Student Abstracts: Environmental Science at ORNL

Development of Educational Materials for fueleconomy.gov. . REBECCA BROCKWELL (Florida State Universtiy, Tallahassee, FL 32306) DAVID L GREENE (Oak Ridge National Laboratory, Oak Ridge, TN 37831) .
The Internet is becoming a more popular resource for educators. One of the biggest challenges for those using the Internet in the classroom is the lack of easily accessible curriculum that utilizes the current data available on the web. Science Educators are being encouraged by the National Science Education Standards to encourage students to consider science as a part of the larger society and as a means to consider societal problems. As a result of this new thrust, more schools are adding environmental studies as a part of the science curriculum. A website, fueleconomy.gov has been developed by DOE to provide up to date information for consumers about vehicle energy use and greenhouse gas and pollutant emissions. The site allows consumers to research the fuel economy of cars from model year 1985 to present. An educational module including a lab activity was developed for the website to encourage students to consider the impact personal vehicle choices have on the production of greenhouse gasses. The students calculate the greenhouse gasses produced by their own vehicle. They then move outside the classroom to examine vehicle exhaust. By collecting exhaust in a plastic bag and using the collected gases to extinguish a candle, students are able to visualize the vast quantities of oxygen depleted gasses vehicles produce. Students are encouraged to consider the impact of personal and group choices on the environment. The webpages will be monitored to determine the popularity of the new materials.

Evaluation of Fuji Prescale Pressure Sensitive Film for Assessing Damage to Fish from Turbine Passage. Jessica Busey (Middle Tennessee State University, Murfreesboro, TN 37132) Glenn Cada (Oak Ridge National Laboratory, Oak Ridge, TN 37830).. JESSICA BUSEY (Middle Tennessee State University, Murfreesboro, TN 37132) GLENN CADA (Oak Ridge National Laboratory, Oak Ridge, TN 37831) .
The passage of fish through hydroelectric turbines is a very important issue to energy production. As a fish passes through a turbine it can experience several different kinds of injury mechanisms (strike, grinding, shear, and pressure changes) and the magnitude of these forces is often unknown. Fuji Prescale Pressure Sensitive Film (PSF) can make an accurate and permanent record of pressures applied to the surface. By sending the PSF through the turbine, the pressures and forces experienced by the fish could be estimated, specifically those related to strike. The PSF must be put in a waterproof package due to the effect of water on the film. The Fuji Prescale Pressure Sensitive Film comes in various weights, enabling it to measure a wide range of pressures. By stacking the film, it can measure a wider range of pressures and better assess the pressures the turbine exerts on the fish. It was found that LLW and LW Fuji Prescale Pressure Sensitive Films were not significantly affected by the waterproof packaging or by stacking several layers of film on top of each other. Fuji Prescale Pressure Sensitive Film is sensitive to temperature and humidity, however, due to the difference in slope the Analysis of Covariance (ANCOVA) could not detect a difference in temperatures. Because humidity can be controlled and recorded during the waterproof packaging of the PSF it is not perceived as a problem. Fuji Prescale Pressure Sensitive Film will work well to test the pressures experienced by turbine passed fish and may aid in development of more fish friendly turbines.

Ozonation of Produced Water from the Oil Industry. MICHELE DINSMORE (Tennessee Technological University, Cookeville, TN 38505) COSTAS TSOURIS (Oak Ridge National Laboratory, Oak Ridge, TN 37831) .
The oil industry, in the process of pumping oil from wells, generates ¡§produced water,¡¨ which is usually seawater contaminated with various organic substances. Before produced water is returned to the environment, it needs to be treated for organics. One method to eliminate organic substances from produced water is oxidation, using ozone. Several experiments have been conducted in this study to investigate the effectiveness of ozone in oxidizing organic substances in real produced water from two oil companies. In these experiments, ozone was produced by a corona-discharge ozone generator and flushed through a large batch reactor containing a stir bar. Produced water was then injected in the reactor with 50-mL syringes to a total volume of 200 mL. Gas and water samples were taken at varying intervals from 0 to approximately 1600 minutes. Sampling events were adjusted depending upon the disappearance of ozone in the gas phase. Samples were analyzed for concentration of CO2, extractable organics, ozone, and organic acids. In some experiments, the produced water was heated to 80 degrees C to attempt to increase the removal of extractables. Results show that organic compounds can be successfully removed from produced water with the use of ozone. Heating the produced water improved the rate of removal. This information will be used for preliminary design and cost estimation.

