Britta Planer-Friedrich – författare

To understand hydrochemistry and to analyze natural as well as man-made impacts on aquatic systems, hydrogeochemical models have been used since the 1960’s and more frequently in recent times. Numerical groundwater flow, transport, and geochemical models are important tools besides classical deterministic and analytical approaches. Solving complex linear or non-linear systems of equations, commonly with hundreds of unknown parameters, is a routine task for a PC. Modeling hydrogeochemical processes requires a detailed and accurate water analysis, as well as thermodynamic and kinetic data as input. Thermodynamic data, such as complex formation constants and solubility products, are often provided as data sets within the respective programs. However, the description of surface-controlled reactions (sorption, cation exchange, surface complexation) and kinetically controlled reactions requires additional input data. Unlike groundwater flow and transport models, thermodynamic models, in principal, do not need any calibration. However, considering surface-controlled or kinetically controlled reaction models might be subject to calibration. Typical problems for the application of geochemical models are: speciation determination of saturation indices adjustment of equilibria/disequilibria for minerals or gases mixing of different waters modeling the effects of temperature stoichiometric reactions (e.g. titration) reactions with solids, fluids, and gaseous phases (in open and closed systems) sorption (cation exchange, surface complexation) inverse modeling kinetically controlled reactions reactive transport Hydrogeochemical models are dependent on the quality of the chemical analyses, the boundary conditions presumed by the program, theoretical concepts (e.g.

To understand hydrochemistry and to analyze natural as well as man-made impacts on aquatic systems, hydrogeochemical models have been used since the 1960’s and more frequently in recent times. Numerical groundwater flow, transport, and geochemical models are important tools besides classical deterministic and analytical approaches. Solving complex linear or non-linear systems of equations, commonly with hundreds of unknown parameters, is a routine task for a PC. Modeling hydrogeochemical processes requires a detailed and accurate water analysis, as well as thermodynamic and kinetic data as input. Thermodynamic data, such as complex formation constants and solubility-products, are often provided as databases within the respective programs. However, the description of surface-controlled reactions (sorption, cation exchange, surface complexation) and kinetically controlled reactions requires additional input data. Unlike groundwater flow and transport models, thermodynamic models, in principal, do not need any calibration. However, considering surface-controlled or kinetically controlled reaction models might be subject to calibration. Typical problems for the application of geochemical models are: • speciation • determination of saturation indices • adjustment of equilibria/disequilibria for minerals or gases • mixing of different waters • modeling the effects of temperature • stoichiometric reactions (e.g. titration) • reactions with solids, fluids, and gaseous phases (in open and closed systems) • sorption (cation exchange, surface complexation) • inverse modeling • kinetically controlled reactions • reactive transport Hydrogeochemical models depend on the quality of the chemical analysis, the boundary conditions presumed by the program, theoretical concepts (e.g.

To understand hydrochemistry and to analyze natural as well as man-made impacts on aquatic systems, hydrogeochemical models have been used since the 1960’s and more frequently in recent times. Numerical groundwater flow, transport, and geochemical models are important tools besides classical deterministic and analytical approaches. Solving complex linear or non-linear systems of equations, commonly with hundreds of unknown parameters, is a routine task for a PC. Modeling hydrogeochemical processes requires a detailed and accurate water analysis, as well as thermodynamic and kinetic data as input. Thermodynamic data, such as complex formation constants and solubility-products, are often provided as databases within the respective programs. However, the description of surface-controlled reactions (sorption, cation exchange, surface complexation) and kinetically controlled reactions requires additional input data. Unlike groundwater flow and transport models, thermodynamic models, in principal, do not need any calibration. However, considering surface-controlled or kinetically controlled reaction models might be subject to calibration. Typical problems for the application of geochemical models are: • speciation • determination of saturation indices • adjustment of equilibria/disequilibria for minerals or gases • mixing of different waters • modeling the effects of temperature • stoichiometric reactions (e.g. titration) • reactions with solids, fluids, and gaseous phases (in open and closed systems) • sorption (cation exchange, surface complexation) • inverse modeling • kinetically controlled reactions • reactive transport Hydrogeochemical models depend on the quality of the chemical analysis, the boundary conditions presumed by the program, theoretical concepts (e.g.

