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A new way to recycle plastic

April 18, 2025 By EarthWise Leave a Comment

Researchers at Northwestern University have developed a new method for recycling plastic that is safer, cleaner, cheaper, and more sustainable than those currently in use. The U.S. is the world’s largest plastic polluter per capita, and we only recycle 5% of our plastics. There is a pressing need for better technologies for processing different types of plastic waste.

The Northwestern method is designed to break down polyethylene terephthalate or PET, which is the most common type of polyester plastic. PET plastic is used in food packaging and beverage bottles and represents 12% of total plastics used globally. It does not break down easily and is therefore a major contributor to plastic pollution. It mostly either ends up in landfills or, over time, degrades into tiny microplastics or nanoplastics that end up almost everywhere.

The non-toxic, environmentally friendly, solvent-free Northwestern process first uses an inexpensive molybdenum catalyst to break apart the bonds in PET. Then the broken plastic is exposed to ambient air. Just from the trace amounts of moisture in air, the broken-down PET is converted into monomers, which are the building blocks of plastic. The monomers could then be recycled back into PET products or used to make other valuable materials.

The process is fast and effective and takes just a few hours. The catalyst is durable and recyclable, meaning it can be used over and over again. It only works on polyesters, which means it can be used for recycling mixed plastics without sorting them since it will select only the PET from its inputs.

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Plastic recycling gets a breath of fresh air

Photo, posted August 10, 2013, courtesy of Lisa Risager via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Microplastics in Antarctica

March 3, 2025 By EarthWise Leave a Comment

Microplastics are small plastic pieces less than five millimeters long and typically far smaller than that. They come from a variety of sources, often from larger plastic debris that degrades into smaller and smaller pieces. There are also microbeads, which are tiny pieces of manufactured polyethylene plastic that are added to various health and beauty products. Tiny bits of plastic easily pass through filtration systems and end up in the ocean and other bodies of water.

Microplastics are a pervasive problem for which nowhere on Earth is truly untouched. Despite stringent regulations on materials entering Antarctica, scientists have discovered microplastics in the snow near some of the deep field camps there.

A study by the British Antarctic Survey made use of a new and advanced technique that can detect microplastics as small as 11 microns – about the size of a red blood cell.

The research team found microplastics at concentrations ranging from 73 to 3,099 particles per liter of snow.

Snow samples from three different sites identified polyamide (used in textiles), polyethylene terephthalate (found in bottles and packaging), polyethylene, and synthetic rubber. The results suggest that at least the polyamide, which accounted for half the microplastics found, came from local sources.

Additional research is needed to fully understand the sources of microplastic pollution in Antarctica and to understand the broader implications of microplastics in that frozen wilderness. Microplastics have already been detected in several penguin, seal, and fish species.

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Microplastics discovered in Antarctica

Photo, posted February 3, 2015, courtesy of Christian Stangl via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Increasing plastic recycling

August 15, 2024 By EarthWise Leave a Comment

Recycling plastic is a complicated matter. There are many different types of plastic and knowing which things are made of which type isn’t easy. There are increasingly widespread recycling systems across the U.S., but the actual rates of recycling have been described as “abysmal”.

The plastic commonly used in beverage bottles is polyethylene terephthalate, or PET. The present nationwide rate of recycling PET is about 24% and has been about at that level for a decade.

A new study by MIT has found that with a nationwide bottle deposit program, the rates could increase to 82%. At that level, nearly two-thirds of all PET bottles could be recycled into new bottles at a net cost of just a penny a bottle.

The study looked at PET bottle collection and recycling rates in different states as well as other nations with and without bottle deposit policies, and with and without curbside recycling programs. The study is the first to look in detail at the interplay between public policies and the detailed end-to-end aspects of the packaging, production and recycling market.

Recycling of PET is highly successful in terms of quality. New products made from all-recycled material is virtually indistinguishable from virgin material. The crucial bottleneck is the collection of sufficient amounts of material to meet the needs of processing plants. So, the conclusion of the study is that with the right policies in place, significant improvements can be made. Several European countries manage to collect more than 90% of PET bottles for recycling. So, it can be done.

