[Jasim]

I saw another post on here that talked about disposal of barium chromate, but it seemed to focus more on the toxicity of barium, which isn't a concern here.

Someone I know has a solution containing sodium dichromate and water with a small amount isopropyl alcohol. He's wanting to get rid of the whole thing but is concerned about the toxicity of the chromate and doesn't want to dump it down the drain unless it's safe to do so. Please help my friend. Thank you.

[408]

acidify and treat with any alcohol till the dichromate colour is gone.  The resulting low-valent chromium solution is then precipitated with a hydroxide, and the low solubility chromium oxides are pretty non-hazardous and can go in the garbage, or if you wish label them as pottery glaze chemicals and take them to a hazardous waste disposal centre.

[Jasim]

Thanks for your help. My friend added HCl to a greenish solution, it changed to a dark burnt orange color and foamed some.  Then he added some isopropyl alcohol. Solution is now a dark orange or brown color. My friend plans on adding NaOH to precipitate. Checking to make sure the pH is within a safe range, he then plans on flushing the whole thing. That should be good right? Thanks for your help.