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Removing nanoplastics from water

September 26, 2024 By EarthWise Leave a Comment

Plastic pollution is a growing problem for people and for the environment in multiple ways. When plastics break down over time, they can form small particles called microplastics – bits smaller than sesame seeds – and these, in turn, can break down into even smaller pieces called nanoplastics. They are too small to be seen with the naked eye and can enter the body’s cells and tissues.

Recent studies have shown that nanoplastics are increasingly showing up in bottled water. In fact, measurements on several popular brands of bottled water found an average of nearly a quarter million tiny pieces of plastic in a single liter of bottled water.

The health effects of ingesting all of this plastic are not really known, but they are unlikely to be anything good. Finding a way of avoiding this contamination of the beverages we drink is a pressing need.

Researchers at the University of Missouri have created a new liquid-based solution that eliminates more than 98% of microscopic plastic particles from water. The method makes use of water-repelling solvents made from safe, non-toxic natural ingredients. A small amount of this designer solvent absorbs plastic particles from a large volume of water.

The solvent sits on the water’s surface. When mixed with the water, it absorbs the plastic and eventually comes back to the surface carrying the plastic leaving behind clean, plastic -free water.

Ultimately, the hope is to scale up the process so it can be applied to increasingly large amounts of water – even lakes and, eventually, oceans. There is work to be done, but it is a potential way to address an increasingly worrisome and pervasive form of pollution.

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Mizzou scientists achieve more than 98% efficiency removing nanoplastics from water

Photo, posted August 9, 2012, courtesy of Enid Martindale via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Another ban on neonics

July 22, 2024 By EarthWise Leave a Comment

There have been ominous declines in many insect populations. Chief among them have been declines in pollinators, which have severe consequences for our food supply. There are multiple possible causes of these declines and undoubtedly several have been involved simultaneously.

A new study on butterfly populations in the Midwest indicates that agricultural insecticides exerted the biggest impact on the diversity of butterfly populations in the Midwest during the period 1998 to 2014. The biggest culprits were the widely used insecticides called neonicotinoids that are absorbed into the tissues of plants.

Neonics are meant for targeted pesticide use but are often used more broadly, including for corn crops.

Neonics are already well-known to be especially harmful to bees and are gradually being restricted in various places. Quebec province passed restrictions on neonic-treated seeds in 2019. Last December, New York signed into law a phase-out of neonic-treated seeds and a ban on non-agricultural uses of them.

Vermont has now become the second state to ban the use of neonicotinoids by virtue of its state legislature overriding a veto from Governor Phil Scott. The law minimizes the use of neonics by requiring potential users to obtain written exemptions.

Opponents to neonic restrictions claim that slashing their use will greatly reduce crop yields. The experience in Quebec over the past five years is that the Canadian neonic restrictions have reduced corn and soybean crop yields by about 0.5%. As a result of this tiny reduction, there has been a strong reduction in the amount of neonics contaminating waterways.

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Vermont Becomes Second State to Ban Bee-Killing Neonic Pesticides

New ‘Detective Work’ on Butterfly Declines Reveals a Prime Suspect

Photo, posted September 7, 2017, courtesy of Watts via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Cryopreserving Corals | Earth Wise

October 3, 2023 By EarthWise Leave a Comment

Recent climate models estimate that if the effects of climate change are not mitigated soon enough, 95% of the world’s corals could die by the mid 2030s. Given the current rate of greenhouse gas emissions, this is an increasingly likely outcome. Coral reefs are estimated to have a $10 trillion economic value apart from their essential role in marine ecosystems.

Researchers at the University of Hawaii at Manoa have demonstrated a successful technique for cryopreserving entire coral fragments; in other words, preserving coral using cold temperatures and successfully reviving them.

Existing coral cryopreservation techniques rely on freezing sperm and larvae, which can only be collected during spawning events, which occur only a few days each year for coral species. This makes it logistically very challenging for researchers and conservationists.

The Hawaiian researchers focused on a process called isochoric vitrification, which is a method of freezing with liquid nitrogen that prevents the formation of ice crystals. They tested the technique with thumbnail-sized fragments of coral, freezing them in small aluminum chambers which restrict the growth of ice crystals that would otherwise damage delicate polyp tissues. Once the chambers were warmed, the fragments were transferred to seawater and allowed to recover. They found that the revived corals behaved the same as those that were never cooled.

The process holds great promise to conserve the biodiversity and genetic diversity of coral. If the process can be scaled up, it may be possible to preserve as many species of coral as possible by 2030, when it may no longer be viable for them to survive in the warming and acidifying oceans.

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Cryopreservation breakthrough could save coral reefs

Photo, posted June 2, 2023, courtesy of USFWS – Pacific Region via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Rare Earths And The Energy Transition | Earth Wise

May 19, 2023 By EarthWise Leave a Comment

Limiting the rise in global temperature to no more than 1.5 degrees Celsius requires decarbonization. This means slashing fossil fuel use, switching to renewable energy sources, and electrifying as many sectors of the economy as possible. Doing these things requires huge numbers of wind turbines, solar panels, electric vehicles, and storage batteries. All of them use rare earth elements and other critical metals.

The 17 rare earth elements are actually common, but they are called rare because they are seldom found in sufficient quantities to be extracted easily or economically.

China once supplied 97% of the world’s rare earth elements as a result of government support, cheap labor, lax environmental regulations, and low prices. Once the world started to realize the dangers of being so dependent on China, many countries began developing their own rare earth element production. (However, today China still produces 60-70% of the world’s rare earth elements).

It is difficult to mine rare earth elements without causing environmental damage. The prevalent extraction techniques involve toxic chemicals that can leach into the environment and, because rare earths are often found near radioactive elements, mining often brings dangerous radioactive waste into the environment.

Researchers are working on ways to make rare earth mining more sustainable. Some of these include biomining – which uses microbes to extract rare earths from ores, electrical methods to free rare earths from ores, and so-called agromining, which is growing plants that hyperaccumulate rare earths from the soil into their tissues.

Making rare earth mining more sustainable and less harmful to the environment is an essential part of the world’s future.

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The Energy Transition Will Need More Rare Earth Elements. Can We Secure Them Sustainably?

Photo, posted November 18, 2008, courtesy of the Oregon Department of Transportation via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio