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Eating To Help The Planet | Earth Wise

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Agriculture accounts for more carbon dioxide emissions than transportation.  Producing our food is one of the largest contributors to climate change.   Experts agree that the world cannot achieve net zero emission targets without changing our diets.  Be that as it may, we still have to eat. 

According to experts from Oxford University, there are things we as individuals can do to lower the impact of the food system on the climate.

There are three primary actions that would have the greatest impact: avoiding eating too much, cutting down on food waste, and reducing consumption of meat and dairy.

We all know that overeating is bad for our health, but it is also bad for the environment as it drives excess production and the emissions associated with it.

Food waste occurs across the supply chain but much of it is in the hands of consumers.  Food waste costs us a lot of money and is associated with emissions that are ultimately unnecessary.  The goal of the consumer should be to buy only the food one needs and to eat what one buys.

Meats, particularly from ruminant animals, result in the highest emissions per pound of food compared with vegetables, grains, and such.  Some people have given up animal proteins entirely, but properly managed livestock are an important part of the agricultural ecosystem and provide valuable services including enhancing the carbon sequestering ability of grasslands.  Nevertheless, it is important to reduce the global demand for meat and thereby prevent the need to clear more land for livestock and reduce emissions from meat animals.  So, we should all eat less meat and dairy even if we don’t become vegetarians.

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How can we eat without cooking the planet?

Photo, posted September 17, 2017, courtesy of Ella Olsson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Better Ways To Make Bioplastics | Earth Wise

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The world produces over 300 million tons of plastics each year, mostly produced from petroleum.  The environmental consequences are substantial and there is a critical need to replace as much of that plastic production with biodegradable plastics as possible.  Thus, there is global research aimed at making bioplastics more economical and as environmentally friendly as possible.

Researchers at Texas A&M University have developed an improved approach for making bioplastics from corn stubble, grasses, and mesquite agricultural production.  Apart from the obvious environmental benefits of having biodegradable plastics, producing bioplastics from common agricultural waste would create new revenue streams for farmers as well as the people who transport harvested feedstock and byproduct crops to refinery operations.

The key to bioplastic production is the efficient extraction and use of lignin, the organic polymer that is the primary structural support material in most plants.  The new research takes five conventional pretreatment technologies for plant materials and modifies them to produce both biofuel and plastics together at a lower cost.  The new method is called “plug-in preconditioning processes of lignin” and it can be directly and economically added into current biorefineries.  The process is designed to integrate dissolving, conditioning, and fermenting lignin, extracting energy from it and making it easily adaptable to biorefinery designs.

The so-called bioeconomy currently supports some 286,000 jobs.  Innovation is the key to achieving more widespread use of biodegradable plastic.  With improved economics of so-called lignocellulosic biorefineries, there can be new avenues to use agricultural waste to produce biodegradable plastics.

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‘Plugging in’ to produce environmentally friendly bioplastics

Photo, posted November 5, 2015, courtesy of Kathryn Faith via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Disposable Masks And The Environment | Earth Wise

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The Covid-19 pandemic has made face masks and other personal protective equipment essential for healthcare workers.  Disposable N95 masks became the key requirement to help prevent the spread of the coronavirus.  But the wide use of these masks has both financial and environmental costs.

The pandemic is estimated to generate over 7,000 tons of medical waste each day and much of that is in the form of disposable masks.  Even though the pandemic has slowed down in many places, health care workers are continuing to wear masks most of the time.

A new study at MIT has looked at the financial and environmental cost of several different mask usage scenarios with an eye on trying to reduce the toll created by the continued need for using them.

If every health care worker in the US used a new N95 mask for each patient they encountered during the first six months of the pandemic, the total number of masks required would be over 7 billion, at a cost of over $6 billion and would generate 92,000 tons of waste (the equivalent of 252 Boeing 747 jets.)

Decontaminating regular N95 masks so that health care workers can wear them for more than one day could drop costs and environmental waste by at least 75% compared with using a new mask for every patient encounter. 

Fully reusable N95 masks could offer an even greater reduction in waste, but such masks are not yet commercially available.  MIT researchers are developing a reusable N95 mask made of silicone rubber that contains an N95 filter than can either be discarded or sterilized after use.  They have started a new company with the goal of commercializing the masks.

