some NOx fumes are an exception, some) that most ambient temperature emissions are NOT gaseous nor are they even fumes ... but can be removed inertially.

Any process involving heat and different materials generates something. Even cooking does. Sometimes the emissions are harmful and have to be 'collected' or destroyed. And if you induce electric currents, i.e., via anodes and cathodes, then even more emissions occur as gas bubbles rise to the surface and implode...........

Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).