purify

A new way to help purify water

February 27, 2025 By EarthWise Leave a Comment

Engineers at the University of Michigan and Rice University have developed a new technology for removing boron from seawater, an important step in turning seawater into safe drinking water.

Boron is a natural component of seawater that remains a toxic contaminant in drinking water after conventional filters remove salts from seawater. The boron levels in seawater are about twice as high as the World Health Organization’s most lenient limits for safe drinking water and 5 to 12 times higher than what many agricultural plants can tolerate.

Boron passes through the reverse osmosis membranes used in desalination plants in the form of boric acid. To remove it, the desalination plants normally add a base to the treated water that causes the boric acid to become negatively charged. An additional membrane then removes the charged boron, and an acid is then added to neutralize the water. All of this is expensive and complicated.

The new technology uses electrodes that remove boron by trapping it inside pores studded with oxygen-containing structures that bind with boron but let other ions pass through. Capturing boron with electrodes enables treatment plants to avoid the need for a second stage of reverse osmosis.

Global desalination capacity reached 95 million cubic meters a day in 2019. The new membranes could save nearly $7 billion a year. Such savings could make seawater a more accessible source of drinking water for a thirsty world. Freshwater supplies are expected to meet only 40% of the world’s demand by 2030.

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New water purification technology helps turn seawater into drinking water without tons of chemicals

Photo, posted August 21, 2018, courtesy of Alachua County via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Electric Steel Furnaces | Earth Wise

August 29, 2023 By EarthWise 1 Comment

Steel was first made thousands of years ago. The discovery that heating up iron ore in a hot enough charcoal fire could purify the iron into a strong and valuable material was the start of the Iron Age. In many ways, things have changed very little since then.

Global iron and steel production accounts for 7% of society’s carbon emissions. Making steel generally involves burning coal in a blast furnace to produce the very high temperatures required to turn iron into steel. The coal is used both as a feedstock and as a fuel. Steel is made from iron and a substance called coke, which is basically coal that has been carbonized at high temperatures. Coal itself is burned to provide the high temperatures needed.

A new analysis from the Global Energy Monitor think tank shows that the global steel industry is slowly embracing electric-arc furnaces to produce the necessary heat, which is a cleaner alternative. The analysis found that 43% of forthcoming steelmaking capacity will rely on electric-arc furnaces, up from 33% last year.

According to the study, the shift to cleaner steel is not happening fast enough. To meet the emissions reductions goals of the Paris Climate Agreement, electric-arc furnaces must account for 53% of global steelmaking capacity by 2050. Based on the current plans, those furnaces would only account for 32% of total capacity by that year.

In order to meet these goals, the steel industry will need to retire or cancel about 381 million tons of coal-based manufacturing capacity and add 670 million tons of electric-arc furnace capacity.

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Steel Industry Pivoting to Electric Furnaces, Analysis Shows

Photo, posted March 3, 2012, courtesy of Jeronimo Nisa via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Cloning Ancient Redwoods

January 30, 2019 By EarthWise Leave a Comment

During the 19th and 20th centuries, many of the world’s largest and oldest tress were cut down for their lumber. Some of these coast redwoods were 3,000 years old and measured 35 feet in diameter.

Today, giant stumps of these ancient redwoods dot the landscape from Oregon to northern California and are a remnant of the old-growth forest that once stretched across much of the Pacific Northwest.

An organization called the Archangel Ancient Tree Archive is dedicated to reestablishing ancient redwood forests to help combat climate change. Coastal redwoods are not only huge but can grow an average of 10 feet a year. One of these enormous trees can sequester 250 tons of carbon dioxide over its lifetime, more than 200 times the amount for an average tree.

While many experts thought that the giant stumps were lifeless, arborists at Archangel collected DNA from the stumps of five giant coast redwoods, all larger than the largest tree living today. They then used this genetic material to grow dozens of saplings, which are clones of the ancient trees, in a process that takes about two-and-a-half years.

To date, the Archangel Ancient Tree Archive has planted nearly 100 of these saplings in the Eden Project garden in Cornwall, England, a couple of hundred in Oregon, and most recently, has planted 75 in the Presidio National Park in San Francisco.

According to arborists at the nonprofit organization, these saplings have extraordinary potential to purify our air, water, and soil for generations to come. Their hopes are that the new San Francisco ‘super grove’ will be allowed to grow unmolested by manmade or natural disasters and thus propagate forever.

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Arborists Have Cloned Ancient Redwoods From Their Massive Stumps

Photo, posted April 8, 2013, courtesy of Michael Balint via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Clean Air And Energy

July 7, 2017 By EarthWise

Researchers in Belgium have engineered a device that uses sunlight to purify polluted air and, in the process, produces hydrogen gas that can be stored and used for power. Two teams of researchers separately investigating processes for air purification and hydrogen production combined their efforts to create the new device.

[Read more…] about Clean Air And Energy