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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.

Tracking Endangered Species From Space | Earth Wise

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Scientists at the University of Bath and the University of Oxford in the UK have developed a technique for remotely surveying elephants and other wildlife using satellite images and deep learning.  The technique has the same accuracy as human counts done on the ground or from low-flying airplanes.

The new computer algorithm can analyze high-resolution satellite images and detect African elephants in both grasslands and forests.  Previous techniques for monitoring wildlife from space were limited to homogenous habitats, such as the case of tracking whales in the open ocean.

On-the-ground or airplane surveys to monitor animal numbers are expensive and time-consuming.  Satellites can collect nearly 2,000 square miles of imagery in a few minutes thereby eliminating the risk of double counting and reducing a process that previously took weeks to just a few days.  The use of satellites also eliminates the logistical problems of monitoring species populations that cross international borders.

Accurate monitoring is important for efforts to save endangered species.  There are only 40,000 – 50,000 African elephants left in the wild.  It is essential to know where the animals are and how many there are in various locations. The new method is able to count elephants in mixed ecosystems, such as savannah and forests, where tree cover would previously have made satellite tracking difficult.

With satellite imagery resolution increasing every few years, it should be possible to see ever-smaller things in greater detail.  The new algorithm works well for elephants; it may eventually become practical to track animals as small as an albatross from space.

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A New Way to Track Endangered Wildlife Populations from Space

Photo, posted March 15, 2008, courtesy of Michelle Gadd/USFWS 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.

More Bugs That Eat Plastic | Earth Wise

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The world continues to struggle with the proliferation of plastic that is polluting the environment.  The Great Pacific Garbage Patch has now grown so large that it has spread across an area four times the size of California.  But there is no silver bullet in the struggle to reduce plastic pollution.  Reducing the use of plastic is probably the most viable approach, but increased recycling, the use of bioplastics, and various other strategies must play a role.

The essence of the problem is that plastic takes from decades to hundreds of years to decompose naturally.  The world produces billions of tons of plastic waste each year and less than 10% of it is recycled.  As a result, researchers around the world seek ways to safely and economically accelerate the decomposition of plastics.

A research team at Andong National University in South Korea has discovered the larvae of a particular species of darkling beetle can decompose polystyrene, which is one of the trickiest plastics to break down.  There are thousands of species of darkling beetles found in different habitats all over the world.  The one they identified is indigenous to East Asia.

The beetle larvae can consume polystyrene and reduce both its mass and molecular weight.  Furthermore, they found that the bacteria in the gut of the larvae could oxidize and change the surface property of polystyrene.  The handful of bacterial strains they identified were not like those of earlier insects found to degrade polystyrene.  As result, the researchers are hopeful that it may be possible to break down the plastic using other insects that feed on rotten wood.  Apart from the insects themselves, using just the bacterial strains found in the darkling beetles may prove to be an effective method for decomposing polystyrene.

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A New Species of Darkling Beetle Larvae That Degrade Plastic

Photo courtesy of Flickr.

I farmaci a base di erbe e omeopatici rappresentano una percentuale significativa (circa una confezione su otto) dell’assortimento da banco delle farmacie. Nel 2017, i farmaci a base di erbe hanno registrato vendite per 1,48 milioni di euro e 120 milioni di confezioni, mentre maschioforte.com i farmaci omeopatici hanno registrato vendite per 630 milioni di euro e 52 milioni di confezioni, secondo l’Associazione federale dell’industria farmaceutica (Bundesverband der Pharmazeutischen Industrie – BPI).

Earth Wise is a production of WAMC Northeast Public Radio.

Generating Hydrogen From Poor-Quality Water | Earth Wise

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Hydrogen could be the basis of a complete energy system.  It could be stored and transported and could be used to power vehicles and to generate electricity in power plants.  Proponents of the so-called hydrogen economy contend that hydrogen is the best solution to the global energy challenge.  But among the challenges faced by a hydrogen economy is the development of an efficient and green method to produce hydrogen.

The primary carbon-free method of producing hydrogen is to break down water into its constituent elements – hydrogen and oxygen.  This can be done in a number of ways, notably by using electricity in a process called electrolysis.  A method that seems particularly attractive is to use sunlight as the energy source that breaks down the water molecule.

While there is an abundance of water on our planet, only some of it is suitable for people to drink and consume in other ways.    Much of the accessible water on earth is salty or polluted.  So, a technique to obtain hydrogen from water ideally should work with water that is otherwise of little use to people.

Researchers in Russia and the Czech Republic have recently developed a new material that efficiently generates hydrogen molecules by exposing water – even saltwater or polluted water – to sunlight. 

The new material is a three-layer structure composed of a thin film of gold, an ultra-thin layer of platinum, and a metal-organic framework or MOF of chromium compounds and organic molecules.  The MOF layer acts as a filter that gets rid of impurities.

Experiments have demonstrated that 100 square centimeters of the material can generate half a liter of hydrogen in an hour.  The researchers continue to improve the material and increase its efficiency over a broad range of the solar spectrum.

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New Material Can Generate Hydrogen from Salt and Polluted Water

Photo courtesy of Tomsk Polytechnic University.

Earth Wise is a production of WAMC Northeast Public Radio.

Better Paint For Cooler Buildings | Earth Wise

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A research team led by scientists at UCLA have developed a super-white paint that reflects as much as 98% of incoming heat from the sun.  Such paint, if used on rooftops and other parts of buildings, could have a major impact on reducing the costs of keeping buildings cool.

Passive daytime radiative cooling is a well-known method to keep buildings cooler.  By having building surfaces reflect sunlight and radiate heat into space, building temperatures can be significantly lowered.  This in turn cuts down on air conditioner use and associated carbon emissions.