Reducing Boron Toxicity by Microbial Sequestration. TRACY HAZEN (University of California, Davis, Davis, CA 94533) TOMMY J. PHELPS (Oak Ridge National Laboratory, Oak Ridge, TN 37831) .
While electricity is a clean source of energy, methods of electricity-production, such as the use of coal-fired power plants, often result in significant environmental damage. Coal-fired electrical power plants produce air pollution, while contaminating ground water and soils by build-up of Boron, which enters surrounding areas through leachate. Increasingly high levels of Boron in soils eventually overcome Boron tolerance levels in plants and trees resulting in toxicity. Formation of insoluble Boron precipitates, mediated by mineral-precipitating bacteria, may sequester Boron into more stable forms less available or toxic to vegetation. Results have provided evidence of microbially-facilitated sequestration of Boron into insoluble mineral precipitates. Analyses of water samples taken from ponds with high Boron concentrations showed algae present contained 3-5 times more Boron. Boron sequestration may also be facilitated by the incorporation of Boron within algal cells. Experiments examining Boron sequestration by algae are in progress. In bacterial experiments with added ferric citrate, the reduction of iron by the bacteria resulted in an iron-carbonate precipitate containing Boron. An apparent color change showing the reduction of amorphous iron, as well as the precipitation of Boron with iron, were more favorable at higher pH. Analysis of precipitates by x-ray diffraction, scanning electron microscopy, and inductively coupled plasma mass spectroscopy revealed mineralogical composition and biologically-mediated accumulation of Boron precipitates in test tube experiments.

A Study of Genetic Diversity Due to Spatial and Temporal Differences Among Southern ?Alamo? Switchgrass (Panicum virgatum L.) Sites. ERIN HOTCHKISS (Oxford College of Emory University, Oxford, GA 30054) LEE E. GUNTER (Oak Ridge National Laboratory, Oak Ridge, TN 37831) .
As environmental concerns continue to surface due to the pollution caused by (and the depletion of) fossil fuels, scientists are looking more and more toward renewable energy sources. Switchgrass (Panicum virgatum L.) is one of the most important potential sources of ethanol fuel, which burns much cleaner than fossil fuels. However, the conversion of switchgrass material into ethanol is still not cheap or efficient enough to compete with the non-renewable energy sources that we use today. We need to better understand the genetic make-up of switchgrass in order to enhance positive switchgrass characteristics needed for quicker ethanol conversion and also to find and manipulate genetic traits that allow for quicker growth and higher crop yields. The purpose of this experiment is to identify 1) whether spatial and temporal changes in gene frequencies are occurring in switchgrass plantings, and ultimately 2) whether a marked differentiation in gene frequencies is having a positive or negative effect on productivity in "Alamo", a switchgrass cultivar that has been adapted to the southern states. Using random amplified polymorphic DNA (RAPD) markers, changes will be assessed in marker frequencies among "Alamo" genotypes collected from four plots at five different research sites (Virginia Tech [2 sites], VA; Lexington, KY; Knoxville, TN; and Jackson; TN) in the southeast over a seven year period. Genetic differences within and among populations and an assessment of changes in gene frequencies will be discussed.

Global Change and Forest Physiology ? Impacts of Elevated Atmospheric CO2 on Photosynthesis in the Low Light Environment of the Forest Understory. REBEKAH HUTTON (University of Tennessee, Knoxville, TN 37916) CARLA GUNDERSON (Oak Ridge National Laboratory, Oak Ridge, TN 37831) .
The effects of increased atmospheric CO2 in the forest understory have been studied very little in comparison to the effects in high light environments. It is, however, important to look at the effects because plants in the understory depend on their ability to carry out photosynthesis both when there is very limited light and when there is direct sunlight. Elevated CO2 might have a bigger impact on photosynthesis at low light because it could cause plants to make better use of limited light availability. This hypothesis was tested in five forest plots, three under ambient conditions, and two with elevated CO2 provided by a free-air CO2 enrichment facility. The impact of elevated CO2 exposure was measured in seedlings of Acer negundo (boxelder) and Lindera benzoin (spicebush). Measurements of photosynthesis and stomatal conductance at multiple light levels were taken from six different trees of each species in each plot. In elevated CO2, light saturated photosynthesis was 22.5% and 41% higher than it was in ambient CO2 seedlings in A. negundo and L. benzoin, respectively. Increases in low light were similar to those at light saturation, ranging from 27.5% to 39%. High CO2 still reduced stomatal conductance in low light by approximately 9.9% to 11%. However, most of these differences were not statistically significant. Thus, impacts of increasing atmospheric CO2 may be minimal for the forest understory.

