Passivation processes of Fe(0)-barriers are well known from lab-studies (Phillips et al., (2000),... more Passivation processes of Fe(0)-barriers are well known from lab-studies (Phillips et al., (2000), Schlicker et al., (2000)) and from field-sites. Normally the passivation processes are correlated with the groundwater composition but quantitative prediction and monitoring of the inhibition velocity under field conditions is a serious problem. Currently, only concentration profiles of contaminants, isotope studies or the measurement of reactivity loss
Der Abbau von Nahrstoffen in den Sedimenten der Astuarbereiche ist ein wichtiger Prozes zur Verri... more Der Abbau von Nahrstoffen in den Sedimenten der Astuarbereiche ist ein wichtiger Prozes zur Verringerung der Eutrophierung der Ozeane. Das Ausmas dieser Reaktionen ist abhangig von den saisonalen Veranderungen der Temperatur, der Verfugbarkeit organischen Materials und von der Intensitat der mikrobiologischen Prozesse (Emerson et al. 1984; Jorgensen u. Sorensen 1985; Viel et al. 1991; Watson et al. 1985). Zur Bilanzierung der Stoffumsatze ist es aufgrund der zeitlichen Anderungen der Stoffflusse notig, diese in hinreichend kleinen Zeitintervallen zu bestimmen. Durch die Anwendung einer mathematischen Beziehung zwischen dem Nitratflus und der Oberflachentemperatur konnte die Aufstellung einer Jahresbilanz des Nitratabbaus fur das untersuchte Gebiet vereinfacht werden.
Removal of contaminant sources or associated residual free phase pools often suffers from a combi... more Removal of contaminant sources or associated residual free phase pools often suffers from a combination of inefficiency, increased risk of contaminant spreading due to uncontrolled mobilization, and/or high treatment costs. The paper gives a brief overview of results from laboratory and field studies where chemical and biochemical in-situ source control actions are evaluated with respect to their efficiency on changes of source emission. The studies focused on the contaminant group of chlorinated ethenes. Chemical approaches aim to mobilize contaminant phases. By now these studies have been mainly executed in the laboratory and only few pilotscale field studies exist. The results indicate large emission rates at the beginning of the phase displacement but give less information on long-term emission rates. Biostimulation and bioaugmentation approaches revealed increased emission on short time scales and accumulation of cis- Dichloroethylene and Vinylchloride due to incomplete degradation of higher chlorinated solvents in the source zone. On long-term scales emission rates decreased and groundwater plumes were shrinking.
ABSTRACT Potential pathways in the subsurface may allow upwardly migrating gaseous CO 2 from deep... more ABSTRACT Potential pathways in the subsurface may allow upwardly migrating gaseous CO 2 from deep geological storage formations to be released into near surface aquifers. Consequently, the availability of adequate methods for monitoring potential CO 2 releases in both deep geological formations and the shallow subsurface is a prerequisite for the deployment of Carbon Capture and Storage technology. Geoelectrical surveys are carried out for monitoring a small-scale and temporally limited CO 2 injection experi-ment in a pristine shallow aquifer system. Additionally, the feasibility of multiphase modeling was tested in order to describe both complex non-linear multiphase flow processes and the electrical behavior of partially saturated heterogeneous porous media. The suitability of geoelec-trical methods for monitoring injected CO 2 and geochem-ically altered groundwater was proven. At the test site, geoelectrical measurements reveal significant variations in electrical conductivity in the order of 15–30 %. However, site-specific conditions (e.g., geological settings, ground-water composition) significantly influence variations in subsurface electrical conductivity and consequently, the feasibility of geoelectrical monitoring. The monitoring results provided initial information concerning gaseous CO 2 migration and accumulation processes. Geoelectrical monitoring, in combination with multiphase modeling, was identified as a useful tool for understanding gas phase migration and mass transfer processes that occur due to CO 2 intrusions in shallow aquifer systems.