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How to increase the rate of plastics recycling

Photo, posted August 10, 2013, courtesy of Lisa Risager via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Humans And Microplastics | Earth Wise

April 13, 2022 By EarthWise Leave a Comment

While plastic comes in all different shapes and sizes, those that are less than five millimeters in length are called microplastics. Primary sources of microplastics include microfibers from clothing, microbeads, and plastic pellets (known as nurdles). Secondary sources of microplastics come from larger plastic debris, like bottles and bags, that degrades into smaller bits over time.

Microplastic pollution can be found everywhere on earth, from the top of the tallest mountains to the bottom of the deepest oceans. Microplastics are in the food we eat, the water we drink, and the air we breathe.

According to research recently published in the journal Exposure & Health, humans ingest an average of five grams of plastic particles per week. This is roughly equivalent to the weight of a credit card. The plastic particles are trafficked in via food, such as seafood and salt in particular, as well as water. In fact, those who rely on plastic bottled water for their drinking needs ingest an additional 1,700 plastic particles each week.

Microplastics have also been detected in human blood for the first time. According to new research recently published in the journal Environment International, scientists detected microplastics in nearly 80% of the people they tested.

Half of the blood samples contained PET plastic, which is commonly used for drinking bottles. One third of the blood samples contained polystyrene plastic, which is often used for food packaging. One quarter of the blood samples contained polyethylene plastic, which is used to make things like shopping bags and detergent bottles.

With plastic production predicted to double by 2040, more research is urgently needed to understand how ingesting microplastics affects human health.

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Health risk due to micro- and nanoplastics in food

Microplastics found in human blood for first time

Discovery and quantification of plastic particle pollution in human blood

Photo, posted November 3, 2012, courtesy of Laura via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Heat And Plastic Bottles

August 21, 2019 By EarthWise Leave a Comment

In the middle of July, Americans along the East Coast and in the Midwest suffered through a massive heat wave that saw actual temperatures soaring and so-called feels-like temperatures go much higher. The punishing heat had many of us reaching for those plastic water bottles all day long as we tried to keep hydrated.

Studies have shown that those single-use plastic bottles do not handle the heat very well. Most plastic items release tiny amounts of chemicals into the beverages or food that they contain. But the hotter it gets, the more the substances in plastic can move into food or drinking water. As temperature and time increase, the chemical bonds in plastics increasingly break down and chemicals are more likely to leach.

A study at Arizona State University in 2008 looked at how heat sped up the release of the element antimony in bottles made of the common plastic PET. Antimony is used to manufacture the plastic and can be toxic in high doses. At mild temperatures, very little antimony is released. But PET and other plastics can leach a variety of chemicals when exposed to higher temperatures.

According to the FDA, the amounts of chemicals released by plastics are too miniscule to cause health problems. However, scientists are still looking at the long-term effects of using so much plastic. The question is whether all those small doses can eventually add up to something not so harmless. Given that we don’t really know the cumulative effect of being surrounded by plastics in the goods we buy as well as the presence of microplastics in our water, it seems like a good idea to try to limit our exposure when alternatives are available.

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Exposed to extreme heat, plastic bottles may ultimately become unsafe

Photo, posted June 7, 2013, courtesy of Tim Stahmer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Supermaterial From Plastic Waste

December 13, 2018 By EarthWise Leave a Comment

Researchers at the National University of Singapore have created a way to convert plastic bottle waste into an ultralight aerogel material that has multiple potential applications.

An Accidental Plastic Eater

May 29, 2018 By EarthWise Leave a Comment

A couple of years ago, scientists in Japan discovered bacteria at a recycling plant that were breaking down a type of plastic called polyethylene terephthalate, or PET. With the world facing a growing plastic pollution problem, British and American researchers began to study the enzyme that the bacteria were using to try to understand how it works.