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Evaluation of Collector Well Configurations to Model Hydrodynamics in Riverbank Filtration and Groundwater RemediationDe Leon, Tiffany Lucinda 2010 August 1900 (has links)
Collector well designs are necessary to maximize groundwater uptake and riverbank filtration without negatively impacting an aquifer. Unfortunately, there is a lack of information and research regarding the implementation of collector well design parameters. In the past, collector well installation was too costly, but recent advances in well technology have made collector wells more cost effective. This research will contribute a set of guidelines to optimize riverbank filtration and groundwater remediation. This study models the hydrodynamics surrounding collector well configurations in riverbank filtration and groundwater remediation. Visual Modflow® was utilized to run a variety of numerical models to test four areas: flux along the laterals of a collector well, collector well interactions with a river, collector well yield, and collector well remediation capability. The two design parameters investigated were lateral length (25 m, 50 m, and 100 m) and number of laterals (3 and 4).
The lateral flux tests confirm flux increases towards the terminal end of each lateral and pumping rate is the controlling factor in flux amount obtained along the laterals. The analysis of the flux-river interaction shows the main factor in determining flux amount is the initial river geometry, followed by the pumping rate, regional background flow, and collector well design, respectively. The models suggest that the 4-lateral collector well design is more effective than the 3-lateral design and in addition, 100 meter length laterals provide the highest amount of yield with the least amount of drawdown. The remediation tests investigate the application of vertical well equations to evaluate collector well designs in two areas: minimum pumping rate to capture line source of particles and first arrival time of particles. The remediation models show 100 meter length laterals provide both the lowest pumping rate and the highest residence time with the surrounding aquifer for maximum remediation. Ultimately, these models provide basic design guidelines and explain which designs are most effective, depending on the collector well purpose.
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Evaluating the Effects of Grain Size and Divalent Cation Concentration on the Attenuation of Viruses and Microspheres through Crushed Silica SandKnappett, Peter January 2006 (has links)
Over the last decade in North America, an increasing number of microbiological drinking water regulations have been used to manage groundwater resources that are potentially influenced by surface water. Regulations such as the Ontario Ministry of Environment Regulation 505, which requires at least a 60 day groundwater travel time between surface waters and drinking water wells, have been created with limited understanding of subsurface pathogen transport processes. Groundwater Under Direct Influence studies (GUDI or GWUDI in USA) are conducted to assess the need to treat well water at an extraction point. Currently, there is a lack of knowledge regarding factors that affect the transport of pathogens through porous media at the surface water-groundwater interface. Such information is required to supply sufficient quantities of drinking water in a cost effective and safe manner. <br /><br /> Factors that affect pathogen transport through porous media include: properties of the pathogen (i. e. surface charge, size, and morphology), properties of the granular media (i. e. mineralogy, size, texture, angularity) and properties of the water (i. e. pH, ionic strength and content, and natural organic matter). This study examines the effects of ionic strength, grain size and influent virus concentrations on pathogen transport in porous media. Fourteen column tests were conducted using the bacteriophage MS2 and 1. 5 µm microspheres; two commonly used non-pathogenic surrogates representative of human viruses and bacteria, respectively. Two size distributions of crushed silica sand, with median grain diameters of 0. 7 and 0. 34 mm, and two ionic strengths of 8 and 95 mmol/L were used. A 2<sup>2</sup> partial factorial design was used with a minimum of two replicates of each combination of the parameters. <br /><br /> The results show that complete breakthrough of both viruses and microspheres occurred in medium sand at low ionic strength. It was found that increasing ionic strength by Ca<sup>2+</sup> addition precluded breakthrough of MS2 in both the medium and fine sands. This represents a greater than 8 log reduction in peak effluent concentration and essentially complete attenuation. <br /><br /> In fine sand, with low ionic strength water, a 5 log reduction in peak MS2 concentrations was observed. In the same sand at high ionic strength, no MS2 broke through the column, corresponding to a greater than 8 log removal. Since complete attenuation occurred in both grain sizes at high ionic strength, the effect of higher ionic strength in the fine sand was indistinguishable from the effect observed from raising the ionic strength in the medium sand. <br /><br /> In contrast to the viruses, microsphere transport was essentially unaffected by increasing ionic strength under the conditions investigated. A 1 log reduction in peak concentration was observed in the high ionic strength water in the medium sand. In spite of this, grain size had a profound effect on the attenuation of microspheres. There was no evidence of microsphere breakthrough in any of the fine sand columns at the low or high ionic strengths, yielding a greater than 5 log reduction in microsphere concentration associated with grain size alone. The effect of varying virus concentration was also investigated. It was found that varying the concentration of viruses between 10<sup>5</sup> and 10<sup>7</sup> pfu/ml had no discernable effect on their observed transport characteristics; normalised peak breakthrough concentration, percent attenuation and retardation relative to a bromide tracer. <br /><br /> Based on the results from this Thesis, in a riverbank filtration environment, there is reason to expect that, at comparable water qualities and in similar porous media, multiple logarithmic reductions of viruses and bacteria would occur over the much longer (than column length) flowpaths associated with RBF. There is also reason to expect this attenuation capability to vary based on riverbank grain size and water chemistry.