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The environmental toll of disposable masks

Photo, posted August 4, 2020, courtesy of the U.S. Navy / Mass Communication Specialist 3rd Class Jake Greenberg via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Regulating Plastic Pollution | Earth Wise

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Much of the world is united in the desire to do something about the problem of plastic waste.  But putting in place regulations that transcend national borders is complicated.

One hundred fifteen countries have established bans on plastic bags, but globally, there are seven different definitions of what is considered a plastic bag.  Things like bag thickness can determine whether something even counts as a plastic bag.  These differences create loopholes that enable illegal bags to be used.  For a global company like Nestle, which sells food products in 187 countries, it means complying with 187 different sets of national regulations on plastic packaging.

At least 100 nations have expressed support for a global plastic treaty.  Preliminary talks are dealing with issues like setting a specific date to eliminate plastic from spilling into the ocean, creating a harmonized set of definitions and standards, coordination of national targets and plans, and creating a fund to build waste management facilities where they are most needed in less developed countries.

New plastic waste is created at a rate of over 300 million tons a year.   To date, 75% of all plastic ever produced has become waste, and plastic production is expected to triple by 2050.

With public concern about plastic waste growing and increasing support by countries around the world, there is growing optimism that a global treaty to address plastic waste could be approved on a pace that could make a difference.  Negotiations for international treaties can drag on for a decade or more.  There is not that kind of time to spare in this case, so perhaps urgency will drive more efficient action.

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Global treaty to regulate plastic pollution gains momentum

Photo, posted February 3, 2015, courtesy of Thad Zajdowicz via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Infinitely Recyclable Plastic | Earth Wise

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The glut of plastics is one of the world’s most challenging environmental problems.  The average American generates over 200 pounds of plastic waste each year and most of that ends up in landfills.  Researchers around the globe continue to work on potential solutions to the plastic waste problem.

Two years ago, scientists at Lawrence Berkeley National Laboratory announced the invention of a new plastic that could be an answer to the plastic waste problem.  The material is called polydiketoenamine or PDK and it differs from traditional plastics in a very important way:  it can be recycled indefinitely with no loss in quality because it can easily be broken down into its constituent component monomers and be used to make brand new plastic.

Only a small percentage of plastics are currently recycled.  When many plastics are melted down together, the polymers are mixed with a slew of incompatible additives, resulting in a new material with much lower quality than newly produced plastic.  As a result, less than 10% of plastic is recycled more than once.

Recently, the Berkeley Lab researchers released a study that shows what could be accomplished if manufacturers began using PDKs on a large scale.  They determined that PDK-based plastic could quickly become commercially competitive with conventional plastics and, furthermore, would get less expensive and more sustainable as time goes on.

PDK is starting to draw interest from companies needing to source plastic.  The best initial application for PDKs are markets where manufacturers have the most access to products at the end of their lifespans such as in the automobile industry and consumer electronics.  Making plastics part of a circular economy is a challenging task.

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The Future Looks Bright for Infinitely Recyclable Plastic

Photo, posted April 19, 2021, courtesy of Ivan Radic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Cleaner Water Using Corn | Earth Wise

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Corn is the largest agricultural crop in the U.S., and it is also one of the most wasteful.  About half of the harvest ends up as stover – corn stalks, leaves, husks, and cobs – once the kernels are used for food.

Corn stover has relatively few commercial or industrial uses.  It can be used to produce biofuel, but that is not very energy efficient.  It is sometimes used as a low-quality livestock feed as well.  Mostly, it is just burned if it is used at all.

Researchers at the University of California Riverside have developed an energy-efficient way to make good use of stover by transforming it into activated carbon for use in water treatment.

Activated carbon – often called activated charcoal – is an organic material that is specially treated to contain millions of microscopic pores that make it highly absorbent.  It has many industrial uses, the most common of which is for filtering pollutants out of drinking water.  Most household water filters such as Brita filters as well as the ones built into refrigerators make use of activated carbon.

The Riverside researchers explored methods for producing activated carbon from charred corn stover and found that processing the material with hot compressed water – a process known as hydrothermal carbonization – produced highly absorbent activated carbon with superior properties compared to material produced by slow pyrolysis, where corn stover is charred at increasing temperatures over a long period of time.

According to the researchers, it is important to create approaches that convert waste into high-value materials, fuels, and chemicals in order to create new value streams and eliminate the environmental harm that comes from a so-called “take-make-dispose” economic model.

