Sciencemadness Discussion Board

Seeking ideas for mercury liquid waste treatment methods

PYRIDINEyade - 8-2-2023 at 03:06


I am planning to synthesize Ag2HgI4 from mercury, silver, concentrated nitric acid, and potassium iodide. Is there any good way to safely dispose of the mercury liquid waste that will be produced at that time by myself?

experimental operation
1) Mix 0.65 g of silver and 0.6 g of mercury.
2) Add 5 ml of concentrated nitric acid and dissolve completely. If it is difficult to dissolve, heat the solution by boiling water as needed. If crystals precipitate, add 5 ml of water.
3) Add a solution of (2) to an aqueous solution of 1.9 g potassium iodide
4) Remove the orange supernatant by decantation, wash the yellow precipitate several times with water, and collect it by filtration (all the liquid waste is collected because the orange supernatant also contains mercury).
5) Wash with an appropriate concentration of sodium thiosulfate solution to remove by-product silver iodide.

chemical equation


BromicAcid - 8-2-2023 at 16:38

Bring the pH to neutral and crash out as the sulfide would be my knee-jerk reaction. Mercury sulfides are basically the go-to 'safe' from of mercury. Generally when I was doing chemistry at home I would boil off the water and then bag up and hold the salt since the volume was so low (labeling it as mercury waste).

PYRIDINEyade - 8-2-2023 at 17:08

Thanks for the reply!
I see. Surely mercury sulfide can be safely stored. I will try to react the liquid waste with sodium sulfide.