disposal

Minerals from seawater

June 27, 2024 By EarthWise Leave a Comment

There are about 18,000 desalination plants around the world that take in 23 trillion gallons of water each year. The plants produce more than 37 billion gallons of brine – enough to fill 50,000 Olympic-size swimming pools – every day. Disposing of this brine is an ongoing challenge. Dumping it into the ocean can damage marine ecosystems. Inland desalination plants either bury this waste or inject it into wells, adding further cost and complexity to the already expensive process of desalination.

According to researchers at Oregon State University, this waste brine contains large amounts of copper, zinc, magnesium, lithium, and other valuable metals. A company in Oakland, California called Magrathea Metals has started producing modest amounts of magnesium from waste brine in its pilot projects. With support from the U.S. Defense Department, it is building a larger-scale facility to produce hundreds of tons of the metal over two to four years.

Most of the world’s magnesium supply comes from China, where producing it requires burning lots of coal and utilizing lots of labor. Magrathea’s brine mining makes use of off-peak wind and solar energy and is much less labor intensive.

No large-scale brine mining operations currently exist and when there are some, they might end up having negative environmental impacts. But in principle, the process should produce valuable metals without the massive land disturbance, acid-mine drainage, and other pollution associated with traditional mining. Brine mining could turn a growing waste problem into a valuable resource.

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In Seawater, Researchers See an Untapped Bounty of Critical Metals

Photo, posted February 18, 2017, courtesy of Jacob Vanderheyden via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Red mud and steel

February 21, 2024 By EarthWise Leave a Comment

Most of us have never heard of red mud. Otherwise known as bauxite residue, it is an industrial waste product generated by the most common process by which aluminum is made and the world produces 200 million tons of red mud each year. The stuff is a significant environmental hazard being extremely alkaline and corrosive. Most of it ends up in large landfills and the costs associated with disposing of red mud are substantial.

Red mud is red because it contains large amounts of iron oxide, often as much as 60% of it. Scientists at the Max-Planck Institute in Germany have developed a method for producing steel from red mud that is much less carbon intensive than traditional steel production and that is economically viable.

The scientists melt the red mud in an electric furnace powered in part by green hydrogen. Running the furnace this way, even when using electricity from only partially renewable sources, results in far fewer greenhouse gas emissions as well as economic benefits. In the furnace, liquid iron separates from the other liquid oxides and can be extracted easily. The resultant iron is so pure that it can processed directly into steel. The remaining metal oxides are no longer corrosive, and they solidify into a glass-like material that can have practical uses in construction.

There are 4 billion tons of red mud that have accumulated worldwide to date. According to the researchers, their process could produce over 700 million tons of green steel from it, potentially saving 1.6 billion tons of carbon dioxide emissions.

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Green steel from toxic red mud

Photo, posted September 7, 2021, courtesy of Healthy Gulf via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Pulling Carbon Dioxide Out Of Seawater | Earth Wise

April 17, 2023 By EarthWise Leave a Comment

The world’s largest sink for carbon dioxide from the atmosphere is the ocean. The world’s oceans soak up 30-40% of all the gas produced by human activities. Dissolving carbon dioxide in water produces carbonic acid. This is the reason that oceans are becoming increasingly acidic, which is causing serious damage to ocean ecosystems.

There are many efforts underway aimed at directly removing carbon dioxide from the air as a way to mitigate the effects of ongoing emissions. But another possibility is to remove CO2 directly from ocean water. Existing methods for doing it involve the use of expensive membranes and complex chemicals. The economics of such methods are quite unfavorable.

Recently, a team of researchers at MIT has identified what they claim is a truly efficient and inexpensive removal mechanism. It involves a reversible process based on membrane-free electrochemical cells. Electrodes in the cells release protons that are introduced to seawater which drive the release of carbon dioxide dissolved in the water. The carbon dioxide can be collected and the processed water ends up being alkaline.

Running this process at a site that is already collecting seawater – such as at a desalination plant – would be an effective way to collect carbon dioxide as well as help mitigate ocean acidification.

Once the carbon dioxide is removed from the water, it still needs to be disposed of, just as is the case for other carbon removal processes. It could be turned into useful chemicals or it could be stored in underground caverns. But this approach is fairly unique in that the carbon dioxide has already been captured by the ocean. The issue remains what to do with it.

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How to pull carbon dioxide out of seawater

Photo, posted January 19, 2016, courtesy of Judy Dean via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Keeping Trash Out Of The Ocean | Earth Wise

February 23, 2023 By EarthWise Leave a Comment

The Ocean Cleanup is a non-profit organization, founded in 2013 by Dutch inventor Boyan Slat, to develop and scale technologies to rid the world’s oceans of plastic. It is an organization that proudly declares that its primary aim is to put itself out of business by successfully cleaning up the oceans.

A major activity of The Ocean Cleanup is efforts to clean the ocean garbage patches that have accumulated in several places, best-known of which is the Great Pacific Garbage Patch. The effort involves use of large U-shaped floating barriers that act as an artificial coastline to trap garbage which is then funneled into a barge for disposal. Ten full-sized systems will be needed to clean up the Great Pacific Garbage Patch.