Artificial carbon dioxide leakage into a shallow aquifer was monitored using stable carbon isotop... more Artificial carbon dioxide leakage into a shallow aquifer was monitored using stable carbon isotope measurements at a field site near the town of Wittstock, Brandenburg, Germany. Approximately 400 000 L of CO(2) were injected into a shallow aquifer at 18 m depth over 10 days. The (13)C/ (12)C ratios of the CO(2) were measured in both groundwater and soil gas samples to monitor the distribution of the injected CO(2) plume and to evaluate the feasibility and reliability of this approach to detect potential CO(2) leakage, for example from carbon capture and storage (CCS) sites. The isotopic composition of the injected CO(2) (δ(13)C -30.5 ‰) was differentiable from the background CO(2) (δ(13)C -21.9 ‰) and the artificial CO(2) plume was monitored over a period spanning more than 204 days. The results demonstrate that this stable isotope monitoring approach can be used to identify CO(2) sources and detect potential CO(2) migration from CCS sites into overlying shallow aquifers or even into the upper subsurface. A significant difference between the isotope ratios of the natural background and the injected CO(2) is required for this monitoring approach to be effective.
... Development of a reactive tracer for iron oxide/hydroxide quantification in sediments MALTE M... more ... Development of a reactive tracer for iron oxide/hydroxide quantification in sediments MALTE MAYER, STEFAN IRMLER & ANDREAS DAHMKE Instilutfur Wasserbau ... Quartz sand with a grain size of 125-250/xm was coated with both iron oxides following Scheidegger et al.(1993 ...
The use of heat storages in the subsurface, especially in urbanized areas, may conflict with exis... more The use of heat storages in the subsurface, especially in urbanized areas, may conflict with existing subsurface contaminations of non-aqueous phase liquids (NAPL). In this work, available data and models regarding temperature influences on parameters for kinetic NAPL dissolution of trichloroethene (TCE) are summarized, discussed and implemented into a numerical simulator. As systematic data on temperature-dependent TCE solubility, diffusion coefficients and dissolution rates are sparse, a set of high-resolution quasi-2D laboratory NAPL dissolution experiments using TCE was conducted at 10, 20, 40 and 70 °C. Because the experimental data show incomplete dissolution of the residual TCE–NAPL, two different classes of TCE–NAPL blobs representing fast and slow dissolution kinetics were introduced in the model. A good agreement of model simulations and experimental measurements of TCE mass flow rates could thus be obtained for each temperature investigated. The numerical model thus can be applied to simulate kinetic dissolution of residual NAPL source zones in groundwater under variable temperature conditions.
The wide spread utilization of the subsurface for energy (heat) and mass (gas) storage in future ... more The wide spread utilization of the subsurface for energy (heat) and mass (gas) storage in future requires an underground land use planning in order to be conducted efficiently and safely. The definition of underground compartments discriminating between spaces of utilization, induced effect, and monitoring is introduced. Numerical scenario simulations help to predict impacts of such underground uses and furthermore to determine sensitive parameters either regulating the induced processes or being influenced by these. For this task, parameters of geological features, of processes occurring underground, and of the intended storage demand are needed. This study presents an overview of the ANGUS joint research project focusing on this synoptic approach, further visualizing parameter availabilities as well as their uncertainties. Thus the needs for focusing further parameter acquisition aiming at an improvement of the mentioned scenario simulations and their expressiveness are deducted.
When decarbonizing a state-wide energy system by introducing a growing share of renewable energie... more When decarbonizing a state-wide energy system by introducing a growing share of renewable energies, underground energy storage can help to deal with fluctuating electric grid feed-in from renewables like wind power. Since besides energy storage other subsurface usages can claim or effect possible scarce suited underground spaces and interact with other usages at the surface, subsurface spatial planning is a growing field of interest for state authorities and in science now. Combining two-dimensional surface geodata on concerned fields like regional planning and energy infrastructure with three-dimensional geological data into one coherent data model could therefore support spatial planners in identifying and locating underground entities suited for energy storage. In this paper, a volumetric grid-based concept to integrate two- and three-dimensional geodata into one coherent data framework is implemented, including available data sets on geology, energy infrastructure and existing spatial plans. Missing spatial data on regional electric energy production and heat energy demand are derived from available primary data. Upon this data basis, a self-developed open source-based 3D webGIS prototype is utilized to identify and visualize potential underground spaces for a compressed air energy storage use case scenario at the example of the federal state of Schleswig–Holstein in North Germany. A first basic and a subsequently extended query via the 3D webGIS on the developed data model provide spatial information on search domains for potential energy storage sites in salt rock structures that could be integrated into emerging subsurface spatial planning.
