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Characterization of planetary subsurfaces with permittivity probes : analysis of the SESAME-PP/Philae and PWA-MIP/HASI/Huygens data / Characterization of planetary subsurfaces with permittivity probes : analysis of the SESAME-PP/Philae and PWA-MIP/HASI/Huygens dataLethuillier, Anthony 21 September 2016 (has links)
Les sondes de permittivité sont des instruments de prospection géophysique non destructifs qui donnent accès aux propriétés électriques, aux basses fréquences (10 Hz-10 kHz), de la proche subsurface. Ce faisant, elles renseignent sur la composition, porosité, température et éventuelle hétérogénéité des premiers mètres sous la surface.Utilisant généralement 4 électrodes, le principe des sondes de permittivité est simple : il consiste à injecter un courant sinusoïdal de phase et d’amplitude connues entre deux électrodes (dipôle émetteur) et à mesurer l'impédance mutuelle (le rapport complexe entre la tension et le courant injecté) entre ce dipôle émetteur et un dipôle récepteur. La permittivité complexe du matériau de surface, à savoir sa constante diélectrique et sa conductivité électrique, sont alors déduites de la mesure de l’amplitude et de la phase de cette impédance mutuelle. Les fréquences d’opération des sondes de permittivités sont basses là où l’approximation quasi-statique s’applique. A ce jour, les propriétés électriques de seulement deux surfaces planétaires extraterrestres ont été étudiées par des sondes de permittivité : celle de Titan par l’instrument PWA-MIP/HASI/Huygens/Cassini-Huygens et celle du noyau de la comète 67P/Churyumov–Gerasimenko par SESAME-PP/Philae/Rosetta.Nous présentons la première analyse des données obtenues par SESAME-PP à la surface de la comète 67P/Churyumov–Gerasimenko. Grâce à un travail précis (1) de modélisation numérique de l’instrument et de son fonctionnement, (2) de campagne de mesures (en laboratoire et dans des grottes de glace) afin de valider la méthode d’analyse et (3) d’hypothèses réalistes sur l’environnement proche de la sonde, nous avons pu contraindre la composition et surtout la porosité des premiers mètres du noyau cométaire montrant qu’ils étaient plus compacts que son intérieur. Nous avons également travaillé à une nouvelle analyse des données obtenues en 2005 par PWA-MIP proposant notamment de nouveaux scénarios pour le changement brutal de propriétés électriques observé 11 min après l’atterrissage de Huygens. Ces nouveaux scénarios s’appuient, entre autres, sur les mesures de caractérisation électrique menées au LATMOS sur des échantillons de composés organiques (tholins), analogues possibles des matériaux recouvrant la surface de Titan. / Permittivity probes are non-destructive geophysical prospecting instruments that give access to the low frequency (10 Hz – 10 kHz) electrical properties of the close subsurface. This provides us with information on the composition, porosity, temperature, and heterogeneity of the first meters of the subsurface.Using 4 electrodes, the technique consists in injecting a sinusoidal current of known phase and amplitude between two electrodes (transmitting dipole) and measuring the mutual impedance (complex ratio of measured potential over injected current) between this dipole and a receiving dipole. The complex permittivity (i.e. dielectric constant and conductivity) of the subsurface material is derived from the measured phase and amplitude of the mutual impedance. The frequency range of operation of permittivity probes is low, therefore the quasi static approximation applies. To this day the electrical properties of only two extra-terrestrial surfaces have been studied by permittivity probes, the surface of Titan by the instrument PWA-MIP/HASI/Huygens/Cassini-Huygens and the surface of the nucleus of comet 67P/Churyumov–Gerasimenko by SESAME-PP/Philae/Rosetta.We present a first analysis of the data collected by SESAME-PP at the surface of the comet 67P/Churyumov–Gerasimenko. With the help of (1) precise numerical models of the instrument, (2) field measurements (in a controlled and natural environment) in order to validate the analysis method, and (3) realistic hypothesis on the close environment we were able to constrain the composition and porosity of the first meters of the comet’s nucleus, showing that the subsurface is more compact than its interior. We also reanalysed of the data collected in 2005 by PWA-MIP, offering new explanations for the abrupt change in the electrical properties observed 11 minutes after the landing of Huygens. These new scenarios were built in the light of lab measurements performed at LATMOS on samples of organic matter (tholins), possible analogue of Titan’s surface material.
