Student Abstracts: Environmental Science at PNNL

Evaluations of Sagebrush Die-Off on the Hanford Site. SHELLEY ALONGI (Washington State University - Tri-Cities, Richland, WA 99352) JANELLE L. DOWNS (Pacific Northwest National Laboratory, Richland, WA 99352) .
In 1993, Hanford Site biologists noticed extensive areas where Wyoming Big Sagebrush (Artemisia tridentata ssp wyomingensis) plants were dying. Big sagebrush is a vital component of the shrub-steppe plant community with many animals relying on if for food and shelter. Six monitoring transects were installed in early 1997 with 5 inside the effected area and one control plot. In December 1997, seedlings raised in-house were transplanted inside and outside the effected area. In March 2001, a direct seed trial was started. The monitoring transects and the transplanted sagebrush have been monitored every year since 1997. Analysis of the data for both of these trials indicates the affected area is still in decline. The area of decline may also be spreading, as the control transect for the monitoring trial has been declining in a similar pattern to the other five transects. The direct seeding trial had no seedlings emerge. This could be due to the drought this year. It is not clear that seedlings cannot germiniate within the effected area. Further monitoring of the seeding trial is necessary to determine the potential for sagebrush germination, recruitment and establishment. The analysis results indicate that a new control plot for the monitoring trial maybe needed, and that a new map of the affected area might show patterns and direction of spread of the die off.

Usage of Infra-Red LED and DataLogger as an Air Sampling Device. ANGELA AYON (Yakima Valley Community College, Yakima, WA 98902) RANDY R. KIRKHAM (Pacific Northwest National Laboratory, Richland, WA 99352) .
An air sampler is used to measure the concentration of a certain substance in the air. An example of two that are used at the Yakima Training Center by Randy R. Kirkham are the mini-vol and sequential sampler. These samplers are set up at various locations with various natural surroundings. My mentor and I prepared an air sampling device with equipment that was readily available in hopes of producing an inexpensive and accurate road dust monitor sampler. The equipment we used consisted of the following: 1 Campbell Scientific data ram, 2 infra-red Light Emitting Diodes that were mounted on tri-pod stands, 1 Kodak PC 290 digital camera, and 1 Sony digital motion camera. The experiment setup occurred on a fairly dusty road just out of cantonment at the Yakima Training Center. Infra-red eyes were positioned on opposite sides and several feet away from the road. The sender was wired to the DataLogger and Kodak digital camera. The receiver was connected to a 12-volt power source. The program that ran from the DataLogger logged data whenever the signal was broken as well as take a picture at that exact moment. Located inside the vehicle were two DataRams of PM size 10 and 2.5. The Data logger recorded time the signal was tripped, time the signal came back on, and the voltage difference between the two eyes. After viewing the results, several factors affecting accuracy were distinguished. The results of this experiment proved the setup to be an inexpensive dust sampler that will be used in future research.

Effects of Soil Particle Size Distribution on Post Fire Vegetation. SARAH BAKER (University of Washington, Seattle, WA 98105) MICHAEL SACKSCHEWSKY (Pacific Northwest National Laboratory, Richland, WA 99352) .
The 2000 Hanford wildfire greatly altered the vegetation on much of the Hanford site. Vegetation re-growth has shown interesting patterns in some areas. One such site, which is west of the 200 W Area, has intermingled patches of distinctive vegetation types. Several of these patches are dominated by cheatgrass (Bromus tectorum), others by Russian thistle (Salsola kali), while others have little vegetation besides scattered Russian thistle and bur ragweed (Ambrosia acanthicarpa). Since the particle size distribution of a soil, especially the percent fines, can influence plant communities, this study was conducted to determine if the soil texture differed under the various vegetation types and if similar vegetation types shared similar soil. To do so, soil samples were collected and particle size analysis performed. Vegetative canopy coverage of each area was also determined. It was shown that the patches dominated by Russian thistle had significantly higher percent fines in the soil than the other vegetation areas. The other areas had little difference in their particle size analyses. Thus, the results are somewhat inconclusive. It appears that while soil texture may have influenced vegetation patterns on this site, other factors probably influenced it as well.

Bioprocess with Filamentous Fungi. SHANA LACROSSE (Pima Community College, Tucson, AZ 85730) ROBERT A. ROMINE (Pacific Northwest National Laboratory, Richland, WA 99352) .
The goal of this project is to achieve the ability to use filamentous fungi for the production of new chemical products. The metabolic versatility of fungi is not well exploited by the fermentation industry. It is used on a limited basis to produce organic acids, industrial enzymes and antibiotics. There is a need to develop fermentation strategies using filamentous fungi for the production of new products. This research involves manipulating filamentous fungi at an early stage (in shake flask experiments) and later in bench top fermentors. This work is targeted at maximizing the production of specific organic acids that can be used as a feedstock to catalytic conversion processes to produce specialty chemicals of interest to industry.