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Cleaner Water Through Corn

Photo, posted September 15, 2010, courtesy of the United Soybean Board / the Soybean Checkoff via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Breaking Down Polystyrene | Earth Wise

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The proliferation of global plastic waste continues to be a growing problem for the world.  Hundreds of millions of tons of plastics are produced each year and most of it is used once and then discarded.  The properties that make plastics so attractive – durability and chemical stability – make it difficult to do anything with discarded plastics other than deposit them in landfills – where they don’t easily degrade over time – or burn them, which dumps carbon dioxide and various hazardous gases into the atmosphere.

Polystyrene is one of the most widely used plastics.  It is found in foam packaging materials, disposable food containers, plastic cutlery, storage containers, and many other places. 

Recycling plastics like polystyrene is generally not economically feasible.  Sorting plastics by type is time and labor intensive and the chemical processes required to break down plastics into usable precursor materials require significant energy input and the use of toxic solvents.

Recently, a team of scientists at Ames Laboratory in Iowa has developed a process based on ball-milling that deconstructs commercial polystyrene in a single step, at room temperature, in ambient atmosphere, and in the absence of harmful solvents.

Ball-milling is a technique that places materials in a milling vial with metal ball bearings which is then agitated to initiate a chemical reaction.  This approach is known as mechanochemistry.

The method represents an important breakthrough that enables dismantling of a polymer that includes its chemical breakdown without requiring solvents or the high temperatures generally needed to thermally decompose it.  This discovery opens up new avenues for low-temperature recovery of monomers from polymer-based systems that include composites and laminates.  It could be a very useful weapon in the battle against plastic waste.

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Polystyrene waste is everywhere, and it’s not biodegradable. Scientists just found a way to break it down.

Photo, posted December 11, 2010, courtesy of Warrenski via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Paving With Plastic | Earth Wise

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The country of Ghana has an ambitious plan to recycle and reuse as much plastic waste as it produces each year (which is over a million tons) by 2030.  As part of this plan, they have started to pave roads in Accra, the capital city, with asphalt containing a slurry of used plastics – shredded and melted bags, bottles, and snack wraps.  Only a quarter of Ghana’s roads are currently paved, so waste plastic has many opportunities for use in paving.

Plastic roads first appeared in India two decades ago.  There are now over 60,000 miles of them in that country.  Several countries have only recently built their first plastic roads including South Africa, Vietnam, Mexico, the Philippines, and the United States.

Studies have shown that roads containing waste plastic have the potential to perform as well or better than traditional roads.  They can last longer, can tolerate wide temperature swings better, are stronger and more durable, and are more resistant to water damage, cracking, and potholes.

Ordinarily, asphalt for roads consists of 90 to 95% aggregate – typically some mixture of gravel, sand, and limestone – and 5 to 10% bitumen, which is a black gooey substance extracted from crude oil that binds the aggregate together.  Plastic-enhanced roads replace varying amounts of the bitumen (often as little as 4-10%, but sometimes much more), with plastic that is actually a stronger binding agent.

Plastic roads reduce the amount of bitumen in roads, thereby reducing carbon emissions.  The plastics are not heated enough to release gases and the roads do not appear to shed microplastics.  Plastic roads will not solve the world’s plastic waste problem, but they can help by diverting lots of plastic from landfills.

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How Paving with Plastic Could Make a Dent in the Global Waste Problem

Photo, posted June 4, 2010, courtesy of Sustainable Initiatives Fund Trust via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Living On Trash | Earth Wise

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Litter is persistent and widespread in rivers worldwide.  The world’s major rivers and estuaries are hotspots for plastic waste.  Trash and microparticles wash down tributaries and build up before rivers enter oceans.

New research published in the journal Freshwater Biology has found that as this waste accumulates, aquatic river species like insects and snails are increasingly choosing to settle on plastic rather than on natural features like rocks and fallen branches.

Researchers from the University of Nottingham in the UK collected plastic waste from three rivers in eastern Britain along with rocks from the same rivers.  Their analysis of all the macroinvertebrates on the items’ surfaces found that the surfaces of plastic waste items had nearly four times the diversity of the small animals as did the rocks.  In addition, the more complex the plastic’s surface was, the higher the diversity.

The growing abundance of plastic waste coincides with a decline in natural habitat features in urban rivers.  This is a result of increasing amounts of sedimentation from development that blankets riverbeds in silt and sand, restricting the supply and movement of rocks, fallen tree branches, and aquatic plants.

