The sweet side of sulphur: cheap mercury clean-up

A cheap and simple material, using sulphur from petroleum industry waste and plant oils from the food industry, is being tested to clean up mercury pollution from soil and water.

The rubbery material will undergo field tests in 2017 in Australian mining and sugarcane sites, the latter of which use fungicides that contain mercury.  The work is supported by funding from the National Environmental Science Programme’s emerging priorities funding.

“Our technology is about as simple as it can get: mix sulphur with plant oils and heat, then add the resulting material into the contaminated area,” says lead researcher Dr Justin Chalker, of Flinders University.

Pellets of the material can be put into pipes, water filters or tanks, or milled into contaminated earth. Toxicity testing has shown that the material is non-toxic even once it has bound with the toxic metal—essentially neutralising the mercury.

“Our long-term goal is to see it used in mine sites in developing countries where liquid mercury in small-scale gold mining is widespread.

“In these mines, liquid mercury is used to extract gold from ore. To isolate the gold, the mixture that forms is often processed by hand without any safety precautions, and burned to vaporise the mercury. Toxic waste can also end up in rivers.

“Approximately 15 million people—including child-miners—are involved in this practice globally, with developing nations disproportionately affected,” Justin says.

Mercury can do severe damage to the nervous system and cause developmental defects in developing babies. It can also be deadly.

Justin and his laboratory and collaborators are working with several non-profits internationally, in the hope of providing an environmentally friendly solution that’s far cheaper than any mercury-capture technology currently available.  

PhD student Max Worthington (left) and Justin examine one form of the mercury-binding material. Credit: Ashton Claridge

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Flinders University
Justin Chalker