Chromatography Forum

LALman wrote:
If you neutralize that acid stream with bicarbonate, then its just a nitrate stream. Call your local water treatment and ask them if that's OK.

James_Ball wrote:
For small volumes of acid or base, we normally just neutralize then flush down the drain. Our building also has another neutralization holding tank in the waste water line before it leaves out to the sewer system.

I'm working in a highly regulated environment where the regulations are enforced by non-chemists (think government labs). To them, neutralizing acids is considered "waste treatment", which is not allowed without a very lengthy permit with multiple organizations, up to the level of the state environmental department. It's goofy, but the powers that be prefer I bottle up any process waste and ship it off site for a contractor to handle.

I've been the metals guy in several labs. One new installation, the ICP-MS vendor told us we should put crushed limestone in the acid waste carboy to keep down acid fumes in the lab and neutralize the ~2.5% nitric plus hydrochloric acid. Typically, because of rinses and few actually high sample, that water has <<0.1 ppb of metals. But we found it was safer to periodically neutralize it while in a secondary containment tub because water stratifies and agitating it with limestone on the bottom can make a fizzy soda fountain.