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Fighting harmful algal blooms with harmful algal blooms

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Harmful algal blooms – HABs – occur when colonies of algae grow out of control and produce toxic or harmful effects on people, marine life, and birds.  HABs occur naturally but their frequency and intensity are often associated with increased nutrient loading (mainly phosphorous and nitrogen) in bodies of water that is the result of runoff from sources like lawncare and agriculture.

Researchers at Florida Atlantic University have developed a technique for transforming cyanobacteria – also known as blue-green algae and a prime HAB material – into an effective material for removing phosphorous from water.

Their process converts blue-green algal biomass – essentially hazardous waste – into a custom-made adsorbent material that can pull harmful phosphorous from water.  The algae is first quickly heated up using microwaves and then it is modified by adding lanthanum chloride. 

The study took blue-green algae from Florida’s Lake Okeechobee, synthesized the adsorbent material in minutes, and using only small amounts of it could remove 90% of the phosphorous present in only half an hour.  It worked perfectly well in the presence of natural organic matter.  Using the harmful algae itself to prevent algal growth in bodies of water is an innovative way to reduce its further occurrence.

Phosphorous is a major contributor to the occurrence of harmful algal blooms, which can lead to toxic water conditions, loss of aquatic life, and significant economic losses for the fishing and tourism industries.  This technique could prove to be an essential tool for managing the growing problem of nutrient pollution.

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FAU Engineering Develops New Weapon Against Harmful Algal Blooms

Photo, posted October 27, 2010, courtesy of Jennifer L. Graham / U.S. Geological Survey via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Fertilizer from thin air

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Ammonia is one of the largest-volume synthetic chemicals produced in the world. Globally, manufacturing plants produce about 200 million tons of it each year.  About 70% of ammonia is used to produce fertilizers.

Most ammonia is produced using the Haber-Bosch process, which converts hydrogen and nitrogen into ammonia.  The process is energy-hungry, running at over 900 degrees Fahrenheit, and therefore results in lots of greenhouse gas emissions – about 1% of the world’s annual CO2 emissions.

Researchers at Stanford University and King Fahd University in Saudi Arabia have developed a prototype device that can produce ammonia using wind energy to draw air through a mesh.  The method allows sustainable production of ammonia using the nitrogen in the air.

The process gets nitrogen from the air along with hydrogen from water vapor.  A mesh coated with catalysts facilitates the necessary chemical reactions.  The process operates at room temperature and standard atmospheric pressure, eliminating the need  for the high temperatures and high pressures of the Haber-Bosch process.

In principle, farmers could run a portable device onsite, eliminating the need to purchase and ship fertilizer from a manufacturer. 

The device is two or three years away from being market ready.  The developers are designing increasingly large mesh systems to produce greater quantities of ammonia.  Ammonia has more uses beyond fertilizers including its use as an energy carrier that can store and transport energy more efficiently than hydrogen gas.

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New device produces critical fertilizer ingredient from thin air, cutting carbon emissions

Photo, posted September 2, 2013, courtesy of Chafer Machinery via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Reducing farm nutrient pollution

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When farmers add nutrients to their fields in excess of their crops’ ability to utilize them, these excess nutrients can enter the surrounding environments and create environmental problems.  The primary culprits are nitrogen and phosphorous.  These fertilizer components emerge from fields and enter local waterways in surface runoff.

Researchers at the University of Illinois Urbana-Champaign have developed a form of designer biochar that can provide phosphorous in a time-released fashion and reduce the amount that escapes into the environment.

The researchers used sawdust and lime sludge, which are byproducts from milling and water treatment plants, respectively.  They mixed the two ingredients and formed pellets which were then slow-burned in low-oxygen conditions to create phosphorous-laden designer biochar.  Once the pellets bind all the phosphorous they can hold, they can be spread onto fields where the nutrient is slowly released over time.

They tested the pellets in working field conditions.  The pellets are used to remove phosphorous from drainage water and then can be reused in the field to provide the nutrient to the plants.   

