Backyard Aquaponics
A place to discuss aquaponics

Just scored some blue barrels - 2 contained Acetic Acid and 1 Sodium Hydroxide.

What's the best way of rinsing/neutralizing them? Just concerned about:

1. Possible strong exothermic reactions causing splattering - you're supposed to add the base/acid to water not add water to the base/acid - but if I wack the hose in to the barrel on full bore should that be OK? Theres only a small amount left in the barrel (maybe 1-2L)

2. disposing of the rinse water in the best way for the environment - is it better down the drain or in a big hole at the bottom of my sandy back yard?

Thanks
Matt

Flood them with lots of water, then mix all the water back and forth between them to neutralise them. I dont think Acetic acid is as bad as Sulphuric or Nitric when it comes to adding water and an exothermic reaction happening.
After you mix, you can use the resultant Sodium Acetate as flavouring on chips ... well assuming you could get it pure enough and then dry it out

From Wikipedia:
>Sodium acetate may be added to foods as a seasoning. It may be used in the form of sodium diacetate — a 1:1 complex of sodium acetate and acetic acid,[3] given the E-number E262. A frequent use is to impart a salt and vinegar flavor to potato chips.

You could always make a vinegar/baking soda volcano. Balance a laundry room size box of Baking soda on top of the barrel and use a string to tip it in from a safe distance.

In seriousness though,
They're standard barrels with the 2 threaded ports in the top, or removable lid barrels? Either way, I'd move them down to the edge of the sandy hole, put the hose in the top such that they're not sealed (need to vent as I'd be more concerned about off gassing than heat) and go back to turn it on from the other end, probably at a very slow rate. Let it fill up half way or so, shut off the water, and go down and tip out the barrel into the sand hole, being careful not to douse oneself in it. Then go turn the hose on full blast and rinse it out, still trying not to soak oneself with the barrel water, but if you do get any on yourself, you have a clear water rinse from the hose. I would do the Sodium Hydroxide first, so as to add the acetic acid water to the basic soaked sand, not reversed.

I'm basing all this on one of my tasks at an old job being to clean carboys of Hydrochloric acid out. Protocol was to make a basic (high pH) slurry in the drain trough, and then very slowly overflow the HCl bottles with clean water until the rinse water stopped fizzing so much when it hit the basic slurry. Then rinse it all down the drain. Higher pH stuff just cleans pipes, doesn't eat them away. Seemed a bit crude but it was a $100M R&D facility, so it had plenty of oversight. I would do your job in the sand pit just because unless you have industrial drains I wouldn't want your plumbing backing up with a large influx of water or possibly hitting a spot of something pH reactive. Rinsing it all out in the sand pit may leave a slight salt residue but after a rain or so you'll not be able to trace any record of the rinsing to a significant degree. Also if you leave an acid residue in your drain pipes, they could get eaten away a bit.

Thanks guys.