Not sure why is it downvoted. Biomining ([1]), which is extracting (heavy) metals from substance using fungi/bacterias is already a proven industrial process. It's entirely conceivable that at least some sorts of toxic waste could be cleaned up like that.

1. https://en.wikipedia.org/wiki/Biomining

There are already several ways to do this sort of bioremediation using mushrooms as bio-sponges (Eg for heavy metals). There’s the question of where to safely store those mushroom after the heavy metal is absorbed.

Important tangent, mushroom’s ability to absorb elements of its environment is a strong case for eating only organic mushrooms from known sources. Heavy metals like lead and mercury have been found in edible mushrooms from questionable sources.

Here's a fungus that eat gamma radiation, discovered at Chernobyl: https://en.wikipedia.org/wiki/Radiotrophic_fungus