Black carbon is not chemically inert as previously thought

Aug 31, 2009 by Diane Kukich

A paper by two University of Delaware researchers was recently highlighted on the web site of Environmental Science & Technology (ES&T), which publishes papers in advance of their appearance in the print version of the journal.

Released on Aug. 14, the paper, "Graphite and Soot-Mediated Reduction of 2,4-Dinitrotoluene and Hexahydro-1,2,5-trinitro-1,3,5-triazine," was coauthored by Pei Chiu, professor in UD's Department of Civil and Environmental Engineering, and Seok-Young Oh, former Ph.D. student and postdoctoral researcher in the department and now an assistant professor at the University of Ulsan in South Korean.

The paper was sixth on the list of ten highlighted papers for the week by ES&T, which is published by the American Chemical Society.

The article documents Chiu and Oh's findings that black carbon, previously thought to be chemically inert, can be conductive and can actually serve as a catalyst.

Chiu explains that black carbon, which is ubiquitous in soils and sediments, is derived from both human activities and natural processes -- for example, it can result from incomplete combustion of fossil fuels and biomass, as well as from weathering of rock. Estimates indicate that from 10 to the 12th power to 10 to the 13th power grams of black carbon are released into the environment every year.

As a geosorbent, black carbon has a significant effect on the fate and transport of hydrophobic pollutants in aquatic and terrestrial systems.

“It's commonly assumed that when an organic molecule is bound to a geosorbent such as black carbon,” Chiu says, “it becomes sequestered and inaccessible. But what we've found, in studying explosives such as DNT and RDX, is that such as soot and graphite has dual roles, serving as both a sorbent and an electron shuttle.”

Chiu cautions that the study is the first confirmation of the hypothesis, and only a limited range of materials has been tested. However, he says, “This process needs to be taken into account when the fate of nitro compounds in groundwater and sediment is modeled and when we try to understand their impact on human health and ecology. On the other hand, we can exploit the process in the remediation of sites contaminated with explosives and related chemicals.”

“Additional studies are needed to identify other classes of compounds that can undergo black carbon-mediated transformation,” he adds, “as well as the reductants and medium conditions that are conducive to this process in complex environmental systems.”

Provided by University of Delaware (news : web)

Explore further: Management of peatlands has large climate impacts

add to favorites email to friend print save as pdf

Related Stories

Coal and black liquor can produce energy from papermaking

Aug 20, 2007

Adding a little coal and processing the papermaking industry's black liquor waste into synthesis gas is a better choice than burning it for heat, improves the carbon footprint of coal-to-liquid processes, and can produce ...

NASA Study Finds Soot May be Changing the Arctic Environment

Mar 23, 2005

NASA continues to explore the impact of black carbon or soot on the Earth's climate. NASA uses satellite data and computer models that recreate the climate. New findings show soot may be contributing to changes happening ...

Arctic climate study reveals impact of industrial soot

Aug 09, 2007

Scientists from the Desert Research Institute (DRI) and their collaborators have determined that Northern Hemisphere industrial pollution resulted in a seven-fold increase in black carbon (soot) in Arctic ...

Studying rivers for clues to global carbon cycle

Feb 08, 2008

In the science world, in the media, and recently, in our daily lives, the debate continues over how carbon in the atmosphere is affecting global climate change. Studying just how carbon cycles throughout the Earth is an enormous ...

Recommended for you

Climate fund signs up first partners

1 hour ago

The global fund created to spearhead climate change financing has selected its first partners to channel funds to developing countries, but says it needs donor nations to move fast in transforming cash pledges ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.