Hexbyte Glen Cove Chilean scientist plans to clean up mining with ‘metal eating’ bacteria

Hexbyte Glen Cove

Chilean biotechnologist Nadac Reales shows a nail and screw inside a jar with metal-eater bacteria in her laboratory at a mining site in Antofagasta.

Starving microorganisms capable of surviving in extreme conditions have already managed to “eat” a nail in just three days.

In Chile, a scientist is testing “metal-eating” she hopes could help clean up the country’s highly-polluting .

In her laboratory in Antofagasta, an industrial town 1,100-kilometers north of Santiago, 33-year-old biotechnologist Nadac Reales has been carrying out tests with extremophiles—organisms that live in .

Reales came up with her idea while still at university as she was conducting tests at a mining plant using microorganisms to improve the extraction of copper.

“I realized there were various needs in the mining industry, for example what happened with the metallic waste,” she told AFP.

Some metals can be recycled in smelting plants but others, such as HGV truck hoppers that can hold 50 tons of rock, cannot and are often discarded in Chile’s Atacama desert, home to the majority of the country’s mining industry.

Chile is the world’s largest producer of copper, which accounts for up to 15 percent of the country’s GDP, resulting in a lot of mining waste that pollutes the environment.

In her research, Reales, who now runs her own company Rudanac Biotec, concentrated on iron-oxidizing bacteria called Leptospirillum.

She extracted the bacteria from the Tatio geysers located 4,200 meters above sea level, some 350 kilometers from Antofagasta.

The bacteria “live in an acidic environment that is practically unaffected by relatively high concentrations of most metals,” she said.

“At first the bacteria took two months to disintegrate a nail.”

But when starved, they had to adapt and find a way of feeding themselves.

After two years of trials, the result was a marked increase in the speed at which the bacteria “ate,” devouring a nail in just three days.

Chilean scientist Nadac Robles hopes her ‘metal eating’ bacteria will make green mining “totally feasible”

Surprising benefit

Reales says “chemical and microbiological tests” have proved the bacteria are not harmful to humans or the environment.

“We’ve always seen a lot of potential in this project that has already passed an important test in the laboratory,” said Drina Vejar, a microbiologist who is part of a four-person team working with Reales.

“It’s really necessary at this time when we have to plan for a more , especially in all these cities with so many polluting industries.”

Mining companies have shown interest in the research but while Rudanac Biotec previously benefitted from a state fund for , the company needs investment to move on to its next stage of trials.

Reales says she needs money to see if her method will “eat a medium sized beam or a hopper.”

When the disintegration process is complete, what remains is a reddish liquid residue, a solution known as a lixiviant that itself possesses a surprising quality.

“After biodisintegration the product generated (the liquid) can improve the recovery of copper in a process called hydrometallurgy,” said Reales.

Essentially, the liquid residue can be used to extract copper from rock in a more sustainable manner than the current use of chemicals in leaching.

Reales says it means green mining is “totally feasible.”

That is of great interest to mining companies that could use it to improve their large scale extraction of copper or other minerals, while also reducing their pollution, something they are required to do by law.

Reales recently submitted a request for an international patent for her technology, but more importantly she hopes it will help reduce metal waste blotting the landscape in the regions of her country.



© 2021 AFP

Citation:
Chilean scientist plans to clean up mining with ‘metal eating’ bacteria (2021, October 9)
retrieved 10 October 2021
from https://phys.org/news/2021-10-chilean-scientist-metal-bacteria.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.

Read More Hexbyte Glen Cove Educational Blog Repost With Backlinks —

Hexbyte Glen Cove Metal deposits from Chinese coal plants end up in the Pacific Ocean, research shows thumbnail

Hexbyte Glen Cove Metal deposits from Chinese coal plants end up in the Pacific Ocean, research shows

Hexbyte Glen Cove

Credit: CC0 Public Domain

Emissions from coal-fired power plants in China are fertilizing the North Pacific Ocean with a metal nutrient important for marine life, according to new findings from a USC-led research team.

