Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UNH Researchers Test Sediment-Scrubbing Technology In Cocheco River

19.06.2008
In a mud flat at the edge of the Cocheco River, just outside downtown Dover, scientists from the University of New Hampshire's Contaminated Sediments Center are testing an innovative way to treat polluted sediment in coastal waterways.

Rather than dredging up the problem, or burying it under several feet of sand, they've created a patch � black geotextile mats designed to cap and stabilize pollution in place. Over the next two years, UNH associate professor Kevin Gardner, research assistant professor Jeffrey Melton, and a team of UNH students will monitor these mats to evaluate the effectiveness of this new approach.

"We need to know how these mats behave when they're buried under mud for a few years, compared to how they performed in the lab," says Melton. "What will happen to them in this intertidal zone with boats, waves, birds, and weather? How will they impact bugs and other aquatic life in the sediment?"

The mats are six feet square and one inch thick. They consist of a mixture of reactive materials sandwiched between two layers of geotextile fabric, creating a sort of quilt that traps pollutants but allows water to flow through. The reactive "filling" of this quilt contains three different substances that bind and stabilize different pollutants. One such substance � a UNH-patented technology based on a natural form of phosphorus � treats toxic heavy metals associated with industrial pollution such as lead, copper, zinc and cadmium.

"But you don't just find one pollutant at a site," says Melton. "Everything is all mixed up in the sediment." So he and his colleagues added organoclay and activated charcoal ("like in your Brita filter," he says), which adhere to and treat toxic chemicals such as polychlorinated biphenyls (PCBs), polyaromatic hydrocarbons, (PAHs), and petroleum products that routinely enter waterways through stormwater runoff.

The project is funded by the Cooperative Institute for Coastal and Estuarine Environmental Technology (CICEET), a partnership of UNH and the National Oceanic and Atmospheric Administration, and NH Sea Grant.

"Polluted sediment is a nationwide problem," says Richard Langan, CICEET's UNH co-director. "We need better tools to identify and treat areas where this pollution has the potential to threaten human and ecosystem health. Technology demonstrations like these, that take advantage of cutting-edge science, are key to making that happen."

The mats present an alternative approach to remediating contaminated sediment; more common responses include dredging or capping sediment beneath several feet of sand. But dredging is expensive, disrupts habitats and poses the problem of how to move - and where to put - all that toxic sediment. Sand caps have questionable long-term effectiveness and can hinder boat traffic and impact aquatic life. "There's no silver bullet. What we are exploring is potentially a great tool to add to the tool box," says Melton.

Melton admits that even as Americans grow increasingly aware of environmental woes, sediment pollution does not score high on the "green glamour" scale. Yet, he points out, everyone is already feeling its impact through regular advisories that close shellfish beds or warn of eating fish contaminated by heavy metals and persistent organic pollutants like PCBs or PAHs.

"You can enjoy a great day of fishing, but if you can't eat the catch, there's a problem," says Melton. It's estimated that 20 percent of the top six inches of all sediment in U.S. rivers, lakes, streams and estuaries is contaminated. In 2004, the U.S. Environmental Protection Agency reported there were 3,221 fish consumption advisories in state waters.

Melton and Gardner chose the Cocheco not because its sediment is especially polluted, but rather because its characteristics as a well-used tidal river and its proximity to UNH make it an ideal laboratory. They plan to compare the performance of the mats in the Cocheco to those they've laid in Cottonwood Bay in Grand Prairie, Texas, adjacent to the Dallas National Air Station, in a demonstration funded by the Department of Defense's Strategic Environmental Research and Development Program (SERDP).

Moving forward, researchers from the Contaminated Sediments Center, part of UNH's Environmental Research Group, plan to test new sampling technologies that measure the scope and potential threat of contamination in sediment. In addition, they're always on the lookout for new test sites.

To learn more about UNH's Contaminated Sediments Center, go to http://www.unh.edu/erg/ccsr/index.html.

Beth Potier | EurekAlert!
Further information:
http://www.unh.edu/erg/ccsr/index.html
http://www.unh.edu

More articles from Ecology, The Environment and Conservation:

nachricht Scientists on the road to discovering impact of urban road dust
18.01.2018 | University of Alberta

nachricht Gran Chaco: Biodiversity at High Risk
17.01.2018 | Humboldt-Universität zu Berlin

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: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

Im Focus: A thermometer for the oceans

Measurement of noble gases in Antarctic ice cores

The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Polymers Based on Boron?

18.01.2018 | Life Sciences

Bioengineered soft microfibers improve T-cell production

18.01.2018 | Life Sciences

World’s oldest known oxygen oasis discovered

18.01.2018 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>