Plastic pollution has reached pandemic levels around the world, and the colossal amounts of plastic waste pose serious risks to the health of ecosystems, both on land and in the oceans. It is also a threat to human health, as microplastics have permeated our food and water, and even our table salt.
There is little that can be done about the vast amount of plastic already in the oceans, but there is still a lot we can do to ensure that we don't add much more plastic waste.
The good news is that several promising initiatives are underway.
One involves the use of chemical recycling. This advanced recycling process, explains Alvin Orbaek White, professor at Swansea University School of Engineering, “breaks down plastic at the molecular level, making platform molecules available that can then be used to make other materials. They are the first days for this idea, but, in principle, it could open up a wide range of opportunities ”.
Meanwhile, China, the world's leading plastic polluter, is working on ways to reuse plastic waste as fuel in its massive cement industry as part of a Norwegian project called Ocean Plastic turned into a circular economy opportunity (OPTOCE).
“Globally, 5 to 13 million tons of plastics end up in the oceans each year. Plastic waste is transported by ocean currents, sometimes over very long distances. It can wash ashore, degrade into microplastics or form dense areas of marine debris trapped in ocean gyres, ”OPTOCE explains on its website.
"UNEP estimates that damage to marine environments is at least USD 8 billion per year globally," the initiative adds.
However, much of this plastic waste can be used as fuel in the manufacture of cement, which involves heating limestone in large kilns at temperatures of 1,450 degrees Celsius until it liquefies. The widely used fuel is coal, of which cement factories burn half a trillion tons every year across the globe. Some of this large amount of carbon could be replaced by non-recyclable plastics.
The potential for plastic waste as an alternative fuel in the cement industry is "huge," according to Kåre Helge Karstensen, a senior research scientist leading the OPTOCE project. "However, even if Asia's cement factories can burn up to 160 million tons of plastic garbage each year, they will only replace 10 to 15 percent of their industrial coal consumption," he stresses.
In five pilot projects in Asia, OPTOCE is using garbage from landfills as industrial fuel. “It is crucial that both the industry itself and the [local] authorities recognize the opportunities that the use of plastic waste offers,” says Karstensen.
“We now have cement factories in China, India, Thailand, Vietnam and Myanmar participating in the project. All of them are testing the use of plastic as fuel. All that remains is to document the environmental and business benefits, ”he adds.
Those benefits could potentially be considerable as these and other Asian countries are the worst plastic polluters in the world.
At the same time, scientists are also creating new, greener types of polymers. A team of chemists at Cornell University in the United States, for example, has developed a new polymer that degrades rapidly when exposed to ultraviolet radiation from the sun.
The new polymer could be used in fishing gear like ropes and nets, which typically end up in the oceans. They then remain there for decades while wreaking havoc on coral reefs and a myriad of sea creatures.
“We have created a new plastic that has the mechanical properties required by commercial fishing gear. If eventually lost to the aquatic environment, this material can degrade on a realistic time scale, "says lead researcher Bryce Lipinski, whose team has spent 15 years developing the new polymer called isotactic polypropylene oxide.
Objects made from the new plastic could degrade rapidly in nature, without leaving a trace, the researchers say. "This material could reduce the persistent build-up of plastic in the environment," says Lipinski.