If you’re anything like us, watching Blue Planet and hearing David Attenborough discuss the extent of human-caused plastic pollution in our oceans makes for difficult viewing.
In fact it is now estimated that every square mile of ocean contains 46,000 pieces of floating plastic and more than 12 million tonnes of new waste enter the sea every year, according to the UN Environment Programme.
As a result more than a million birds and 100,000 sea mammals and turtles die every year from eating and getting tangled in plastic waste.
But now a new study from the University of Houston has confirmed that addressing this issue has become a “key priority” for emerging technologies.
Less than 30% of plastic is recycled Europe (the figure in the USA is only 9%) and changing this will not only be beneficial for the environment, but could also have economic advantages as it is estimated that recycling all global plastic solid waste could save a huge $176 billion.
Professor Megan Robertson said: “[New research] raises hope that before long, recycling rates for plastics will be much higher than today.”
Scientists are working on a two-strand approach, the first of which will involve developing new plastics that are more easily recycled.
Robertson’s team are looking at making thermoset plastics out of bio-renewable components made from vegetable oils or other plant-based materials. This could lead to new end-of-life options such as composting or chemical recycling.
The second approach is looking at more efficient ways of recycling plastics that already exist, as Robertson says: “New materials enter the market slowly, and thus the biggest impact is in developing more efficient methods to recycle the plastics that are produced in large quantities today.”
Currently plastics must be sorted for recycling, because polymers are comprised of large molecules, so most don’t mix when heated, similar to the interaction between oil and water.
This process of sorting each into a separate waste stream before it can be recycled adds effort and expense, meaning plastics are less likely to be recycled.
Now research is focused on finding substances that can facilitate the mixing of different types of plastics, known as compatibilizers, allowing them to be recycled together. Finding a compatibilizer that works for all polymers would be ideal.
“Enhancing plastics recycling beyond the current level has many potential societal advantages, such as reducing greenhouse gas emissions, avoiding waste buildup in the environment, decreasing the dependence on finite petroleum resources for its production, and recovering the economic value of plastic solid waste,” said Robertson.