Presentation on theme: "Multi-tracer approach to understanding contaminant fate and transport in karst aquifers Amanda Laskoskie 1, Dr. Dorothy Vesper 1, Dr. Harry Edenborn 2,"— Presentation transcript:
Multi-tracer approach to understanding contaminant fate and transport in karst aquifers Amanda Laskoskie 1, Dr. Dorothy Vesper 1, Dr. Harry Edenborn 2, Dr. Akram Alshawabkeh 3, Dr. Ingrid Padilla 4 1 West Virginia University, 2 Department of Energy, 3 Northeastern University, 4 University of Puerto Rico Mayagüez Superfund Annual Meeting, Lexington, Kentucky, October 24-25, 2011 Abstract # 4205 Project PROTECT Babies born preterm (before 37 weeks of gestation) are the leading cause of neonatal death in the U.S. and cost an estimated $26 billion annually as well are at risk of having lifelong disabilities. Known risk factors do not explain the increase in preterm births experienced in Puerto Rico, therefore, environmental risk factors need to be assessed including pollution in the underlying karst aquifers of Puerto Rico. However, contaminant fate and transport in karst systems is poorly understood. PROTECT’s goal is to 1) define the relationship between exposure to Superfund and related contaminants and preterm birth and 2) develop new technology for discovery, transport characterization, and green remediation of Superfund and related contaminants in karstic aquifers. To incorporate the influence of the hydrologic system, the suites will be tested over two different cave morphologies at the field research site. The Canyon: a relatively straight, rock-lined stream section with higher water levels and more concentrated flow The Meandering Stream: a meandering stream with low water levels and gravel sized bed load The results of the field tests will be analyzed in Qtracer2 (U.S. EPA 2002) to quantify the differences between the tracers and the cave segments. Buckeye Creek Cave Research Site Buckeye Creek Cave, located near Lewisburg, West Virginia, developed in the Union Limestone. There is also no additional input or output of water as determined by discharge measurements over both sections. The cave is transversable which makes it ideal for this research. It is also a well studied cave and past tracer tests report success using fluorescein, rhodamine, and acid yellow 93. The cave will be split into two segments for study: the canyon (95 meters long) and the meandering stream (240 meters long). How the beads are made: Dissolve sodium alginate to produce 2% w/v Prepare a gelation solution of 0.1 M CaCl 2 ·H 2 O Dropwise add alginate solution to gelation solution using a syringe and needle under constant stirring Cure beads in 0.1 M CaCl 2 ·H 2 O and refrigerated for at least 24 hours Current Activities and Challenges Finding innocuous ways to alter the properties of the beads Developing a method to make the beads microns in size Bead recovery and detection Bead stability Getting beads keep fluorescence in natural waters Sampling frequency in Buckeye Creek Cave Acknowledgements This work was supported by Award Number P42ES from the National Institute Of Environmental Health Sciences. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute of Environmental Health Sciences or the National Institutes of Health. I would like to thank the following projects/agencies for allowing me to work with them: Puerto Rican Testsite for Exploring Contaminant Threats, Superfund Research Project, National Institute of Health, and the Department of Energy. A special thank you to everyone involved with Project PROTECT for their hard work, collaboration, and general enthusiasm for the project. I’m grateful to have my first research experience be with a group of people that are so wonderful, diverse and dedicated. To my colleagues at West Virginia University for their help and support: John Tudek, Ph. D student who has been an incredible help with caving and brainstorming, and Annie Berlingheiri and John Moore, M.S. students, for assistance retrieving data. To Doug Boyer and Derek Hall for assistance installing equipment in Buckeye Creek Cave. And the biggest thank you goes to Dr. Dorothy Vesper. Without her support, expertise, and knowledge this research would not be nearly as exciting or valuable. References Bajpai SK, Tankhiwale R, Investigation of water uptake behavior and stability of calcium alginate/chitosan bi-polymeric beads: Part-1. React Funct Polym ;66(6): Benischke R, Goldscheider N, Smart CC, Tracer techniques. Methods in Karst HydrogeologyLondon, UK: Taylor & Francis. p Buchanan TJ, Somers WP, Discharge Measurements at Gaging Stations. Washington, DC: U.S. Geological Survey Techniques of Water-Resources Investigations. p. 65. Dasher GR, Balfour WM, The caves and karst of the Buckeye Creek Basin, Greenbrier County, West Virginia. Maxwelton, W. Va.: West Virginia Association for Cave Studies. Ford DC, Williams PW, Karst hydrogeology and geomorphology. 2nd ed. Hoboken, NJ: John WIley & Sons. Ghanem A, Soerens TS, Adel MM, Thoma GJ, Investigation of Fluorescent Dyes as Partitioning Tracers for Subsurface Nonaqueous Phase Liquid (NAPL) Characterization. J.Environ.Eng. ;129(8):740. Goldscheider N, Meiman J, Pronk M, Smart C, Tracer tests in karst hydrogeology and speleology. Int.J.Speleol. ;37(1): Kass W, Tracing Technique in Geohydrology. A.A. Balkema, Brookfield, 1998, 581 pages,;234(1-2): Kram ML, Keller AA, Massick SM, Laverman LE, Complex NAPL Site Characterization Using Fluorescence Part 1: Selection of Excitation Wavelength Based on NAPL Composition. Soil Sed.Contam. ;13(2): U.S. EPA. The Qtracer2 Program for Tracer-Breakthrough Curve Analysis for Tracer Tests in Karstic Aquifers and Other Hydrologic Systems. U.S. Environmental Protection Agency, Office of Research and Development, National Center for Environmental Assessment, Washington Office, Washington, DC, EPA/600/R-02/001, Vesper DJ, Loop CM, White WB, Contaminant transport in karst aquifers. Speleogenesis and evolution of karst aquifers ;1(2 ). Scan to watch beads being born (at full term) TracerTransport behavior Bromide (dissolved solute)Conservative, transported with water Florescent dyes (eosine, fluoroscein, rhodamine WT, uranine, pyranine, sulforhodamine B) Dissolved solutes but transport is retarded due to sorption on sediments and organic matter; suites of dyes with different retardation factors will be used Hydrogel Tracer Beads (being developed in this project) Transport as a separate phase (a proxy for NAPLs). Can be constructed with different buoyancies and sizes. Mimicking Contaminant Transport in Karst Systems A suite of tracers is being developed including hydrogel bead proxies for non-aqueous phase liquids (NAPLs). The following tracers will be injected simultaneously so their transport can be compared under the same hydrologic conditions. Goals for this Project The goal of this specific research task is to develop proxy tracers that mimic contaminant movement to better understand and predict contaminant fate and transport in karst aquifers. (Dasher and Balfour 1994) The canyon with flowstone (J. Tudek) Lab experiments were conducted to test the stability of the beads after curing in cave water. Measuring stream discharge in the cave (J. Tudek) Bead Creation and Preliminary Bead Studies Installing temperature loggers in the meandering stream section (J. Tudek) Hollow glass beads were used, in different proportions to the gel, to alter buoyancy.