Clearly litter can serve as a place for various species to colonize, but trash is not a good environment for them.  Trash can release toxic chemicals and entangle animals.  Microplastics pose risks for the animals if ingested.

Estimates are that between 1.15 and 2.41 million tons of plastic waste enter the ocean every year from rivers around the world.  Natural habitats have become rare in urban rivers.  River ecosystems built around piles of trash are not a good thing.

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As Plastic Pollution in Rivers Gets Worse, Species Are Increasingly Living on Litter

Photo, posted August 17, 2010, courtesy of Renee_McGurk via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Turning Food Waste Back Into Food | Earth Wise

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Scientists at the University of California Riverside have discovered that fermented food waste can boost bacteria that increase crop growth, make plants more resistant to pathogens, and reduce the carbon emissions resulting from farming.

Food waste is a serious problem from multiple perspectives.  As much as 50% of food is thrown away in the United States and most of that simply ends up in landfills, taking up more than 20% of America’s landfill volume.  Food waste is a huge economic loss as well as a significant waste of freshwater resources used to produce food.

The researchers studied byproducts from two kinds of food waste readily available in Southern California:  beer mash – a byproduct of beer production – and mixed food waste discarded by grocery stores.

Both types of waste were fermented and then added to the irrigation system watering citrus plants in a greenhouse.  Within 24 hours, the average population of beneficial bacteria was two to three orders of magnitude greater than in plants that did not receive the treatments. This led to improvements in the carbon to nitrogen ratio in crops.  When there are enough so-called good bacteria in plants, they produce antimicrobial compounds and metabolites that help plants grow better and faster.

The results of the study suggest that the use of food waste products in agriculture is beneficial and could complement the use of synthetic chemical additives by farmers, perhaps eliminating it entirely.  Crops would in turn become less expensive.

Making use of food waste in agriculture is a step towards a more circular economy in which we use something and then find a new purpose for it.

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Turning food waste back into food

Photo, posted October 28, 2012, courtesy of Daniel Lobo via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Compost And Landfills | Earth Wise

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Composting is popular as a way to keep solid waste out of landfills and many people turn much of their kitchen waste into rich soil amendments.   Cities and towns across the country have composting programs that collect waste from residents to produce large quantities of compost rather than adding the waste to landfills.  A new study from North Carolina State University looked into the environmental benefits of actually using compost at landfills.

Most municipal composting programs require that the compost they produce gets used “beneficially”.  The new research shows that using compost as an alternative daily cover at landfills is competitive and often superior to the use of compost as a soil amendment in terms of its environmental benefits.

Landfills apply a layer of daily cover to reduce odors, reduce windblown debris, and keep vermin out of landfill waste.  Federal regulations require six inches of soil as a daily cover.

Compost from food waste in particular is not always suitable for soil amendment in gardens and agricultural fields because it often contains broken glass and other contaminants.

The North Carolina State study looked at the environmental impact of using compost as daily cover in landfills compared with its use as a soil amendment.  They looked at global warming potential, acidification potential, eutrophication (which is the amount of nutrients released to ground and surface water), cumulative energy demand, and the depletion of resources.

The study concluded that using compost as landfill daily cover is environmentally superior with regard to eutrophication, acidification, and global warming potential.  On the other hand, soil amendment was better in terms of resource depletion and cumulative energy demand.

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Applying Compost to Landfills Could Have Environmental Benefits

Photo, posted April 22, 2008, courtesy of Alachua County via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Electronic Waste On The Decline | Earth Wise

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A new study published in the Journal of Industrial Ecology has found that the total mass of electronic waste generated by Americans has been declining since 2015.  Given that electronic devices are playing an ever-growing role in our lives, this finding seems rather surprising.  It also seems like pretty good news, but the underlying facts should dampen our level of enthusiasm.

The main reason for the decline is the disappearance of large, bulky cathode-ray tube televisions and computer monitors.  Since about 10 years ago, CRT displays have been on the decline in the waste stream, thereby leading to an overall decline in total e-waste mass.

Many state regulations with respect to e-waste recycling have targets based on product mass.  The regulations were typically designed to keep electronics with high levels of lead and mercury out of landfills.

At present, the more pertinent concern is how to recover valuable elements like cobalt (from lithium-ion batteries) and indium (from flat-panel displays).  These elements are not so environmentally toxic, but rather are relatively scarce in the earth’s crust. 

