brine

More eco-friendly desalination

May 14, 2025 By EarthWise Leave a Comment

There are about 16,000 operational desalination plants, located across 177 countries, which generate an estimated 25 billion gallons of fresh water daily.

For every gallon of drinking water produced at a typical desalination plant, one and a half gallons of brine are produced. Much of it is stored in ponds until the water evaporates, leaving behind solid salt or concentrated brine for further treatment. There are various other techniques for concentrating brines, but they are energy-intensive and environmentally problematic. The process called electrodialysis uses electrified membranes to concentrate salts.

Water flows into many channels separated by membranes, each of which has the opposite electrical charge of its neighbors. Positive salt ions move towards negatively charged electrodes and negative ions move toward positive electrodes. Two streams result, one containing purified water and one containing concentrated brine.

This eliminates the need for evaporation ponds, but existing electrodialysis membranes either result in leakage of salts into the environment or are too slow, making the process impractical for large-scale use.

Researchers at the University of Michigan have developed a new kind of membrane for electrodialysis. The new membranes don’t leak and are ten times more conductive than those on the market today which means that they can move more salt using less power. The membranes can be customized to suit a broad range of water types, which may help make desalination a more sustainable solution to the world’s growing water crisis.

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Making desalination more eco-friendly: New membranes could help eliminate brine waste

Photo, posted February 4, 2012, courtesy of David Martinez Vicente via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Lithium in Arkansas

November 28, 2024 By EarthWise Leave a Comment

Lithium is the critical raw material in the batteries that power electric cars as well as cell phones, computers, and other gadgets. The stuff has been nicknamed “white gold” for good reason. Chile and Australia are the world’s largest producers of the metal, which is mostly extracted from brine in evaporation ponds. The majority of it is then processed in China. The energy industry has been increasingly working to produce the raw materials needed to produce lithium-ion batteries in the United States and process those materials domestically. There are multiple projects at various stages across the country.

Researchers at the US Geological Survey and the Arkansas state government recently announced that they have discovered a vast trove of lithium in an underground brine reservoir in Arkansas.

With a combination of water testing and machine learning, the researchers determined that there could be 5 to as much as 19 million tons of lithium in the geological area called the Smackover Formation. This is more than enough to meet all the world’s demand for it.

Several companies – including Exxon Mobil, which is covering its bets on the future of oil as an energy source – are developing projects in Arkansas to produce lithium. If these companies can develop and scale up economical new ways to extract lithium from salty water, the region in Arkansas could become the lithium capital of the world.

Energy and mining companies have produced oil, gas, and other natural resources in the Smackover Formation, which extends from Texas to Florida. The same brines have long been the source of other valuable substances.

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Arkansas May Have Vast Lithium Reserves, Researchers Say

Photo, posted May 22, 2020, courtesy of the European Space Agency via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

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

Lithium in Arkansas

April 11, 2024 By EarthWise Leave a Comment

There are more and more electric cars on the road and utilities are installing record amounts of battery storage to back up solar and wind power generation. Both of these things currently use lithium-ion batteries so the need for them keeps growing.

There is actually plenty of lithium in the world. Sources of more than 100 million tons have been identified, which is enough to meet the projected needs for decades. But lithium is not easy, cheap, or environmentally friendly to extract. It is either blasted out of rocks that are then roasted at 2000-degree temperatures, or it is extracted from brine in places like the high Andes where it leaves behind toxic residues. Ramping up lithium production could greatly diminish the environmental benefits derived from green technologies.

A technique called direct lithium extraction, or DLE, may be a possible solution. The lithium is pulled out of brine while leaving other dissolved compounds behind. It is being tested in many places around the world and appears to offer the lowest negative impacts of available extraction technologies.

The Salton Sea area in California has rich deposits of lithium and is a good candidate for DLE. But conditions may be even better in Arkansas whose Smackover Formation is a brine-rich expanse of limestone.

The area was a productive oil field a hundred years ago and then undertook brine-processing in the 1950s to extract bromine. So, the area already has industrial infrastructure and no new land would need to be cleared.

The former oil fields of Arkansas may become an important domestic source of lithium.

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In Rush for Lithium, Miners Turn to the Oil Fields of Arkansas

Photo, posted February 26, 2021, courtesy of Ivan Radic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Lithium In The Salton Sea | Earth Wise

October 2, 2023 By EarthWise Leave a Comment

The Salton Sea is a shallow, landlocked, extremely salty body of water in the southern end of California. It was formed from an inflow of water from the Colorado River in 1905 in the aftermath of a collapse of a canal during spring floods. At one time, it was a thriving tourist destination and site of real estate speculation. It was also a crucial habitat for migratory birds and various aquatic species.

