Kathleen Smith, with the U.S. Geological Survey, and her team discovered the precious metals. If the metals were in rock form, then the concentrations would be large enough to mined.
The research was presented at the national meeting of the American Chemical Society last week on Monday. The recovery of the gold and other metals may be commercially viable, but it may also be able to decrease the need for mining, which could reduce damage to the environment.
The researchers, are now looking for ways to squeeze the metals out of solid waste.
When feces arrives at a wastewater treatment plant, it undergoes a process which involves separating it into bio-solids, as well as treated water. About half of the bio-solids is either incinerated or sent to landfills, and the other half is used as fertilizer.
The researchers demonstrated that feces running through the sewage beneath a number of Rocky Mountain towns that showed levels of precious metals that were comparable to the precious metals that are found in commercial mines.
The research confirmed a previous study’s findings, which was the sewage produced annually by a million-person city contained more than $10 million of precious metals.