Passivation processes of Fe(0)-barriers are well known from lab-studies (Phillips et al., (2000),... more Passivation processes of Fe(0)-barriers are well known from lab-studies (Phillips et al., (2000), Schlicker et al., (2000)) and from field-sites. Normally the passivation processes are correlated with the groundwater composition but quantitative prediction and monitoring of the inhibition velocity under field conditions is a serious problem. Currently, only concentration profiles of contaminants, isotope studies or the measurement of reactivity loss
Der Abbau von Nahrstoffen in den Sedimenten der Astuarbereiche ist ein wichtiger Prozes zur Verri... more Der Abbau von Nahrstoffen in den Sedimenten der Astuarbereiche ist ein wichtiger Prozes zur Verringerung der Eutrophierung der Ozeane. Das Ausmas dieser Reaktionen ist abhangig von den saisonalen Veranderungen der Temperatur, der Verfugbarkeit organischen Materials und von der Intensitat der mikrobiologischen Prozesse (Emerson et al. 1984; Jorgensen u. Sorensen 1985; Viel et al. 1991; Watson et al. 1985). Zur Bilanzierung der Stoffumsatze ist es aufgrund der zeitlichen Anderungen der Stoffflusse notig, diese in hinreichend kleinen Zeitintervallen zu bestimmen. Durch die Anwendung einer mathematischen Beziehung zwischen dem Nitratflus und der Oberflachentemperatur konnte die Aufstellung einer Jahresbilanz des Nitratabbaus fur das untersuchte Gebiet vereinfacht werden.
Removal of contaminant sources or associated residual free phase pools often suffers from a combi... more Removal of contaminant sources or associated residual free phase pools often suffers from a combination of inefficiency, increased risk of contaminant spreading due to uncontrolled mobilization, and/or high treatment costs. The paper gives a brief overview of results from laboratory and field studies where chemical and biochemical in-situ source control actions are evaluated with respect to their efficiency on changes of source emission. The studies focused on the contaminant group of chlorinated ethenes. Chemical approaches aim to mobilize contaminant phases. By now these studies have been mainly executed in the laboratory and only few pilotscale field studies exist. The results indicate large emission rates at the beginning of the phase displacement but give less information on long-term emission rates. Biostimulation and bioaugmentation approaches revealed increased emission on short time scales and accumulation of cis- Dichloroethylene and Vinylchloride due to incomplete degradation of higher chlorinated solvents in the source zone. On long-term scales emission rates decreased and groundwater plumes were shrinking.
ABSTRACT Potential pathways in the subsurface may allow upwardly migrating gaseous CO 2 from deep... more ABSTRACT Potential pathways in the subsurface may allow upwardly migrating gaseous CO 2 from deep geological storage formations to be released into near surface aquifers. Consequently, the availability of adequate methods for monitoring potential CO 2 releases in both deep geological formations and the shallow subsurface is a prerequisite for the deployment of Carbon Capture and Storage technology. Geoelectrical surveys are carried out for monitoring a small-scale and temporally limited CO 2 injection experi-ment in a pristine shallow aquifer system. Additionally, the feasibility of multiphase modeling was tested in order to describe both complex non-linear multiphase flow processes and the electrical behavior of partially saturated heterogeneous porous media. The suitability of geoelec-trical methods for monitoring injected CO 2 and geochem-ically altered groundwater was proven. At the test site, geoelectrical measurements reveal significant variations in electrical conductivity in the order of 15–30 %. However, site-specific conditions (e.g., geological settings, ground-water composition) significantly influence variations in subsurface electrical conductivity and consequently, the feasibility of geoelectrical monitoring. The monitoring results provided initial information concerning gaseous CO 2 migration and accumulation processes. Geoelectrical monitoring, in combination with multiphase modeling, was identified as a useful tool for understanding gas phase migration and mass transfer processes that occur due to CO 2 intrusions in shallow aquifer systems.
