Mining pollution, when not treated properly, can have devastating consequences for the environment: Mining waste, heavy metals and acidic water often find their way to streams and rivers, polluting the springs of more than 40% of western watersheds. In fact, according to the EPA, metal mines generated nearly 2 billion pounds of toxic waste in 2017 alone.
In response to this growing problem, a team of researchers led by biotechnologist Nadak Reales of Chile may have found a possible solution that could help clean up the country’s highly polluting mining industry by demonstrating that a special type of bacteria can eat a nail for three days when starving.
Chile is the world’s leading producer of honey, accounting for up to 15 percent of the country’s GDP. Therefore, there is a lot of mining waste that pollutes the environment, so it could definitely use some help to control it, and if technology can somehow be increased with appropriate investment, it could help the rest of the world.
Feeding bacteria while helping the world
The newly discovered method involves extremophiles, which are microorganisms that can survive and thrive in the harshest environments. Reales and her team are concentrating on an iron-oxidizing bacterium known as Leptospirillum, which it isolated from the Tatio geysers, which are located 13,779 feet (4,200 meters) above sea level and about 220 miles (350 kilometers) from Antofagasta.
In addition to having an appetite for metals, Leptospirillum is also used in industrial bioleaching, conversion of metals into soluble form and biooxidation, metal extraction. They thrive in an acidic environment, where relatively large amounts of most metals have no effect, and when the experiments began, it took them two months to “eat” the nail. The researchers wanted to take this to the next level, and the result of two years of testing was a significant increase in speed, with one nail swallowed in just three days.
Of course, bacteria are not harmful to humans or the environment, as shown by chemical and microbiological tests. When this decomposition process is complete, only a purple liquid residue, known as a liquidant, remains, which has a surprising quality. According to researchers, this liquid can “improve the recovery of copper in a process called hydrometallurgy.” The liquid residue can be used to remove copper from the rocks in a more environmentally friendly way than the current chemical leaching method, and thanks to this, the green yield is “absolutely feasible,” says Reale.