The results were very encouraging.  The biochar proved to be a very effective way to provide phosphorous to crops and then reduce how much phosphorous enters the environment.  The cost of producing the biochar pellets was less than half that of alternative substances for phosphorous removal. 

There is currently no regulation that requires farmers to remove phosphorous from drainage water but there are a growing number of conservation-minded farmers who want to reduce nitrogen and phosphorous losses from their fields.  The idea that the recyclable pellets can both provide and control phosphorous is an attractive one.

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Scientists tackle farm nutrient pollution with sustainable, affordable designer biochar pellets

Photo, posted July 16, 2016, courtesy of Rick Obst via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Fertilizers from wastewater sludge

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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

Palm oil and water quality

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Palm oil is the world’s cheapest and most widely used vegetable oil.  In fact, more than 86 million tons of palm oil was consumed last year alone.  Even though few of us cook with it, palm oil can be found in approximately half of all packaged grocery items – everything from ice creams and pizzas to detergents and cosmetics. 

This massive global demand for palm oil is driving tropical deforestation around the world.  While many studies have shown how converting rainforests to oil palm plantations causes biodiversity loss, researchers from UMass Amherst are the first to demonstrate how these plantations also cause wide-ranging disturbances to nearby watersheds.

In the study, which was recently published in the journal Science of the Total Environment, the research team focused on the Kais River watershed of West Papua, a province in the far east of Indonesia.  Approximately 25% of the watershed has been turned into oil palm plantations. The watershed is also one of the oldest continually inhabited homes for different groups of Indigenous Papuans.

The researchers found that the conversion of tropical rainforest to oil palm plantation has increased precipitation, runoff, and soil moisture. Water quality in the watershed has also gotten dramatically worse: sedimentation has increased by 16.9%, nitrogen by 78.1%, and phosphorus by 144%.

The research team hopes regulators will work to limit the use of pesticides, conduct continuous water quality monitoring, and ensure that downstream communities have access to water quality information. 

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Oil Palm Plantations Are Driving Massive Downstream Impact to Watershed

Photo, posted December 13, 2008, courtesy of Fitri Agung via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Golf courses gone wild

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Golf courses are a significant burden on the environment.  The US has 16,000 golf courses which use 1.5 billion gallons of water a day and are treated with 100,000 tons of nitrogen, phosphorus, and potassium each year.  In recent years, the golf industry has taken steps to lighten its environmental toll by using less water, introducing pollinator-friendly plants, and decreasing pesticide and fertilizer use.  The US has more golf courses than any other country, accounting for 42% of all courses worldwide.

There is really an oversupply of golf courses and, as a result, more golf courses have closed than have opened since 2006.  Most closed golf courses end up in the hands of commercial or residential developers, but some of them are allowed to return to nature.

For this to happen, there has to be a willing seller and, more importantly, a conservation-minded buyer who can afford both to purchase the land and to restore it to a natural state.  There have been 28 former golf courses transformed into public green spaces between 2010 and the end of 2022.  But that number seems to be growing.

In 2023, the former Cedar View Golf Course on the eastern shore of Cayuga Lake in upstate New York was bought by the Finger Lakes Land Trust.  In California, places like Santa Barbara, Marin County, and even Palm Springs have all undertaken the transformation of former golf courses into public parklands.

Rewilding a golf course is undoubtedly a disappointment to local golfers, but it can bring big benefits to animals, plants, and people. 

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After Shutting Down, These Golf Courses Went Wild

Photo, posted October 19, 2016, courtesy of Cabo Girao via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Sustainable hydrogen from methane

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Hydrogen could serve as a viable alternative to fossil fuels that can be used directly as a fuel or can be used to generate electricity to power cars and other devices. However, large-scale production of hydrogen currently relies on fossil fuels and creates carbon emissions in the process.

So-called green hydrogen involves using electricity to split water into its component elements to produce it.  If the electricity is generated without emissions, then the hydrogen is truly green.

