Serving Science and Society Into the New Millenium (1998) / Chapter Skim
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Restoring the Environment via Bioremediation and Molecular Sciences
Restoring the Environment via Bioremediation and Molecular Sciences
Pages 104-122
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From page 104... ...
Rawson William R Wiley Environmental Molecular Sciences Laboratory Pacific Northwest National Laboratory Richland, Washington There is a tremendous national and international legacy of environmental contamination from defense production, general industrial activity, and agriculture that poses an enduring threat to the health of humanity and to the survival of ecosystems throughout the biosphere.
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From page 105... ...
, which can mobilize sparingly soluble hydrophobic organic compounds, were disposed of with PCBs. Organic compounds that can stimulate subsurface microbial
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From page 106... ...
The gaps in understanding of how complex hydrologic, geochemical, and biologic processes interact to affect subsurface contamination have formed the basis for much of the BER program's research aimed at restoration of DOE lands. BER PROGRAM ACCOMPLISHMENTS The BER program's studies in subsurface science since 1985 have contributed substantially to the fundamental understanding of microbial ecosystems in pristine aquifers and unsaturated zones.
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From page 107... ...
i9 Some of the concepts of long-lived, subsurface permeable barriers call upon microbially catalyzed iron reduction as an integral part of the remedial treatment of metals and radionuclides.5 The program's research findings indicate that microbial populations with metabolism adapted to perform the kind of subsurface metal oxidation and reduction important to contaminant transformation are already present in the subsurface. Previous research addressed the issue of how microbial ecosystems were established in subsurface environments.
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From page 108... ...
Wiley Environmental Molecular Sciences Laboratory at Pacific Northwest National Laboratory in Richland, Washington, in October 1997. The mission of the facility is to develop a molecular-level understanding of the physical, chemical, and biologic processes that underlie environmental remediation, water processing and storage, human-health effects, and atmospheric chemistry.
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From page 109... ...
As the BER program initiates research in its NABIR program and brings the power of modern physics and biology to bear on key environmental processes related to bioremediation, the scientific community has the opportunity to contribute fundamental scientific research of direct relevance to addressing a major societal issue, the environmental legacy of the Cold War. The BER program' s new national scientific user facility, the Environmental Molecular Sciences Laboratory is expected to provide resources to research teams nationwide for improving the understanding of molecular science related to the environment.
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From page 110... ...
Pseudomonas fluorescens a&esion and transport through porous media are affected by lipopolysaccharide composition. Appl Environ Microbiol 1996;62:100-4.
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From page 111... ...
William R Wiley Environmental Molecular Sciences Laboratory Pacific Northwest National Laboratory Richland, Washington In the late 1980s, recognizing that the Department of Energy (DOE)
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From page 112... ...
· Gas-phase monitoring and detection, for the development of new techniques for detecting and monitoring molecular species. As one of DOE's national scientific-user facilities, the EMSL makes its research instruments available to researchers worldwide for studies in the environmental molecular sciences or related disciplines of national importance.
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From page 113... ...
In addition, it does not require the protein to be crystallized, an often-daunting problem itself, and the species can be studied in aqueous solution, a far more natural setting than the crystalline environment. The initial focus of the research effort in the EMSL is on understanding of the molecular processes involved in nucleotide excision repair (NER)
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From page 114... ...
COMPUTATIONAL MOLECULAR SCIENCE AND MATERIALS FOR SEPARATING RADIONUCLIDES The production of plutonium during the Cold War generated about 10 x 103 gal of high-level radioactive waste, which is currently stored in large underground tanks at the Hanford and Savannah River sites. The highlevel wastes are complex mixtures of highly radioactive elements, such as cesium-~37 and strontium~90; long-lived radionuclides, such as americium~24i, plutonium~239, and technetium~99; and RCRA-listed chemical wastes, such as heavy metals, solvents, chelating agents, and nitrates.
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From page 115... ...
As can be seen even in this rather simple example, the developers of NWChem pioneered many innovations to take advantage of the power offered by massively parallel computer systems. NWChem greatly expands the range and accuracy of modern molecular-modeling approaches and will have a large influence, not only in environmental molecular science, but also in chemistry, materials science, and molecular biology.
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From page 116... ...
Wiley Environmental Molecular Sciences Laboratory, in whose hands the future of the EMSL rests.
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From page 117... ...
More research on the role of bacterial transport in the ecology of subsurface microbial communities that ultimately degrade contaminants is also needed. FUTURE RESEARCH CHALLENGES Geehydrologic Complexities Many of the field experiments in which labeled bacteria were injected directly into an aquifer with a conservative tracer (nonreactive solute)
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From page 118... ...
However, the apparent discrepancies between field and laboratory results, and the growing recognition that processes that control subsurface microbial transport behavior can be interrelated and operate on spatial and temporal scales that are not conducive for laboratory study, emphasize the need for more in situ transport studies. Accurate assessment of the potential role of bacterial transport in the restoration of contaminated groundwater at many DOE sites might require injection-and-recovery experiments on scales that are larger than those of previous studies.
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From page 119... ...
in organically contaminated aquifer sediments.24~25 At least one organically contaminated sandy aquifer yielded evidence that protists might be more efficient at removing unattached bacteria being advected downgradient than are the organic and mineral coatings on the sediment grains. Also, growth of bacteria being transported downgradient in organically contaminated aquifers can be substantial and can offset the losses that occur as a result of attachment.2i The dearth of information on the importance of biologic controls on subsurface bacterial transport is due largely to the fact that many aspects of the subsurface ecosystem are so poorly understood that their effects on bacterial transport are not fully appreciated.
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From page 120... ...
Protozoa in subsurface sediments from sites contaminated with aviation gasoline or jet fuel. Appl Environ Microbiol 1993;59:467-72.
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From page 121... ...
One of the 2 regions of the world that geologists think has been permanently frozen from the time that the sediments were laid down. In principle, given the depth of these sediments, we can take samples out of the freezer of microbial communities that lived there some 3 million years ago.
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From page 122... ...
The spatial-isolation hypothesis has a lot to do with our understanding of biodiversity in microbial communities. To conclude with an application of biodiversity, I note a case in which nature has not made an organism to do a job that we would like done to grow on polychlorinated biphenyls (PCBs)
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