Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Landfill Cover Soil Methane Oxidation Underestimated

28.04.2009
A literature review reveals that landfill cover soils oxidize more methane than guidelines suggest.

Landfilled waste decomposes in the absence of oxygen and results in the production of methane. Landfills are classified as the second-largest human-made source of CH4 in the U.S. Additionally, landfill gas contains numerous non-methane hydrocarbons that are either volatilized directly from waste materials or produced through biochemical reactions during waste degradation.

Microbial methane oxidation reduces the emissions of methane and other volatile hydrocarbons from landfills. Determining the importance of this process is one of the major uncertainties in estimating national or global CH4 emissions from landfills. Landfill gas that is not collected passes through landfill cover soils on the way to being released to the environment. Bacteria in the soil consume methane and other volatile hydrocarbons that are produced by decomposition in the underlying waste by reacting it with oxygen.

A value of 0 to 10% oxidation has been recommended by the Intergovernmental Panel on Climate Change guidelines for national greenhouse gas inventories. Currently, for regulatory purposes the USEPA has recommended a default value for landfill cover CH4 oxidation of 10% due to the uncertainty involved and the lack of a standard method to determine oxidation rate.

Drs. Jeffrey Chanton, David Powelson, and Roger Green of Florida State University and Waste Management Inc. reviewed and compiled literature results from 42 determinations of the fraction of methane oxidized and 30 determinations of methane oxidation rate in a variety of soil types and landfill covers. The results were published in the March-April issue of the Journal of Environmental Quality. The means for the fraction of methane oxidized upon transit across the differing types of soil covers ranged from 22% in clayey soil to 55% in sandy soil. The overall mean fraction oxidized across all studies was 36% with a standard error of 6%. For a subset of fifteen studies conducted over an annual cycle the fraction of methane oxidized ranged from 11 to 89% with a mean value of 35 ± 6%, a value that was nearly identical to the overall mean.

The literature summarized in this paper indicates that the fraction of methane oxidized in landfill cover soils is considerably greater than the default value of 10%. Of the 42 determinations of methane oxidation only four reported values of 10% or less. One reported a value of 10%. This particular study was the first to report a well constrained value for the fraction of methane oxidized in a specific landfill, and because of this, it has received undue weight in the determination of regulations. The default value of 10% should be updated based upon technological advancements in soil engineering and state-of-the-practice applications in cover design as well as recent studies detailed journals such as Journal of Environmental Quality.

The full article is available for no charge for 30 days following the date of this summary. View the abstract at http://jeq.scijournals.org/cgi/content/abstract/38/2/654.

The Journal of Environmental Quality, http://jeq.scijournals.org is a peer-reviewed, international journal of environmental quality in natural and agricultural ecosystems published six times a year by the American Society of Agronomy (ASA), Crop Science Society of America (CSSA), and the Soil Science Society of America (SSSA). The Journal of Environmental Quality covers various aspects of anthropogenic impacts on the environment, including terrestrial, atmospheric, and aquatic systems.

The American Society of Agronomy (ASA) www.agronomy.org, is a scientific society helping its 8,000+ members advance the disciplines and practices of agronomy by supporting professional growth and science policy initiatives, and by providing quality, research-based publications and a variety of member services.

Sara Uttech | EurekAlert!
Further information:
http://www.agronomy.org

More articles from Agricultural and Forestry Science:

nachricht Crop achilles' heel costs farmers 10 percent of potential yield
24.01.2017 | Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign

nachricht How much drought can a forest take?
20.01.2017 | University of California - Davis

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

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

Im Focus: Scientists spin artificial silk from whey protein

X-ray study throws light on key process for production

A Swedish-German team of researchers has cleared up a key process for the artificial production of silk. With the help of the intense X-rays from DESY's...

Im Focus: Quantum optical sensor for the first time tested in space – with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Breaking the optical bandwidth record of stable pulsed lasers

24.01.2017 | Physics and Astronomy

Choreographing the microRNA-target dance

24.01.2017 | Life Sciences

Spanish scientists create a 3-D bioprinter to print human skin

24.01.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>