A team of U.S. researchers has given the expression “where there’s muck there’s brass” a whole new meaning by claiming you can extract gold and other precious metals from human faeces.
According to their research, presented at the national meeting of the American Chemical Society, the microscopic particles of gold, lead, copper and other valuable metals found in biosolids could be worth “mining.”
So far the group has already identified gold in waste from American sewage treatment plants at levels which if found in rock would be seen as commercially viable by traditional prospectors.
Lead by Kathleen Smith of the U.S. Geological Survey, the team of researchers initially set out to find better ways of extracting foreign particles from human waste. They realized that once it is treated, about half of it (3.5 million tons in the U.S. to be exact) is used to fertilize farms and forests across the country.
What Smith and her team want is to get those metals — which get into our waste by way of their presence in cleaning agents, beauty and hygiene products, and clothing — out of this end-product and instead, turn them into fertilizer and reusable metals.
The team has a two-pronged approach. In one part of the study, they will continue looking at removing some regulated metals from the biosolids that limit their use for land application.
In the other phase, they are interested in collecting valuable metals that could be sold, including some of the more technologically important metals, such as vanadium and copper that are in cell phones, computers and alloys.
A similar study published earlier this year in the journal Environmental Science and Technology estimated that the waste from one million Americans could contain as much as US$13 million worth of metals.