Gold in faeces 'is worth millions and could save the environment'
http://www.theguardian.com/science/2015/mar/23/gold-in-faeces-worth-millions-save-environment
Geologist suggests extracting precious metals from human waste would keep harmful substances out of the ground – and recover valuable objects
People could be flushing gold – and other precious metals – down the toilet.
Fortunes could be saved from going down the drain by extracting gold and precious metals from human excrement, scientists suggest.
Sewage sludge contains traces of gold, silver and platinum at levels that would be seen as commercially viable by traditional prospectors. “The gold we found was at the level of a minimal mineral deposit,” said Kathleen Smith, of the US Geological Survey.
Smith and her colleagues argue that extracting metals from waste could also help limit the release of harmful metals, such as lead, into the environment in fertilisers and reduce the amount of toxic sewage that has to be buried or burnt.
“If you can get rid of some of the nuisance metals that currently limit how much of these biosolids we can use on fields and forests, and at the same time recover valuable metals and other elements, that’s a win-win,” she said.
A previous study, by Arizona State University, estimated that a city of 1 million inhabitants flushed about $13m (£8.7m) worth of precious metals down toilets and sewer drains each year.
The eight-year study, which involved monthly testing of treated sewage samples, found that 1kg of sludge contained about 0.4mg gold, 28mg of silver, 638mg copper and 49mg vanadium
http://www.theguardian.com/science/2015/mar/23/gold-in-faeces-worth-millions-save-environment
Geologist suggests extracting precious metals from human waste would keep harmful substances out of the ground – and recover valuable objects
People could be flushing gold – and other precious metals – down the toilet.
Fortunes could be saved from going down the drain by extracting gold and precious metals from human excrement, scientists suggest.
Sewage sludge contains traces of gold, silver and platinum at levels that would be seen as commercially viable by traditional prospectors. “The gold we found was at the level of a minimal mineral deposit,” said Kathleen Smith, of the US Geological Survey.
Smith and her colleagues argue that extracting metals from waste could also help limit the release of harmful metals, such as lead, into the environment in fertilisers and reduce the amount of toxic sewage that has to be buried or burnt.
“If you can get rid of some of the nuisance metals that currently limit how much of these biosolids we can use on fields and forests, and at the same time recover valuable metals and other elements, that’s a win-win,” she said.
A previous study, by Arizona State University, estimated that a city of 1 million inhabitants flushed about $13m (£8.7m) worth of precious metals down toilets and sewer drains each year.
The eight-year study, which involved monthly testing of treated sewage samples, found that 1kg of sludge contained about 0.4mg gold, 28mg of silver, 638mg copper and 49mg vanadium
