LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 85

Search options

  1. Article: New insights into particle transport in karst conduits using comparative tracer tests with natural sediments and solutes during low‐flow and high‐flow conditions

    Richter, Dominik / Goeppert, Nadine / Goldscheider, Nico

    Hydrological processes. 2022 Jan., v. 36, no. 1

    2022  

    Abstract: Colloidal particles are an important vector for the transport of contaminants in karst aquifers, characterized by a high degree of hydrologic variability. Understanding this heterogeneity and hydrogeological functioning is of particular importance for ... ...

    Abstract Colloidal particles are an important vector for the transport of contaminants in karst aquifers, characterized by a high degree of hydrologic variability. Understanding this heterogeneity and hydrogeological functioning is of particular importance for water management strategies. Until now, transport parameters for particles were mostly determined by injection of solutes or surrogates for natural sediments. But suspended particles are easier to analyse, less expensive and better represent natural conditions. Therefore, tracer tests with sediments represent natural transport and a conservative solute dye were conducted simultaneously in an active and partly accessible cave system in Vietnam during constant high‐flow and low‐flow conditions. Breakthrough curves (BTCs) for 10 different particle sizes classes ranging from 1 to 15 μm and the solute were recorded in situ at the two main resurgences of the cave stream at high temporal resolution. This study gives new insights into the transport processes of suspended particles and the highly dynamic exchange between mobile and immobile regions. Major findings include: (1) at low‐flow conditions, inflow from the surrounding aquifer matrix and the velocity distribution inside the karst conduits themselves lead to hydrodynamic focusing, mainly affecting particles; (2) this highly advective, preferential transport of particles in the centre of the karst conduits results in narrow BTC. The more dispersive transport of solutes results in a longer tailing; (3) at high‐flow conditions a more homogeneous distribution of the particles indicates a reversal of the conduit‐matrix interaction; (4) by comparing the results at different hydraulic conditions, the activation of additional flow paths with increasing discharge could be identified. This study also presents the first tracer test in the field resulting in pronounced double peaks for the particulate tracer but only a single, right‐skewed BTC for the simultaneously injected solute, including a conceptual model for particle transport.
    Keywords aquifers ; dyes ; hydrodynamics ; karsts ; models ; solutes ; streams ; tracer techniques ; water management ; Vietnam
    Language English
    Dates of publication 2022-01
    Publishing place John Wiley & Sons, Inc.
    Document type Article
    Note JOURNAL ARTICLE
    ZDB-ID 1479953-4
    ISSN 1099-1085 ; 0885-6087
    ISSN (online) 1099-1085
    ISSN 0885-6087
    DOI 10.1002/hyp.14472
    Database NAL-Catalogue (AGRICOLA)

    Full text online

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  2. Article ; Online: High-resolution multi-parameter monitoring of microbial water quality and particles at two alpine karst springs as a basis for an early-warning system

    Frank, Simon / Fahrmeier, Nikolai / Goeppert, Nadine / Goldscheider, Nico

    Hydrogeol J. 2022 Dec., v. 30, no. 8 p.2285-2298

    2022  

    Abstract: Karst aquifers are important resources for drinking water supply and are very vulnerable to contamination. Microbial concentrations at karst springs, in particular, often vary quickly over a short period of time. In this study, the response of microbial ... ...

