[thfuran]

>heavy metal removal. If you do nothing at all, natural bacteria and fungi in the environment will do the remediation - so maybe just mix in some substrate, turn the soil and let nature do the rest.

And where exactly will the bacteria send the heavy metal?

[Pine_Mushroom]

This is beyond my expertise, but here is a quote from a paper on the subject:

"Bacteria have several methods of processing heavy metals through general resistance mechanisms, biosorption, adsorption, and efflux mechanisms. Bacillus spp. are model Gram-positive bacteria that have been studied extensively for their biosorption abilities and molecular mechanisms that enable their survival as well as their ability to remove and detoxify heavy metals. This review aims to highlight the molecular methods of Bacillus spp. in removing various heavy metals ions from contaminated environments."

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8402239/