The main conclusion to be drawn from the declining mass of electronic waste is not that we are necessarily winning the battle against generating it but rather that e-waste is changing and regulations concerning it need to be rethought.  Focusing regulations on capturing critical elements not only would have significant economic benefits but also would be important in addressing geopolitical uncertainties that potentially could threaten what could be termed the mineral security of the U.S.

E-waste recycling is regulated at the state level and only half the states have e-waste recycling laws.  It may be time for more uniform policies across the country.

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Electronic Waste on the Decline, New Study Finds

Photo, posted January 22, 2013, courtesy of Thorsten Hartmann via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Replacing Plastic Tableware | Earth Wise

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Plastics have been described as the “ubiquitous workhorse material of the modern economy.”  But their versatility, pliability, and durability comes at a heavy price to the environment.  Plastic pollution is quite literally everywhere.  Plastic debris and microplastic particles can be found in every corner of the globe, including the Arctic and Antarctic. 

The scourge of plastic pollution is driving scientists to create ecologically-friendly alternatives.  According to a paper recently published in the journal Matter, scientists have developed “green” tableware made from sugarcane and bamboo that doesn’t sacrifice on convenience or functionality.  This eco-friendly tableware could serve as a permanent replacement for plastic cups and other disposable plastic containers. 

Traditional plastic polymers, a product of petroleum, can take as long as 1,000 years to decompose in landfills.  The new material only takes 60 days to break down.

To create this material, scientists used bamboo and bagasse, also known as sugarcane pulp.  Bagasse is one of the largest food-industry waste products.  The researchers wound the fibers together to form a mechanically stable and biodegradable material.  They added an alkyl ketene dimer, an eco-friendly chemical, to increase the oil and water resistance of the material.  The green material is durable enough to hold liquids like hot coffee and hot greasy foods like pizza.   

There’s another advantage: the green material’s manufacturing process emits 97% less CO2 than the process to make commercial plastic containers.  The next step is to lower the manufacturing cost.  While the cost of cups made from the green material is $2,333 per ton, traditional cups made from plastic are still slightly cheaper at $2,177 per ton.

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This tableware made from sugarcane and bamboo breaks down in 60 days

Photo, posted May 19, 2013, courtesy of Henry Burrows via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

More Plastic Pollution From The United States | Earth Wise

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A new study published in the journal Science Advances has revealed that the United States is contributing far more to coastal plastic pollution than was previously believed.  A previous study using 2010 data ranked the US 20th globally, in its contribution to ocean plastic pollution from mismanaged waste.  The new study ranks the U.S. third among the world’s countries.

The largest contributor to the discrepancy is that the earlier study did not account for plastic scrap exports.  Using plastic waste generation data from 2016 – which is the most recent global data available – the study’s authors calculated that more than half of all plastics collected for recycling in the US were shipped abroad.  This amounts to over 2 million tons.  Of this amount, some 88% went to countries struggling to effectively manage, recycle, or dispose of plastics, and between 15-25% was, in fact, low-value or contaminated, meaning that it was effectively unrecyclable.  When all of these factors were taken into account, the researchers estimated that a million tons of US-generated plastic waste ended up polluting the environment.  It just occurred beyond our own borders.

Overall, 2-3% of all plastic waste generated in the US – about a million tons – is either littered or illegally dumped into the domestic environment.  When this is combined with the exported waste, the US is responsible for more than 2 million tons of plastic waste being dumped into the environment.  About two-thirds of that ends up in coastal environments, where it is likely to enter the ocean by wind or through waterways.

The United States generates the most plastic waste of any country in the world.  Unfortunately, we have been operating under the illusion that we were doing a pretty good job of dealing with it.

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New Study Reveals United States a Top Source of Plastic Pollution in Coastal Environments

Photo, posted April 3, 2015, courtesy of Vaidehi Shah via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Getting Value From Plastic Waste | Earth Wise

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To date, the world has produced more than five billion tons of plastic and is making more all the time.  Based on the way things are currently done, most of that will end up in landfills or in the natural environment.  By 2050, the amount of plastic is expected to exceed 13 billion tons.   This is one of the world’s biggest environmental problems.

Recently, an international collaboration by universities and institutions in the UK, China, and Saudi Arabia has developed a method of converting plastic waste into hydrogen gas and high-value solid carbon.