    Title translation Hochauflösendes Multiparameter-Monitoring von mikrobieller Wasserqualität und Partikeln an zwei alpinen Karstquellen als Grundlage für ein Frühwarnsystem Suivi multi-paramètres haute-résolution de la qualité microbiologique de l’eau et de la matière en suspension sur deux sources karstiques alpines comme base à un système d’alerte précoce Monitoreo multiparamétrico de alta resolución de la calidad microbiana del agua y las partículas en dos manantiales kársticos alpinos como base para un sistema de alerta temprana 高分辨率多参数监测两个高山喀斯特泉的微生物水质和颗粒并作为预警系统的基础 Monitoramento multiparâmetro de alta resolução da qualidade microbiana da água e de partículas em duas nascentes cársticas alpinas como base para um sistema de alerta precoce
    Abstract Karst aquifers are important resources for drinking water supply and are very vulnerable to contamination. Microbial concentrations at karst springs, in particular, often vary quickly over a short period of time. In this study, the response of microbial water quality and particle-size distribution of two alpine karst springs to rainfall events was investigated to test and validate parameters that can be used as early-warning systems for fecal contamination. At both investigated karst springs, total organic carbon, particle-size distribution (especially small particle fractions), and particle load show a good correlation to the fecal indicator bacteria E. coli and can therefore be used as a real-time indicator of fecal contamination at the investigated springs. In addition to conventional bacterial determination methods, the β-D-glucuronidase activity, which can be measured in near real-time, was used as a novel indicator parameter for fecal contamination. At the event scale, the β-D-glucuronidase (GLUC) activity shows a good correlation to E. coli and can be used as an additional real-time indicator of fecal contamination. For the studied springs, when they show two peaks in turbidity and small particles, these two parameters are suitable for an early warning system because the bacterial contamination occurs during the secondary peak of these parameters. These results highlight the vulnerability of karst aquifers and demonstrate the applicability of advanced measurement techniques in detecting fecal contamination in real-time, which is especially important given the time-consuming nature of conventional bacterial detection methods.
    Keywords Escherichia coli ; bacterial contamination ; early warning systems ; karsts ; microbial detection ; particle size distribution ; rain ; total organic carbon ; turbidity ; water quality ; water supply
    Language English
    Dates of publication 2022-12
    Size p. 2285-2298.
    Publishing place Springer Berlin Heidelberg
    Document type Article ; Online
    ZDB-ID 1227482-3
    ISSN 0941-2816 ; 1431-2174
    ISSN 0941-2816 ; 1431-2174
    DOI 10.1007/s10040-022-02556-8
    Database NAL-Catalogue (AGRICOLA)

    Full text online

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    ((Einzelsign.)): Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  3. Article ; Online: Multi-scale characterization of a complex karst and alluvial aquifer system in southern Germany using a combination of different tracer methods

    Fahrmeier, Nikolai / Frank, Simon / Goeppert, Nadine / Goldscheider, Nico

    Hydrogeol J. 2022 Sept., v. 30, no. 6 p.1863-1875

    2022  

    Abstract: Water suppliers face major challenges such as climate change and population growth. To prepare for the future, detailed knowledge of water resources is needed. In southern Germany, the state water supplier Zweckverband Landeswasserversorgung provides 3 ... ...

    Title translation Maßstabsübergreifende Charakterisierung eines komplexen Karst- und Porenaquifer-Systems in Süddeutschland mittels einer Kombination verschiedener Tracermethoden Caractérisation multi-échelle d’un système aquifère complexe karstique et alluvial dans le Sud de l’Allemagne par la mise en œuvre de différentes méthodes de traçage Caracterización multiescala del sistema acuífero kárstico y aluvial en el sur de Alemania utilizando una combinación de diferentes métodos de trazadores 联合利用不同示踪方法对德国南部复杂岩溶和冲积含水层系统进行多尺度表征 Caracterização multiescala de um sistema aquífero cárstico e aluvial complexo no sul da Alemanha usando uma combinação de diferentes métodos de traçadores
    Abstract Water suppliers face major challenges such as climate change and population growth. To prepare for the future, detailed knowledge of water resources is needed. In southern Germany, the state water supplier Zweckverband Landeswasserversorgung provides 3 million people with drinking water obtained from a complex karst and alluvial aquifer system and the river Danube. In this study, a combination of different tracing techniques was used with the goal of a multi-scale characterization of the aquifer system and to gain additional knowledge about groundwater flow toward the extraction wells in the Danube Valley. For the small-scale characterization, selected groundwater monitoring wells were examined using single-borehole dilution tests. With these tests, a wide range of flow behavior could be documented, including fast outflow within just a few hours in wells with good connection to the aquifer, but also durations of many weeks in low-permeability formations. Vertical flow, caused by multiple flow horizons or uprising groundwater, was detected in 40% of the tested wells. A regional multi-tracer test with three injections was used to investigate the aquifer on a large scale. For the highly karstified connection between a swallow hole and a spring group, high flow velocities of around 80 m/h could be documented. Exceptionally delayed arrivals, 250 and 307 days after the injection, respectively showing maximum velocities of 0.44 and 0.39 m/h, were observed in an area where low-permeability sediments overlay the karst conduits. With the chosen methods, a distinct heterogeneity caused by the geological setting could be documented on both scales.
    Keywords alluvial aquifer ; climate change ; groundwater ; groundwater flow ; karsts ; people ; population growth ; spring ; Danube River ; Germany
    Language English
    Dates of publication 2022-09
    Size p. 1863-1875.
    Publishing place Springer Berlin Heidelberg
    Document type Article ; Online
    ZDB-ID 1227482-3
    ISSN 0941-2816 ; 1431-2174
    ISSN 0941-2816 ; 1431-2174
    DOI 10.1007/s10040-022-02514-4
    Database NAL-Catalogue (AGRICOLA)