Another way to get hydrogen is by breaking down hydrocarbons like methane, which itself is a very powerful greenhouse gas.  This so-called blue hydrogen could be environmentally friendly if an appropriate method for producing it can be developed.

Existing techniques for converting methane into hydrogen involve the use of metal catalysts – often nickel – that are energy-intensive to mine and manufacture, and can negatively affect the environment.  Research at the University of Surrey in the UK has shown promising results for the use of nitrogen-doped nanocarbons as metal-free catalysts for the direct conversion of methane into hydrogen.  One of the biggest problems with using metal catalysts for hydrogen production is that they get poisoned by carbon.  The carbon that comes out of the methane ends up stopping the catalyst from continuing to do its chemical job.  It turns out that the doped nanocarbon approach to hydrogen catalysis appears to be resistant to this problem.

The development of sustainable hydrogen production methods, including efficient and sustainable electrolysis of water as well as catalysis of hydrocarbons like methane, is crucial to realizing the potential of hydrogen fuel as a clean energy source.

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‘Game-changing’ findings for sustainable hydrogen production

Photo, posted April 30, 2021, courtesy of California Energy Commission via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

How to reduce pollution from food production

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Present in animal manure and synthetic fertilizers, nitrogen is an essential nutrient for plant growth and is a critical input to enhance agricultural productivity on farms around the world.  But excessive and inefficient use of this nutrient is widespread.  In fact, up to 80% of it leaks into the environment, mostly in various polluting forms of nitrogen: ammonia and nitrogen oxides (which are harmful air pollutants), nitrous oxide (a potent greenhouse gas), and nitrate (which affects water quality).

A new report prepared for the United Nations has put forth some solutions to greatly reduce nitrogen pollution from agriculture in Europe.  A group of researchers coordinated by the U.K. Centre for Ecology & Hydrology, the European Commission, the Copenhagen Business School, and the National Institute for Public Health and the Environment of The Netherlands produced the report.

In it, the research team puts forth its recipe to reduce nitrogen pollution in Europe.  The report’s ingredients include:

  • Reducing by 50% the average European meat and dairy consumption
  • More efficient fertilizer application and manure storage
  • Reducing food production demand by reducing food waste by retailers and consumers
  • Better wastewater treatment to capture nitrogen from sewage
  • Adopting policies addressing food production and consumption to transition them towards more sustainable systems

Taking action to reduce nitrogen pollution will require a holistic approach involving farmers, policymakers, retailers, water companies, and individuals. 

Do Europeans have an appetite for change?

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Scientists provide recipe to halve pollution from food production

Photo, posted March 10, 2022, courtesy of USDA NRCS Montana via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Seabirds rescuing coral reefs

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A new study by researchers at Lancaster University in the UK has found that the presence of seabirds on islands adjacent to tropical coral reefs can more than double the coral growth rates on those reefs.

The study found that when coral reefs grow faster, they can bounce back more quickly from bleaching events that occur when the seas become too warm.  The focus of the study was a type of coral called Acropora, which provides complex structures supporting fish populations and reef growth. 

The researchers found that Acropora around islands populated by seabirds recovered from bleaching events about 10 months faster than reefs located away from seabird colonies.  Speeding up coral recovery times could prove the difference between continuing to bounce back from bleaching events and dying off.

The seabirds are helping the coral reefs with their droppings.  The birds feed on fish in the open ocean far from islands and then return to the islands to roost.  They deposit nitrogen- and phosphorus-rich nutrients in the form of guano, some of which is washed off of the islands by rain and into the surrounding seas.  The nutrients fertilize corals and other marine species.

To determine whether the faster growth rates were really due to the bird-supplied nutrients, the researchers studied rat-infested islands that had no bird populations.  The study confirmed that it was the presence of seabirds that provided enhanced nutrients for the coral reefs.  In fact, a primary outcome of the study was to add further weight to the growing body of evidence of the ecological damage across ecosystems on land and sea from invasive rats on tropical islands.

