Mercury removal is easy in toxic environments

Mercury pollution is a global problem of water, air and soil near gold mines, cement and some metals, and other heavy industries that burn fossil fuels, with removal too expensive or difficult in some of the world’s poorest countries.

Flinders University has now expanded its testing of a stable extraction material capable of absorbing almost all of the mercury in contaminated water in minutes – made entirely of inexpensive waste oil, citrus and agricultural production.

In fact, tests showed almost complete absorption of mercury within minutes under test conditions, say senior author Professor Justin Chalker and his colleagues in an article in a new journal published by the Royal Chemical Society.

“Research shows that this mercury-binding material, invented at Flinders University, is very fast in its ability to remove mercury from water. In some cases, more than 99% of mercury is captured in just a few minutes,” says Professor Chalker.

Co-author of the Chalker Lab, Dr. Max Worthington, says the testing was conducted on a new material created by coating silica with sulfur and limonene – a new chemical combination that effectively absorbs mercury waste.

“This silica, coated with an ultra-thin coating of poly (Sr-limonene), using sulfur left over from oil production and orange oil from orange peel discarded by the citrus industry, has been extensively tested at various pHs and salt concentrations,” he says. . .

“This new mercury sorbent is not only able to bind quickly to mercury in water, but is also selective in mercury uptake, but not to other metallic contaminants such as iron, copper, cadmium, lead, zinc and aluminum.”

Importantly, this means that only mercury will bind to the orange-sulfur sorbent, which helps in safety after the capture of inorganic mercury, adds co-author Dr. Max Mann of Chalker Laboratory at Flinders University.

“The particles contained in just 27 g of this loose orange powder have an approximate surface area of ​​the football field and can be quickly produced in large enough volumes to match the level of contamination,” he says.

Chalker Lab Ph.D. Candidate Alfretz Ticaalu says silica derived from agricultural wastes such as wheat or rice production can also be used to make the material even more sustainable.

“This mercury rehabilitation technology can become a circular economy for a more sustainable world because this value-added material is made entirely from waste,” he says.

To support the findings, mathematical modeling was used to qualitatively understand the rate of mercury uptake – data that are critical to measuring and optimizing a new sorbent in rehabilitation.

“This is an interesting new development in creating renewable and affordable solutions to the major environmental challenges facing the world today,” says applied mathematician Dr. Tony Miller, another co-author of the publication in Physical Chemistry Chemistry Physics.

The project is “an excellent example of cooperation in the field of chemical and physical sciences and math to understand the rate of mercury uptake by our new innovative sorbent, ”says Professor Chalker.

Article “Simulation mercury sorption of polysulfide coating of sulfur and limonene ”, published in Physical Chemistry Chemistry Physics.