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Evaluating the Effects of Grain Size and Divalent Cation Concentration on the Attenuation of Viruses and Microspheres through Crushed Silica SandKnappett, Peter January 2006 (has links)
Over the last decade in North America, an increasing number of microbiological drinking water regulations have been used to manage groundwater resources that are potentially influenced by surface water. Regulations such as the Ontario Ministry of Environment Regulation 505, which requires at least a 60 day groundwater travel time between surface waters and drinking water wells, have been created with limited understanding of subsurface pathogen transport processes. Groundwater Under Direct Influence studies (GUDI or GWUDI in USA) are conducted to assess the need to treat well water at an extraction point. Currently, there is a lack of knowledge regarding factors that affect the transport of pathogens through porous media at the surface water-groundwater interface. Such information is required to supply sufficient quantities of drinking water in a cost effective and safe manner. <br /><br /> Factors that affect pathogen transport through porous media include: properties of the pathogen (i. e. surface charge, size, and morphology), properties of the granular media (i. e. mineralogy, size, texture, angularity) and properties of the water (i. e. pH, ionic strength and content, and natural organic matter). This study examines the effects of ionic strength, grain size and influent virus concentrations on pathogen transport in porous media. Fourteen column tests were conducted using the bacteriophage MS2 and 1. 5 µm microspheres; two commonly used non-pathogenic surrogates representative of human viruses and bacteria, respectively. Two size distributions of crushed silica sand, with median grain diameters of 0. 7 and 0. 34 mm, and two ionic strengths of 8 and 95 mmol/L were used. A 2<sup>2</sup> partial factorial design was used with a minimum of two replicates of each combination of the parameters. <br /><br /> The results show that complete breakthrough of both viruses and microspheres occurred in medium sand at low ionic strength. It was found that increasing ionic strength by Ca<sup>2+</sup> addition precluded breakthrough of MS2 in both the medium and fine sands. This represents a greater than 8 log reduction in peak effluent concentration and essentially complete attenuation. <br /><br /> In fine sand, with low ionic strength water, a 5 log reduction in peak MS2 concentrations was observed. In the same sand at high ionic strength, no MS2 broke through the column, corresponding to a greater than 8 log removal. Since complete attenuation occurred in both grain sizes at high ionic strength, the effect of higher ionic strength in the fine sand was indistinguishable from the effect observed from raising the ionic strength in the medium sand. <br /><br /> In contrast to the viruses, microsphere transport was essentially unaffected by increasing ionic strength under the conditions investigated. A 1 log reduction in peak concentration was observed in the high ionic strength water in the medium sand. In spite of this, grain size had a profound effect on the attenuation of microspheres. There was no evidence of microsphere breakthrough in any of the fine sand columns at the low or high ionic strengths, yielding a greater than 5 log reduction in microsphere concentration associated with grain size alone. The effect of varying virus concentration was also investigated. It was found that varying the concentration of viruses between 10<sup>5</sup> and 10<sup>7</sup> pfu/ml had no discernable effect on their observed transport characteristics; normalised peak breakthrough concentration, percent attenuation and retardation relative to a bromide tracer. <br /><br /> Based on the results from this Thesis, in a riverbank filtration environment, there is reason to expect that, at comparable water qualities and in similar porous media, multiple logarithmic reductions of viruses and bacteria would occur over the much longer (than column length) flowpaths associated with RBF. There is also reason to expect this attenuation capability to vary based on riverbank grain size and water chemistry.
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Temporal variability of riverbed conductance at the Bolton Well Field along the Great Miami River, Southwest Ohio: Characterization of riverbed sediments during low-flow conditionsIdris, Omonigho 04 May 2006 (has links)
No description available.
