A team of researchers from Australia has developed a material that combines waste from the citrus and petroleum industries and can be used to draw out mercury from water and soil.
Considered by the World Health Organisation as a chemical of major public health concern, mercury can have detrimental affects on humans and the environment and is most often released via mining, the burning of coal and waste incineration. Man-made pollution has seen mercury levels in the ocean triple since the Industrial Revolution. Consequently, humans are most often exposed to the organic compound methylmercury via the consumption of fish and shellfish. Exposure to mercury can affect the central nervous system, lungs, kidneys, neurological development and is particularly harmful to foetuses who are exposed to it through their mother. The rise in the amount of electronic devices (many of which contain mercury) being improperly disposed of in landfills is also leading to mercury seeping into the ground and contaminating the soil.
Researchers from Flinders University in Australia have created a polymer out of sulphur (a waste product produced by the petroleum industry) and limonene (a by-product of the citrus industry) that turns yellow when it comes into contact with mercury and sucks it out of water and soil.
The development represents a cost-effective method for trapping and eliminating mercury from water supplies and soil and could be put to use to assist large-scale environmental clean ups, coat water pipes that carry domestic and waste water and could even remove mercury from large bodies of water.
And it does so by 'recycling' waste materials that already exist in abundance. In a blog post on the university's website, lead scientist behind the project, Dr. Justin Chalker, stated:
“More than 70 million tonnes of sulphur is produced each year by the petroleum industry, so there are literally mountains of it lying, unused, around the globe, while more than 70 thousand tons of limonene is produced each year by the citrus industry (limonene is found mainly in orange peels). So not only is this new polymer good for solving the problem of mercury pollution, but it also has the added environmental bonus of putting this waste material to good use while converting them into a form that is much easier to store so that once the material is ‘full’ it can easily be removed and replaced.”
The polymer can also be used to remove smaller amounts of other toxic chemicals from water. Find out more about the project via the Flinders University website.