compounds

Sun powered carbon capture

June 30, 2025 By EarthWise Leave a Comment

As the world struggles to implement technologies and find the political will to reduce carbon emissions, there are also ongoing efforts to find ways to capture carbon from emitting sources and from the atmosphere itself. After capturing carbon dioxide, there is then the need to safely store it or make use of it.

Current methods for capturing and then releasing carbon dioxide are expensive and energy intensive. In fact, some methods even require the use of fossil fuels. Recently, researchers at Cornell University have developed a method for capturing carbon dioxide that is powered by sunlight.

The Cornell method mimics the mechanisms that plants use to store carbon which involves using sunlight to make a reactive enol molecule that grabs carbon dioxide.

Existing chemical-based carbon capture techniques make use of amines, which are organic ammonia-derived compounds that react selectively with carbon dioxide. But amines are not stable in the presence of oxygen and don’t last, which necessitates the energy-intensive production of more and more amines.

The Cornell method uses the same method that the plant enzyme RuBisCo uses in photosynthesis. It is based on an inexpensive sorbent material that is capable of a high rate of carbon capture.

The researchers tested the system using flue samples from Cornell’s Combined Heat and Power Building, an on-campus power plant that burns natural gas. The system was successful in isolating carbon dioxide.

Ultimately, they would like to stage the reaction on what looks like a solar panel, but one that would capture carbon instead of generating electricity.

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In a first, system uses sunlight to power carbon capture

Photo, posted August 8, 2015, courtesy of Holly Victoria Norval via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A green battery from industrial waste

February 11, 2025 By EarthWise Leave a Comment

Flow batteries are rechargeable batteries in which liquid electrolytes flow through one or more chemical cells from one or more tanks. The electrolytes are redox pairs, that is, chemical compounds that can reversibly undergo reduction and oxidation reactions. The most common redox electrolytes include elements like vanadium, chromium, iron, zinc, and bromine. Flow batteries can provide large amounts of both electrical power and stored energy based on the size of the electrolyte tanks. As a result, they can be scaled up far more readily than other battery technologies.

Flow batteries are safe, stable, long-lasting, and their electrolytes can easily be refilled. They have significant potential for use in utility-scale storage for renewable energy systems.

Researchers at Northwestern University have developed a redox flow battery based on an organic industrial-scale waste product. The material – triphenylphosphine oxide or TPPO – is produced in the thousands of tons each year. It is byproduct of producing a variety of substances including some vitamins, pharmaceuticals, agrochemicals, and other bulk chemicals. For the most part, TPPO is of little use and must be carefully discarded.

The current market for redox flow batteries is very small but is expected to grow over time as the need for utility-scale energy storage continues to expand. A battery technology based on a waste material that is already produced in high volume and that must otherwise be disposed of with caution would have significant advantages.

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Green battery discovery turns trash into treasure

Photo, posted January 12, 2015, courtesy of California Energy Commission via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Mining extinct volcanoes

December 2, 2024 By EarthWise Leave a Comment

Rare earth elements are a group of 17 elements that are used to improve the performance, efficiency, and durability of a wide range of products. More than 200 products across a diverse set of applications make use of rare earth elements. Although the amount of rare earth used in a particular product may not be very much of its weight, volume, or monetary value, it may often be necessary for the device even to function. Rare earth elements react with other elements to form compounds that are essential because of their specific chemical behaviors.

Rare earth elements are not actually rare; in fact, they are fairly common. But they are mostly not found in their pure form and are generally difficult to refine. China accounts for more than 90% of global production of rare earth elements and this represents a strategic problem for the rest of the world.

New research by scientists from the Australian National University has found that some extinct volcanoes, which have not erupted for thousands or even millions of years, may be rich sources of rare earth elements. Furthermore, those elements may be easier to extract than the ones from other sources because the iron-rich magma that formed the volcanoes could be up to 100 times more efficient at concentrating rare-earths than magma found in active volcanoes today.

The clean tech industry uses rare earths for wind turbines, solar panels, and electric cars. The demand for rare earths may grow fivefold by the end of this decade. Relying on just one country for the world’s supply is a major concern. There are ancient volcanoes all over the planet and they may represent a solution to a global problem.