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Hydrogeologie Skorkovského a Sojovického jímacího řadu na základě nových údajů z vrtů / Hydrogeology of Skorkov and Sojovice waterworks based on data from new water wellsRybářová, Magdalena January 2015 (has links)
The Riverbank Filtration (RBF) water supply system Karany has been affected by increasing NO3- concentrations during recent decades. This thesis deals with flow and chemical composition of groundwater in Skorkov and Sojovice RBF systems, which are the most problematic ones according to their quality in long term. Twelve new groundwater wells (V1- V12) were drilled in study area in 2013. Data derived from the wells were used to improve the conceptual hdrogeological model of the area and I tried to specify information about the origin of nitrate pollution. The Groundwater level logging showed hydraulic connection between the river and the wells situated up to 130 m faraway from the river (V1, V2 andV10), which were also demonstrated by the short- term temperature fluctuations caused by fast penetration of surface water from The Jizera River during higher flow rate to wells. I compiled geological sections which show the geometry of The Quaternary fluvial deposits and groundwater level. The chemical analysis of groundwater showed that it is not possible to differentiate groundwater from the shallow part of The Cretaceous aquifer from the aquifer of fluvial deposits by major chemical components. The result of infiltration experiments showed higher permeability in the environment with grass cover (kv=...
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Temporal variability of riverbed conductance at the Bolton well field along the Great Miami River, southwest Ohio characterization of riverbed sediments during low-flow conditions /Idris, Omonigho. January 2006 (has links)
Thesis (M. En.)--Miami University, Institute of Environmental Sciences, 2006. / Title from first page of PDF document. Includes bibliographical references (p. 33-35).
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Hydrochemical Aspects of Riverbank Filtration in VietnamCovatti, Gustavo Luis 27 March 2024 (has links)
Riverbank filtration (RBF) is defined as the infiltration of river water into the aquifer. It can either be induced by pumping or as a result of a losing river stretch. It is used worldwide as a pre-treatment technique for surface water, which allows for lower abstraction of groundwater and usually an increase in the infiltrated water (bank filtrate) quality. In Vietnam, RBF offers a potential alternative to reduce groundwater overexploitation and an effective pre-treatment for the high turbidity characteristic of Vietnam’s rivers. However, a few water quality problems may arise during RBF, mainly caused by the development of reducing conditions during infiltration, which may trigger in particular conditions the mobilization of manganese, iron, arsenic and ammonium. Arsenic is typically a regional problem in groundwater/bank filtrate and therefore not an issue in the majority of RBF sites. However, the Red River Delta (RRD) in north Vietnam is one of the regions affected by geogenic arsenic contamination. Arsenic alongside with ammonium, are two of the biggest water quality issues in the RRD and are therefore the main points of investigation of this thesis.
Ammonium is an undesirable substance in the abstracted water of RBF schemes, due mainly to the complications it causes during post-treatment. A literature review of case studies from 40 RBF sites around the world was done. Typical concentrations of ammonium in the bank filtrate are between 0.1 and 1.7 mg/l. The most common source of ammonium in the bank filtrate was found to be the mineralization of organic nitrogen occurring in the riverbed, while the most common sink of ammonium was nitrification in the riverbed. Ammonium surface water concentrations do not directly translate to abstracted concentrations. Transformations in the riverbed play a critical role in determining ammonium concentrations, whereby riverbeds with high amounts of organic material in the riverbed lead to higher mineralization rates and have more electron donor competitors, thus limiting ammonium attenuation via nitrification.
Column experiments with riverbed sediments and river water from the Elbe were performed to evaluate the controls on ammonium concentrations during riverbed infiltration. Concentrations of ammonium went from <0.1 mg/l in the feed water up to 1 mg/l in the columns effluent. Higher temperatures and lower infiltration rates led to increased ammonium concentrations in the effluent. This shows higher susceptibility to ammonium increases of RBF settings in warmer climates, such as in Vietnam. In the later phases of the experiments, after the columns have been flushed their pore volumes several times, ammonium concentrations continually decreased. This behavior was attributed to the partial consumption of easily degradable organic material in the sediments, leading to lower mineralization rates. Based on operation with varied nitrate concentrations and 15N isotopic measurements, dissimilatory nitrate reduction to ammonium (DNRA) was not shown to be relevant in the formation of ammonium. Anaerobic ammonium oxidation (anammox), however, was hypothesized to be an important sink of ammonium inside the columns, which indicates that rivers with high nitrate concentrations, such as the Elbe, may have a buffer of protection against ammonium formation during RBF.
Geogenic arsenic contamination of groundwater poses a health threat to millions of people worldwide, particularly in Asia. A study in Hanoi was made, where the water quality of 48 RBF wells from 5 large well fields located in the Pleistocene aquifer along the Red River was analyzed. More than 80% of the wells had arsenic concentrations above the WHO limit of 10 µg/l. The riverbed sediment and riverbed pore-water from 23 sites along a stretch of 30 km of the Red River near the well fields was also analyzed. Muddy riverbeds were found to be a hotspot for arsenic release. Already at a 30 cm depth from the riverbed sediment surface, the pore-water at many sites had high concentrations of arsenic (>100 µg/l). Arsenic concentrations in the pore-water of sites where mud layers were present in the riverbed were significantly higher compared to sites with sandy riverbeds. At well fields along stretches of the Red River where riverbed was mostly muddy, higher arsenic concentrations were found than at well fields where the riverbed was mostly sandy. This indicates that river muds deposition and river morphology can influence arsenic concentrations in the aquifer in Hanoi and potentially other RBF sites in regions with geogenic arsenic contamination. In summary, processes in the hyporheic zone were assessed to be of key importance to the behavior of both ammonium and arsenic during RBF.
