AN ABSTRACT OF THE THESIS OF Lisa Marie Windom for the degree of Master of Science in Soil Science and Water Resource Science presented on March 19, 2020. Title: Calcium Ion Transport via Seeping Flow Events through Epikarst Microfissures. Abstract approved: ______________________________________________________ Maria Dragila John Selker Solute transport models in karst groundwater must consider variable and complex flow regimes. Within fissures less than 2 mm in aperture, during unsaturated flow events, seeping flow may flow as films or under capillary tension as a capillary rivulet. This project focuses on exploring the mass transport characteristics of seeping film by quantifying the transport effectiveness of capillary rivulets in comparison to a flat, thin film. A laboratory constructed fissure comprised of a limestone slab and a glass plate was used to quantify the mass of calcium ions transferred from the rock to the film during the passage of seeping water as either a film or capillary rivulet. While film flow extracted 170% more calcium ion mass than the capillary rivulets, when normalized by the wetted area, the capillary rivulet extracted 300% more calcium ions than the film flow. As mass flux, capillary rivulets exhibit greater potential for solute transfer across the rock-liquid interface than film flow. ©Copyright by Lisa Marie Windom March 19, 2020 All Rights Reserved Calcium Ion Transport via Seeping Flow Events through Epikarst Microfissures by Lisa Marie Windom A THESIS submitted to Oregon State University in partial fulfillment of the requirements for the degree of Master of Science Presented March 19, 2020 Commencement June 2020 Master of Science thesis of Lisa Marie Windom presented on March 19, 2020 APPROVED: Co-Major Professor, representing Soil Science Co-Major Professor, representing Water Resource Science Head of the Department of Crop and Soil Science Director of the Water Resources Graduate Program Dean of the Graduate School I understand that my thesis will become part of the permanent collection of Oregon State University libraries. My signature below authorizes release of my thesis to any reader upon request. Lisa Marie Windom, Author ACKNOWLEDGEMENTS I wish to share sincere gratitude and appreciate to Dr. Maria Dragila for her steady vision, patience and kindness. In a line of work so often frenzied with chaos, Maria brings focused calm to her every encounter. Though my heart aches from my non- traditional path through graduate school, Maria has remained a loving ally. Her compassion, love and respect towards her students knows no bounds, and for that we are all changed for the better. The faculty and staff within the Crop and Soil Science Department and the Water Resource Science group have given me endless encouragement, support and wisdom throughout my time in graduate school and I cannot thank them enough. I send my gratitude to Noam Weisbrod for his creative and valuable input towards project design. And I wish to acknowledge the United States-Israel Binational Science Foundation for their financial support. TABLE OF CONTENTS Title Page Chapter 1: Introduction ................................................................................................................... 1 Project Motivation ...................................................................................................................... 1 Project Focus ............................................................................................................................... 2 Scientific Background ................................................................................................................. 2 Hydrodynamics through Fractured Rock ................................................................................ 2 Hydrodynamics of Modes of Flow ....................................................................................... 13 Hydrodynamic Exchange with Porous Media ...................................................................... 18 Calcium Mass Continuity ..................................................................................................... 20 Chapter 2: Experimental Methods, Results, and Discussion ........................................................ 21 Materials and Methods .............................................................................................................. 21 Experimental Design ............................................................................................................. 21 Statistical Analysis ................................................................................................................ 28 Results ....................................................................................................................................... 30 Experimental Controls .......................................................................................................... 30 Experimental Results ............................................................................................................ 32 Data Analysis ........................................................................................................................ 41 Discussion ................................................................................................................................. 47 Discussing the Results .......................................................................................................... 47 Reflection on Competing Mechanisms ................................................................................. 48 Chapter 3: Conclusion................................................................................................................... 51 References ................................................................................................................................. 54 LIST OF FIGURES Figure Page Figure 1.1 Defining the coordinate system. .................................................................................... 3 Figure 1.2 The Nusselt height signifies the representative height of wavy film flow. ................... 5 Figure 1.3 Top-down view of contact area calculation scheme...................................................... 6 Figure 1.4 Cross-sectional view of film flow profile. ..................................................................... 7 Figure 1.5 Cross-section of capillary rivulet: Force diagram show net force vectors along meniscus surface. ............................................................................................................................ 8 Figure 1.6 Cross-section of capillary rivulet showing meniscus corner geometry. ........................ 9 Figure 1.7 Linear method for calculating the wetted area estimate for the capillary rivulet. ....... 10 Figure 1.8 Applying the conservation of energy, the effective angle can be derived ................... 11 Figure 1.9 Visualization of mult-segment method. ...................................................................... 12 Figure 1.10 Predominant capillary rivulet behavior within this experiment. With distance, the capillary rivulet either remains as a single rivulet, splits and recombines (Y), or splits into two more narrow rivulets called a double. ........................................................................................... 13 Figure 1.11 Film Flow: Semi-parabolic velocity profile of film with distance from rock surface for a film height of 250 microns. .................................................................................................. 15 Figure 1.12 Capillary rivulet: Parabolic velocity profile of rivulet with distance form rock for an apperture of 700 microns. ............................................................................................................. 16 Figure 1.13 Mass exchange between film and matrix pores. ........................................................ 18 Figure 2.1 Edwards Formation limestone sample and set up. ...................................................... 22 Figure 2.2 Capillary rivulet created between limestone and glass. ............................................... 23 Figure 2.3 Design of Mariotte bottle supplying the influent solvent. ........................................... 25 Figure 2.4 Subsection scheme for single, Y and double rivulet behavior. ................................... 34 Figure 2.5 Time series of calcium ion concentration of effluent measured in each captured effluent sample over time by trial ................................................................................................. 39 Figure 2.6 Statistical analysis of the data for the calcium ion concentration of the effluent. ....... 40 Figure 2.7 Statistical analysis (box and wisker plot) of effluent calcium ion concentration for the capillary rivulet, grouped by flow behavior (single, Y, and double). ........................................... 41 Figure 2.8 Time series of calcium ion mass discharge for film flow and capillary rivulet flow. 42 Figure 2.9 Time series of calcium ion flux for film and capillary rivulet. ................................... 43 Figure 2.10 Statistical analysis (box and whisker plot) of calcium ion flux................................. 44 Figure 2.11 Effluent calcium ion versus magnesium ion concentration ....................................... 45 Figure 2.12 Calcium vs magnesium flux per unit surface area. .................................................... 46 Figure 2.13