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Feathered friends can become unlikely helpers for tropical coral reefs facing climate change threat

Photo, posted September 15, 2019, courtesy of Rickard Zerpe via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Fossil-free fertilizer

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Ammonia is a major industrial commodity.  About 70% of it is used to make fertilizer, with the rest for a wide range of industrial applications.  Ammonia is the starting point for all mineral nitrogen fertilizers. 

Typically, ammonia is a byproduct of isolating hydrogen from natural gas, which releases large amounts of carbon dioxide.  On a global scale, the climate impact of ammonia production is comparable to that of air travel.  The world needs more ammonia but really cannot afford the emissions that come with its production.

There are also political implications of ammonia production.  Because it relies so heavily on natural gas, ammonia supply is vulnerable to disruptions from events like the Russian invasion of Ukraine.  Sanctions imposed after the invasion have hindered fertilizer exports, driving up costs, especially in places like Africa.

A small fertilizer plant near Nairobi, Kenya will be the first farm in the world to produce its own nitrogen fertilizer on site that is free of fossil fuels.  The plant is being built by an American startup company Talus Renewables and will use solar power to strip hydrogen from water.  The hydrogen will then bond with nitrogen from the air to form liquid ammonia.  The plant will produce one ton of ammonia each day.

The typical bag of fertilizer in sub-Saharan Africa travels 6,000 miles to get there, which of course only adds to the environmental burden of using it as well as its cost.  By building a small green ammonia plant like the one coming online in Kenya, it is possible to locally produce a critical raw material in a carbon-free manner.

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Farm in Kenya First to Produce Fossil-Free Fertilizer On Site

Photo courtesy of Talus Renewables via LinkedIn.

Earth Wise is a production of WAMC Northeast Public Radio

Salt Marshes And Climate Change | Earth Wise

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Salt marshes are coastal wetlands that are flooded and drained by salt water brought in and out by the tides. These low-lying wetlands are also sometimes called tidal marshes because they occur in the zone between low and high tides. These wetlands are some of the most biologically productive ecosystems on Earth.

Cape Cod’s beautiful salt marshes are as important as they are iconic.  They act as carbon sinks, protect coastal development from storm surge, play an outsized role in nitrogen cycling, and provide critical habitats for many fish, shellfish, and coastal birds.

According to scientists from the Marine Biological Laboratory in Woods Hole, Massachusetts, more than 90% of salt marshes around the world are likely to be underwater by the end of the century. 

Since 1971, scientists from the Marine Biological Laboratory have mapped vegetative cover in Great Sippewissett Marsh in Falmouth, Massachusetts, to examine whether increased nitrogen in the environment would impact species of marsh grass.  Because of the length of the study, the researchers were also able to investigate the impacts of climate change on the ecosystem, especially those driven by accelerating sea level rise. 

The research team found that increased nitrogen favored higher levels of vegetation and accretion of the marsh surface.  However, the researchers found that salt marshes will not be able to outpace the submergence from global sea level rise – no matter how much nitrogen is applied.

Sea level rise is the biggest threat to salt marshes around the world.  Mitigating some of these projected losses is critical in order for salt marshes to continue to provide their important ecosystem services for people and the planet.  

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Most of the World’s Salt Marshes Could Succumb to Sea Level Rise by Turn of Century

Photo, posted September 27, 2011, courtesy of Chris M Morris via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Seaweed On The Way | Earth Wise

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A type of seaweed called sargassum has long formed large blooms in the Atlantic Ocean.  It gets its name from the Sargasso Sea in the western Atlantic.  Since 2011, scientists have been tracking massive accumulations of the stuff each year that starts out off the coast of Africa and works its way across the Atlantic to end up in the Gulf of Mexico. 

The amount of sargassum present each year can shift depending on factors like changes in nutrients, rainfall, and wind conditions.  But since the 1980s, nitrogen content in the Atlantic has gone up by 45%.  This is likely due to human activities such as agriculture and fossil fuel production dumping materials into the rivers that feed into the ocean.