    Full text online

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    ((Einzelsign.)): Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  4. Article: A novel probe for point injections in groundwater monitoring wells

    Fahrmeier, Nikolai / Goeppert, Nadine / Goldscheider, Nico

    Hydrogeology journal. 2022 May, v. 30, no. 3

    2022  

    Abstract: Groundwater monitoring wells or boreholes often show complex flow behaviors that are essential to understand for the characterization of aquifer systems. In karst or fractured aquifers, where complex conduit and/or fracture networks with differing ... ...

    Title translation Eine neuartige Sonde für Punktinjektionen in Grundwassermessstellen Une nouvelle sonde pour des injections ponctuelles dans des piézomètres Una novedosa sonda para inyecciones puntuales en pozos de monitoreo de aguas subterráneas 一种新型的地下水监测井点注入式探头 Uma nova sonda para injeções pontuais em poços de monitoramento de águas subterrâneas
    Abstract Groundwater monitoring wells or boreholes often show complex flow behaviors that are essential to understand for the characterization of aquifer systems. In karst or fractured aquifers, where complex conduit and/or fracture networks with differing hydraulic heads can be intersected by a well or borehole, vertical flow is highly probable. Single-borehole dilution tests (SBDT) with uniform injections are, in general, a good method to gain knowledge about a specific well or borehole, but tend to deliver ambiguous results regarding vertical flow, while SBDTs with point injections are an effective method to identify vertical flow. This technical note introduces a newly developed probe for point injections in groundwater without disturbing the natural flow field. In order to evaluate this probe, several tests were conducted in the laboratory and in groundwater monitoring wells that show vertical flow. During repeated tests in the laboratory, the new point injection probe showed a good reproducibility regarding the shape and extent of the tracer cloud after an injection. The opening mechanism was found to be well-functioning and reliable. Field tests lead to significant results for all tested wells and showed that the probe can easily be operated by a single person. Due to the flexibility regarding tracer, aquifer and injection depth, combined with the easy handling, it is a useful device, suitable for the investigation of boreholes and groundwater monitoring wells, and a good alternative to existing methods.
    Keywords aquifers ; groundwater ; karsts
    Language English
    Dates of publication 2022-05
    Size p. 1021-1029.
    Publishing place Springer Berlin Heidelberg
    Document type Article
    ZDB-ID 1227482-3
    ISSN 0941-2816 ; 1431-2174
    ISSN 0941-2816 ; 1431-2174
    DOI 10.1007/s10040-022-02477-6
    Database NAL-Catalogue (AGRICOLA)

    Full text online

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    ((Einzelsign.)): Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  5. Article ; Online: Experimental field evidence for transport of microplastic tracers over large distances in an alluvial aquifer.

    Goeppert, Nadine / Goldscheider, Nico

    Journal of hazardous materials

    2020  Volume 408, Page(s) 124844

    Abstract: The transport of microplastic tracer particles in comparison to the solute conservative tracer uranine was experimentally investigated in a shallow alluvial aquifer over distances from 3.1 to 200 m by means of a natural-gradient tracer test. The ... ...

    Abstract The transport of microplastic tracer particles in comparison to the solute conservative tracer uranine was experimentally investigated in a shallow alluvial aquifer over distances from 3.1 to 200 m by means of a natural-gradient tracer test. The microplastic particles (MPs) with diameters of 1, 2 and 5 µm were artificially injected into an observation well to simulate microplastic transport; water samples were taken at eleven observation wells further downgradient over a time span of 171 days. In total, 44 individual breakthrough curves of microplastics and uranine were obtained at all sampling sites, allowing a detailed analysis of the size-dependency of microplastics transport in porous media at field scale. Results clearly show that (i) microplastics of 1-5 µm can be transported in significant amounts in sand-and-gravel aquifers; (ii) peak concentrations of microplastics can exceed those of conservative solutes, in particular for longer flow distances; (iii) microplastic peak velocities are in a similar range or exceed those of conservative solutes; (iv) retardation and filtration processes did not efficiently attenuate microplastics in groundwater at the study site. To our best of knowledge, this is the first experimental field evidence for microplastics transport over large distances in an alluvial aquifer.
    Language English
    Publishing date 2020-12-16
    Publishing country Netherlands
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1491302-1
    ISSN 1873-3336 ; 0304-3894
    ISSN (online) 1873-3336
    ISSN 0304-3894
    DOI 10.1016/j.jhazmat.2020.124844
    Database MEDical Literature Analysis and Retrieval System OnLINE

