Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Iron legacy leaves soil high in manganese

13.12.2010
Iron furnaces that once dotted central Pennsylvania may have left a legacy of manganese enriched soils, according to Penn State geoscientists. This manganese can be toxic to trees, especially sugar maples, and other vegetation.

The research, which quantified the amounts of manganese in soil core samples, was part of work done at the Shale Hills Critical Zone Observatory funded by the National Science Foundation.

"Our group's focus was to study the soil chemistry," said Elizabeth M. Herndon, graduate student in geosciences. "We saw excess manganese in the soil and decided that we needed to quantify the manganese and determine where it came from."

Typically, manganese in soils comes from the disintegration of the bedrock as soil forms. Bedrock in this area is shale and the average amount of manganese in the shale is about 800 parts per million. However, the researchers found 14,000 parts per million of manganese in some of the soil samples. This is more than 17 times as much manganese as in the bedrock.

The researchers sampled 21 sites along a ridge at Shale Hills. They took core samples from the surface down to bedrock. At 20 of the sites they found elevated manganese. The core samples, which are about 12 inches long, encompass about 7,000 years of soil formation.

"We needed to quantify how much extra manganese there actually was in the samples," said Herndon. "While soil formation puts manganese into the soil, chemical weathering and physical erosion remove manganese from the soil, so we used a mass balance model to account for these inputs and outputs."

The researchers found that "53 percent of manganese in ridge soils can be attributed to atmospheric deposition from anthropogenic sources." They reported their results online in Environmental Science and Technology.

"Because the amount of manganese in the soil was highest near the surface, the added manganese was very likely industrial pollution," said Herndon.

This area of central Pennsylvania was the site of numerous iron furnaces beginning in the late 1700s. While some furnaces stayed in operation into the 20th century, most were abandoned by the 1860s. The legacy of the ores and fuels they burned remained behind in the soil.

Although the researchers, who include Herndon, Lixin Jin, postdoctoral fellow in geosciences, and Susan L. Brantley, professor of geosciences and director of the Penn State Earth and Environmental Systems Institute, knew there was added manganese, they needed to show that the element came from industry. They looked at a location near a steel mill in Burnham, in Mifflin County and found a similar pattern of manganese concentrations in the soil suggesting that the steel mill was the source of the manganese.

They also examined datasets for soils across the United States and Europe and found that a majority of these soils have excess manganese. This may indicate that manganese pollution is not just a local phenomenon but could be widespread throughout industrialized areas.

Because manganese is naturally found in soils and is readily taken up and cycled by trees, the researchers looked to see if the pattern of manganese deposition matched that of areas where trees were manipulating the manganese. In those cases, trees move manganese from deep in the soil creating deficits near the bedrock, but concentrate the manganese nearer the surface. According to Herndon, the manganese pattern did not show a depletion near bedrock and the case for industrial pollution was strengthened.

Manganese is an exceptionally reactive element and is considered toxic if inhaled, but its presence in the soil, where it occurs naturally and is less likely to be inhaled, is not typically a danger to humans. Trees, however, may be adversely effected. While sugar maples can be detrimentally affected if they have a manganese deficiency, too much manganese can be toxic especially for saplings. High levels of manganese can also damage other vegetation and crops.

"Manganese oxides could also change the chemical properties of the soil," said Herndon. "Even if the sources of manganese pollution are no longer active, the remnants remain in the soil. I find it interesting that we have to consider the kinds of contamination left over from the past that might impact us today."

The National Science Foundation supported this work.

A'ndrea Elyse Messer | EurekAlert!
Further information:
http://www.psu.edu

More articles from Earth Sciences:

nachricht PR of MCC: Carbon removal from atmosphere unavoidable for 1.5 degree target
22.05.2018 | Mercator Research Institute on Global Commons and Climate Change (MCC) gGmbH

nachricht Monitoring lava lake levels in Congo volcano
16.05.2018 | Seismological Society of America

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Designer cells: artificial enzyme can activate a gene switch

22.05.2018 | Life Sciences

PR of MCC: Carbon removal from atmosphere unavoidable for 1.5 degree target

22.05.2018 | Earth Sciences

Achema 2018: New camera system monitors distillation and helps save energy

22.05.2018 | Trade Fair News

VideoLinks
Science & Research
Overview of more VideoLinks >>>