There’s Gold In Them Thar Poop

The members of the American Chemical Society must be very curious people.  For example, a presentation at the most recent national meeting of the ACS addressed the prospects for recovery of gold, silver, copper, vanadium, palladium, and other precious metals that are found in . . . human waste.

According to a BBC report, the ACS presentation concluded, through a study that must have been incredibly disgusting to conduct, that gold is found in waste from American sewage treatment plants at the same levels found in a minimal mineral deposit. A prior study had found that the waste from 1 million Americans includes about $13 million in rare metals, and scientists are evaluating whether an extraction process using certain leaches could be applied to the solid waste produced by waste water treatment plans to see whether the rare metals could be pulled out, presumably cleaned up, and then sold.

The concept of extracting metals from solid waste is similar to the notion of “mining” metals from landfills and waste dumps.  Some experts estimate that landfills contain billions of dollars in metals, if they could just figure out an economical way to separate the metals from the disposable diapers and other vile items that have American landfills filled to the brim.  Already some “landfill mining” operations are underway.

Metals, if improperly disposed of, can be environmentally damaging, so I’m all in favor of any process that results in more complete recycling — even if it means sifting through smelly tons of human waste.  The BBC story about the ACS presentation left unanswered my central question about this issue, however:  how in the world does gold and vanadium get into the human digestive system, and its end product, in the first place?