Dissolution Kinetics of LAWA44, a Candidate Low Activity Waste Glass, In Relation to Solution pH. SUZIE LANCASTER (Truckee Meadows CC, Reno, NV 89557) JONATHAN ICENHOWER (Pacific Northwest National Laboratory, Richland, WA 99352) .
Secure storage of radioactive waste from the Cold War atomic defense legacy is a pressing environmental concern. Current Hanford remediation plans call for vitrification of the low activity portion of liquid waste and subsequent repository emplacement. Corrosion resistance of Immobilized Low Activity Waste (ILAW) Glass has been tested for varying environmental factors; our focus was the range of potential interstitial pore water pH. We used a single-pass flow through apparatus to measure dissolution rates for LAWA44, a candidate waste form, using a range of solutions from pH 7 to 11. Analysis of effluent samples indicates that the power law coefficient, eta, for the dependence of the rate on solution pH is 0.43. Therefore, the constant temperature rate in dilute solution can be written as:rate = ko*(aH+)^0.43 , where ko is the intrinsic rate constant and aH+ is the activity of the hydronium ion. The value of eta is identical to that of other silicate glasses and minerals. These results imply that the dissolution mechanism is the same for all silicate materials, regardless of crystalline structure and Si-O bond length or angle.

Microencapsulation of Volatile Atmospheric Particles. NATHAN MOORE (University of Washington, Seattle, WA 98195) JAMES P. COWIN (Pacific Northwest National Laboratory, Richland, WA 99352) .
Volatile aerosols, such as ammonium nitrate, sulfuric acid, and tarry organic particles, are known to comprise a large portion the total airborne particulates in certain polluted areas, such as Houston, and yet are difficult to study due to their short shelf-life and high volatility under typical operating conditions of SEM/EDX and other laboratory analyses. This work aims to improve the method of field particle collection used by Laskin, et al1, by encapsulating collected particles within a thin film to substantially reduce their rate of evaporation, thereby allowing more accurate determination of particle size, composition, and number using SEM/EDX laboratory analysis. Several methods of encapsulation are screened, including passive and electrostatic vapor deposition, and evaporation of a solvent carrier. Each is presented as feasible with future refinements.

Columbia River Recreational Survey 2001 - General Overview. RACHEL PARKHILL (Eastern Washington University, Cheney, WA 99004) AMORET BUNN (Pacific Northwest National Laboratory, Richland, WA 99352) .
PNNL is conducting a research study for the U.S. Department of Energy. The Columbia River Recreational Survey was designed to determine the type of recreational activities conducted on the Columbia River. It is also to estimate the impact of recreational activities on the regional economy. Survey teams visited 25 sites and conducted interviews and observations. The survey aspect of our research helped us determine the number of hours and day's people spend on the river and also their recreational activities on or around the river. The observational aspect of our project aided us in determining which sites are most popular with out-of-state and in-state individuals and the activities that were engaged in at each site. All the critical information gathered by our survey team may be used in both human health risk assessment and the economic impact predictions at the U.S Department of Energy's Hanford site.

Columbia River Recreation Survey 2001:Geographic Distribution of Recreational Activities. KATHLEEN TRUJILLO (Montana State University-Northern, Havre, MT 59501) KENNETH HAM (Pacific Northwest National Laboratory, Richland, WA 99352) .
Although the importance of river-based recreation is acknowledged, little specific information is available about geographic distribution of these recreational activities. This information is needed to assess potential risks to human health, as well as impacts on the local economy of future remediation plans for the Hanford site. The Columbia River Recreation Survey 2001 was designed in response to these needs. Survey teams visited 25 sites and conducted interviews as well as doing 15-minute observations. The observational part of the survey was intended to supplement the interview questionnaires by quantifying the number of recreationists observed during a 15-minute period at each site. This was to correct for the recreationists who declined to participate (or were inaccessible) in the survey, ensuring the total number of river users is not under-represented. In addition, the observations were used to determine which sites are most popular with out-of-state visitors and which activities are prevalent at each site. Preliminary analysis with Microsoft Excel shows Howard Amon Park had the most out-of-state vehicles (mean =3.5 vehicles), while Columbia Point had the most Washington State vehicles (mean = 50.7 vehicles). Water-based activities such as swimming and boating were the most common forms of recreational activity (mean = 15.7 persons), while shore-based activities such as picnics and walking were less popular (mean = 12.8 persons) and less evenly distributed among the locations. This information may be used in both the human health risk assessment and the economic impact predictions at the U.S. Department of Energy's Hanford Site.