A second activity of The Ocean Cleanup is preventing garbage in rivers from making its way into the oceans. Rivers are the main source of ocean plastic pollution. The Ocean Cleanup has developed river machines called Interceptors that capture garbage for disposal. Last fall, they installed a machine called Interceptor 007 in Ballona Creek, a waterway in the Los Angeles area. In the first rainfall after installation, the Interceptor managed to stop 35,000 pounds of waste from entering the ocean in just a few days.

The original Interceptor models have been deployed in Indonesia, Malaysia, the Dominican Republic, and Vietnam. A different type called the Interceptor Trashfence is being tested in Guatemala.

The Ocean Cleanup states that if fleets of its barrier systems are installed in all the garbage patches and Interceptors in the 1000 most significant rivers, 90% of floating ocean plastic can be removed by 2040.

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The Interceptor 007 Stops 35,000 Pounds Of Trash From Entering Ocean

The Ocean Cleanup

Photo, posted February 23, 2015, courtesy of Ministerie van Buitenlandse Zaken via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Carbon Footprint Of Electric Vehicles | Earth Wise

November 29, 2022 By EarthWise Leave a Comment

Electric vehicles are widely known to be the environmentally friendly alternative to internal combustion-based cars. But there are skeptics who argue that EVs actually have a larger carbon footprint than nonelectric vehicles. The argument is that the manufacturing and disposal of vehicle batteries is very carbon intensive. They also point to the reliance on coal to produce the electricity that powers the cars.

These claims have led to multiple studies in the form of life-cycle analyses comparing the amount of greenhouse gases created by the production, use, and disposal of a battery electric vehicle to that associated with a gasoline-powered car of a similar size.

In short, the studies have found that while it is true that the production of a battery electric vehicle results in more emissions than a gasoline-powered one, this difference disappears as the vehicle is driven.

According to a study conducted by the University of Michigan and financed by the Ford Motor Company, the emissions equation evens out in 1.4-1.5 years for sedans, 1.6-1.9 years for S.U.V.s, and about 1.6 years for pickup trucks.

Emissions from driving come from burning gas in the nonelectric vehicles and from the generation of electricity used by the battery-powered cars. In the current average power mix across the U.S., driving an EV results in a 35% reduction in emissions. However, it varies tremendously by location. There are some places with very dirty power and some with very clean power. But of the more than 3,000 counties in the U.S., only 78 end up with higher emissions from electric cars. Of course, as the electric grid gets greener, the advantages of electric cars only become greater.

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E.V.s Start With a Bigger Carbon Footprint. But That Doesn’t Last.

Photo, posted May 21, 2022, courtesy of Ivan Radic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Plastic Recycling Isn’t Working | Earth Wise

June 13, 2022 By EarthWise Leave a Comment

A recent report from several environmental organizations shows that plastic recycling rates in the U.S. have actually declined in the last several years from about 8.7% of discarded plastic to less than 6%. Meanwhile, since 1980, per capita plastic waste generation has increased 263%, totaling 218 pounds of plastic waste per person as of 2018.

Diminishing recycling rates don’t necessarily indicate a lack of interest by the public. Plastic recycling is a complicated process. There are multiple types of plastic that can’t be intermingled and there are no simple and sustainable ways to recycle many forms of plastic. On top of that, the declining recycling rate also reflects the fact that we no longer can export our plastic waste to countries like China and Turkey, which have banned U.S. waste imports.

Recycling in general is a successful practice. Paper recycling rates are around 66% as of 2020. Cardboard recycling was at 88.8% in 2020, and metal recycling rates range from 27% to 76%, depending on the type of metal. Glass recycling rates are a little over 30%. Only plastic recycling has never reached 10%, even before shipping our waste overseas and declaring it to be recycled was going on.

According to environmental organizations focused on the global plastic problem, there is no circular economy of plastics. Perhaps if truly biodegradable plastics became practical, economical, and widely utilized, the situation would be different. As things stand, the only solution is to reduce the production, use, and disposal of plastics.

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Plastics Recycling ‘Does Not Work,’ Environmentalists Stress as U.S. Recycling Rates Drop to 5%

Photo, posted May 13, 2021, courtesy of Ivan Radic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Takeout Food And Ocean Litter | Earth Wise

August 5, 2021 By EarthWise Leave a Comment

The Covid-19 pandemic saw most of us making use of take-out or delivery services as our only access to restaurant food. It was a valuable link to normal life. But unfortunately, the packaging of takeout food is a major contributor to the global plastic waste problem that isn’t going to disappear just because people are returning to eating in restaurants.

A new analysis of more than 12 million items by UK researchers published in the journal Nature Sustainability has found that the majority of ocean litter collected around the world is in the form of takeout food items: bags, wrappers, containers, straws and cutlery, aluminum cans, and plastic and glass bottles. Eighty percent of all the items surveyed were made of plastic.

Wrappers and packaging tended to concentrate along coasts, gathering on the shore and the sea floor. Takeout trash was rarer in the open ocean. In those areas, fishing debris accounted for half of the litter.