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Extinct Volcanoes Could Be Source of Key Metals Needed for Clean Tech

Photo, posted June 6, 2020, courtesy of Dennis Jarvis via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Fertilizers from wastewater sludge

July 30, 2024 By EarthWise Leave a Comment

Sewage sludge is the mud-like residue that is produced as a byproduct during wastewater treatment. In the U.S., sewage sludge is referred to as biosolids after it’s been treated. The term is meant to distinguish the higher quality, treated sludge from raw sludge and from sludge that contains large quantities of environmental pollutants.

However, according to a new study by researchers from Johns Hopkins University, fertilizers manufactured from the sludgy leftovers of wastewater treatment processes can still contain traces of potentially hazardous organic chemicals.

The research, which was recently published in the journal Environmental Science & Technology, provides one of the most comprehensive looks at the chemical composition of biosolids across the country.

Biosolids do contain valuable organic matter and nutrients, including nitrogen and phosphorus. According to the U.S. Environmental Protection Agency, more than half of the 3.76 million tons of biosolids produced in the U.S. in 2022 fertilized agricultural lands, golf courses, and other landscaped areas.

In the study, the research team screened 16 samples of biosolids from wastewater treatment facilities in nine U.S. and three Canadian cities. The researchers then created lists of the chemicals found in each sample. They found 92 common compounds that were present in 80% or more of the samples. The researchers cross-referenced those 92 compounds against the EPA’s CompTox Chemical Dashboard to identify which chemicals were most likely to pose threats to human health or the environment.

The findings could help the EPA identify which organic compounds to investigate further and which chemical contaminants may need government regulation.

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Team Aims to Improve Safety of Fertilizers Made from Wastewater Sludge

Photo, posted November 2, 2011, courtesy of Susana Secretariat via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Car tires in your salad

June 26, 2024 By EarthWise Leave a Comment

There seems to be no end to the types of pollution we have introduced into the environment. One that has only recently started to gain attention is pollution caused by vehicle tires.

Through normal wear and tear, as vehicles drive along roadways, their tires cast off countless bits of rubber. These particles can linger in the atmosphere or can be washed down sewage drains and into waterways. In the water, these particles leach compounds that are toxic to wildlife.

Tires contain various chemical additives that prevent them from cracking and degrading along with various metals and other materials added to rubber and artificial rubber. Some of these additives are acutely toxic or even carcinogenic.

A recent study by researchers at the University of Vienna tested leafy vegetables that were grown in Switzerland, Spain, and Italy, and were sold in Swiss supermarkets. The study also tested vegetables harvested directly from Israeli farmlands.

Tire ingredients were found in 11 out of 15 samples gathered from Swiss supermarkets and 9 out of 13 samples collected from Israeli fields. Among these are 6PPD, a tire additive that has been identified as the cause of the extensive deaths of coho salmon on the US West Coast.

The researchers say that farmers may be introducing tire additives by irrigating crops with treated wastewater or by using sewage sludge as fertilizer. Airborne tire particles may also be settling on farm soil.

The concentration of tire particles found in the leafy vegetables are relatively low, but it is troubling that we are eating dangerous chemicals used to improve the quality of tires.

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Leafy Vegetables Found to Contain Tire Additives

Photo, posted October 14, 2014, courtesy of Green Mountain Girls Farm via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Forever chemicals in water

April 23, 2024 By EarthWise Leave a Comment

So-called forever chemicals are pervasive in a wide range of products. These are man-made substances called per- and polyfluoroalkyls or PFAS. They get their unfortunate nickname because the chemical bonds in them are so strong that the compounds don’t break down for hundreds or even thousands of years.

PFAS compounds are used in makeup, dental floss, nonstick pans, food wrappers, pesticides, stain-resistant fabrics and carpets, firefighting foams, and more. High level exposure to some of these chemicals has been linked to a variety of health problems include high cholesterol, liver and immune system damage, pregnancy problems, and kidney and testicular cancer.

A recent study published in the journal Nature Geoscience has found that PFAS chemicals are showing up in water around the world. The study looked at more than 45,000 water samples and found that about 31% of ground water tested that wasn’t even near any obvious source of PFAS contamination had levels of the chemicals that are considered harmful to human health by the EPA. About 16% of surface water samples – streams, rivers, ponds, and lakes – also not near any known source, had similar hazardous PFAS levels.