Further investigations in two different regions of Vietnam were conducted, in the Red River Delta (RRD) and in the Binh Dinh province (central Vietnam). The results from the geological and water quality investigations are presented. The deltaic depositional environment of the RRD presents hydrogeological challenges to the application of RBF. Thick loamy layers overlaying the topmost aquifer can prevent hydraulic connection between river and aquifer, which is the principal pre-condition for RBF. Furthermore, aquitards separating the aquifers make RBF by abstraction in the deeper aquifer(s) not possible. In Binh Dinh, on the other hand, there are rarely clay layers separating the aquifers and often the topmost aquifer is close to the surface and has high hydraulic conductivity, which makes bank filtration application in Binh Dinh very cost efficient. Water quality of the bank filtrate in Binh Dinh was also generally high, especially in comparison with the RRD. / Unter Uferfiltration (UF) wird die Infiltration von Flusswasser in einen Grundwasserleiter verstanden. Die UF kann durch eine Wasserentnahme durch Brunnen in Gewässernähe induziert werden oder natürlich an einem infiltrierenden Flussabschnitt erfolgen. Die UF wird weltweit als Voraufbereitung für Oberflächenwasser eingesetzt, zur Verringerung von Grundwasserentnahmen und normalerweise zur Verbesserung der Qualität des infiltrierten Wassers (Uferfiltrats). In Vietnam ist die UF eine potenzielle Alternative zur Verringerung der Grundwasserübernutzung und als effektive Voraufbereitung für das für vietnamesische Flüsse charakteristische stark trübstoffhaltige Wasser. Allerdings kann es bei der UF zu einigen Probleme mit der Wasserqualität kommen, hauptsächlich durch die Entwicklung reduzierender Bedingungen während der Infiltration, die unter bestimmten Bedingungen zur Mobilisierung von Mangan, Eisen, Arsen und Ammonium führen können. Arsen ist in der Regel nur regional im Grundwasser/Uferfiltrat zu finden und daher an den meisten UF-Standorten kein Problem. Das Red River Delta (RRD) in Nordvietnam ist jedoch eine der Regionen mit geogen bedingter Arsenkontamination. Hohe Arsen- und Ammoniumkonzentrationen sind zwei der größten Probleme für die Wasserqualität im RRD und deshalb die Schwerpunkte dieser Arbeit.
Ammonium ist eine unerwünschte Substanz im Rohwasser von UF-Anlagen, vor allem wegen der Schwierigkeiten bei der Trinkwasseraufbereitung. Im Rahmen einer Literaturrecherche wurden Fallstudien von 40 UF-Standorten in der ganzen Welt ausgewertet. Im Uferfiltrat sind Ammoniumkonzentrationen zwischen 0,1 und 1,7 mg/l typisch. Als häufigste Quelle für Ammonium im Uferfiltrat wurde die Mineralisierung von organischem Stickstoff im Flussbett ermittelt und als häufigste Senke die Nitrifikation in der Flusssohle. Die Ammoniumkonzentrationen im Oberflächenwasser können nicht direkt mit denen im Rohwasser gleichgesetzt werden. Stoffumwandlungsprozesse in der Flusssohle spielen eine entscheidende Rolle bei der Veränderung der Ammoniumkonzentrationen, wobei Flusssohlsedimente mit einem hohen Anteil an organischem Kohlenstoff zu höheren Mineralisierungsraten führen und mehr Elektronendonatoren als Konkurrenten für die Verringerung der Ammoniumkonzentration durch Nitrifikation aufweisen.