According to recent observations, the mass of seaweed now heading for Florida and other coastlines throughout the Gulf of Mexico may be the largest on record.  The giant blob of sargassum spans more than 5,000 miles in extent.  It is moving west and will pass through the Caribbean and up into the Gulf during the summer.  The seaweed is expected to become prevalent on beaches in Florida around July.

The seaweed provides food and protection for fishes, mammals, marine birds, crabs, sea turtles, and more.  But unfortunately, when sargassum hits the beaches, it piles up in mounds that can be difficult to walk through and eventually emits a gas that smells like rotten eggs.

Tourist destinations in the Caribbean region have their work cut out for them to remove seaweed that can pile up several feet deep.  For example, in Barbados, locals were using 1,600 dump trucks a day to clean their beaches.  Caribbean and Florida resorts spend millions of dollars each year to remove sargassum seaweed.

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A 5,000-mile-wide blob of seaweed is headed for Florida, threatening tourism across the Caribbean

Photo, posted February 24, 2020, courtesy of Bernard Dupont via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Electricity From Bacteria | Earth Wise

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Microbiologists at Radboud University in the Netherlands have demonstrated in the laboratory that methane-consuming bacteria can generate electrical power.  Their study was recently published in the journal Frontiers in Microbiology.

The bacteria studied is called Candidatus Methanoperedens and in the natural environment it consumes methane in water sources that are contaminated with nitrogen including places like water-filled ditches and some lakes. The bacteria in the study make use of the nitrates in the water to break down and digest the methane. Methanogens, which are bacteria that reduce carbon dioxide to form methane, are the source of the methane in these places. 

The researchers exploited these complex interactions of bacteria to create a source of electrical power that is essentially a kind of battery with two terminals.  One of the terminals is a chemical terminal and one is a biological terminal.  They grew the bacteria on one of the electrodes where the bacteria donate electrons that result from its conversion of methane.  (Other microbiologists at the same institution had previously demonstrated electrical generation from a similar battery containing anammox bacteria that use ammonium rather than methane in their metabolic processing).

In the study, the Radboud scientists managed to convert 31% of the methane in the water into electricity but they are aiming at higher efficiencies. 

This approach represents a potential alternative to conventional biogas electricity generation.  In those installations, methane is produced by microorganisms digesting plant materials and the methane is subsequently burned to drive a turbine to generate power.  Those systems in fact have an efficiency of less than 50%.  The researchers want to determine whether microorganisms can do a better job of generating electricity from biological sources than combustion and turbines can do.

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Bacteria generate electricity from methane

Photo, posted December 3, 2008, courtesy of Martin Sutherland via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Storing Sunshine To Make Electricity On Demand | Earth Wise

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Researchers at Chalmers University in Sweden have developed an entirely new way of capturing and storing energy from sunlight.  The system is called the Molecular Thermal Energy Storage System or MOST.  It is based on a specially designed molecule that changes shape when it is exposed to sunshine.

The molecule is composed of carbon, hydrogen, and nitrogen.  When sunlight hits it, it changes into an energy-rich isomer – a molecule made up of the same atoms but arranged together in a different way.  That isomer is stable and can be stored for many years.  When a specially designed catalyst is applied, the stored energy is released in the form of heat and the molecule returns to its original form and can be reused. 

The Chalmers researchers sent some of the energy-laden isomer to researchers in China who used it to operate a micron-thin thermoelectric generator, which used the heat released by the isomer material to generate electricity.  The generator is an ultra-thin chip that could be integrated into electronics such as headphones, smart watches, and telephones.  It is currently only at the proof-of-concept stage, but the results are quite promising.  The integration with the MOST technology provides a way that solar energy can generate electricity regardless of weather, time of day, season, or geographical location.  The results of the study were recently published in the journal Cell Reports Physical Science.

In effect, for this demonstration, Swedish sunshine was sent to the other side of the world and converted into electricity in China. The ultimate goal of this research is to create self-charging electronics that uses stored solar energy on demand.