    Full text online

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  6. Article: Field Tracer Tests to Evaluate Transport Properties of Tryptophan and Humic Acid in Karst

    Frank, Simon / Goeppert, Nadine / Goldscheider, Nico

    Ground water. 2021 Jan., v. 59, no. 1

    2021  

    Abstract: The monitoring of water quality, especially of karst springs, requires methods for rapidly estimating and quantifying parameters that indicate contamination. In the last few years, fluorescence‐based measurements of tryptophan and humic acid have become ... ...

    Abstract The monitoring of water quality, especially of karst springs, requires methods for rapidly estimating and quantifying parameters that indicate contamination. In the last few years, fluorescence‐based measurements of tryptophan and humic acid have become a promising tool to assess water quality in near real‐time. In this study, we conducted comparative tracer tests in a karst experimental site to investigate the transport properties and behavior of tryptophan and humic acid in a natural karst aquifer. These two tracers were compared with the conservative tracer uranine. Fluorescence measurements were conducted with an online field fluorometer and in the laboratory. The obtained breakthrough curves (BTCs) and the modeling results demonstrate that (1) the online field fluorometer is suitable for real‐time fluorescence measurements of all three tracers; (2) the transport parameters obtained for uranine, tryptophan, and humic acid are comparable in the fast flow areas of the karst system; (3) the transport velocities of humic acid are slower and the resulting residence times are accordingly higher, compared to uranine and tryptophan, in the slower and longer flow paths; (4) the obtained BTCs reveal additional information about the investigated karst system. As a conclusion, the experiments show that the transport properties of tryptophan are similar to those of uranine while humic acid is partly transported slower and with retardation. These findings allow a better and quantitative interpretation of the results when these substances are used as natural fecal and contamination indicators.
    Keywords aquifers ; fluorescence ; groundwater ; humic acids ; karsts ; tryptophan ; water quality
    Language English
    Dates of publication 2021-01
    Size p. 59-70.
    Publishing place Blackwell Publishing Ltd
    Document type Article
    Note NAL-AP-2-clean ; JOURNAL ARTICLE
    ZDB-ID 246212-6
    ISSN 1745-6584 ; 0017-467X
    ISSN (online) 1745-6584
    ISSN 0017-467X
    DOI 10.1111/gwat.13015
    Database NAL-Catalogue (AGRICOLA)

    Full text online

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    Z 4456: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  7. Article: Improved understanding of dynamic water and mass budgets of high‐alpine karst systems obtained from studying a well‐defined catchment area

    Frank, Simon / Goeppert, Nadine / Goldscheider, Nico

    Hydrological processes. 2021 Apr., v. 35, no. 4

    2021  

    Abstract: Large areas of Europe, especially in the Alps, are covered by carbonate rocks and in many alpine regions, karst springs are important sources for drinking water supply. Because of their high variability and heterogeneity, the understanding of the ... ...

    Abstract Large areas of Europe, especially in the Alps, are covered by carbonate rocks and in many alpine regions, karst springs are important sources for drinking water supply. Because of their high variability and heterogeneity, the understanding of the hydrogeological functioning of karst aquifers is of particular importance for their protection and utilisation. Climate change and heavy rainfall events are major challenges in managing alpine karst aquifers which possess an enormous potential for future drinking water supply. In this study, we present research from a high‐alpine karst system in the UNESCO Biosphere Reserve Großes Walsertal in Austria, which has a clearly defined catchment and is drained by only one spring system. Results show that (a) the investigated system is a highly dynamic karst aquifer with distinct reactions to rainfall events in discharge and electrical conductivity; (b) the estimated transient atmospheric CO₂ sink is about 270 t/a; (c) the calculated carbonate rock denudation rate is between 23 and 47 mm/1000a and (d) the rainfall‐discharge behaviour and the internal flow dynamics can be successfully simulated using the modelling package KarstMod. The modelling results indicate the relevance of matrix storage in determining the discharge behaviour of the spring, particularly during low‐flow periods. This research and the consequent results can contribute and initiate a better understanding and management of alpine karst aquifers considering climate change with more heavy rainfall events and also longer dry periods.
    Keywords United Nations Educational, Scientific and Cultural Organization ; aquifers ; carbon dioxide ; carbonate rocks ; carbonates ; climate change ; conservation areas ; electrical conductivity ; hydrodynamics ; karsts ; rain ; spring ; water supply ; watersheds ; Alps region ; Austria
    Language English
    Dates of publication 2021-04
    Publishing place John Wiley & Sons, Inc.
    Document type Article
    Note NAL-AP-2-clean ; JOURNAL ARTICLE
    ZDB-ID 1479953-4
    ISSN 1099-1085 ; 0885-6087
    ISSN (online) 1099-1085
    ISSN 0885-6087
    DOI 10.1002/hyp.14033
    Database NAL-Catalogue (AGRICOLA)