A roof painted white will result in lower indoor temperatures than a darker roof.  But a white roof will do even more:  it can reject heat at infrared wavelengths that are invisible to our eyes.  This results in even more radiative cooling.

The best performing white paints currently available reflect about 85% of incoming solar radiation.  The rest is absorbed by materials in the paint.  The new research has identified simple modifications in paint ingredients that lead to a major increase in reflectivity.

Current reflective white paints use titanium dioxide, which absorbs UV radiation and therefore heats up under sunlight.  The researchers studied replacing it with other substances such as barite – an artist’s pigment – or with powdered Teflon, both of which allow the paint to reflect more of the sun’s radiation. 

Many cities are encouraging the use of cool-roof technologies on new buildings.  Using the most reflective coatings possible on rooftops, if applied on a sufficiently large scale, could have a real impact on climate change as well as saving significant amounts of energy used for running air conditioners in buildings.

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UCLA-led Team Develops Ways to Keep Buildings Cool with Improved Super White Paints

Photo, posted August 15, 2012, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Turning Trash Into Treasure

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Every year, 380 million tons of plastic are created worldwide, and that number continues to grow.  Furthermore, more than 75% of these materials are discarded after one use.  Much of it ends up in oceans and waterways, harming wildlife and spreading toxins.

Recycling most plastics is difficult because while they can be melted and reprocessed, the resultant material is not as structurally strong as the original material.  Thus, plastics are often down-cycled such as turning plastic bottles into molded park benches.

Researchers at Northwestern University, Argonne National Laboratory, and Ames Laboratory have developed a new method for upcycling abundant, seemingly low-value plastics into high-quality liquid products, such as motor oils, lubricants, detergents, and even cosmetics.  The catalytic method  could remove plastic pollution from the environment and contribute to a circular economy.

Plastics don’t degrade when disposed of because they have very strong carbon-carbon bonds.  Instead they just break into smaller bits, known as microplastics.  The researchers viewed these strong bonds as an opportunity rather than a problem.

The new technique actually recoups the high energy that holds these bonds together by catalytically converting polyethylene molecules into value-added commercial products.  The catalyst consists of platinum nanoparticles deposited onto perovskite nanocubes.  Under moderate pressure and temperature, the catalyst cleaves the carbon-carbon bonds in plastic to produce high-quality liquid hydrocarbons. 

The researchers believe these findings could lead to a future in which we can continue to benefit from plastic materials but do so in a way that is sustainable and less harmful to the environment.

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Turning plastic trash into treasure

Photo, posted August 15, 2012, courtesy of Emilian Robert Vicol via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Protecting Canola Crops From Frost

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Canola is one of Canada’s most valuable crops.  In fact, Canada is the world’s largest exporter of canola oil.  The international market for canola oil is $27 billion a year.  The oil is very popular because it has a relatively low amount of saturated fat, a substantial amount of monosaturated fat, and is very neutral tasting.

Canadian canola farmers worry a great deal about late season, non-lethal frosts because the frosts prevent chlorophyll – a photosynthetic pigment in the seeds – from breaking down, a process they call “degreening”.  The farmers seek to have high-quality yellow embryos at seed maturity.  When the harvest contains more than 2% of green seeds, it can no longer produce Grade No. 1 quality oil.  When green seeds are processed to extract canola oil, the chlorophyll in the seeds reduces the oil’s storability and quality.  As a result, farmers receive a lower price for frost-damaged green seed canola.  This costs Canadian farmers and estimated $150 million annually.

Researchers at the University of Calgary have developed gene-based technology to produce canola plants that can withstand late-season frost and still produce high-quality seed.  They identified a specific protein that controls chlorophyll breakdown and seed maturity.  Genetic manipulation is able to enhance the seed degreening system.  They were able to reduce the amount of chlorophyll in the genetically modified canola lines by 60% after the plants were exposed to non-lethal frost. 

Ultimately, the researchers plan to develop a method to incorporate the modification into canola hybrid lines in such a way that it will be readily accepted by consumers concerned about genetically modified organisms.

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New technology helps protect valuable canola crops from frost

Photo, posted August 29, 2018, courtesy of Tinker and Rove via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Removing Microplastics with Magnetism

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A new method for removing microplastics from the oceans has emerged from, of all things, a science fair project.  An Irish 18-year-old named Fionn Ferreira developed his project for the annual Google Science Fair and it won the grand prize of $50,000 in educational funding.

The teenager was walking on the beach in his hometown and ran across a stone with oil and plastic stuck to it and became focused on the problem of microplastics increasingly entering the environment.

His idea was to make use of ferrofluids, which are nontoxic magnetic fluids made of oil and magnetite, which is an iron-based mineral.  In the presence of water, the ferrofluids attract microplastics because both have similar properties.

Ferreira added oil and magnetite to water and mixed in a solution of microplastic particles.  When the microplastics latched onto the ferrofluids, he dipped a magnet into the solution several times and the magnet removed both substances, leaving clear water.  After almost 1000 tests, he demonstrated the method to be 88% effective in removing a variety of microplastics from water; a result even better than his original hypothesis of an 85% removal rate.

Ferreira is planning to further his education at a prestigious chemistry institute in the Netherlands starting in the fall.

According to a recent study, Americans eat, drink and breathe between 74,000 and 121,000 microplastic particles each year and, if they drink bottle water only instead of tap water, an additional 90,000 particles.  So, a science fair project that might provide a way to get rid of most these things is definitely prize-worthy.

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This Irish teenager may have a solution for a plastic-free ocean

Photo, posted April 25, 2016, courtesy of Boe Eide via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

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