Waste tuned for mercury removal
Researchers have come up with a better way to remove mercury from the environment.
Mercury pollution is a global problem in water, air and soil near goldmines, cement and some metal production, and other heavy industries burning fossil fuels – with removal too expensive or difficult in some of the poorest countries in the world.
Now Flinders University experts have expanded testing of a sustainable extraction material capable of absorbing almost all mercury in polluted water in minutes – itself made entirely from low-cost waste from petroleum, citrus and agricultural production.
The tests have shown almost total absorption of mercury within minutes in trial conditions, says senior author Professor Justin Chalker.
“It is clear from the study that this mercury-binding material, invented at Flinders University, is ultra-fast in its ability to remove mercury from water. In some cases, more than 99 per cent of the mercury is captured in just a few minutes,” says Professor Chalker.
Chalker Lab co-author Dr Max Worthington says testing was done on a new material created by coating silica with sulphur and limonene – a novel chemical combination already shown to effectively absorb waste mercury.
“This silica covered with an ultra-thin coating of poly(S-r-limonene), using sulphur left over in petroleum production and orange oil from orange peel discarded by the citrus industry, was extensively tested in various pH and salt concentrations,” he says.
“Not only is this new mercury sorbent able to rapidly bind to mercury in water, but is also selective in taking up mercury but not other metal contaminants such as iron, copper, cadmium, lead, zinc and aluminium.”
Importantly this means that only mercury will bind to the orange-sulphur sorbent, which helps with safety after capturing the inorganic mercury, adds co-author Dr Max Mann from the Flinders University Chalker Lab.
“The particles contained in just 27g of this free-flowing orange powder has an approximate surface area of a soccer field, and it can be quickly produced in large enough volumes to suit contamination levels,” he says.
More details are accessible here.