Regional variation of chemical groundwater composition in Hessen, Germany, and its relation to the aquifer geology INAUGURALDISSERTATION zur Erlangung des Doktorgrades der Fakultät für Chemie, Pharmazie und Geowissenschaften der Albert-Ludwigs-Universität Freiburg im Breisgau vorgelegt von Florian Ludwig aus Koblenz Freiburg 2011 Vorsitzender des Promotionsausschusses: Prof. Dr. Thorsten Koslowski Referent: Prof. Dr. Kurt Bucher Korreferentin: Prof. Dr. Ingrid Stober Datum der Promotion: 1. Dezember 2011 Drum hab ich mich der Magie ergeben, Ob mir durch Geistes Kraft und Mund Nicht manch Geheimnis würde kund; Daß ich nicht mehr, mit sauerm Schweiß, Zu sagen brauche, was ich nicht weiß; Daß ich erkenne, was die Welt, Im Innersten zusammenhält… Faust – Johann Wolfgang von Goethe Für meine Familie Table of contents Table of contents Acknowledgements ............................................................................................................. 5 Abstract................................................................................................................................... 7 Introduction .......................................................................................................................... 9 Chapter 1: Hydrochemical Groundwater Evolution in the Bunter Sandstone Sequence of the Odenwald Mountain Range, Germany – A Laboratory and Field Study Abstract .................................................................................................................................... 15 1. Introduction .................................................................................................................. 15 2. Study Area.................................................................................................................... 17 2.1. Geography and Climate Data ..................................................................... 17 2.2. Geological Setting...................................................................................... 17 2.3. Hydrogeology............................................................................................. 21 3. Methods........................................................................................................................ 22 4. Results and Discussion................................................................................................. 26 4.1. Modal Mineral Composition and Analytical Rock Data............................ 26 4.2. Composition of Leachates and Interpretation of Batch Experiments ........ 28 4.3. Groundwater Chemistry and Hydrochemical Evolution............................ 34 4.3.1. Sulfate Adsorption.......................................................................... 40 4.3.2. Hydraulic Properties....................................................................... 41 4.3.3. Stability Constraints ....................................................................... 42 5. Conclusions .................................................................................................................. 44 References ................................................................................................................................ 45 - 1 - PhD Thesis Florian Ludwig 2011 Chapter 2: Groundwater Evolution and Mineral Alteration Reactions in the Basaltic Rock Sequence of Mt. Wasserkuppe, Germany - A Case Study Abstract ................................................................................................................................... 53 1. Introduction .................................................................................................................. 53 2. Study Area.................................................................................................................... 55 2.1. Geography and Climate Data ..................................................................... 55 2.2. Geology ...................................................................................................... 55 2.3. Hydrogeology............................................................................................. 59 3. Methods........................................................................................................................ 60 4. Results and Discussion................................................................................................. 64 4.1. Analytical Rock Data and Modal Mineral Composition............................ 64 4.2. Groundwater Chemistry ............................................................................. 67 4.3. Composition of Leachates and Interpretation of Column Experiments..... 73 4.4. Hydrochemical Groundwater Evolution .................................................... 81 4.4.1. Near-surface Groundwater (Early-stage Weathering).................... 81 4.4.2. Groundwater at greater Depth (Late-stage Weathering)................ 82 4.4.3. Cation Exchange ............................................................................ 83 4.4.4. Interpretation of Hydrochemical Clusters...................................... 85 4.4.5. Stability Constraints ....................................................................... 87 5. Conclusions .................................................................................................................. 88 References ................................................................................................................................ 89 - 2 - Table of contents Chapter 3: Estimating the Effect of pH, Eh, and Sorption on Iron Hydroxides on the Mobility of Arsenic and Heavy Metals in various Aquifer Lithologies in Hessen, Central Germany Abstract ................................................................................................................................... 97 1. Introduction .................................................................................................................. 97 2. Study Areas .................................................................................................................. 99 2.1. Devonian Shale, Idstein Depression, Middle Rhine Highlands............... 100 2.2. Permian Rotliegend Sedimentary Rocks, Lower Main Plain................... 100 2.3. Triassic Bunter Sandstone, Odenwald Mountain Range.......................... 102 2.4. Triassic Bunter Sandstone, Lower Hessian Depression........................... 103 2.5. Tertiary Basaltic Rocks, Mt. Wasserkuppe, High Rhön .......................... 103 2.6. Tertiary Basaltic Rocks, Vogelsberg Mountain Range............................ 104 2.7. Quaternary Fluviatile Sediments, Upper Rhine Graben........................... 105 3. Methods...................................................................................................................... 105 4. Results and Discussion............................................................................................... 113 4.1. Groundwater Composition and Input by Meteoric Water........................ 113 4.2. Aquifer Lithologies .................................................................................. 114 4.3. Speciation and Mobility of Iron and Aluminium..................................... 115 4.4. Mobility Controls of Arsenic and Heavy Metals ..................................... 118 4.4.1. Arsenic ......................................................................................... 120 4.4.2. Copper and Lead .......................................................................... 122 4.4.3. Cadmium, Cobalt, Nickel, and Zinc............................................. 124 4.4.4. Chromium..................................................................................... 127 5. Conclusions ................................................................................................................ 129 References .............................................................................................................................. 130 - 3 - PhD Thesis Florian Ludwig 2011 General conclusions........................................................................................................ 135 Appendix App. 1 List of abbreviations ................................................................................................ A-1 App. 2 Complete groundwater data..................................................................................... A-3 App. 3 Complete rock data................................................................................................ A-15 App. 4 Complete data leaching experiments..................................................................... A-17 App. 5 Analytical specimen images .................................................................................. A-21 Publications Curriculum Vitae - 4 - Acknowledgements Acknowledgements Special thanks are due to my supervisor Prof. Dr. Kurt Bucher at the University of Freiburg for the competent mentoring of my PhD, for his patience and precious advice, for encourage- ment in critical moments, and gentle guidance throughout this study. I very much appreciate Prof. Dr. Ingrid Stober as second examiner for supporting and for contribution of valuable ideas. I am grateful to all colleagues at the University of Freiburg for their support during the lab experiments and sample conditioning, with special regard to Sigrid Hirth-Walther, Melanie Schrage, Dagmar Flemming, and Isolde Schmidt at the University of Freiburg. For exciting discussion, I would like