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Emissions from sulfuric acid anodizing

I am an environmental engineer and I need to determine the air emissions from a sulfuric acid anodizing process. I am looking for emission factors, technical papers, or any article or document that has ever been published that could help me determine these emissions. I have looked in the USEPA TTNCIEF AP-42 manuals and found some emission factors for Chromic acid anodizing but none for sulfuric acid anodizing. based on the particular process of interest, I am expecting emissions of NaOH (Etch), H2SO4 and HNO3 (De-Ox), H2SO4 (anodizing) and acetic acid [on eBay or Amazon] (Seal) + possibly some other compounds in lesser amounts. I would appreciate any input on the matter as I am trying to avoid having to perform full-scale source testing (quite expensive).

Alex Ballez
Stephen Lamming Associates Ltd - Toronto, Ontario, Canada
2005

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2005

Hi Alex,

May I suggest that first of all you have a gander in the archives at # 4396, # 6733, # 14944 & # 26468

Then, perhaps, you might like to contact the local Air Management people who surely, surely could be of some help.

In a nutshell, there are two major chemicals ... sulfuric and nitric.

sulfuric is dead easy and very inexpensive to collect. The nitric can present problems but I was always lucky because the fumes are low concentration and hence the exhaust airflow is 'high' on oxygen (i.e., air) and hence, as you know better than I (I hope), the bad NOx fumes ideally need a good (long) retention time plus oxygen so that they can revert to a scrubbable mode.

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

The amount of fumes from sulfuric acid anodizing will be governed by the size of the load and the amount of air agitation used. Generic values mentioned in the ventilation spec, engineering books and the metal finishing guide book work quite well.

James Watts
- Navarre, Florida
2005