Connect with us

Hi, what are you looking for?

Tech & Science

Shifting through sewage to get valuable metals

Researchers have discovered that sewage entering municipal wastewater treatment plants contains up to 58 valuable elements, including gold and copper. This has inspired some scientists to consider ways to extract these valuable metals from the sewage.

The finding came after researchers analyzed treated sewage samples from 94 sites around the U.S. Checking through the sewage was a dirty job, Science News notes, and the metals were identified through the use of electron microscopy. Through this the researchers found many rare group elements, platinum group elements, copper and gold.

The value of the metals, based on an extrapolation of the research findings, are remarkable:

$500 million – the approximate value of elements in a metric ton of treated sewage sludge.
$13 million – the approximate value of a year’s worth of sewage from 1 million people.

As to the sources of these metals (which people will have ingested), the research team speculate that the gold could be coming from dentists’ offices, bakeries, gold plated items and industrial waste; whereas copper could derive from tainted water held in copper pipes.

The findings have been published in the journal Environmental Science & Technology. The paper is called “Characterization, Recovery Opportunities, and Valuation of Metals in Municipal Sludges from U.S. Wastewater Treatment Plants Nationwide.”

The discovery may not herald a new gold rush era but it does signal the start of “nano-prospecting”, as nanotechnology is used to hunt for rare metals. Here, various sources are being looked at. For example, a waste treatment centre in Japan recorded 1,890 grams of gold per tonne of ash from incinerated sludge as compared to the 20 – 40 grams of gold per tonne of ore recovered from one of the world’s top producing gold mines.

One of the drivers to look for small quantities of rare metals is antibacterial action. Tiny quantities of materials such as silver, titanium, silica and platinum are being used in fabrics, clothing, shampoos, toothpastes, tennis rackets and even food products to provide antibacterial protection.

Avatar photo
Written By

Dr. Tim Sandle is Digital Journal's Editor-at-Large for science news. Tim specializes in science, technology, environmental, business, and health journalism. He is additionally a practising microbiologist; and an author. He is also interested in history, politics and current affairs.

You may also like:

Social Media

Wanna buy some ignorance? You’re in luck.

Business

United Airlines CEO Scott Kirby said the carrier was reviewing recent incidents and would redouble safety initiatives as needed - Copyright AFP Logan CyrusUnited...

World

US President Joe Biden speaks during a reception honoring Women's History Month at the White House - Copyright AFP Brendan SMIALOWSKIDanny KEMPUS President Joe...

Business

A Milei marks 100 days in office, thousands protest his austerity measures - Copyright AFP Luis ROBAYOLeila MACORArgentina’s President Javier Milei has slashed public...