The researchers believe these metals could change the , though it’s unclear whether it would be for better or worse.

The study shows that smoke from power plants carries and other metals to the surface waters of the North Pacific Ocean as westerly winds blow emissions from Asia to North America. Peak measurements show that up to nearly 60% of the iron in one vast swath of the northern part of the emanates from smokestacks.

“It has long been understood that burning alters Earth’s climate and ocean ecosystems by releasing into the atmosphere,” said Seth John, lead author of the study and an assistant professor of Earth sciences at the USC Dornsife College of Letters, Arts and Sciences. “This work shows fossil fuel burning has a side effect: the release of iron and metals into the atmosphere that carry thousands of miles and deposit in the ocean where they can impact marine ecosystems.”

“Certain metal deposits could help some thrive while harming other life,” he added. “There are inevitable tradeoffs when the ocean water’s chemistry changes.”

The study was published on Thursday in the Proceedings of the National Academy of Sciences. Researchers from USC, Columbia University, University of Washington, MIT and the University of Hawaii, among others, collaborated.

USC-led team confirms that ocean metals stem from China

While wind-blown mineral dust from deserts has long been considered an important source of iron to open ocean waters, the new study shows how manmade sources contribute important micronutrients that plankton and algae need. Moreover, the study shows how fossil fuel burning affects not only global warming but marine environments, too.

Previous studies have shown widely divergent estimates about how much iron is carried from various land-based sources to the ocean, especially from anthropogenic sources. Iron is a key limiting factor for marine productivity for about one-third of the world’s oceans.

Instead, the USC-led research team measured metals in surface seawater. They focused on a remote part of the Pacific Ocean, hundreds of miles north of Hawaii and about midway between Japan and California. The region is downwind of industrial emissions in east Asia.

In May 2017, they boarded a research vessel and took water samples along a north-south transect at latitudes between 25 degrees and 42 degrees north. They found peak iron concentrations in about the middle, which corresponded with a big wind event over east Asia one month before. The peak iron concentrations are about three times greater than background ocean measurements, the study shows.

In addition, the scientists found elevated lead concentrations coincided with the iron hot spots. Other research has shown that most of the lead at the ocean surface comes from manmade sources, including cement plants, coal-fired and smelters.

Moreover, the metals in the seawater samples bear telltale traces of Chinese industrial sources, the study says.

“When we collected samples in the ocean, we found that the iron isotope and lead isotope ‘fingerprints’ from seawater matched those of anthropogenic pollution from Asia,” said Paulina Pinedo-Gonzalez, a USC post-doctoral scientist and study author who is now at the Lamont-Doherty Earth Observatory at Columbia University.

Finally, the scientists also ruled out upwelling from the deep ocean as a source of the metals by testing at depth.

What does the abundance of metals mean for marine life?

The study has important implications for marine life in the ocean. The North Pacific notably lacks iron, a key micronutrient, so an influx of metals and other substances can help build the foundation for a new ecosystem—a ‘good news, bad news’ outcome for Earth.

“Microscopic iron-containing particles released during coal burning impacts algae growth in the ocean, and therefore the entire ecosystem for which algae form the base of the food chain,” John explained. “In the short term, we might think that iron in pollution is beneficial because it stimulates the growth of phytoplankton, which then take carbon dioxide out of the atmosphere as they grow to offset some of the carbon dioxide released during the initial burning process.

“However, it’s totally unsustainable as a long-term geoengineering solution because of the deleterious effects of pollution on human health. Thus, the take-home message is perhaps a better understanding of an unintended side effect of coal burning and the ways in which that can impact ocean ecosystems thousands of miles away.”



More information:
Paulina Pinedo-González et al. Anthropogenic Asian aerosols provide Fe to the North Pacific Ocean, Proceedings of the National Academy of Sciences (2020). DOI: 10.1073/pnas.2010315117

Citation:
Metal deposits from Chinese coal plants end up in the Pacific Ocean, research shows (2020, October 23)

Read More Hexbyte Glen Cove Educational Blog Repost With Backlinks —