The technique was achieved with a new type of catalysis that uses microwaves to activate catalyst particles that effectively strip hydrogen from plastic polymers.  The work was recently published in the journal Nature Catalysis and details how the researchers mixed mechanically pulverized plastic particles with a microwave-susceptor catalyst of iron oxide and aluminum oxide.  That mixture was then subjected to microwave treatment and yielded a large volume of hydrogen gas and a residue of carbonaceous material, most of which was identified as carbon nanotubes.

The process is more rapid than most methods for dealing with plastic waste and can extract over 97% of the hydrogen in plastic without producing any carbon dioxide emissions. 

The new method represents an attractive potential solution to the problem of plastic waste.  Instead of polluting the planet, plastics could become a valuable feedstock for producing clean hydrogen fuel as well as valuable carbon materials.  Proponents of the so-called hydrogen economy have continued to seek a green and economical way to produce hydrogen.  This new work might be just what they are looking for.

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Turning plastic waste into hydrogen and high-value carbons

Photo, posted April 21, 2007, courtesy of Redwin Law via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A New Super-Enzyme For Breaking Down Plastic | Earth Wise

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The problems caused by plastic waste continue to grow.  Plastic pollution is everywhere, from the Arctic to the depths of the ocean.  We consume microplastics in our food and breathe them in the air.  It is very difficult to break down plastic bottles into their chemical constituents in order to make new ones from old ones. Therefore, we continue to produce billions of single-use plastic bottles, creating more and more new plastic from oil each year. 

Scientists at the University of Portsmouth in the UK have developed a new super-enzyme that degrades plastic bottles six times faster than before.  They believe that the new enzyme could be used for plastic recycling within a year or two.

The super-enzyme was derived from bacteria that naturally have the ability to eat plastic.  The researchers engineered it by linking two separate enzymes, both of which were found in a plastic-eating bug discovered in a Japanese waste site in 2016.  They revealed an engineered version of the first enzyme in 2018, which started breaking down plastic in a few days.  They had the idea that connecting two enzymes together would speed up the breakdown of plastic.  Such linkage could not happen naturally in a bacterium. 

Carbios, a French company, announced a different enzyme in April that can degrade plastic bottles within 10 hours but requires heating above 160 degrees Fahrenheit.  The new super-enzyme works at room temperature.

The team is now examining how the enzymes can be tweaked to make them work even faster.  Meanwhile, they plan to work in partnership with companies like Carbios, to bring super-enzymes for breaking down plastics into commercial use.

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New Super-Enzyme Can Break Down Plastic at Rapid Pace

Photo, posted March 24, 2017, courtesy of the USFWS – Pacific Region via Flickr. Photo credit: Holly Richards/USFWS.

Earth Wise is a production of WAMC Northeast Public Radio.

The Cost of Cleaning Up Ocean Plastic | Earth Wise

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Small island developing states increasingly find themselves with large amounts of plastic waste.  A recent study looked at the financial cost for removing it.

Aldabra Atoll is a UNESCO World Heritage Site in the Seychelles.  It is the world’s second-largest coral atoll and is the home of 307 species of animals and plants, including the largest population of giant tortoises in the world.  Aldabra has been called one of the wonders of the world and one of the crown jewels of the Indian Ocean.

Last year, a team from the University of Oxford and the Seychelles Island Foundation, spent five weeks removing litter that had washed up on Aldabra’s shores.  In total, they removed 25 tons of plastic litter which, to their surprise, was dominated by waste from the fishing industry.  The researchers now estimate that over 500 tons of litter remain on the island, 83% of which consists of buoys, ropes, nets, and, of all things, over 300,000 individual flipflops.  This is the largest accumulation of plastic waste reported for any single island in the world.

According to the study, the cost to clean up the entire island would be nearly $5 million, requiring 18,000 person-hours of labor.  A project of this magnitude is beyond the capacity of non-profit organizations like the Seychelles Islands Foundation.

The plastic pollution in Aldabra is related to the fishing industry in Seychelles, which provides tuna to high-income markets around the world.  The research highlights how even remote highly protected island ecosystems are impacted by global pollution and how difficult and costly it is to remedy.

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Millions of dollars to clean up tuna nets and flip flops from island state

Photo, posted December 27, 2016, courtesy of David Stanley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Recycling Solar Panels | Earth Wise

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It is inevitable that the things we make and use eventually outlive their useful lives and become waste that we have to deal with.  Solar panels, despite their impressively long lifetime, can’t escape this general principle.   As pioneering solar panels near the end of their 30-year electronic lives, they could well become the world’s next big wave of e-waste.