Artificial carbon dioxide leakage into a shallow aquifer was monitored using stable carbon isotop... more Artificial carbon dioxide leakage into a shallow aquifer was monitored using stable carbon isotope measurements at a field site near the town of Wittstock, Brandenburg, Germany. Approximately 400 000 L of CO(2) were injected into a shallow aquifer at 18 m depth over 10 days. The (13)C/ (12)C ratios of the CO(2) were measured in both groundwater and soil gas samples to monitor the distribution of the injected CO(2) plume and to evaluate the feasibility and reliability of this approach to detect potential CO(2) leakage, for example from carbon capture and storage (CCS) sites. The isotopic composition of the injected CO(2) (δ(13)C -30.5 ‰) was differentiable from the background CO(2) (δ(13)C -21.9 ‰) and the artificial CO(2) plume was monitored over a period spanning more than 204 days. The results demonstrate that this stable isotope monitoring approach can be used to identify CO(2) sources and detect potential CO(2) migration from CCS sites into overlying shallow aquifers or even into the upper subsurface. A significant difference between the isotope ratios of the natural background and the injected CO(2) is required for this monitoring approach to be effective.
... Development of a reactive tracer for iron oxide/hydroxide quantification in sediments MALTE M... more ... Development of a reactive tracer for iron oxide/hydroxide quantification in sediments MALTE MAYER, STEFAN IRMLER & ANDREAS DAHMKE Instilutfur Wasserbau ... Quartz sand with a grain size of 125-250/xm was coated with both iron oxides following Scheidegger et al.(1993 ...
The use of heat storages in the subsurface, especially in urbanized areas, may conflict with exis... more The use of heat storages in the subsurface, especially in urbanized areas, may conflict with existing subsurface contaminations of non-aqueous phase liquids (NAPL). In this work, available data and models regarding temperature influences on parameters for kinetic NAPL dissolution of trichloroethene (TCE) are summarized, discussed and implemented into a numerical simulator. As systematic data on temperature-dependent TCE solubility, diffusion coefficients and dissolution rates are sparse, a set of high-resolution quasi-2D laboratory NAPL dissolution experiments using TCE was conducted at 10, 20, 40 and 70 °C. Because the experimental data show incomplete dissolution of the residual TCE–NAPL, two different classes of TCE–NAPL blobs representing fast and slow dissolution kinetics were introduced in the model. A good agreement of model simulations and experimental measurements of TCE mass flow rates could thus be obtained for each temperature investigated. The numerical model thus can be applied to simulate kinetic dissolution of residual NAPL source zones in groundwater under variable temperature conditions.
The wide spread utilization of the subsurface for energy (heat) and mass (gas) storage in future ... more The wide spread utilization of the subsurface for energy (heat) and mass (gas) storage in future requires an underground land use planning in order to be conducted efficiently and safely. The definition of underground compartments discriminating between spaces of utilization, induced effect, and monitoring is introduced. Numerical scenario simulations help to predict impacts of such underground uses and furthermore to determine sensitive parameters either regulating the induced processes or being influenced by these. For this task, parameters of geological features, of processes occurring underground, and of the intended storage demand are needed. This study presents an overview of the ANGUS joint research project focusing on this synoptic approach, further visualizing parameter availabilities as well as their uncertainties. Thus the needs for focusing further parameter acquisition aiming at an improvement of the mentioned scenario simulations and their expressiveness are deducted.
When decarbonizing a state-wide energy system by introducing a growing share of renewable energie... more When decarbonizing a state-wide energy system by introducing a growing share of renewable energies, underground energy storage can help to deal with fluctuating electric grid feed-in from renewables like wind power. Since besides energy storage other subsurface usages can claim or effect possible scarce suited underground spaces and interact with other usages at the surface, subsurface spatial planning is a growing field of interest for state authorities and in science now. Combining two-dimensional surface geodata on concerned fields like regional planning and energy infrastructure with three-dimensional geological data into one coherent data model could therefore support spatial planners in identifying and locating underground entities suited for energy storage. In this paper, a volumetric grid-based concept to integrate two- and three-dimensional geodata into one coherent data framework is implemented, including available data sets on geology, energy infrastructure and existing spatial plans. Missing spatial data on regional electric energy production and heat energy demand are derived from available primary data. Upon this data basis, a self-developed open source-based 3D webGIS prototype is utilized to identify and visualize potential underground spaces for a compressed air energy storage use case scenario at the example of the federal state of Schleswig–Holstein in North Germany. A first basic and a subsequently extended query via the 3D webGIS on the developed data model provide spatial information on search domains for potential energy storage sites in salt rock structures that could be integrated into emerging subsurface spatial planning.
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