Cleaning The Oceans With Sulfur And Orange Peels

An unlikely pair—sulfur and orange peels—form a new material that can absorb toxic mercury from both the ocean and the soil.

AsianScientist (Nov. 2, 2015) – A brand new, dirt cheap, non-toxic polymer that literally sucks mercury out of water and soil is set to become a game changer in the battle against one of the world’s most reviled pollutants—mercury. This finding was published in Angewandte Chemie.

Mercury pollution occurs as a consequence of a number of industrial activities, including mining and the burning of fossil fuels, and mercury levels in the ocean have tripled since the beginning of the Industrial Revolution. Mercury contaminates fish and seafood, entering the human food chain where it has been linked to health problems, and lower IQ in children. Mercury also compromises the reproductive health of birds and fish.

This has significant implications for human health and wellbeing as mercury exposure—whether through the skin or through ingestion, such as eating contaminated fish, is proven to damage the central nervous system and is particularly dangerous to pregnant women and children.

“Mercury contamination plagues many areas of the world, affecting both food and water supplies and creating a serious need for an efficient and cost effective method to trap this mercury,” said Dr. Justin Chalker from Flinders University.

Until now, there has been no such method, but a new sulphur-limonene polysulfide developed by Chalker and colleagues addresses this urgent need.

The dark red material is made from the industrial waste products sulphur and limonene and turns bright yellow when it absorbs mercury.

Chalker said that the new polymer is cheap to produce due to the global abundance of waste sulphur and limonene. That makes it affordable for use in large-scale environmental clean-ups, to coat water pipes carrying domestic and waste water, and even in removing mercury from large bodies of water.

“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,” added Chalker.

Another bonus that comes with Chalker’s polymer is that it has been found to remove toxic metals from water—and even in small amounts can be used as a mercury detector in areas where pollution is suspected because of the chemical reaction, which causes it to turn yellow.

The article can be found at: Crockett et al. (2015) Sulfur-Limonene Polysulfide: A Material Synthesized Entirely from Industrial By-Products and Its Use in Removing Toxic Metals from Water and Soil.


Source: Flinders University; Photo: Shutterstock.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

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