Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New Monitoring Methods More Accurately Measure Coal Ash Impacts

30.11.2010
As the Environmental Protection Agency weighs whether to define coal ash as hazardous waste, a study by Duke University researchers identifies new monitoring protocols and insights that can help investigators more accurately measure and predict coal ash contaminants’ ecological impacts.

“The take-away lesson is we need to change how and where we look for coal ash contaminants,” says Avner Vengosh, professor of geochemistry and water quality at Duke’s Nicholas School of the Environment. “Risks to water quality and aquatic life don’t end with surface water contamination, but much of our current monitoring does.”

The study, published online this week in the peer-reviewed journal Environmental Science and Technology, documents contaminant levels in aquatic ecosystems over an 18-month period following a massive coal sludge spill in 2008 at a Tennessee Valley Authority power plant in Kingston, Tenn.

By analyzing more than 220 water samples collected over an 18-month period, the Duke team found that high concentrations of arsenic from the TVA coal ash remained in pore water – water trapped within river-bottom sediment – long after contaminant levels in surface waters dropped back below safe thresholds. Samples extracted from 10 centimeters to half a meter below the surface of sediment in downstream rivers contained arsenic levels of up to 2,000 parts per billion – well above the Environmental Protection Agency’s thresholds of 10 parts per billion for safe drinking water, and 150 parts per billion for protection of aquatic life.

“It’s like cleaning your house,” Vengosh says of the finding. “Everything may look clean, but if you look under the rugs, that’s where you find the dirt.”

The potential impacts of pore water contamination extend far beyond the river bottom, he explains, because “this is where the biological food chain begins, so any bioaccumulation of toxins will start here.”

The research team, which included two graduate students from Duke’s Nicholas School of the Environment and Pratt School of Engineering, also found that acidity and the loss or gain of oxygen in water play key roles in controlling how arsenic, selenium and other coal ash contaminants leach into the environment. Knowing this will help scientists better predict the fate and migration of contaminants derived from coal ash residues, particularly those stored in holding ponds and landfills, as well as any potential leakage into lakes, rivers and other aquatic systems.

The study comes as the EPA mulls whether to define ash from coal-burning power plants as hazardous waste. The deadline for public comment to the EPA was November 19; a final ruling – what Vengosh calls “a defining moment” – is expected in coming months.

“At more than 3.7 million cubic meters, the scope of the TVA spill is unprecedented, but similar processes are taking place in holding ponds, landfills and other coal ash storage facilities across the nation,” he says. “As long as coal ash isn’t regulated as hazardous waste, there is no way to prevent discharges of contaminants from these facilities and protect the environment.”

Laura Ruhl, a PhD student in Vengosh’s lab, is lead author of the study, which was funded by the National Science Foundation. Vengosh is corresponding author. Coauthors are Gary S. Dwyer, senior research scientist; Heileen Hsu-Kim, assistant professor of environmental engineering; and Amrika Deonarine, a PhD student in Hsu-Kim’s lab.

Note to Editors: Avner Vengosh can be reached at vengosh@duke.edu, (919) 681-8050 (office), or (919) 491-6792 (cell).

Tim Lucas | EurekAlert!
Further information:
http://www.duke.edu

More articles from Ecology, The Environment and Conservation:

nachricht Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main

nachricht Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Closing the carbon loop

08.12.2016 | Life Sciences

Applicability of dynamic facilitation theory to binary hard disk systems

08.12.2016 | Physics and Astronomy

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D

08.12.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>