Sorption of Cesium on the Upper and Lower Sands of the Upper Ringold Formation and the Plio-Pleistocene. JENNIFER LADD (Tennessee Technological University, Cookville, TN 38505) PHILIP M. JARDINE (Oak Ridge National Laboratory, Oak Ridge, TN 37831) .
Large amounts of radioactive, chemical and mixed wastes were generated for decades at the Department of Energy Hanford reservation located in Richland, Washington. Underground waste tanks were utilized to dispose of a variety of radionuclides and mixed wastes in concentrated sodium nitrate. Leaks have resulted in discharge of radionuclides to the surrounding vadose zone, and 137Cs has been detected at more than 38m in depth and more than 30m from the source. Samples of the Miocene age upper Ringold formation and the Plio-Pleistocene caliche layer were taken from an area near the Hanford site. Both disturbed and undisturbed samples were obtained in order to quantify the coupled hydrologic and geochemical mechanisms contributing to contaminant mobility. The goal of this study was to quantify Cs+ sorption onto each solid phase. Isotherms were determined using batch techniques for initial Cs+ concentrations ranging from 0-20 ppm. The effects of background ionic strength were investigated by performing experiments at two ionic strengths, 0.02M and 0.2M. The effects of background cation on Cs+ sorption were investigated using two different matrices, Ca(NO3)2 and NaNO3. The overall distribution coefficients (Kd) follow the trend: 0.02MNa>0.02MCa>0.2MCa>0.2MNa. Overall Kds reflect 2:1 ratio that would be expected based on the charge of the matrix cation. This enables the prediction of Cs+ sorption as a function of ionic strength. The 0.2M ionic strength Ca2+ matrix is best for transport experiments based on analytical difficulties with Na+ and similarities of results. These results now make it possible to predict transport times through the large undisturbed cores.

Modification of an Individual-Based Model for Use in Biodiversity Studies. ALLEN MCBRIDE (Swarthmore College, Swarthmore, PA 19081) MICHAEL HUSTON (Oak Ridge National Laboratory, Oak Ridge, TN 37831) .
The study of the effects of species diversity on ecosystem processes has been controversial among ecologists in recent years. Several studies designed to manipulate species number have focused on herbaceous plant growth over periods of a few years. However, critical ecosystem issues involve large trees over periods of centuries. Such experiments are difficult to conduct, and will not produce results for decades or longer. Computer modeling can broaden the study of biodiversity by simulating the growth of mixed-species forests over periods of several centuries. An individual-based model of forest growth developed at ORNL, called LINKAGES, was modified for simulation of biodiversity experiments to investigate the ecosystem effects of different numbers and types of trees. Some modifications were made with the aim of improving the accuracy of the model generally, such as the reformulation of growth rates for tree species based on tree-ring data. Other modifications were made specifically to facilitate biodiversity studies, such as an option to grow several forests of one species each. It is hoped that this modified forest model can be used to explore unanswered questions about the long-term effects of biodiversity.

Development of entries and updates to CDIAC Trends Online.. DARIA SCOTT (St. Cloud State University, St. Cloud, MN 56301) DALE KAISER (Oak Ridge National Laboratory, Oak Ridge, TN 37831) .
In the study of global climate change, the scientific community's access to global data is crucial. To accurately gauge trends in global temperature, data must be shared between countries and then made available to the scientists who need to study it. Three sets of data were added to CDIAC's electronic publication, Trends Online. The first is by Russian scientist A.M. Sterin. The second and third were updates to data sets by Jones et al. and Lugina et al. These data sets were compiled from either stations reporting surface temperature or from radiosonde data. The data were received at CDIAC in raw format. Calculations were done for seasonal and global means. The data sets were formatted and put into data files and graphs. The were then put on web pages with accompanying background information and made accessible via Trends Online. This enables everyone in the world to use this very important data.

Solubility of Chloromethane in Aqueous Systems Containing High Levels of Biomass. CHRISTOPHER VODRASKA (Whitman College, Walla Walla, WA 99362) JOHN W. BARTON (Oak Ridge National Laboratory, Oak Ridge, TN 37831) .
Chloromethane, also known as methyl chloride, is a common environmental pollutant in landfills and waste sites due to its use in the production of silicones, butyl rubber, methyl cellulose and agricultural chemicals. Although various health effects are associated with chloromethane even at low concentrations, very little data exist for the solubility of chloromethane in systems other than pure water. Reaction vessels were constructed containing varying concentrations of yeast. Chloromethane was injected into the headspace of these reactors and given time to equilibrate between the headspace and the aqueous phase. The headspace was then sampled and tested by gas chromatography to measure the amount of chloromethane present. These data were used to calculate Henry's Law constants for each reactor system as a function of biomass/yeast concentration. Constants were then compared to literature and experimental values for the solubility of methyl chloride in water. Preliminary results show that the solubility of chloromethane in water is increased by the presence of biomass.