Um die die Ammoniumkonzentration bei der Infiltration bestimmenden Prozesse zu analysieren, wurden Säulenversuche mit Flusssohlsedimenten aus Buhnenfeldern an der Elbe und Elbewasser durchgeführt. Die Ammoniumkonzentrationen reichten von <0,1 mg/l im Zufluss bis zu 1 mg/l im Ablauf der Säulen. Höhere Temperaturen und niedrigere Infiltrationsraten führten zu höheren Ammoniumkonzentrationen im Ablauf. Dies zeigt, dass in wärmeren Klimazonen, wie z. B. in Vietnam, die Zunahme der Ammoniumkonzentration bei der UF wahrscheinlicher ist. In der Endphase der Versuche nahm die Ammoniumkonzentration kontinuierlich ab, nachdem das Porenvolumen der Säulen mehrfach ausgetauscht war. Dieses Verhalten wurde auf den teilweisen Verbrauch von leicht abbaubarem organischem Material im Sediment zurückgeführt, der dann zu geringeren Mineralisierungsraten führte. Durch die Beschickung der Säulen mit Wasser unterschiedlicher Nitratkonzentrationen und Messungen von 15N-Isotopen wurde gezeigt, dass die dissimilatorische Nitratreduktion zu Ammonium (DNRA) für die Bildung von Ammonium nicht relevant ist. Es wurde jedoch die Hypothese formuliert, dass die anaerobe Ammoniumoxidation (Anammox) eine wichtige Senke für Ammonium in den Säulen ist, so dass es in Flüssen mit erhöhten Nitratkonzentrationen, wie z. B. der Elbe, zu einer Begrenzung der Ammoniumfreisetzung bei der UF kommt.
Die geogene Arsenkontamination des Grundwassers stellt eine gesundheitliche Bedrohung für Millionen von Menschen weltweit dar, insbesondere in Asien. In Hanoi wurde eine Studie durchgeführt, bei der die Wasserqualität von 48 UF-Brunnen aus 5 großen Brunnenfeldern im pleistozänen Aquifer entlang des Red River analysiert wurde. Bei mehr als 80 % der Brunnen lag die Arsenkonzentration über dem WHO-Grenzwert von 10 µg/l. Außerdem wurden das Flusssohlsediment und das Porenwasser in der Flusssohle an 23 Standorten entlang eines 30 km langen Abschnitts des Red River in der Nähe der Brunnenfelder untersucht. Es wurde festgestellt, dass Flussabschnitte mit Schlammablagerungen ein Hotspot für die Freisetzung von Arsen sind. Bereits in 30 cm unter der Flusssohle wies das Porenwasser an vielen Stellen hohe Arsenkonzentrationen auf (>100 µg/l). Die Arsenkonzentrationen im Porenwasser war an Standorten mit Schlammablagerungen bzw. Schlammschichten in der Flusssohle deutlich höher als an Standorten mit sandigen Flusssohlsedimenten. In Brunnenfeldern entlang von Abschnitten des Red River, in denen die Flusssohle mehr organisches Feinmaterial enthielt, wurden höhere Arsenkonzentrationen festgestellt als in Brunnenfeldern, die Uferfiltrat aus Abschnitten mit sandiger Flusssohle gewinnen. Dies zeigt, dass Schlammablagerungen und die Flussmorphologie die Arsenkonzentration im oberen Grundwasserleiter in Hanoi und möglicherweise an anderen UF-Standorten in Regionen mit geogener Arsenkontamination beeinflussen. Zusammenfassend wurde festgestellt, dass Prozesse in der hyporheischen Zone für das Verhalten von Ammonium und Arsen bei der UF von entscheidender Bedeutung sind.
Weitere hydrogeologische und hydrochemische Untersuchungen zur UF wurden in zwei verschiedenen Regionen Vietnams durchgeführt, im RRD und in der Provinz Binh Dinh (Zentralvietnam). Die Ablagerungsbedingungen im RRD bestimmen die mögliche Nutzung der UF. Mächtige lehmige Deckschichten, die den obersten Grundwasserleiter überlagern, können eine hydraulische Verbindung zwischen dem Fluss und dem Grundwasserleiter verhindern, welche Hauptvoraussetzung für die UF ist. Darüber hinaus machen geringdurchlässige Schichten (Aquitards) eine UF durch Wasserentnahmen aus tieferen Grundwasserleitern unmöglich. Dagegen gibt es in Binh Dinh kaum Aquitards, die die Grundwasserleiter voneinander trennen, oft hat der oberflächenahe, oberste Grundwasserleiter eine hohe hydraulische Durchlässigkeit, was die Nutzung der UF in Binh Dinh kosteneffizient macht. Auch die Qualität des Uferfiltrats war in Binh Dinh generell höher, insbesondere im Vergleich zum RRD.
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TEMPORAL VARIABILITY OF RIVERBED HYDRAULIC CONDUCTIVITY AT AN INDUCED INFILTRATION SITE, SOUTHWEST OHIOBirck, Matthew D. 04 August 2006 (has links)
No description available.
