treatment

Reducing emissions from ocean shipping

August 13, 2025 By EarthWise Leave a Comment

Ocean shipping is a significant contributor to global carbon emissions, accounting for about 3% of the total. It is a key part of international trade, moving goods like electronics, automobiles, and oil. It relies on fossil fuels, and, without significant changes, shipping’s emissions could more than double by 2050. Ocean shipping is one of the world’s most difficult to decarbonize industrial sectors.

Scientists at the University of Southern California and Caltech, collaborating with a startup company called Calcarea, have developed a shipboard system that could remove up to half of the carbon dioxide emitted by shipping vessels. The system is fairly simple and scalable.

The process mimics a natural chemical reaction that takes place in the ocean. As a cargo ship moves through seawater, the CO2 from the ship’s exhaust is absorbed into water that is pumped onboard. This makes the water more acidic. The treated water is then passed through a bed of limestone, where it reacts with the rock to form bicarbonate, which is a stable compound that already exists naturally in seawater. The treated seawater, now stripped of the carbon dioxide, is dumped back into the ocean.

Sophisticated ocean modeling examined what would happen when the bicarbonate-rich water is released back into the sea over a hypothetical 10-year period. The model showed a negligible impact on ocean pH and chemistry.

The researchers estimate that widespread adoption of the technique could reduce shipping-related carbon dioxide emissions by 50%. The startup company Calcarea is working to bring the technology to market and is in early discussions with commercial shippers.

**********

Web Links

USC technology may reduce shipping emissions by half

Photo, posted November 14, 2017, courtesy of Bernard Spragg via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

PFAS and groundwater

November 26, 2024 By EarthWise Leave a Comment

Per- and polyfluoroalkyl chemicals, more commonly known as PFAS, are a family of human-made chemicals that have been manufactured and used in a variety of industries since the 1940s. They provide water-resistance, oil-resistance, dirt-resistance, and corrosion-resistance to a wide range of products, including food wrappers and packaging, clothing, dental floss, nonstick cookware, textiles, and electronics.

Exposure to PFAS has been linked to birth defects, thyroid disease, liver disease, kidney disease, and cancer. These chemicals do not break down in the environment and therefore, over time, become concentrated in plants, animals, and people.

According to a new first-of-its kind study by scientists at the U.S. Geological Survey, more than 20% of the U.S. population could be drinking groundwater contaminated with PFAS. The study, which was recently published in the journal Science, found that those living in the Eastern U.S. are particularly likely to be exposed.

The study is the first to report national estimates of PFAS in untreated groundwater that supplies drinking water to private and public wells. The USGS research also provides the first estimate of the total number of Americans – anywhere from 71 to 95 million – who might be exposed to this contamination.

The researchers note that their estimates merely measure the existence of PFAS – before the water has undergone any treatment or filtering – meaning that, while they may be present, they may be at very low levels.

To find a link to the detailed USGS map showing the probability of PFAS groundwater contamination in your region, visit our website: EarthWiseRadio.org.

**********

Web Links

PFAS in US Groundwater Interactive Dashboard

Predictions of groundwater PFAS occurrence at drinking water supply depths in the United States

Photo, posted January 12, 2008, courtesy of Andrew Kraker 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.

**********

Web Links

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

A Vaccine For Bees | Earth Wise

February 27, 2023 By EarthWise Leave a Comment

The US has seen annual reductions in honey bee colonies since 2006. According to the USDA, there are many factors that have contributed to the decline. These include parasites, pests, insecticides, disease, and a phenomenon called Colony Collapse Disorder in which worker bees abandon a hive and leave behind the queen.

One of major threats to bee colonies is American foulbrood disease, which is a bacterial condition that attacks bee larvae. It is highly contagious and has no cure. Until now, the only treatment method required burning the colony of infected bees along with the hives and equipment and treating nearby bee colonies with antibiotics.

Recently, the USDA has approved a conditional license for the world’s first vaccine for honey bees. The vaccine contains inactive bacteria of the type that causes American foulbrood disease.

The vaccine is incorporated into the royal jelly fed by worker bees to the queen bee. The queen ingests the feed and keeps some of vaccine in her ovaries. This gives bee larvae immunity to the disease as they hatch and thereby reduces death from the illness.

According to the California State Beekeepers Association, the new vaccine could be a major breakthrough for protecting bees. Preventing the infection in hives could avoid costly, destructive measures and allow the beekeepers to focus on other important elements of keeping bees healthy.

Bees as pollinators play a critical role in many ecosystems. For humankind, pollinators such as bees, birds, and bats are responsible for about a third of the world’s crop production.