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Converting solar energy to electricity on demand

Photo, posted March 11, 2013, courtesy of Steve Slater via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Florida’s Starving Manatees | Earth Wise

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Manatees, also called “sea cows”, have been the victims of farm runoff.  They have starved to death by the hundreds along Florida’s east coast because algae blooms fed by nitrogen-rich fertilizer runoff are proliferating on the ocean surface and blocking sunlight from reaching seagrass below.  Seagrass is the primary source of food for manatees in the winter.  As seagrass dies off, so do the manatees.

Over 1,000 manatees have been found dead so far this year.  It is estimated that fewer than 8,000 remain in Florida waters.  Efforts are underway to restore coastal seagrass in the region as well as clams and oysters, which filter pollutants from water.  Unless the water is cleared up, it will be difficult to regrow the seagrass.  But the current situation is that manatees are so short on food that they are eating seagrass roots, killing the plants and thwarting efforts to help seagrass recovery.

Given this dire situation, the federal governmental has approved a program of feeding manatees.  The starving animals will be fed by hand in Florida, which is a rare wildlife intervention.  Conservation agencies tend to favor leaving wild animals to their own foraging and hunting so that they don’t become dependent on human handouts.

During the trial phase of the program, wildlife experts are likely to feed the animals romaine lettuce and cabbage, which is what manatees in captivity eat.  The hope is to give the animals enough additional food for them to get through the winter.  The trial feeding will begin on private property.  It remains illegal for the public to feed manatees.

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Florida to feed starving manatees in rare conservation move

Photo, posted February 21, 2008, courtesy of Keith Ramos/USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Decarbonizing The Most Polluting Heavy Industries | Earth Wise

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The production of steel, cement, and ammonia accounts for about 20% of the carbon dioxide humans pour into the atmosphere.  Modern cities are largely constructed from concrete and steel and most of our food is grown using fertilizer made from ammonia. 

The most widely discussed solutions to decarbonizing these industries are green hydrogen and carbon capture and storage or CCS.

Steel manufacture is responsible for 11% of society’s emissions.  Most production starts by burning coal in a blast furnace. Using CCS could reduce emissions from burning the coal.  But the blast furnace could be eliminated entirely by the use of electrolysis to produce the pure iron needed to make steel.  This would be extremely energy-intensive but using a low-carbon source like green hydrogen could greatly reduce the emissions from making steel.

Ammonia is made by producing hydrogen from natural gas and then combining it with atmospheric nitrogen.  Both the hydrogen production and ammonia synthesis are energy intensive.  Using green hydrogen would eliminate emissions from the hydrogen production itself and new research on catalysts aims at lower-temperature, less-energy intensive ammonia synthesis.

Decarbonizing cement manufacturing is perhaps the toughest challenge.  Cement is made in a high-temperature kiln, typically heated by burning fossil fuels.  The process converts calcium carbonate and clay into a hard solid called clinker.  The main byproduct of that is even more carbon dioxide.  Burning green hydrogen and capturing carbon emission are about the best hope for reducing cement manufacturing emissions.

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Can the World’s Most Polluting Heavy Industries Decarbonize?

Photo, posted June 30, 2009, courtesy of Portland Bolt via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Wastewater And Ammonia | Earth Wise

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Ammonia is the second most produced chemical in the world.  More than half of it is used in agriculture to produce various kinds of fertilizer, to produce cotton defoliants that make cotton easier to pick, and to make antifungal agents for fruits.  Globally, ammonia represents more than a $50 billion a year market.

Current methods to make ammonia require enormous amounts of heat – generated by burning fossil fuels – to break apart nitrogen molecules so that they can bind to hydrogen to form the compound. Ammonia production accounts for about 2% of worldwide fossil energy use and generates over 400 million tons of CO2 annually.

Engineers at the University of Illinois Chicago have created a solar-powered electrochemical reaction that uses wastewater to make ammonia and does it with a solar-to-fuel efficiency that is 10 times better than previous comparable technologies.

