Zusammenfassung Der Oberjura-Aquifer im Süddeutschen Molassebecken, bestehend aus den Karbonaten des Oberjura und der Unterkreide (Purbeck), ist derzeit wichtigste geothermische Explorationshorizont in Deutschland. Dieser bis zu 600 m mächtige Aquifer erstreckt sich von Fränkischen Schwäbischen Alb Norden zum nördlichen Alpenrand Süden. Hydrogeologische Kernthemen bei wissenschaftlichen Beschreibung sind unter anderem die Fließsystematik Lokalisierung potenzieller Einzugsgebiete...

A high spatial resolution data set documenting carbon and sulfur isotope fractionation at a tar oil-contaminated, sulfate-reducing field site was analyzed with reactive transport model. Within comprehensive numerical model, the study links distinctive observed depth profiles degradation of various monoaromatic polycyclic aromatic hydrocarbon compounds (BTEX/PAHs) under conditions. In microbial dynamics were simulated explicitly directly linked to differential uptake lighter heavier isotopes...

In batch experiments, we studied the isotope fractionation in N and O of dissolved nitrate during dentrification. Denitrifying strains Thauera aromatica "Aromatoleum aromaticum strain EbN1" were grown under strictly anaerobic conditions with acetate, benzoate, toluene as carbon sources. (18)O-labeled water nitrite added to microcosm experiments study effect putative backward reactions on stable fractionation. We found no evidence for a reverse reaction. Significant variations enrichment...

Abstract In geothermal reservoir systems, changes in pore pressure due to production (depletion), injection or temperature result a displacement of the effective stresses acting on rock matrix aquifer. To compensate for these intrinsic stress changes, is subjected poroelastic deformation through and volume. This turn may induce network thus hydraulic properties Therefore, conception precise models long-term simulations, sensitivity porosity permeability required parametrization. Stress was...

Concentrations and stable isotope compositions of nitrate from 11 karst springs in the Franconian Alb (Southern Germany) were determined during low flow high conditions to assess sources processes affecting groundwater nitrate. During flow, concentrations around 0.10 mM draining forested catchments, whereas agricultural areas typically higher reaching up 0.93 mM. The isotopic composition (δ15N values −3.1 6.7 ‰, δ18O +2.1 4.0 ‰) concert with concentration data suggests that is formed by...

High-resolution depth-resolved monitoring was applied to groundwater and sediments samples in a tar oil contaminated aquifer. Today, it is not fully clear, whether groundwater-based lines of evidence are always sufficient adequately assess natural attenuation (NA) potentials processes going on situ. Our data unveiled small-scale heterogeneities, steep physical-chemical microbial gradients, as well hot spots contaminants biodegradation the supposedly homogeneous sandy The comparison basic...

ABSTRACT Globally occurring nitrate pollution in groundwater is harming the environment and human health. In situ hydrogen addition to stimulate denitrification has been proposed as a remediation strategy. However, observed nitrite accumulation incomplete are severe drawbacks that possibly stem from specific microbial community composition. We set up microcosm experiment comprising sediment polluted oxic oligotrophic aquifer. After microcosms were sparged with gas, samples taken regularly...

Dissimilatory sulphate reduction (DSR) leads to an overprint of the oxygen isotope composition by water. This is assumed occur via cell-internally formed sulphuroxy intermediates in pathway. Unlike sulphate, can readily exchange isotopes with Subsequent exchange, these intermediates, e.g. sulphite, are re-oxidised reversible enzymatic reactions thereby incorporating used for re-oxidation sulphur intermediates. Consequently, rate and expression DSR-mediated between water depend not only on...

Abstract Fiber optic sensing has gained importance for wellbore monitoring and reservoir characterization in geothermal fields as it allows continuous, spatially highly resolved measurements. Distributed acoustic (DAS) distributed temperature (DTS) technologies, among others, enable of flow regimes heat transport inside the to describe dynamical behavior reservoir. The technically challenging installation a permanent fiber system production well over entire length was conducted first time at...

Ebullition transports large amounts of the potent greenhouse gas methane (CH

Under anoxic redox conditions dissolved nitrate in groundwater can be converted microbially into N2. However, the lack of microbial available organic and inorganic electron donors such as Fe(II) or carbon may lead to insufficient denitrification aquifers concentrations above drinking water limit 50 mg/L are often observed. In view increasing drinking-water scarcity associated with climate change continuously high near-surface aquifers, it is urgently necessary prudent develop...

Chemical and isotope analyses on groundwater sulfate 3H measurements groundwaterwere used to determine the sources sulfur transformation processes in a heterogeneous karst aquifer of Franconian Alb, southern Germany. Sulfate was found be derived from atmospheric deposition. Young characterized by high concentrations delta34S values similar those recent However, delta18O SO4(2-) were depleted several per mil with respect This isotopic shift is indicative mineralization carbon-bonded S vadose...

Groundwater samples collected in a shallow oxic and reduced deep groundwater system revealed the influence of dissolved sulfide on chemical isotopic composition fulvic acid associated sulfur. Stable isotope compositions sulfate sulfur K-edge X-ray absorption near edge structure (XANES) spectroscopy data were used to determine sources processes affecting aquifer. A δ34S value 2.2 ‰ for acids 4.9 accompanied by contribution up 49% most oxidized species (S+6) documented that is mainly derived...

Abstract Heat transport in natural porous media, such as aquifers or streambeds, is generally modeled assuming local thermal equilibrium (LTE) between the fluid and solid phases. Yet, mathematical hydrogeological conditions implications of this simplification have not been fully established for media. To quantify occurrence effects disequilibrium during heat transport, we systematically compared breakthrough curves from a LTE with those calculated using nonequilibrium (LTNE) model,...

A comprehensive hydrogeological understanding of the deep Upper Jurassic carbonate aquifer, which represents an important geothermal reservoir in South German Molasse Basin (SGMB), is crucial for improved and sustainable groundwater resource management. Water chemical data environmental isotope analyses δD, δ18O 87Sr/86Sr were obtained from 24 wells coupled with a few noble gases (3He/4He, 40Ar/36Ar) gas infiltration temperatures. Hierarchical cluster analysis revealed three major water...

Abstract This study presents a 25 ka reconstruction of the Pleistocene paleoclimate in South German Molasse Basin. Deep groundwater was sampled at 19 wells Upper Jurassic aquifer (UJA). Calculating gas temperatures (NGT) using UA model with noble gases Ar, Kr, and Xe led to recharge between 0.4 4.7°C. Combined innovative 14 C DOC dating, calculated NGTs revealed up 8°C cooler soil during compared modern temperature. interpretation agrees well observed depleted stable water isotope signature...