 |
 |
Ask the Expert Question-and-Answer Archive (Wastewater Treatment)
by Mike McGinness, EcoShield Environmental Systems, Inc.
January, 2011Titanium Pickling Wastewater
Q. Have you even come across a technology to selectively remove and possibly recycle Ti from pickling wastewater (HF and HNO3).
A. No, but I would be surprised if the big players in the titanium business, like titanium dioxide pigment makers for paint, or mining industry people dont know how to do it already. The Metal Finishing industry does not have a national EPA limit for discharge on titanium. Some of the dialysis or electrodialysis technologies may know how to do it.
HF could be removed as a calcium salt (CaF2 solid precipitant) but if you used Calcium hydroxide I would think the Titanium would drop out with the calcium, but most NO3 compounds are water soluble. Then you would need to separate the calcium from the titanium in the solids.
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.