Australia's Science Forum

What is the consensus on disposal of waste produced from reacting:

a) dilute potassium dichromate (0.1M), sulfuric acid (0.05M) and potassium iodide (0.1M), with starch added as an iodine indicator (a black solid, presumably iodine complexed with the starch is present)?

b) dilute potassium permanganate (0.1M) with dilute hydrogen peroxide (0.1M), then dilute sulfuric acid (0.05M)? Again, I have a blackish precipitate that does not dissolve in water.

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They are both screaming heavy metal waste bottle to me .
Depending on how much you have to get rid of , I’d evaporate as much water out of it first ( in a fume hood)
I hate paying ti dump water