Progress in Hydrogeochemistry

1 Scope.- 2 Polar Organic Substances and Their Role in the Water-Saturated and -Unsaturated Zones.- 2.0 Introduction.- 2.1 Isolation Procedures and Characterization Methods.- 2.1.1 Isolation and General Characterization of Organic Acids from Pore Water.- 2.1.2 Isolation and Characterization of Soil Humic Matter.- 2.1.3 Isolation and Characterization of Organic Substances in Ground Water and Sediments.- 2.1.4 Chromatographic Characterization of the Acid-Soluble Part of Humic Substances.- 2.1.5 Spectroscopic Characterization of Humic Substances in the Ultraviolet and Visible Region and by Infrared Spectroscopy.- 2.1.6 Temperature-Programmed/Time-Resolved Pyrolysis Field Ionization Mass Spectrometry - a New Method for the Characterization of Humic Substances.- 2.1.7 Interpretation of the Pyrolysis Products of Isolated Humic and Fulvic Acids.- 2.1.8 Characterization of Isolated Humic Material by 13C Nuclear Magnetic Resonance Spectroscopy.- 2.1.9 Characterization of Humic Substances Extracted by Organic Solvents.- 2.2 Interaction of Inorganics with Humic Substances.- 2.2.1 Investigation of Metal Complexation by Polarography and Fluorescence Spectroscopy.- 2.2.2 Determination of Complexation Equilibria by the Ion-Exchange Method.- 2.2.3 Sorption of Metals on Humic Material.- 2.2.4 Interactions of Humic Substances with Iodine.- 2.2.5 Experiments on the Influence of Organic Ligands upon Kinetics of Feldspar Weathering.- 2.3 Characterization of Some Organic Acids in the Subsurface of the Sandhausen Ecosystem.- 2.3.4 Organic Acids.- 2.3.5 Conclusions.- 3 Carbonate Systems.- 3.0 Introduction.- 3.1 Dissolution Kinetics in the Generation of Carbonate Ground Waters.- 3.1.1 Theoretical and Experimental Results of the Kinetics of Calcite Dissolution and Precipitation.- 3.1.2 Field Measurements and Laboratory Experiments on Calcite Dissolution Kinetics of Natural Porous Media.- 3.2 Field Studies on Subsurface Water of Selected Sites.- 3.2.1 Pore Water Sampling in Carbonate Terrains.- 3.2.2 Variation of Inorganic Carbon in the Unsaturated Zone of a Carbonate Gravel System.- 3.2.3 Isotope Geochemistry of the Subsurface Carbonate System in Sandhausen and Bocholt.- 3.2.4 Application of Stable Carbon and Sulfur Isotope Models to the Development of Ground Water in a Limestone-Dolomite-Anhydrite-Gypsum Area.- 3.2.5 A dissolution Front at the Contact of Sands to Marly Limestone Aquifers.- 3.2.6 Carbonate Rock Dissolution Under Intermediate System Conditions.- 3.3 Alteration in Karst Systems.- 3.3.1 Mineralogy and Hydrogeochemistry of the Gypsum Karst of Foum Tatahouine, South Tunisia.- 3.3.2 Dedolomitization and Salt Formation in a Semi-Arid Environment.- 3.3.3 Transformation Processes in Paleokarst Sediments and Chemistry of Modern Waters in the Aladag Region, Turkey.- 4 Silicate Systems.- 4.0 Introduction.- 4.1 Redox Reactions in the Subsurface.- 4.1.1 Anoxic Reaction Zones in an Aquifer Influenced by Increasing Nitrate and Sulfate Contents.- 4.1.2 Nitrogen and Oxygen Isotopes as Indicators for Nitrification and Denitrification.- 4.1.3 Redox Conditions and Microbial Sulfur Reactions in the Fuhrberger Field Sandy Aquifer.- 4.1.4 Influence of Fine-Grained Cover Beds on the Chemistry of Shallow Ground Water.- 4.1.5 Hydrogeochemical Processes During the Passage of Surface Water and Ground Water Through Genetically Different Organic Sediments.- 4.1.6 Hydrochemical Phenomena in the Dorsten Leakage System.- 4.1.7 Hydrogeochemical Processes in the Hamburg Deep Aquifer System.- 4.2 Rock-Water Interaction.- 4.2.1 Aluminium Speciation in Acid Soil Water and Ground Water.- 4.2.2 Mineral-Pore Water Interaction in Two Soil Types on Pleistocene Sediments at Hamburg.- 4.2.3 Subsurface Hydrochemical Reactions in the Sandhausen Forest Ecosystem.- 4.3 Reaction Kinetics.- 4.3.1 Experimental Methods for Determining Dissolution Rates of Silicates - a Comparison.- 4.3.2 Field Studies on the Kinetics of Silicate Minerals/Water Interaction.- 5 Microbiology.- 5.0 Introduction.- 5.1 Characterization of the Natural Subsurface Environment.- 5.1.1 Morphological and Taxonomic Diversity of Ground Water Microorganisms.- 5.1.2 Methods of Studying Ground Water Microbiology: Critical Evaluations and Method suggestions.- 5.1.3 Organic Substances in Ground Water and Sediments and Their Relationships to Microorganisms in a Sandy Aquifer.- 5.2 Microbial Activities.- 5.2.1 Observations on the Physiology of Microorganisms from Pristine Ground Water Environments.- 5.2.2 Formation and Transformation of Manganese Oxidation States by Bacteria.- 5.2.3 Interactions Between Humic Acids and Microorganisms.- 5.3 Microbiology of Selected Locations.- 5.3.1 Subsurface Microbial Activities in the Sandhausen Forest Ecosystem.- 5.3.2 Heterotrophic Bacterial Communities in the Bocholt Aquifer System.- 5.3.3 The Natural Microflora of the Segeberger Forest Aquifer System.- 5.3.4 Microbiological Observations of the Unsaturated Zone of a Quaternary Gravel Profile.- 6 Hydrogeochemical and Geochemical-Hydraulic Models and Model Concepts.- 6.0 Introduction.- 6.1 Hydrogeochemical Models and Concepts.- 6.1.1 Development of Secondary Permeability of a Fracture Aquifer in Carbonate Rocks: a Model.- 6.1.2 Some Aspects of Modelling the Carbon System in the Unsaturated Zone.- 6.1.3 Methodical Concepts in Silicate-Water Interaction - a Comparison of Results.- 6.2 Combination of Transport and Geochemical Reactions.- 6.2.1 Water Movement and Geochemical Reactions in the Unsaturated Zone of Sands with Low Calcite Contents.- 6.2.2 Physical and Biochemical Processes Affecting Mass Transport in the Bocholt Aquifer System.- 6.2.3 Tritium and 3He Measurements as Calibration Data for Ground Water Transport Models.- 6.2.4 89Ar-, 85Kr-,3He-and 3H Isotope Dating of Ground Water in the Bocholt and Segeberger Forst Aquifer Systems.- 6.2.5 Modelling of Mass Balance and of Microbial Transformations in the Fuhrberger Feld Sandy Aquifer.- 6.3 Description of Geochemical Environments with Thermodynamic Equilibrium Models.- 6.3.1 Approach.- 6.3.2 Geochemical Models and Limiting Reactions.- 6.3.3 Calculation Errors.- 6.3.4 Sensitivity Analyses.- 6.3.5 Limiting Phases.- 6.3.6 Conclusions.- 7 Perspectives and Needs for Future Work.- References.