Just found an article where they are pumping heavy metal toxic soil with edta solution. They then extract the solution which picks up the toxic metals and they are able to separate them from the edta to be used again. Just be aware that after your plants are delivered their dose of what’s usually iron that the edta is going back for seconds and thirds and oops no more iron whats next. When synthetically feeding your plants take careful consideration in sourcing and testing for heavy metals. Most companies have test results posted online and material safety data sheets will let you know which chelates are used for sure.