The EPA has now imposed strict new drinking water limits for six types of PFAS. Going forward, water systems are required to monitor for these chemicals and remove them if they are found above allowable levels. The new rules make the United States one of the strictest countries in the world in terms of regulating PFAS in water.

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EPA puts limits on ‘forever chemicals’ in drinking water

Photo, posted May 5, 2020, courtesy of Brandon Shaw via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Protecting wine grapes from wildfire smoke

February 27, 2024 By EarthWise Leave a Comment

In recent years, wildfires have become a major threat to the wine industry because of the effects of smoke on wine grapes. Smoke taint from the California fires of September 2020 significantly impacted the quality of wine grapes. In total, smoke taint cost the wine industry in Western states more than $3 billion in losses from the hundreds of thousands of tons of wine grapes that could not be harvested because of the off flavors imparted by the smoke. The California wine industry alone is a $43 billion a year business and the state’s frequent wildfires are a major threat to it.

Researchers at Oregon State University have developed techniques for eliminating the effects of three volatile chemical compounds that contribute to smoke taint in grapes. The compounds are guaicol, syringol, and meta-cresol.

The researchers developed cellulose nanofiber-based coatings that can be applied to grapes in the vineyard. The coatings can block guaicol and syringol and capture meta-cresol.

Blocking is ideal because the coating doesn’t absorb the wildfire smoke compounds. Therefore, it doesn’t have to be washed off. Capturing means the coating absorbs the compounds and would need to be washed off. Ideally, a coating that doesn’t need to be washed off would save time, money, and water.

Two years of studies at Oregon State found that the coatings do not impact the growth and quality of wine grapes. In an era when wildfires are increasingly common and extensive, growers need something they can spray on their vines to protect their grapes. If the Oregon State technology can be commercialized, it would be a game-changer for the Western U.S. wine industry.

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Spray coating for grapes shows promise in battle between wildfire smoke and wine

Photo, posted October 3, 2006, courtesy of Naotake Murayama via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Protecting berries with sunflower extract

November 30, 2023 By EarthWise Leave a Comment

Many of us buy blueberries, raspberries, blackberries, and more in those little clear plastic clamshell boxes. We try to check them out at the store to make sure they are ok and even if are, many soon end up coated with gray mold and other fungi. It is a problem that is both disappointing and expensive.

Researchers from several Chinese Universities recently reported that compounds extracted from sunflower crop waste are quite effective at preventing rotting in blueberries. They suggest that the food industry could use these natural compounds to protect berries from postharvest diseases.

Sunflowers are grown globally for their seeds and oil. The flower stems themselves are generally considered to be a waste product. Sunflowers are known to be particularly resistant to many plant diseases so the researchers decided to investigate whether there might be chemical constituents within the plants that are responsible for the protective property.

Their research led to the isolation of 17 different compounds known as diterpenoids, including four that have never been identified before. They found that 4 of the compounds, including 2 of the newly discovered ones, were effective at preventing the growth of fungus on the blueberries.

Berries were wetted with the compounds and then dried off and injected with mold spores. Half of the treated berries were protected from the mold.

There is no reason that the method couldn’t be applied to a variety of crops. There is great appeal in the concept of using a harmless extract from a plant to render a food crop safe from fungal infestation. The technique holds great promise in preventing postharvest disease in fruit.

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Sunflower extract fights fungi to keep blueberries fresh

Photo, posted August 26, 2006, courtesy of Liz West via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Solar thermochemical hydrogen

November 23, 2023 By EarthWise Leave a Comment

For decades, there has been talk of the hydrogen economy in which hydrogen would take the place of fossil fuels in a wide range of domestic and industrial applications. Over time, hydrogen’s potential advantages in some applications have diminished but it is still seen as perhaps the most promising way to decarbonize long-distance truck, ship, and plane transportation as well as many heavy-duty industrial processes.

Hydrogen is the most common element in the universe, but here on Earth, it is tightly bound up in chemical compounds, notably water and hydrocarbons. Extracting hydrogen from these compounds takes lots of energy. To date, most hydrogen is produced from fossil fuel sources, resulting in carbon dioxide emissions. So-called green hydrogen is made by splitting up water into its component elements.

Getting hydrogen from water generally uses electrolysis, which requires lots of electrical power. That is why it isn’t the standard way to produce hydrogen; it costs too much to pay for all that power.