Auch die zweite Auflage von „Grundwasserchemie" bietet als praxisorientierter Leitfaden einen schnellen Einstieg in die thermodynamische Modellierung. Neben einem minimalen theoretischen Hintergrund liegt der Fokus auf praktischen Beispielen mit dem Computerprogramm PHREEQC. In der Neuauflage sind nun zusätzlich die Möglichkeiten des CD-MUSIC Konzepts zur Oberflächenmodellierung erklärt. Beispiele zum reaktiven Stofftransport umfassen nicht nur den 1d Transport in PHREEQC, sondern auch ein 3d Beispiel mittels PHAST und der graphischen Benutzeroberfläche WPHAST. Unsicherheiten thermodynamischer Daten können mit Hilfe des Programms LJGUNSKILE modelliert werden. Wie in der ersten Auflage helfen detaillierte Beschreibungen der Lösungen dem Nutzer, Schritt für Schritt von einfachen hin zu immer komplexeren hydrogeochemischen Modellierungen zu gelangen. Alle Programme sowie die Lösungen zu den Aufgaben befinden sich auf der CD zum Buch.

Preface Uranium is a radioactive element and a heavy metal which is naturally occurring in ground and surface water. Although uranium is enriched in granites and gneiss ground water from these host rocks often shows low to intermediate uranium con­ centrations, while some ground waters from sandstone and carbonate aquifers show elevated uranium concentrations up to several hundred mg/1 without man made impact. On the other side, surface water contains increased anthropogenic uranium concentrations due to the intensive use of phosphate fertilizers and in mining areas due to mining and milling activities. Saxony and Thuringia both be­ ing states of the reunified Germany are probably an area where uranium mining activities have impacted the environment more severely than in any other part of the world. Thus, the federal government of Germany allocated huge amounts of money for the rehabilitation work, a unique proceeding without precedent in min­ ing history. In October 1995 the first international conference on Uranium Mining and Hydrogeology (UMM I) was held in Freiberg being organized by the Department of Geology at the technical University Freiberg by the support of the Saxon State Ministry of Geology and Environment. Due to the large scientific interest in the topic ofuranium a second conference (UMH II) took place in Freiberg in Septem­ ber 1998.

Preface Uranium is a radioactive element and a heavy metal which is naturally occurring in ground and surface water. Although uranium is enriched in granites and gneiss ground water from these host rocks often shows low to intermediate uranium con­ centrations, while some ground waters from sandstone and carbonate aquifers show elevated uranium concentrations up to several hundred mg/1 without man made impact. On the other side, surface water contains increased anthropogenic uranium concentrations due to the intensive use of phosphate fertilizers and in mining areas due to mining and milling activities. Saxony and Thuringia both be­ ing states of the reunified Germany are probably an area where uranium mining activities have impacted the environment more severely than in any other part of the world. Thus, the federal government of Germany allocated huge amounts of money for the rehabilitation work, a unique proceeding without precedent in min­ ing history. In October 1995 the first international conference on Uranium Mining and Hydrogeology (UMM I) was held in Freiberg being organized by the Department of Geology at the technical University Freiberg by the support of the Saxon State Ministry of Geology and Environment. Due to the large scientific interest in the topic ofuranium a second conference (UMH II) took place in Freiberg in Septem­ ber 1998.

Die Autoren konzentrieren sich in ihrem Werk auf die Lösung praxisorientierter hydrogeochemischer Fragestellungen und schließen damit eine Lücke im Bereich anwendungsorientierter Lehrbücher. Ein erster Teil fasst dabei die Theorie soweit zusammen, daß es auch Neulingen im Bereich der Modellierung und Nichtchemikern leicht gemacht wird, das anspruchsvolle Thema zu erfassen. Akademikern mit hydrogeologischer oder chemischer Grundausbildung sowie Studenten höherer Semester in den relevanten Fachgebieten erlaubt das Buch, anhand der beschriebenen Beispiele und Lösungen, eine eigenständige Erarbeitung der Sachverhalte. Die beiliegende CD-ROM ermöglicht zudem eine rasche Überprüfung der Ergebnisse, bzw. das Nachvollziehen aller Aufgaben und Lösungen anhand der beigefügten PhreeC-Eingabedateien. Da das Programm PhreeC kostenfrei verfügbar ist und mit Windows-Oberfläche auf der CD-ROM vorhanden ist, kann sofort mit der Modellierung begonnen werden.