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Untersuchungen zur Steuerung der Mangankonzentration bei der Uferfiltration und Unterirdischen Enteisenung / EntmanganungPaufler, Sebastian 20 May 2019 (has links)
Die Uferfiltration und die unterirdische Enteisenung / Entmanganung (UEE) sind bewährte Verfahren für die natürliche, unterirdische Voraufbereitung von Wasser. In Abhängigkeit von der Wasserbeschaffenheit und den geochemischen Eigenschaften des Grundwasserleiters können Redoxreaktionen, Sorptions- und Auflösungsprozesse oder eine ungünstige Bewirtschaftung der Brunnen bei beiden Verfahren zu erhöhten Mangankonzentrationen im Rohwasser führen. Erhöhte Mangankonzentrationen sind häufig für Verockerungsprozesse im Filterbereich der Brunnen und Ablagerungen in Pumpen und Steigleitungen verantwortlich. Diese beeinträchtigen den langfristigen Brunnenbetrieb und führen zu höheren Kosten der Wasseraufbereitung. Außerdem führt Mangan zur Färbung des Wassers und muss in der Trinkwasseraufbereitung auf < 0,05 mg/L verringert werden. Für Wasserwerksbetreiber ist die Kenntnis über die Ursache und das Verhalten von Mangan essentiell für einen optimalen Betrieb.
Die ägyptische Hauptstadt Kairo steht einem stark wachsenden Wasserbedarf gegenüber. Für die Bewertung einer möglichen Anwendung der Uferfiltration am Nil wurden vorhandene Versuchsbrunnen teufenabhängig beprobt und das Flusssohlsediment untersucht. Das Flusssohlsediment wies hohe Eisen- und Mangangehalte auf und wurde als Ursache für erhöhte Eisen-, Mangan- und Ammoniumkonzentrationen im Uferfiltrat identifiziert.
Für den Uferfiltrationsstandort Dresden-Tolkewitz wurde der Einfluss von Temperatur und Infiltrationsrate auf die Manganfreisetzung aus der Elbsohle untersucht. Betriebsdaten der Jahre 2006 bis 2016 und Säulenversuche bildeten die Grundlage. Die Manganfreisetzung wurde primär von der Temperatur kontrolliert, die Infiltrationsrate war weniger wichtig und verlor mit steigender Temperatur weiter an Bedeutung. Eine Manganfreisetzung wurde bei Wassertemperaturen von 20 °C und Infiltrationsraten von ≥ 0,3 m³/(m²×d) ausgelöst.
Während der Inbetriebnahme eines UEE-Wasserwerks in Khabarovsk (Russland) wurde an einigen Brunnen eine intensive Manganfreisetzung beobachtet. Außerdem führte biologische Kolmation zu einem raschen Leistungsverlust und erforderte die Desinfektion der Brunnen. Die Auswertung der ersten 194 UEE-Zyklen eines Förderbrunnens und ergänzende Batchversuche ergaben, dass die Auflösung des im Grundwasserleiter vorhandenen, manganhaltigen Siderits die Ursache der Mn-Freisetzung war. Die Auflösungsprozesse hingen stark von der Korngröße des GWL-Materials und dem pH-Wert des Grundwassers ab. Die Filterkiesschüttung des Brunnens zehrte weniger als 1 % des infiltrierten Chlors und das Natriumhypochlorit drang ca. 2 bis 3,5 m in den Grundwasserleiter ein.
Das Wasserwerk Eggersdorf nutzt die UEE für die Voraufbereitung von eisenhaltigem Grundwasser und dient, entgegen den Empfehlungen für die UEE, der Abdeckung von Bedarfsspitzen. In einem Feldversuch wurde die mögliche Umnutzung der UEE-Brunnen für die dauerhafte Grundwasserförderung getestet. Die dabei aufgetretene Manganfreisetzung wurde auf die chemische Reduktion von abgeschiedenen Mangan(hydr)oxiden durch eisenhaltiges Grundwasser zurückgeführt.:Kurzfassung i
Abstract iii
Danksagung iv
Inhaltsverzeichnis v
Abkürzungsverzeichnis vii
1 Einleitung 1
1.1 Ausgangssituation 1
1.2 Motivation und Ziele 3
1.3 Gliederung der Arbeit 5
2 Auftreten und Verhalten von Mangan bei der Uferfiltration 6
2.1 Eintragspfade von Mangan in das Uferfiltrat 6
2.2 Einflussgrößen auf den Mangangehalt im Uferfiltrat 7
3 Erkundung eines neuen Uferfiltrationsstandortes in Embaba 9
3.1 Einleitung und Standortbeschreibung 9
3.2 Teufenabhängige Probennahme während des regulären Betriebes 9
3.3 Ursache der Manganfreisetzung und Bewirtschaftung des Standortes 10
4 Einfluss der Infiltrationsrate und der Temperatur auf die Manganfreisetzung aus der Elbsohle in Dresden 12
4.1 Einleitung und Standortbeschreibung 12
4.2 Einfluss der Temperatur auf die Manganfreisetzung 12
4.3 Einfluss der Infiltrationsrate auf die Manganfreisetzung 13
5 Freisetzung von Mangan beim Start einer UEE in Khabarovsk 15
5.1 Einleitung und Standortbeschreibung 15
5.2 Untersuchungen zur Ursache der Manganfreisetzung 15
5.3 Begrenzung der Leistungsabnahme der UEE-Brunnen 16
6 Manganfreisetzung bei der geplanten Umstellung des UEE-Wasserwerks
