Presented in Partnership with:
 
 

Ask the Expert Question-and-Answer Archive
(Wastewater Treatment)

by Mike McGinness, EcoShield Environmental Systems, Inc.
May, 2008

Nitric Aidic Pickle Liquor Waste Treatment

Q. Do your have or know of a process for treating very strong nitrate waste (25 -50,000 mg/L) pickle waste from a SS mill? Location in China.

A. I really need to know more about what else is in the waste. If it was just nitric acid with traces of iron I would consider pH neutralization with potassium hydroxide to make a potasium nitrate fertilizer, but alas, I suspect the SS means stainless steel, and thus nickel and chrome are involved. I have heard of dialysis, and electrodialysis units being used successfully to purify the nitric acid for reuse as far back as 16 years ago, and to concentrate the metal salts, but I have not had any hands on experience with them myself. Reverse osmosis is another potential candidate with a track record. Lastly, ion exchange resins to remove trace metals, and restore or purify the nitric acid is another option that has been used.

I would look for a way to purify the nitrates for reuse, or recycling first by removing the metals.

Sincerely,

Mike McGinness

 

 


The information contained in this site is provided for your review and convenience. It is not intended to provide legal advice with respect to any federal, state, or local regulation.
You should consult with legal counsel and appropriate authorities before interpreting any regulations or undertaking any specific course of action.

Please note that many of the regulatory discussions on STERC refer to federal regulations. In many cases, states or local governments have promulgated relevant rules and standards
that are different and/or more stringent than the federal regulations. Therefore, to assure full compliance, you should investigate and comply with all applicable federal, state and local regulations.