New Tech Gets Gold From Wastewater

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Precious metals could be extracted from wastewater. The water we're talking about comes from recycling plants, where the process involves dissolving components in acid and water. That leaves small concentrations of precious metal in the water. Typically, this water is treated but most methods don't extract the tiny particles of metals left behind because it's been too expensive.

Researchers at Magpie Polymers, a

French start-up company, think they've found a way to do it, though. The group has developed beads of a special resin, based on

polystyrene, that bonds with metals dissolved in water. Passing the water over the resin leaves the metals

behind.

Nanoprinter Achieves Insane Resolution

This accomplishes two things: it removes metals so

they can be used again and it purifyies the water. Etienne Almoric,

administrative and commercial director of the company, told Discovery

News that the resin can get the concentrations down to micrograms per

liter, or parts per billion. For many metals that's below the limits

considered safe to drink by the U.S. Environmental Protection Agency.

It

takes about a quart of the resin to filter out anywhere from five to

ten cubic yards of water, which would yield a few ounces of metal. An

ounce of gold sells for about $1,700 at current prices. But even without

the precious metals, disposing of electronics in an environmentally

friendly fashion will mean removing the toxic ones such as lead in any

case.

Mining Legacy: Tale of a Toxic Town

The

ability to filter out toxic metals is useful for recycling electronics,

but it could also play a role in cleaning up water near, for example,

mines, where huge pools of metal-laden water are often a serious

environmental concern.

Credit: Wikimedia Commons