    Full text online

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  8. Article: Spatial and temporal dynamics of suspended particles and E. coli in a complex surface-water and karst groundwater system as a basis for an adapted water protection scheme, northern Vietnam

    Richter, Dominik / Goeppert, Nadine / Zindler, Björn / Goldscheider, Nico

    Hydrogeology journal. 2021 Aug., v. 29, no. 5

    2021  

    Abstract: Karst aquifers in subtropical regions are characterized by high variability of water availability and quality due to changes associated with rainy and dry seasons. An additional challenge for water management is the combination of surface-water and karst ...

    Title translation Dynamique spatiale et temporelle des particules en suspension et d’E. Coli dans un système complexe d’eaux de surface et d’eaux souterraines karstiques comme base d’un programme adapté à la protection de l’eau, nord du Vietnam Dinámica espacial y temporal de partículas en suspensión y E. coli en un complejo sistema de aguas superficiales y subterráneas kársticas como base para un plan adaptativo de protección del agua, norte de Vietnam 复杂地表水和喀斯特地下水系统中悬浮颗粒和大肠杆菌的时空动态演变--越南北部调整水资源保护方案的基础 Dinâmica espacial e temporal de partículas suspensas e E. coli em um sistema complexo de águas superficial e subterrânea cársticas como base para um esquema adaptado de proteçã o de água, norte do Vietnã
    Abstract Karst aquifers in subtropical regions are characterized by high variability of water availability and quality due to changes associated with rainy and dry seasons. An additional challenge for water management is the combination of surface-water and karst groundwater systems since high spatiotemporal dynamics cause high variability of water quality. In these cases, adapted protection strategies are required. In this study, a protection approach for the catchment of a river-water diversion point in a rural area in northern Vietnam is developed. The variability of water quality was evaluated by rainy and dry season synoptic surveys of suspended particles and microbial contamination at 49 sites and time series at three sets of paired sites under constant hydraulic conditions. The anthropogenic land-use activities in the catchment were mapped to identify potential contamination sources and to highlight the challenging combination of surface-water and karst groundwater management. The analyzed data indicate differences in water quality between the dry and rainy seasons and a higher influence on water quality from land use than from hydrologic conditions. Furthermore, the results suggest a high risk of contamination resulting from residential areas, agriculture, and livestock farming, and reveal the necessity of implementation of appropriate measures such as restricted farming and the hook-up of buildings to municipal sewage disposal. Finally, the data show that water quality can be improved by adjusting water withdrawals by the time of day. The applied methods can be transferred to other surface-water and karst groundwater systems in similar subtropical environments.
    Keywords Escherichia coli ; dry season ; groundwater ; karsts ; land use ; livestock ; microbial contamination ; risk ; river water ; rural areas ; sewage ; surface water ; temporal variation ; time series analysis ; water management ; water quality ; watersheds ; Vietnam
    Language English
    Dates of publication 2021-08
    Size p. 1965-1978.
    Publishing place Springer Berlin Heidelberg
    Document type Article
    ZDB-ID 1227482-3
    ISSN 0941-2816 ; 1431-2174
    ISSN 0941-2816 ; 1431-2174
    DOI 10.1007/s10040-021-02356-6
    Database NAL-Catalogue (AGRICOLA)

    Full text online

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    ((Einzelsign.)): Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  9. Article: Comparative application and optimization of different single-borehole dilution test techniques

    Fahrmeier, Nikolai / Goeppert, Nadine / Goldscheider, Nico

    Hydrogeology journal. 2021 Feb., v. 29, no. 1

    2021  

    Abstract: Single-borehole dilution tests (SBDTs) are a method for characterizing groundwater monitoring wells and boreholes, and are based on the injection of a tracer into the saturated zone and the observation of concentration over depth and time. SBDTs are ... ...

