Demand for lithium is now driving industrial activity to one of the most famous salt flats on earth, a place long admired for its beauty and isolation.
New evidence shows that extracting this metal It silently amplifies toxic risks and its effects can extend far beyond the mine site.
Uyuni salt flats where tensions rise
The world’s largest known lithium deposit lies beneath Bolivia’s Salar de Uyuni. Here, highly saline groundwater is pumped, concentrated and fed into battery production.
Today, tourism and early mining share the Uyuni Salar on the Bolivian plateau, where the salt temporarily turns into a mirror when it rains.
The research is led by Dr. Avner Vengosh, who studies how metals move through water in mining and energy regions.
in duke universityHis team checks chemical risks before big projects, including new lithium ventures, are scaled up.
“Salar is a magical place for travelers from all over the world who come to see the colors and reflections in this endless white landscape,” said Dr. Vengosh.
Operators pump brine from layers up to 160 feet deep and pump salty, mineral-rich groundwater into the pond.
As the sun and wind remove moisture, unwanted salts crystallize and the dissolved lithium becomes more concentrated in each pond.
Workers move the final concentrate to a factory where it is converted into lithium carbonate, a powder used in many batteries. Any remaining brine will remain on site.
international energy agency report Lithium demand is predicted to increase more than 40 times by 2040.
research focus
In the Duke University study, the research team tracked water and waste from a pilot operation, from raw brine to the factory.
Lab tests were used to measure acidity and track trace metals and salts to see how chemistry changes between sites.
Sampling for the study included natural brine pumped underground, brine from eight ponds, and wastewater from a treatment facility.
Natural salt water remains nearly neutral and retains 1 to 9 ppm of arsenic, a toxic element that can harm nerves and organs.
As the concentration increases, sourness increases
When brine is concentrated, each pond Less dissolved material remains and the water becomes rougher.
Measurements show that pH, a scale that tracks the acidity of water, drops to about 3.2 in the most concentrated salt water.
In their tests, salt water has a concentration of dissolved salts in the water approaching about 36 percent by weight.
The associated acidity can alter the minerals that are formed and can also limit where waste fluids can be stored or released.
Arsenic spikes across the pond
Since the metal remains molten, arsenic becomes the biggest red flag as the pond sequence progresses.
By the last pond, arsenic had reached nearly 50 parts per million, an outstanding level for salt flat mining.
“These arsenic concentrations are extremely high,” Dr. Vengosh said, pointing to his group’s comparison of samples from each pond.
A leak or intentional release can spread concentrated metals throughout. salt The crust is food for birds and insects.
Food webs store doses
Wildlife around salt flats often subsists on small crustaceans and algae, which can introduce pollutants into the food chain.
Bioconcentration, or the accumulation of chemicals within organisms over time, can increase internal doses even when water levels appear modest.
Clinical tests revealed that artemia franciscana Arsenic concentrations up to 8 ppm were tolerated, but survival rates began to decline as concentrations increased.
Flamingos feed on brine shrimp, so if the bottom collapses, it can leave birds on the flats without food.
Wastewater treatment is not easy
This treatment plant produces its own wastewater stream, and its chemistry does not match the pond’s brine.
Some rivers run at high pHs near 10, and their alkalinity can change how metals dissolve or precipitate.
Compared to pond brine, industrial wastewater does not contain arsenic or boron, elements that can harm plants in high doses.
Re-injecting spent brine or wastewater from lithium processing underground can be counterproductive by clogging underground flows and diluting remaining lithium.
Keep the ecosystem stable
Drawing large amounts of salt water can cause subsidence, or the slow sinking of the ground as liquid is removed, throughout the salt flat basin.
three dimensional Atacama Salt Lake The model links saltwater pumping to changes in the water table that extend beyond the production zone.
Such water droplets can dry out nearby wetlands and shallow wells, especially where fresh water is near salty aquifers.
Researchers suggest that mixing used brine with wastewater may be more in line with nature brine Chemistry, but still needs testing.
The future of energy security
Indigenous communities live around the salt flats, and their wells and grazing lands depend on water, which is scarce in the arid climate.
If mine wastewater escapes containment, metals can enter drinking supplies, wildlife, and even people through food and dust.
A parallel project by researchers at Duke University is evaluating health and well-being impacts as well as conducting chemical monitoring. water Close to the community.
“We believe lithium is the future of energy security and are trying to analyze lithium from different angles to ensure sustainable development and supply,” Dr. Vengosh said.
Taken together, the chemistry shows that concentrating lithium also condenses acidity and metals, making waste management a core design issue.
Better containment, careful reinjection testing, and transparent community monitoring can limit damage, but only if the spread is linked to data.
Information from online publishing By Duke University.
Image credit: NASA
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