The process uses nitrate – which is one of the most common groundwater contaminates – to supply nitrogen and uses sunlight to power the reaction.  The system produces nearly 100% ammonia with almost no hydrogen side reactions.  No fossil fuels are needed, and no carbon dioxide or other greenhouse gases are produced.  The new method makes use of a cobalt catalyst that selectively converts nitrate molecules into ammonia.

Not only is the reaction itself carbon-neutral, which is good for the environment, but if it is scaled up for industrial use, it will consume wastewater, thereby actually being good for the environment.  The new process is the subject of a patent filing and the researchers are already collaborating with municipal corporations, wastewater treatment centers, and others in industry to further develop the system.

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Combining sunlight and wastewater nitrate to make the world’s No. 2 chemical

Photo, posted August 29, 2018, courtesy of Montgomery County Planning Commission via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Pesticide From Beer | Earth Wise

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Researchers from the Neiker Basque Institute for Agricultural Research and Development in Spain have demonstrated that a combination of rapeseed cake and beer bagasse can be used to reduce populations of soil parasites and increase crop yields. 

Beer bagasse is spent brewers’ grain – the stuff that is left over after the beer is made.  Beer brewing generates substantial amounts of by-products, including large amounts of spent grain.  It already has some practical uses, including as a feedstock for biofuel, as a food additive, and it even has some medical uses.  But the new research has shown that the bagasse can be the basis for a biodisinfestation treatment to be used in agriculture.  The aim is to disinfect soils, protect soil microorganisms, and increase crop yields.

The actual material studied was a mixture of beer bagasse, rapeseed cake, and a generous amount of fresh cow manure.  The high nitrogen content of the mixture promotes the activity of beneficial microorganisms in the soil, which helps to break down organic matter and kill off nematodes and other parasites that damage crops.

Nematodes are common parasites that can penetrate plant roots to lay their eggs, which damages the root and prevents the plants from absorbing nutrients effectively.  Application of the bagasse-based mixture over 12 months increased crop yields by 15% and boosted healthy soil microbes.

The study demonstrated that agricultural byproducts can be an effective treatment for root-knot nematodes and other soil parasites, increase crop yields, and help promote sustainable food systems to reduce waste from the agricultural industry.  The researchers hope to identify other potential organic treatments for tackling soil parasite problems.

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Beer byproduct mixed with manure proves an excellent organic pesticide

Photo, posted July 1, 2011, courtesy of Quinn Dombrowski via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The World’s Largest Harmful Algal Bloom | Earth Wise

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Brown sargassum seaweed floats in surface water in a bloom that stretches all the way from West Africa to the Gulf of Mexico.  Sargassum provides habitat for turtles, crabs, fish, and birds.

The stuff carpets beaches along the tropical Atlantic, the Caribbean Sea, the Gulf of Mexico, and the east coast of Florida disrupting tourism.  Florida’s Miami-Dade County alone spends $45 million a year cleaning up sargassum.  Annual Caribbean clean-up is in excess of $120 million.

A study by Florida Atlantic University has discovered dramatic changes in the chemistry and composition of sargassum which has transformed the so-called Great Atlantic Sargassum Belt into a toxic dead zone.

The findings of the study suggest that increased nitrogen availability from both natural and human-generated sources, including sewage, is supporting blooms of sargassum and turning a critical marine nursery habitat into harmful algal blooms with catastrophic impacts on coastal ecosystems, economies, and human health.

The study found that today’s sargassum tissues compared with those of the 1980s have 35% more nitrogen content and 42% less phosphorus.  Much of the nitrogen increase is a result of agricultural and industrial runoff from the Congo, Amazon, and Mississippi Rivers. 

The fact that the bloom itself has expanded so tremendously was already suspected to be the result of significant changes in the ocean’s chemistry.  Given the negative effect that the Great Atlantic Sargassum Belt is having on the coastal communities, additional research is essential to guide mitigation and adaptation efforts.

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Sargassum now world’s largest harmful algal bloom due to nitrogen

Photo, posted June 5, 2016, courtesy of J Brew 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.

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