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CFR 433 Metal Finishing Requirements

2003

Under CFR 433 Metal Finishing, we treat 300,000 liters a year of waste water to remove 128,000 mg (4.5 ounces)of copper because the concentration is over our permit limit. Our total plant discharge is 5,600,000 liters per year.

Is there anything that takes into account our total plant discharge and/or the very small amount of copper in our waste flow that would eliminate us from having to remove the copper?

Alfred De Litizia
- Toccoa, Georgia, USA

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First of two simultaneous responses

From your quick description it sounds like you are in the same situation as many other manufacturing facilities. The fact that you use 5.6 million liters of water per year, which could dilute the 300 thousand liters you treat, does not help you; you must treat the copper-contaminated water, not dilute it with copper-free water.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2003

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Second of two simultaneous responses --

If you use your total discharge, your concentration is .023 ppm. Using the 300,000 L volume, you've got .427 ppm. the 40CFR433 limit for Cu (4 day avg.) is 2.07 ppm.

James Totter, CEF
- Tallahassee, Florida
2003

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Your real issue is probably treatment cost. Mr. Trotter suggests you are removing essentially all of your Cu, which practically requires a cation exchange resin bed. If you are not already doing so,* this is an efficient means to remove highly dilute concentrations of metals. But, if you are removing the Cu from a tapwater rinse, frequent regeneration raises the cost. I suggest using RO or DI rinsewater to avoid picking up extraneous cations such as Ca, Mg, Fe. Alternatively, invest in a selective cation resin.

*Are you using another method to merely reduce Cu effluent from ~278 g/yr to less than 150 g/yr?

Ken Vlach [deceased]
- Goleta, California
Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.
2003

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2003

Based upon the small amount of copper present, assuming that there are no cyanides or EDTA or a high suspended solids concentration, I would recommend a bag filter and a non-regenerating tank of chelating IX resin. Since this resin can hold 1-2 pounds of copper per cubic foot, there would never be a need to regenerate it. It would be cheaper to dispose of the resin and replace it every several years.

The size of the tank and the amount of resin that you would need depend upon your maximum flow rate.

Lyle Kirman
consultant - Cleveland Heights, Ohio