Over the past 20 years, the Salton Sea has become increasingly desiccated and polluted with agricultural runoff and waste. Rising salinity and the shrinking water supply from the Colorado River has made it uninhabitable for many species.

Recently, the Salton Sea has attracted new attention because of untouched lithium deposits located beneath its shores. The general area has acquired the moniker “Lithium Valley” and has become a place where major energy companies are exploring advanced mining techniques such as Direct Lithium Extraction (DLE). This new technique enables lithium to be captured from brine deposits without resource-intensive open-pit mining or evaporation pond processes.

Lithium is crucial for making the batteries that power electric vehicles. DLE mining has attracted large investments from billionaires like Warren Buffet, Bill Gates, and Jeff Bezos.

Lithium mining has generated major controversies because of its potential to damage the environment. Whether the new mining techniques can avoid these problems and tap into the potential resources near the Salton Sea remains to be seen. According to experts, the aquifers near the Salton Sea hold enough lithium to supply close to 40% of the global demand.

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As Companies Eye Massive Lithium Deposits in California’s Salton Sea, Locals Anticipate a Mixed Bag

Photo, posted October 28, 2021, courtesy of Christian Collins via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Water For Arizona | Earth Wise

July 17, 2023 By EarthWise Leave a Comment

The Phoenix area is the fastest growing region in the country. Arizona’s two major sources of water – groundwater and the Colorado River – are dwindling from drought, climate change, and overuse. Officials in the state are considering a radical plan to construct a desalination plant off the Mexican coast that will take the salt out of seawater, and then pipe that water hundreds of miles, much of it uphill, to Phoenix.

The project is the brainchild of the Israeli company, IDE, which is one of the world’s largest desalination companies. IDE has asked Arizona to sign a 100-year contract to buy water from the project.

There are multiple complications surrounding the plan. Desalination plants are common in California, Texas, and Florida, and in more than 100 other countries. But the Arizona project is unusual because of the distance involved and because the state is landlocked. The water would have to travel 200 miles and climb 2,000 feet along the way.

There is also the issue of waste brine, which is a major output of desalination plants. In this case, the brine would flood the northern Gulf of California, potentially threatening a productive fishery. In addition, the pipeline, as well as electrical transmission lines, would have to go through the Organ Pipe Cactus National Monument, a UNESCO biosphere reserve.

The plant would be located in Puerto Peñasco, a struggling town with its own water problems.

With booming home construction going on in the Phoenix area, the need for more water continues to grow. Whether this plan will be approved by Arizona and by Mexico remains to be seen.

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Arizona, Low on Water, Weighs Taking It From the Sea. In Mexico.

Photo, posted September 26, 2008, courtesy of Dan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Great Salt Lake In Danger | Earth Wise

March 20, 2023 By EarthWise Leave a Comment

Utah’s Great Salt Lake has been plagued by excessive water use and extensive drought conditions. As of January, the lake dropped to record-low water levels, losing 73% of its water and exposing 60% of its lakebed. According to scientists, the lake could disappear entirely within five years.

Great Salt Lake is what is known as a “terminal lake,” which means that it is fed only by rain, snow, and runoff and has no rivers that take water to the ocean. As a result, salt and minerals build up over time. With so much salt in the water, only brine flies and shrimp can survive in it. The unique ecosystem supports 10 million migratory birds. As the lake continues to dry up, the water is becoming too salty for even algae and microbes to survive. With shallow mud replacing previous shallow water, the nests of the 80,000 white pelicans that annually come to the lake are endangered by predators that can simply walk over to the eggs.

The historic low water levels have exposed 800 square miles of lakebed. This lakebed holds centuries of natural and manmade toxins like mercury, arsenic, and selenium. The exposed mud ultimately turns to dust that is carried off into the air. This is contributing to what is already some of the worst winter air pollution in the nation. Scientists warn that the unfolding ecological disaster may become a human health disaster.

State officials and university researchers have formed a “Great Salt Lake Strike Team” looking for ways to get more water to the lake. There are a number of so-called moonshot proposals to save the lake. It remains to be seen what will be done, but the clock is ticking.

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Great Salt Lake will disappear in 5 years without massive ‘emergency rescue,’ scientists say

Scientists fear a Great Toxic Dustbowl could soon emerge from the Great Salt Lake

Photo, posted September 19, 2009, courtesy of John Morgan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Saving The Sea From Salt

July 18, 2016 By WAMC WEB

The Persian Gulf along with the Red and Mediterranean seas are getting saltier all the time because of the waste products of desalination. The United Arab Emirates, Saudi Arabia, Kuwait, Qatar, Bahrain and Oman account for 45% of the world’s desalination capacity. And the byproduct of desalination is brine, which is twice as salty as seawater. Even advanced desalination plants produce two cubic meters of waste brine for every one cubic meter of clean water.