Eggersdorf auf kontinuierliche Förderung 18
6.1 Einleitung und Standortbeschreibung 18
6.2 Umstellung eines UEE-Brunnens auf dauerhafte Förderung 18
6.3 Ursache der Manganfreisetzung aus dem ehemaligen Reaktionsraum 19
7 Zusammenfassung und Ausblick 21
Literaturverzeichnis 24
Beiliegende Publikationen 29
Beiliegende Publikation 1 31
Beiliegende Publikation 2 53
Beiliegende Publikation 3 69
Beiliegende Publikation 4 83
Beiliegende Publikation 5 103
Beiliegende Publikation 6 135
Beiliegende Publikation 7 167
Beiliegende Publikation 8 189 / Bank filtration and Subsurface Iron Removal (SIR) are proven technologies for the natural subsurface pre-treatment of water. Depending on the water quality and the geochemical properties of the aquifer, redox reactions, sorption and dissolution or unfavorable well management can lead to increased manganese concentrations in both treatment options. Increased manganese concentrations often cause filter screen clogging of the well or deposits in pumps and standpipes. This can affect the long-term well operation and lead to higher costs of water treatment. Furthermore, increased manganese concentrations can cause a coloring of the water and must be lowered to < 0.05 mg/l during drinking water treatment. For waterworks operators, the knowledge about the source and the behavior of manganese is essential for an optimal operation.
The Egyptian capital Cairo faces a growing water demand. To evaluate a potential riverbank filtration site, depth-dependent sampling at existing test wells was carried out and sediment samples from the Nile riverbed were taken. The riverbed sediment showed elevated iron and manganese contents and was identified as cause of increased iron, manganese and ammonium concentrations in the riverbank filtrate.
For the bank filtration site Dresden-Tolkewitz, the impact of temperature and infiltration rate on the manganese release from the riverbed sediment of the Elbe river was investigated. The investigations were based on monitoring data of the years 2006 to 2016 and column experiments. The manganese release was primarily controlled by temperature, the infiltration rate was less important. With increasing temperature, the infiltration rate became even less critical. Manganese was released at water temperatures of 20 °C and infiltration rates of ≥ 0.3 m³/(m²×d).
During the start-up phase of a SIR waterworks in Khabarovsk, Russia, an intense manganese release was observed in several wells. In addition, biological clogging led to a rapid perfor-mance loss of the wells and required well disinfection. The evaluation of the first 194 SIR cycles of a production well and accompanying batch experiments indicated that the dissolution of the manganese-bearing siderite, which was present in the aquifer, caused the Mn release. The dissolution heavily depended on the grain size of the aquifer material and the pH of the groundwater. The filter gravel pack of the well consumed less than 1 % of the infiltrated chlorine and the sodium hypochlorite approximately penetrated between 2 and 3.5 m into the aquifer.
The waterworks Eggersdorf has been using SIR for the pre-treatment of ferrous groundwater and, contrary to general recommendations for SIR well operation, served for covering peaks in water demand. In a field trial, the possible conversion of the SIR wells for permanent groundwater extraction was tested. An observed manganese release was attributed to the chemical reduction of former precipitated Mn(hydr)oxides by iron-containing groundwater.:Kurzfassung i
Abstract iii
Danksagung iv
Inhaltsverzeichnis v
Abkürzungsverzeichnis vii
1 Einleitung 1
1.1 Ausgangssituation 1
1.2 Motivation und Ziele 3
1.3 Gliederung der Arbeit 5
2 Auftreten und Verhalten von Mangan bei der Uferfiltration 6
2.1 Eintragspfade von Mangan in das Uferfiltrat 6
2.2 Einflussgrößen auf den Mangangehalt im Uferfiltrat 7
3 Erkundung eines neuen Uferfiltrationsstandortes in Embaba 9
3.1 Einleitung und Standortbeschreibung 9
3.2 Teufenabhängige Probennahme während des regulären Betriebes 9
3.3 Ursache der Manganfreisetzung und Bewirtschaftung des Standortes 10
4 Einfluss der Infiltrationsrate und der Temperatur auf die Manganfreisetzung aus der Elbsohle in Dresden 12
4.1 Einleitung und Standortbeschreibung 12
4.2 Einfluss der Temperatur auf die Manganfreisetzung 12
4.3 Einfluss der Infiltrationsrate auf die Manganfreisetzung 13
5 Freisetzung von Mangan beim Start einer UEE in Khabarovsk 15
5.1 Einleitung und Standortbeschreibung 15
