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Cleaning up Oil-Contaminated Salt Marshes
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Project Title: Natural and enhanced in situ bioremediation of
petroleum of contaminated salt marshes
Research Locations: Foreriver Marsh: Portland,Maine
Last Update: 8-28-01
Of all estuarine/coastal environments,salt marshes are the most ecologically sensitive with regard to oil spills. Clean-up measures can be as harmful as the oil itself, resulting in even greater damage to the marsh. The goal of this project is to test various ways of accelerating the natural process by which microbes break down petroleum. Researchers injected three treatments (air, nitrate, nutrients) into the marsh surface in order to determine which amendments were most effective in breaking down various components of oil. Continued research will validate preliminary conclusions and develop a prototype injection system for delivering the amendments to the marsh.
Determining What to Inject
The nutrient amendments proved effective in accelerating the degradation
of some oil components (short chain aliphatics and aromatics), while the
air and nitrate amendments were effective in removing other chemical components
(long chain aliphatics). Figure 3 shows total petroleum hydrocarbons at
a control plot and at a plot that received nitrate injections. (Researchers
are no longer pursuing air amendments because of the logistical difficulties
involved with injecting air into the marsh.)
Determining How to Inject It
One of the most challenging tasks of this project is injecting the amendments
into the marsh in a way that is effective, but not damaging to the habitat.
Project researchers, together with University of New Hampshire engineers,
are designing a mobile, floating injection platform that will be used
at high tide in order to lessen the impacts to the salt marsh. Engineers
are designing the system to be remotely operated using data from a geographic
positioning system. The system's syringes (seen in Figure 2) must also
be built so that they will retract or deflect when they encounter something
hard in the marsh, such as a rock or plant root.
How Low Can the Levels Go?
Currently, researchers are not sure how quickly a bioremediation
system can degrade hydrocarbons, nor do they know the lowest
TPH concentrations achievable. Part of this project will be to
determine these limits for future clean up projects.
Testing the Prototype
Researchers also plan to test the injection system at different tidal
stages and with differently spaced injection grids to determine the
optimum approach for bioremediating spilled oil in salt marshes.
Other Marshes, Other Habitats
Principal investigators will talk with private-sector technology
developers about applying this work to other oil-contaminated
salt marshes, and even to other shallow habitats where an
automated injection system is an alternative.
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Project Coordinator
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Nancy Kinner University of New Hampshire (603)862-422 nancy.kinner@unh.edu |
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Start -End Date:
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09/01/2000 -09/01/2002 (Phase 2)
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Location:
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Foreriver Marsh: Portland,Maine
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| For more information: |
Dolores Jalbert Leonard Phone: (603) 862-3685 Email: dolores.leonard@unh.edu |