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A COUPLED HYDROLOGICAL- GEOTECHNICAL FRAMEWORK FOR FORECASTING SHALLOW LANDSLIDE HAZARD / 水文学と地盤工学の手法を融合した表層崩壊の発生予測に関する研究NGUYEN, DUC HA 25 November 2019 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22125号 / 工博第4655号 / 新制||工||1726(附属図書館) / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 渦岡 良介, 教授 角 哲也, 准教授 佐山 敬洋 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
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Simulated Laser Triangulation with Focus on Subsurface ScatteringKihl, Hilma, Källberg, Simon January 2021 (has links)
Practical laser triangulation sessions were performed for each measurement object to obtain ground truth data. Three methods for laser line simulations were implemented: reshaping the built-in light sources of Blender, creating a texture projector and approximating a Gaussian beam as a light emitting volume. The camera simulation was based on the default camera of Blender together with settings from the physical camera. Three approaches for creating wood material were tested: procedural texturing, using microscopic image textures to create 3D-material and UV-mapping high resolution photograph onto the geometry. The blister package was simulated with one material for the pills and another for the semi-transparent plastic packaging. A stand-alone Python script was implemented to simulate anisotropic/directed subsurface scattering of a point laser in wood. This algorithm included an approach for creating vector fields that represented subsurface scattering directions. Three post-processing scripts were produced to simulate sensor noise, blurring/blooming of the laser line and lastly to apply simulated speckle patterns to the laser lines. Sensor images were simulated by rendering a laser line projected onto a measurement object. The sensor images were post-processed with the three mentioned scripts. Thousands of sensor images were simulated, with a small displacement of the measurement object between each image. After post-processing, these images were combined to a single scattering image. SICK IVP AB provided the algorithms needed for laser centre extraction as well as for scattering image creation. / <p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>
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Can We Increase Crop Yield Adopting Tile Drainage in Fargo Clay Soil?Acharya, Umesh January 2018 (has links)
Subsurface drainage has recently become common for agriculturally productive soils and key to maintain and improve crop production in poorly drained, frigid clay soils. The first study was conducted for four years (2014-17) at Casselton, ND to determine best combination of drainage, tillage and crop rotation for higher corn yield. Our finding suggested corn yield was highest with no drainage, CS and CH combination in years with drought conditions. The second study was conducted for three years (2015-17) to evaluate subsurface drainage spacing (9, 12, and 15m) and depth (0.9 and 1.2m) combination on corn, soybean and sugarbeet yields and residual soil nitrate-nitrogen (NO3-N) contents. Results indicated that 9 m drain spacing produced highest corn and soybean yield when average across three years in contrast with drain depth that has no effect on corn and soybean yield except for sugarbeet where the 1.2m depth yielded higher than the 0.9m depth. / North Dakota Corn Council / North Dakota Soybean Council / North Dakota Water Resources Research Institute
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Application of SWAT for Impact Analysis of Subsurface Drainage on Streamflows in a Snow Dominated WatershedRahman, Mohammed Mizanur January 2011 (has links)
The wet weather pattern since the early 1990's has created two problems for the people living in the Red River Valley (RRV): (1) wet field conditions for farmers and (2) more frequent major spring floods in the Red River system. Farmers in the region are increasingly adopting subsurface drainage practice to remove excess water from their fields to mitigate the first problem. However, it is not clear whether subsurface drainage will deteriorate or mitigate the spring flood situation, the second problem. The Soil and Water Assessment Tool (SWAT) model was applied to evaluate the impacts of tile drainage on the Red River's streamflows. The model was calibrated and validated against monthly streamflows at the watershed scale and against daily tile flows at the field scale. The locations and areas of the existing and potential tile drained (PTD) areas were identified using a GIS based decision tree classification method. The existing and maximum PTD areas were found to be about 0.75 and 17.40% of the basin area, respectively. At the field scale, the range of Nash-Sutcliffe efficiency (NSE) for model calibration and validation was 0.34-0.63. At the watershed scale, the model showed satisfactory performance in simulating monthly streamflows with NSE ranging from 0.69 to 0.99, except that the model under-predicted the highest spring flood peak flows in three years. The results of modeling a 100% tiled experimental field showed that about 30-40% of water yield was produced as tile flow. Surface runoff and soil water content decreased about 34% and 19%, respectively, due to tile drainage. However, the impact of subsurface drainage on evapotranspiration (ET) and water yield was mixed. ET slightly decreased in a wet year and slightly increased in a dry year, while the pattern for water yield was opposite to that of ET. The watershed-scaled modeling results showed that a tiling rate of 0.75-5.70% would not have significant effects on the monthly average streamflows in the Red River at Fargo. For the 17.40% tiling rate, the streamflow in the Red River at Fargo might increase up to 1% in April and about 2% in Fall (September to November), while decreasing up to 5% in the remaining months. This SWAT modeling study helped to better understand the impact of subsurface drainage on the water balance and streamflows in the Red River of the North basin. The findings will also help watershed managers in making decisions for the purpose of managing agricultural drainage development in the RRV and other snow dominated watersheds around the world.
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Mikrogravimetrický průzkum a monitoring podpovrchových nehomogenit / Microgravity survey and monitoring of subsurface inhomogeneitiesSpěšný, Marek January 2010 (has links)
Marek Spěšný - abstract This thesis has the nature of a survey report of a specific area. The task was to localize with the help of microgravimetry anomalous places in an area of a by-pass road construction, where subsurface inhomogeneities may possibly exist due to subsurface and surface historical mining of ceramic clay. The gravimetrical measurements were carried out with a relative gravimeter Scintrex model CG-5 AUTOGRAV. After the first stage of the gravimetrical measurements and following two weeks of recultivation works our assignment was to verify the success of the first measurements by the means of repeated microgravimetric control measurements. The results from both stages of measurement were processed into a 4D gravimetrical form. The results of the 4D gravimetry displayed that contrary to the expectations, the measured gravity of most of the area of interest decreased as much as by 30 ?Gal. We conclude that this is due to the drainage of injected material beyond the recultivated mining area, which washed and carried away a portion of the existing material. Our proposition was also supported by results of repeated leveling, which discovered subsidence of the road at times by up to 3 centimeters.
