[labnetwork] Piranha Bath Alternatives or Substitutes

[Paolini, Steven]

Kolin,
   I'm not sure what alternatives are as effective as piranha but I can suggest a couple of methods of safely disposing it, that's assuming you have electro-fusion welded polypropylene drain lines leading to a PH treatment hold.
My first choice would be to have a dedicated disposal sink with a dilution drain valve. These valves use city water to mix with the waste at a rate that is much too water rich to enhance more exothermic heat from the sulfuric. Dilution rates vary for the intended purpose, in other words, ratios of 20:1 will ensure a much cooler and diluted waste stream but will drain twice as slow as 10:1. Generally, this type of piping will be OK at temperatures up to 120 Deg. C. and the 20:1 dilution will lessen the shock to the treatment tank.
I am reluctant to suggest the second choice as it has a tendency to be less than perfectly safe and that would be the use of an aspirator. Aspirators have built in dilution as a result of the water needed to create the venturi effect. The reason I am reluctant to suggest their use is because of the Teflon "dip" tube used in submerging into the waste, the tube can spring out of the container and "fling" droplets of waste to an undesired place such as a person. I recall some meetings that I had with a particularly large industrial insurance company and how their representatives shunned the use of aspirators and I tend to agree with them.
Best of luck,

Steve Paolini
Equipment Dood
Harvard University Center for Nanoscale systems

From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Kolin Brown
Sent: Thursday, December 04, 2014 1:03 PM
To: labnetwork at mtl.mit.edu
Subject: [labnetwork] Piranha Bath Alternatives or Substitutes

To all:

Currently our Environmental Health and Safety office  is creating new disposal procedures for Piranha Bath.  They are also encouraging us to find alternative processes.  In the past at WVU, we used SummaClean by Malinkrodt Baker as a substitute; however, this product was discontinued about a year ago.  Does anyone know of any other Piranha bath substitutes?

Kolin Brown
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20141204/bc41b730/attachment.html>