SCIENTISTS DEVELOP WASTE COOKING OIL TO PREVENT MERCURY POLLUTION

Waste cooking oil from cafes and fast food outlets is being used to capture mercury pollution from Australian mine sites and industrial plants, according to a report in FoodNavigator.com last week.  Mercury leaching into the environment through mining and burning fossil fuel can be a biological disaster, and will soon be regulated by a United Nations convention to prevent harm to humans.  The technology was developed at Flinders University by a team of chemists led by Justin Chalker and is being tested at mine sites as plans for commercial production take shape.  

The team developed a polymer called sulfur-limonene polysulfide (SLP) from orange oil in 2015 to tackle the issue.  However, the relatively high cost of SLP, its limited application and lack of durability to handle a serious field trial meant the team needed alternatives.  They found canola waste cooking oil a cheap alternative.  Moreover, it is more durable as it survives higher temperatures and can capture a much more diverse range of mercury species like the ones encountered in the field.

The new polymer only has two ingredients, second hand canola oil and sulphur a common, low-cost by product from petroleum production.  It can be used in remediation of soil, water and air.  After absorbing mercury pollution, the rubber-like polymer changes colour from brown to black to indicate the job is done.  The mercury remains permanently bound in the polymer and can be safely stored without further environmental risk.  Dr. Chalker said the team had shown that the canola oil-based sulphur polymer could capture organic mercury, inorganic mercury, mercury of metal and the gaseous form of mercury.