According to the International Renewable Energy Agency, nearly 90 million tons of solar panels will have reached their end of life by the year 2050, resulting in about 7 million tons of new solar e-waste per year.

Solar photovoltaic deployment has grown at unprecedented rates in recent years.  The total global installed capacity is about 600 GW today; projections are that there will be 1,600 GW by 2030 and 4,500 GW by 2050.

Solar panels contain valuable materials, including silver and high-purity silicon.  But current recycling procedures are not cost-effective.   Only about 10% of panels are currently recycled in the U.S.   The rest go to landfills or are shipped overseas to become another country’s problem.

Before solar waste becomes a major problem, the industry needs to better address the issue.  Strategies include improving the design of panels to align with recycling capabilities as well as developing new recycling methods that can more efficiently extract and purify the valuable materials in the panels.  Industry researchers are also looking into ways to repair and resell panels that are still in good condition and to repurpose old panels for less demanding functions like e-bike charging stations and housing complexes.

Like most things, solar panels do fail over time and with a rapidly growing number of them in the world, we need to figure out how to avoid them adding to the world’s problems.

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Solar Panels Are Starting to Die. Will We be Able to Recycle the E-Waste?

Photo, posted January 6, 2006, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Sustainable Flip-Flops | Earth Wise

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Flip-flops are the world’s most popular shoe.  They are lightweight, comfortable, affordable, and durable.  In fact, the global market for flip-flops is expected to reach a whopping $23.8 billion by the year 2025. 

But the popularity comes with a price.  Flip-flops account for a troubling percentage of plastic waste that ends up in our landfills and oceans.  As a result, demand for alternatives is compelling researchers to develop more sustainable versions of the popular footwear.

Scientists at the University of California San Diego have spent years working on this issue, and recently announced a breakthrough.  According to a study recently published in Bioresource Technology Reports, the research team has formulated polyurethane foams – made from algae oil – to meet commercial specifications for mid-sole shoes and the foot-bed of flip-flops.   In other words, the scientists have created sustainable, biodegradable, and consumer-ready materials that could replace plastics in some footwear. 

The UC San Diego scientists collaborated with Algenesis Materials – a technology startup – on the research.  Together, they worked to not only create the shoes, but to degrade them as well.  The team tested their customized foams by immersing them in traditional compost and soil.  The algae-based materials degraded after just 16 weeks.  

The life of any material should be proportionate to the life of the product.  The researchers point out that it doesn’t make sense to create a product that will last 500 years if it’ll only be used for a year or two. 

The research team is currently working on production details with its manufacturing partners.  The creation of biodegradable flip-flops that meet commercial footwear standards could eliminate tons of plastic waste from the environment.   

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New science behind algae-based flip-flops

Flip Flops Market Size Worth $23.8 Billion by 2025

Photo, posted December 12, 2019, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Recycling Tough Plastics | Earth Wise

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Thermoset plastics are ones that contain polymers that cross-link together during the curing process to form an irreversible chemical bond.  This improves the material’s mechanical properties, provides chemical resistance, heat resistance, and structural integrity.  Thermosets include epoxies, polyurethanes, and rubber used for tires.  The big problem with thermosets is that they cannot be easily recycled or broken down after use.

Seventy-five percent of all plastics are thermoplastics, which can be recycled by heating them until they become liquid and can then be remolded.   Thermoset plastics, on the other hand, have such strong chemical bonds that they simply will not melt.  They will typically burn before they can be remolded.

Chemists at MIT have recently developed a way to modify thermoset plastics with a chemical linker that makes them much easier to break down, but still retain the mechanical properties that make them so useful.

In a study published in Nature, the researchers produced a degradable version of a thermoset plastic called pDCPD.  They then broke the plastic down into a powder and were able to use the powder to create more pDCPD.  The paper also proposed a theoretical model that suggests that their approach could be used for a wide range of other plastics and polymers, including rubber.

By adding a chemical called a silyl ether monomer to the liquid precursors that from pDCPD plastic, they found that the resultant material retained its mechanical strength but can be broken down into a soluble powder upon exposure to fluoride ions.

Using this approach with other thermoset materials, the researchers believe it will be possible to create recyclable versions of many of the toughest plastic materials.

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Chemists make tough plastics recyclable

Photo, posted September 1, 2019, courtesy of Luke McKernan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

WAMC Northeast Public Radio

WAMC/Northeast Public Radio is a regional public radio network serving parts of seven northeastern states (more...)