    Title translation Vergleichende Anwendung und Optimierung verschiedener Techniken für Einzel-Bohrloch-Verdünnungsversuche Application par comparaison et optimisation de différentes techniques de test de dilution pour un seul forage Aplicación comparativa y optimización de diferentes técnicas de prueba de dilución de una sola perforación 不同单孔稀释实验技术的比较应用和优化 Aplicação comparativa e otimização de diferentes técnicas de teste de diluição em poço único
    Abstract Single-borehole dilution tests (SBDTs) are a method for characterizing groundwater monitoring wells and boreholes, and are based on the injection of a tracer into the saturated zone and the observation of concentration over depth and time. SBDTs are applicable in all aquifer types, but especially interesting in heterogeneous karst or fractured aquifers. Uniform injections aim at a homogeneous tracer concentration throughout the entire saturated length and provide information about inflow and outflow horizons. Also, in the absence of vertical flow, horizontal filtration velocities can be calculated. The most common method for uniform injections uses a hosepipe to inject the tracer. This report introduces a simplified method that uses a permeable injection bag (PIB) to achieve a close-to-uniform tracer distribution within the saturated zone. To evaluate the new method and to identify advantages and disadvantages, several tests have been carried out, in the laboratory and in multiple groundwater monitoring wells in the field. Reproducibility of the PIB method was assessed through repeated tests, on the basis of the temporal development of salt amount and calculated apparent filtration velocities. Apparent filtration velocities were calculated using linear regression as well as by inverting the one-dimensional (1D) advection-dispersion equation using CXTFIT. The results show that uniform-injection SBDTs with the PIB method produce valuable and reproducible outcomes and contribute to the understanding of groundwater monitoring wells and the respective aquifer. Also, compared to the hosepipe method, the new injection method requires less equipment and less effort, and is especially useful for deep boreholes.
    Keywords aquifers ; equations ; equipment ; filtration ; groundwater ; karsts ; regression analysis
    Language English
    Dates of publication 2021-02
    Size p. 199-211.
    Publishing place Springer Berlin Heidelberg
    Document type Article
    Note NAL-AP-2-clean
    ZDB-ID 1227482-3
    ISSN 0941-2816 ; 1431-2174
    ISSN 0941-2816 ; 1431-2174
    DOI 10.1007/s10040-020-02271-2
    Database NAL-Catalogue (AGRICOLA)

    Full text online

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    ((Einzelsign.)): Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  10. Article ; Online: Improved understanding of particle transport in karst groundwater using natural sediments as tracers.

    Goeppert, Nadine / Goldscheider, Nico

    Water research

    2019  Volume 166, Page(s) 115045

    Abstract: Colloids and particles act as vectors for contaminant transport. In karst aquifers, particle transport is particularly efficient and plays critical roles in soil erosion and in the process of karstification. However, available techniques for particle ... ...

    Abstract Colloids and particles act as vectors for contaminant transport. In karst aquifers, particle transport is particularly efficient and plays critical roles in soil erosion and in the process of karstification. However, available techniques for particle tracing are either expensive or not representative for the transport of natural colloids and particles. We developed a new method for particle tracing, using natural sediments as artificial tracers, and first applied this method at a karst experimental site in the Alps. Suspended particles were injected into a swallow hole together with a conservative solute tracer for comparison. Breakthrough curves for 32 different particle size classes between 0.8 and 450 μm were recorded at a karst spring 230 m away using a mobile particle counter that allows quantitative detection at high temporal resolution. Results show that (i) sediments can be used as efficient particle tracers in karst groundwater; (ii) recoveries are similar for particles and solutes; (iii) mean velocity increases with increasing particle size; (iv) dispersion decreases with increasing particle size; (v) these observations point to exclusion processes. As a conclusion, this new experimental technique allows new insights into the transport and fate of colloids and particles in groundwater at affordable costs.
    MeSH term(s) Colloids ; Groundwater ; Particle Size ; Water Movements
    Chemical Substances Colloids
    Language English
    Publishing date 2019-09-03
    Publishing country England
    Document type Journal Article
    ZDB-ID 202613-2
    ISSN 1879-2448 ; 0043-1354
    ISSN (online) 1879-2448
    ISSN 0043-1354
    DOI 10.1016/j.watres.2019.115045
    Database MEDical Literature Analysis and Retrieval System OnLINE

    Full text online

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    Z 78/260: Show issues
    Z 3381: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

To top