**********

Web Links

US approves world’s first vaccine for declining honey bees

Photo, posted June 6, 2022, courtesy of Bernd Thaller via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Capturing Methane To Feed Fish | Earth Wise

December 30, 2021 By EarthWise Leave a Comment

Methane in the atmosphere is an extremely potent greenhouse gas. Its warming potential is about 85 times that of carbon dioxide over a 20-year period. It also worsens air quality by increasing atmospheric ozone. Many human activities add methane to the atmosphere, notably emissions from landfills and oil and gas facilities.

Capturing methane from these sources for subsequent use is currently uneconomical but new research from Stanford University analyzes the market for using the methane to feed bacteria to produce fishmeal.

Methane-consuming bacteria called methanotrophs can be grown in chilled, water-filled bioreactors containing pressurized methane, oxygen, and nutrients. The bacteria produce a protein-rich biomass that can be used as fishmeal in aquaculture. This could offset demand for fishmeal made from small fish or plant-based feeds that require land, water, and fertilizer.

Some companies already do this using natural gas provided by utility pipelines, but it would be far better for the environment to use methane emitted at large landfills, wastewater treatment plants, and oil and gas facilities.

Consumption of seafood has more than quadrupled since 1960, depleting wild fish stocks. Farmed fish now provide half of all the animal-sourced seafood we eat.

The Stanford research analyzed the cost of methanotrophic fishmeal production under various scenarios and found it to be very competitive with and in some cases considerably cheaper than current market prices for fishmeal.

According to the study, this process could profitably supply total global demand for fishmeal with methane captured in the U.S. alone.

**********

Web Links

Stanford researchers reveal how to turn a global warming liability into a profitable food security solution

Photo, posted April 30, 2017, courtesy of Artur Rydzewski via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Pesticide From Beer | Earth Wise

July 23, 2021 By EarthWise Leave a Comment

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.

**********

Web Links

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.

Cleaner Water Using Corn | Earth Wise

May 12, 2021 By EarthWise Leave a Comment

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

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

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

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

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

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

**********

Web Links

Cleaner Water Through Corn

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

Earth Wise is a production of WAMC Northeast Public Radio.

Antibiotics In The Environment

June 6, 2019 By EarthWise Leave a Comment

Antibiotics make their way into the environment in many ways. Sources of antibiotic pollution include the waste from large-scale animal farms and the wastewater from hospitals, municipalities, and antibiotic manufacturing.

A new study has discovered concentrations of antibiotics in some of the world’s rivers exceed safe levels by up to 300 times. In the project, researchers looked for 14 commonly used antibiotics in rivers in 72 countries across six continents. They found antibiotics at 65% of all the sites they examined.

The antibiotic ciproflaxacin was the compound that most frequently exceeded safe levels, surpassing that threshold in 51 places. The antibiotic metronidazole exceeded safe levels by the biggest margin. Concentrations of this antibiotic at one site in Bangladesh was 300 times greater than the safe level. The most prevalent antibiotic was trimethoprim. It was detected at 307 of the 711 sites.

Some of the world’s most iconic rivers were sampled as a part of this study, including the Danube, Mekong, Seine, Thames, Tiber and Tigris.

The project, which was led by the University of York, found that high-risk sites were often located near wastewater treatment systems, waste or sewage dumps, and in some areas of political unrest.

Safe levels for antibiotics, which were recently established by the AMR Industry Alliance, range from 20,000 to 32,000 nanograms per liter depending on the compound.

According to the research team, solutions to the problem of antibiotic contamination should include infrastructure investment, tighter regulation, and the remediation of already contaminated sites.

**********

Web Links

Antibiotics found in some of the world’s rivers exceed ‘safe’ levels, global study finds

Photo, posted October 7, 2013, courtesy of Nicola via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Llamas And The Flu

December 21, 2018 By EarthWise Leave a Comment

Last year’s flu season was the worst in 40 years. More than 80,000 people died in the U.S. last year from the flu and its complications. Flu vaccines are the best preventative we have, but there are still high mortality rates around the world. Some individuals respond poorly to vaccination, and variations in viruses makes targeting with the optimal antigen very difficult. The World Health Organization estimates that between 290,000 and 650,000 people die from seasonal flu worldwide each year.

[Read more…] about Llamas And The Flu

Urban Streams Are Breeding Superbugs

August 14, 2018 By EarthWise Leave a Comment

City streams are subjected to a constant onslaught of synthetic chemicals found in pharmaceuticals and personal care products. Wastewater treatment facilities are not designed to filter out these compounds. Instead, they flow into surface waters where they impact aquatic organisms like microbes – which perform key ecosystem services like removing excess nutrients and breaking down leaf litter.