MIT scientists have been developing a process to make solar thermochemical hydrogen, or STCH. STCH uses the sun’s heat to split apart water and no other energy source. An existing source of solar heat drives a thermochemical reaction in which a heated metal surface grabs oxygen from steam and leaves hydrogen behind. MIT did not invent the concept; their efforts are to make it practical.

Previous STCH designs were only capable of using 7% of incoming solar heat to make hydrogen. The MIT process may be able to harness up to 40% of the sun’s heat and therefore generate far more hydrogen.

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MIT design would harness 40 percent of the sun’s heat to produce clean hydrogen fuel

Photo, posted August 23, 2017, courtesy of Evan Lovely via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Pollution From Tires | Earth Wise

October 16, 2023 By EarthWise Leave a Comment

A few years ago, researchers investigating massive deaths of coho salmon in West Coast streams discovered that the water contained particles from vehicle tires. The cause of the fish mortality turned out to be a chemical called 6PPD that is added to tires to prevent cracking and degradation. The mystery was solved, but so far, the chemical continues to be used by all major tire manufacturers and is found on roads and in waterways around the world.

Worse still, the acute toxicity of 6PPD and the chemicals that it transforms into when exposed to ground-level ozone is only the tip of the tire pollution iceberg. Tire rubber contains more than 400 chemicals and compounds, many of which are carcinogenic.

About 2 billion tires are sold across the globe each year and that number is expected to reach 3.4 billion by 2030. Tires are made from about 20% natural rubber and 24% synthetic rubber, which requires about 4 gallons of petroleum per tire. Hundreds of other ingredients – including steel, fillers, heavy metals like copper, cadmium, lead, and zinc – make up the rest.

Tire wear particles are emitted continually as vehicles travel. They range in size from visible pieces of rubber or plastic to microparticles. Research has shown that a car’s four tires collectively emit half a trillion ultrafine particles per mile driven. These particles are small enough to be breathed into the lungs and can travel throughout the body and even cross the blood-brain barrier. Particle pollution from tires exceeds that from tailpipes.

Tire pollution is a huge problem that is just starting to receive the attention it deserves.

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Road Hazard: Evidence Mounts on Toxic Pollution from Tires

Photo, posted June 22, 2018, courtesy of Tony Webster via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Lampshades And Indoor Air Pollution | Earth Wise

September 26, 2023 By EarthWise Leave a Comment

We mostly think of air pollution as an outdoor problem. Common sources of air pollution include emissions from vehicles, byproducts of manufacturing and power generation, and smoke from wildfires. What we don’t often spend a lot of time thinking about is indoor air quality.

Indoor air pollution refers to harmful pollutants within buildings and structures, which can lead to a myriad of health issues. Sources of indoor air pollution include smoke from tobacco products, as well as volatile organic compounds (VOCs), including acetaldehyde and formaldehyde, emitted from things such as paints, cleaning products, plastics, and cooking.

A team of scientists from South Korea’s Yonsei University has developed a special coating that when applied to lampshades can convert pollutants into harmless compounds. Composed of titanium dioxide and a small amount of platinum, this thermocatalyst can be applied to the inside surface of a lampshade and is triggered to break down VOCs when warmed by the lamp’s existing incandescent or halogen bulb.

In lab tests, the coating was applied to the inside of an aluminum lampshade, warmed by a halogen bulb, and then placed into a sealed chamber containing air and acetaldehyde gas. The researchers found that the material quickly converted the gas into acetic acid, then into formic acid, and finally into carbon dioxide and water. The scientists are now looking for ways to extend the pollutant-destroying-lampshade concept to LED lightbulbs.

The findings offer a promising and eco-friendly solution to improve indoor air quality and reduce the health risks associated with prolonged exposure to VOCs.

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Clever coating turns lampshades into indoor air purifiers

Photo, posted March 21, 2009, courtesy of Levent Ali via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Aluminum And Deodorants | Earth Wise

October 2, 2020 By EarthWise Leave a Comment

Aluminum is the third most common element in the earth’s crust. That element and its compounds are contained in numerous foods and products intended for consumers. Aluminum can occur naturally in certain foods and it can be a part of food additives. Apart from that, it is also possible for aluminum to transfer to food from packaging and tableware. We also can take in aluminum from cosmetic products like whitening toothpaste, lipsticks, particles in sunscreens, and in the form of aluminum chlorohydrate in antiperspirants.

