Avner Vengosh / Universidade de Duke
Salar also sleep
Study shows that the lithium evaporation lagoons of Sweats significantly increase arsenic levels.
O largest lithium deposit of the world is also a threat to the environmentfor several ecosystems, reveals a new investigation.
The largest lithium reserve is in the Salar also sleepwhich in turn is the largest and highest salt desert on the planet. There are thousands of km2 at the top of a plateau in Bolivia. Salt crystals, white as powdered sugar, fill the space in much of the year. When it rains, the accumulated rainwater reflects the mountains and the surrounding sky.
But this magical place for tourists also has this vast reserve of lithium dissolved in highly saline brine; and can become a crucial resource in the field of renewable energies.
But a new one made the first Full Chemical Analysis of wastewater associated with lithium mining in this Uyuni Salar.
This mining goes through several Stages: The brine is pumped under the surface to a series of shallow evaporation lagoons above the ground. As the liquid evaporates in successive lagoons, they precipitate undesirable salts.
Lithium, however, is more concentrated in the brine in each phase. The concentrated lithium is eventually taken from the evaporation lagoons to a nearby lithium carbonate processing – which is the material used in rechargeable batteries.
Lithium extraction at Uyuni’s Salar is at a preliminary phase, recalls the.
But, according to this study, If lithium mining continues, in the long run it can cause the reducing groundwater levels and the sinking of the earth. And can affect the future of lithium mining.
In this investigation, was analyzed the lithium chemistry of Salmra and the residual materials associated with a mining operation. Determined the acidity and presence of oligoelements – Like arsenic, a toxic metal that can cause a number of health problems in exposed wild people and wildlife.
Samples from the mine site revealed underground pumping natural brine; brine of eight evaporation lagoons; and wastewater of the lithium processing installation.
In natural brine samples, the team measured arsenic levels between 1 and 9 parts per million, as well as relatively neutral acidity. In comparison, the brine of the Evaporation Lagoon became increasingly acidic as it became more concentrated.
The levels of arsenium They also increased dramatically from lagoon to lagoon. The last lake even revealed levels of arsenic in almost 50 parts per million – about 1,400 times higher than the reference value considered ecologically acceptable by the US Environmental Protection Agency.
The team admitted that I had never found this level of arseniumanywhere.
Intentional leaks or discharges of brine from the evaporation lagoons to the surrounding salines can harm. A bioaccumulation – Ingestion and (in) ability to eliminate chemicals in living beings that lead to its gradual accumulation over time
The levels of boro – which can cause health effects, depending on the nature of the exhibition – increased from lagoon to lagoon.
The wastewater of the lithium processing factory showed relatively low levels of boron and arsenium, similar to the levels found in natural saves, and in some even inferior cases.
In addition, scientists investigated possible repercussions on collect used brine – brine that is left after the removal of the lithium – or from residual waters lithium processing and injecting them back into the lithium warehouse. The lithium mining industry indicated that these approaches can contradict soil sinking.
According to this study, The two injection methods have undesirable consequences: The used brine would probably mingle badly with the natural brine, making it difficult for the flow of brine below the surface and potentially interfering with pumping; and the injection of wastewater back into the deposit could dilute the lithium feature.
Solution To avoid sinking of the soil? Carefully mix the brine used with wastewater to reach a chemical balance with natural brine.
