From:
Nancy Carraway <000020898e9fd3e6-dmarc-request**At_Symbol_Here**LISTS.PRINCETON.EDU>
Subject:
[DCHAS-L] A real-world question 04.04.2025
Date:
Apr 4, 2025 18:05 UTC
Reply-To:
ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**Princeton.EDU>
Message-ID:
<1229307199.1572792.1743789944531**At_Symbol_Here**mail.yahoo.com>
In-Reply-To:
Dear all: 04.04.2025
I am working with a team responsible for excavating soil where a plating facility used to exist ... before the fire. Sodium cyanide and potassium cyanide have both been identified in the soil.
Misting will be part of the dust-suppression protocol whenever the soil is disturbed. Since cyanides in an acid environment will evolve effective levels of hydrogen cyanide, I have required that the mist be treated with an alkali to maintain a pH of the water at a level high enough to preclude the formation of airborne hydrogen cyanide.
My questions are:
-- Would ammonia be an effective agent to raise the pH of the water to levels well above neutrality ... depending upon the concentration of ammonia added?
-- Is there a preferrred alkali additive?
-- Is there not a colorimetric pH indicator that could be added to the water to be able to provide a readily evident assurance that the water is maintaining its higher pH level?
I will appreciate every and all suggestions. I have a deadline of Monday, April 7, 2025 to submit my recommendations.
Nancy Carraway
ngcarraway**At_Symbol_Here**yahoo.com
626 676 7681