The concern about aluminum intake is related to its effects on the nervous system, on the mental and motor development of children, and upon possible negative effects on the kidneys and bones. When aluminum is ingested via food, its toxicity is low and for healthy people, the kidneys do a good job of excreting it. However, people with chronic kidney disease may not be able to get rid of aluminum as readily and it can accumulate in the body.

Six years ago, a study looked at the amount of aluminum absorbed through the skin from the use of antiperspirants, but the data at that time was considered to be unreliable and a need for further research was identified.

Recently, the results of two new studies have been published by a German research institute that quantifies the absorption of aluminum salts through the skin. The results were that significantly less aluminum is absorbed through the skin than previously calculated and that a significant absorption of aluminum from antiperspirants is unlikely.

The total burden of aluminum from all sources can be high among some population groups, but it appears that use of aluminum-containing antiperspirants is not an important contribution to that burden.

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Aluminium in antiperspirants: Low contribution to the total intake of aluminium in humans

Photo courtesy of NutritionFacts.org.

Earth Wise is a production of WAMC Northeast Public Radio.

PFAS In The Food Chain | Earth Wise

July 8, 2020 By EarthWise Leave a Comment

Per- and polyfluoroalkyl substances (PFAS) are a family of human-made chemicals that have been manufactured and used in a variety of industries around the globe. PFOA and PFOS have been the most extensively produced and the most extensively studied of these chemicals.

Exposure to PFAS has been linked to a host of adverse health effects, including thyroid hormone disruption and cancer.

PFAS compounds can be found in such things as non-stick cookware, stain-resistant carpets, water-repellent outdoor gear, and food packaging, like fast food wrappers and microwave popcorn bags.

According to a new study, researchers from North Carolina State University have found PFAS substances in every step of the Yadkin-Pee Dee River food chain, even though the river doesn’t have a known industrial input of these compounds.

The team collected water, sediment, algae, plant, insect, fish, crayfish, and mollusk samples at five sites along the river and analyzed them for 14 different PFAS compounds. Nearly every sample tested contained PFAS compounds. Biofilm contained the largest concentrations of 10 of the 14 PFAS compounds measured. Insects, which primarily eat biofilm, had the greatest accumulation of PFAS compounds of all the living taxa the researchers sampled.

When PFAS compounds are present at every step of the food chain, the compounds accumulate at each step leading to greater concentrations in animals that sit higher on the food chain – including humans. This is known as biomagnification.

Studies like this that reveal how prevalent PFAS can be within ecosystems without an industrial input highlight the need for further research into how these compounds affect the environment and human health.

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PFAS present throughout the Yadkin-Pee Dee river food chain

Photo, posted May 24, 2011, courtesy of the U.S. Fish and Wildlife Service via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Safer Disposal Of Printed Circuit Boards | Earth Wise

March 4, 2020 By EarthWise Leave a Comment

Printed circuit boards are key elements of modern electronic devices that support and connect all of their electronic components. On average, they are composed of 30% metallic and 70% nonmetallic substances.

Once the circuit boards have served their purpose, they are often burned or buried in landfills, and can pollute the air, soil, and water. The biggest problem is that they have brominated flame retardants added to them in order to keep them from catching fire. Compounds in brominated flame retardants have been linked to endocrine disorders and fetal tissue damage.

Many circuit boards are recycled to recover valuable materials – generally the metals they contain. But recycling has its own problems. Metallic components can be recovered from crushed circuit boards by magnetic and high-voltage electrostatic separations. When the metals are removed, what remains are resins, reinforcing materials, brominated flame retardants, and other additives, which are of little value and present various dangers.

Researchers at Sun Yat-sen University in China have developed a ball-milling method to break down these potentially harmful compounds, enabling safe disposal. A ball mill is a rotating machine that uses small agate balls to grind up materials. The researchers also added iron powder, which helps remove bromine from organic compounds by breaking the carbon-bromine bonds in the flame retardants. The result was particles with half of their bromine content removed as well as decomposition of phenolic resin compounds.

The ever-increasing proliferation of device technology had led to a new set of pollution and waste challenges facing society. Research on ways to reduce the impact of high-tech garbage is an important need for society.

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