The authors of the study argue that efforts to curb plastic waste should prioritize takeout food and beverage containers. They recommend that avoidable takeout items, like single-use plastic bags, should be replaced with non-plastic and biodegradable materials. The authors also recommended making plastic producers responsible for the collection and disposal of plastic products.

As of July 1, the European Union has banned the 10 most common plastic and Stryofoam products found on European beaches. The EU is also establishing an active European market for recycled plastics based on the principles of extended producer responsibility.

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Takeout Food and Drink Containers Account for Bulk of Ocean Litter

Photo, posted September 14, 2009, courtesy of Susan White/USFWS 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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Toward safer disposal of printed circuit boards

Photo, posted February 18, 2018, courtesy of Diego Torres Silvestre via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Fishers Helping To Clean The Oceans

August 2, 2019 By EarthWise Leave a Comment

Marine litter – particularly plastics – is a global, persistent, and increasing threat to the oceans. Much of it comes from discarded materials on shore that makes their way to the sea but waste from the fishing industry is a also a major contributor to the problem.

Commercial fishers are acutely aware of the potential for marine litter to damage and even destroy their livelihoods and are starting to try to be part of the solution instead of just part of the problem.

An initiative called Fishing for Litter, which has been operating around the British coastline since 2006, is an example.

With hubs in Scotland and South West of England, FFL aims to reduce the amount of marine litter in the sea by physically removing it while also highlighting the importance of good waste management in the fishing fleet. Fishers have to assume responsibility for their own waste and dispose of it in a responsible manner. They also have a unique ability to access remote and hard to reach marine litter caused by others.

A survey of 120 commercial fishers revealed that they often found marine litter in their hauls and that keeping the sea and coasts clean was important to them.

The responsibility for reducing marine litter does not belong to any single industry or organization. It requires a collective global change of behavior. The problem directly affects fishers, so they are especially motivated to do something about it. They can make an important contribution to an issue that ultimately affects us all. Groups like Fishing for Litter are providing a model for behavior that we can only hope that others around the world can emulate.

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Fishers keen to help address the problem of marine litter

Photo, posted July 9, 2009, courtesy of Rennett Stowe via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Cleaning Up Mount Everest

May 31, 2019 By EarthWise Leave a Comment

Mount Everest is the highest mountain above sea level with an elevation over 29,000 feet. As such, it is a prime attraction for mountain climbers seeking that ultimate achievement. The summit was first reached in 1953 and for a long time, only major expeditions by the best mountaineers sought to repeat the feat.

In recent years, climbing Everest has become much more common. In fact, since 1953, more than 4,000 people have reached the summit of the world’s highest mountain. A record 807 accomplished the feat last year alone. Thousands more visit lower elevations.

But climbing Everest is neither safe nor easy. Ice and snow, powerful winds, and generally harsh conditions make Everest a treacherous place. Over the decades, hundreds of climbers have died on its slopes and many of their bodies are still up there. Apart from human remains, there are decades worth of garbage left behind by hikers and tourists.

The government of Nepal has mounted an ambitious project to clean up the refuse on Mount Everest. In just the first two weeks, volunteers removed more than three tons of trash from the mountain. Among the rubbish removed from Everest are tents, climbing equipment, bottles, cans, empty oxygen containers, and human waste. They also discovered the bodies of four climbers that had emerged from melting snow and ice.

Helicopters carried a third of the garbage to Kathmandu for recycling. The rest was taken to a local district for disposal in landfills. The initial work started at Everest’s base camp. They are next moving to sites higher on the mountain. They hope to remove at least 10 tons of trash this year.

Nepal would like to make the world’s tallest mountain clean.

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Volunteers Remove 3 Tons of Trash From Mount Everest in Two Weeks

Photo, posted May 23, 2012, courtesy of Gunther Hagleitner via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Drugs In The Water

April 15, 2019 By EarthWise Leave a Comment

According to a new study published in the journal Environmental Research Letters, concentrations of pharmaceuticals in rivers and lakes have dramatically increased across the globe over the past 20 years.

Traces of medicines get passed into waterways through the excretion of active drugs in human waste, the disposal of unused medicines down drains, and runoff from livestock farms.

The study looked in detail at two specific drugs: carbamazepine, an anti-epileptic drug, and ciprofloxacin, an antibiotic. The study found that the risk of ecological damage from the residue from these two drugs was 10 to 20 times higher in 2015 than in 1995.

Chronic exposure to carbamazepine, for example, has been shown to alter feeding behavior and reduce egg viability in zebrafish, as well as reduce reproductive success in crustaceans. Antibiotics can alter major nutrient cycles and decrease the effectiveness of bacteria-based wastewater treatment systems.

The study, led by researchers from the Netherlands, created a new model estimating concentrations of the two drugs over a 20-year period in 449 aquatic systems around the globe. The model predicts a relatively high environmental risk in densely populated and dry areas such as the Middle East.

When the researchers compared the model’s results to samples from four river systems in various locations, they found that the actual drug concentrations were even higher than model results, in some cases by a factor of 10 to 100.

The new model should act as a guide for a more thorough investigation into pharmaceutical residues in waterways, which pose significant environmental risks all over the world.

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