5.2 Untersuchungen zur Ursache der Manganfreisetzung 15
5.3 Begrenzung der Leistungsabnahme der UEE-Brunnen 16
6 Manganfreisetzung bei der geplanten Umstellung des UEE-Wasserwerks
Eggersdorf auf kontinuierliche Förderung 18
6.1 Einleitung und Standortbeschreibung 18
6.2 Umstellung eines UEE-Brunnens auf dauerhafte Förderung 18
6.3 Ursache der Manganfreisetzung aus dem ehemaligen Reaktionsraum 19
7 Zusammenfassung und Ausblick 21
Literaturverzeichnis 24
Beiliegende Publikationen 29
Beiliegende Publikation 1 31
Beiliegende Publikation 2 53
Beiliegende Publikation 3 69
Beiliegende Publikation 4 83
Beiliegende Publikation 5 103
Beiliegende Publikation 6 135
Beiliegende Publikation 7 167
Beiliegende Publikation 8 189
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Development of a GIS and model-based method for optimizing the selection of locations for drinking water extraction by means of riverbank filtrationZhou, Yan 12 January 2021 (has links)
The lack of safe drinking water worldwide has drawn the attention of decision makers to riverbank filtration (RBF) for its many advantages in purifying surface water. This study provides an overview of the hydrogeologic, fluvial, and environmental influences on the performance of RBF systems and aims to develop a model for RBF site selection. Using multi-attribute utility theory (MAUT), this study structured the RBF siting problem and assessed a multiplicative utility function for the decision maker. In a case study, geostatistical methods were used to acquire the necessary data and geographic information systems (GIS) were used to screen sites suitable for RBF implementation. Those suitable sites were then evaluated and ranked using the multi-attribute utility model. The result showed that sites can be identified as most preferred among the selected suitable sites based on their expected utility values. This study definitively answers the question regarding the capability of MAUT in RBF site selection. Further studies are needed to verify the influences of the attributes on the performance of RBF systems.:Abstract iii
Zusammenfassung iv
Acknowledgments v
Table of Contents vi
List of Tables viii
List of Figures x
Definition of terms xiii
1. Abbreviations xiii
2. Symbols xiii
Part I Introduction 1
1. Introduction 2
2. Statement of purpose 2
3. Research questions 3
4. Overview of methodology 3
5. Organization of the dissertation 3
Part II Fundamentals and Literature Review 5
1. The definition of bank filtration 6
2. The Significance of RBF 7
2.1 RBF in drinking water supply 7
2.2 Benefits of RBF for China 14
3. RBF Site Selection 19
3.1 RBF site selection model 20
3.2 Definition of successful RBF sites 24
4. Factors Affecting RBF Site Selection 26
4.1 River hydrology/hydraulics 27
4.2 Geology 28
4.3 Land cover 36
4.4 Well field location 36
4.5 Water quality 37
4.6 Aquifer properties 38
4.7 Distance to river 41
4.8 Riverbed characteristics 43
5. Effect of Clogging on Yield 46
6. Summary 51
Part III Developing a Multi-attribute Utility Model for RBF Site Selection 53
1. Introduction 54
2. Objectives and Attributes 54
3. Assessment of the Utility Function 57
3.1 Investigation of the qualitative preference structure 58
3.2 Assessment of component utility function 62
3.3 Assessment of the scaling constants 63
4. Results 67
5. Discussion 69
6. Summary 74
Part IV Case Study 75
1. Introduction 76
2. Materials and Methods 78
2.1 GIS data collection 78
2.1.1 Geologic data 79
2.1.2 Land cover data 79
2.1.3 Groundwater quality data 80
2.1.4 Aquifer properties data 80
2.1.5 Surface water area data 80
2.1.6 Surface water quality data 81
2.1.7 Streambed material data 81
2.2 Kriging the saturated thickness 91
2.3 Aggregation of all constraint maps 103
3. Results 105
3.1 Kriging 105
3.2 Suitable sites 105
4. Discussion 109
4.1 A discussion of the kriging results 109
4.2 A discussion of the multi-attribute utility model results 117
5. Summary 122
Part V Conclusions and Recommendations 123
1. Conclusion and Recommendation 124
Appendix 1 Environmental quality standards for surface water (GB 3838-2002) 125
Appendix 2 Quality standard for groundwater (GB14848-93) 127
Appendix 3 Explanation to Germany’s RBF site location data 130
Appendix 4 Layer information of drillings 133
Appendix 5 Streambed materials used by Schälchli (1993) 141
Appendix 6 Interview and questionnaires 143
Appendix 7 Surface water area of Jilin City 150
Bibliography 152
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