Ran across this online:
"Researchers at Arizona State University estimate that in a city of one million people, $13 million dollars worth of metals could be accumulating annually in sludge, the byproduct of treated sewage.
The study, which analyzed sludge from treatment centers in Arizona and samples from across the country stored at the U.S. National Biosolids Repository, focused on 13 minerals with the highest value, including gold, silver, copper, and platinum. If every bit of the metals is retrieved, researchers reported there could be $280 per ton of sludge."
Full article here:
There
I think some of the minds on here could come up with a way to process this material!
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