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Building a Predictive Model for Stratigraphic Transitions and Lateral Facies Changes in the Cretaceous Almond Formation, WyomingPhillips, Joseph E. 07 December 2020 (has links)
The Cretaceous Almond Formation, located in the Greater Green River Basin, records deposition of coastal plain fluvial sandstones and shallow marginal-marine sandstones in a net-transgressive sequence along the western margin of the Cretaceous Interior Seaway (CIS) from the late Campanian to early Maastrichtian. The Almond Formation is an important hydrocarbon reservoir, with development mainly along the Wamsutter Arch and the northeast margins of the Washakie Basin. Previous studies have primarily focused on outcrops along the eastern flank of the Rock Springs Uplift and subsurface data targeting the Wamsutter Arch. Further development of the Almond petroleum system requires extending our understanding of lateral facies changes and sequence stratigraphic architecture away from areas that have been previously studied. The aim of this research is to build a predictive model of lateral and temporal facies transitions and associated reservoir character along the Cherokee Arch in southern Wyoming. This structural feature marks the southern margin of the Washakie Basin and is roughly perpendicular to the shoreline of the CIS. Outcrop examination at either end of the arch shows that lower Almond strata along the western margin of the Washakie Basin transition from coastal plain facies associations to time-equivalent shallow-marine strata to the east, while the upper Almond strata transition from shallow-marine sands to offshore and prodeltaic muds across the ~125 km separating the two outcrop localities. This reveals clear facies associations shifts at the basin scale, which are difficult to interpret using only well data. The preservation of shoreface strata and related near-shore, fluvio-deltaics across large distances in the dip direction shows the large magnitude of shoreline migration. This also suggests that the system gradient was likely very gentle, leading to wide facies belts, and that reservoir continuity could be complex over significant distances. Stacking patterns observed in outcrop, core, and log curves demonstrate an early progradational sequence across the basin from the west to east. This time equivalent strata suggests sediment supply outpaced accommodation during deposition of the lower Almond and equivalent basinward strata, leading to progradation and eventually to some aggradation before relative sea-level rose. This is significant as the Almond is thought primarily as an overall retrogradational system. Within the upper Almond and basinward equivalent strata, stacking patterns reveal a well preserved retrogradational sequence as accommodation outpaced sediment supply during the final transgression of the Mesaverde Group. Core and outcrop analysis to the east at this time show facies associations that potentially represent an inundated, estuarine deltaic environment of deposition transitioning to deltaic depofacies to the west. Clinoformal geometry and an additional sand found in the subsurface of a cluster of only southern wells corroborate a deltaic interpretation. This sand is interpreted as a lobate deposit flanked by shale to the north. Shorelines span a short distance in the east and a much broader distance to the west with a clear facies shift in between allowing for marine shale to directly overlay coastal plain facies. Outcrop, core, and subsurface datasets have led to a better understanding of sediment partitioning and preservation during this transgressive phase of the CIS in the western United States. A better understanding of these spatial and temporal patterns will help to remove risk associated with exploration along this trend, as well as serve as an analogue for other transgressive deposits. Additional data would increase knowledge of this system and lead to solidification of new ideas presented for the Almond Formation along the Cherokee Arch.
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Metoda termální desorpční spektroskopie (TDS) a její aplikace pro výzkum povrchových procesů / Thermal Desorption Spectroscopy (TDS) and its Application for Research of Surface ProcessesPotoček, Michal January 2011 (has links)
ermal desorption spectroscopy (TDS) is a common method for surface analysis of adsorbed molecules. In chapter 1 the work deals with the theoretical background of this method and shows the principles of a desorption process influenced by subsurface diffusion. Chapter 2 first shows application of TDS for detection of surface molecules and determination of binding energy.Experiments were mainly focused on ditermination of surface adsorbents and impurities on Si wafers. The second part of chapter 2 describes desorption of atoms of a Ga layer on Si surface and their subsurface diffusion. A Ga diffusion process was also observed by with secondary ion mass spectrometry (SIMS) and numerically simulated.
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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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Nutrient And Pathogen Removal In A Subsurface Upflow Wetland System Using Green Sorption MediaXuan, Zhemin 01 January 2009 (has links)
Due to environmental health and nutrient impact concerns, the conventional on-site sewage collection, treatment, and disposal systems are no longer able to meet the nutrient reduction requirements for wastewater effluent and may represent a large fraction of pollutant loads. The loads include not only nitrogen (N) and phosphorus (P), but also pathogens such as fecal coliform and E. coli which indicate the presence of other disease-causing bacteria flowing into aquatic system that adversely affect public health. A subsurface upflow wetland, which is an effective small-scale wastewater treatment system with low energy and maintenance requirements and operational costs, fits the current nutrient and pathogen removal situation having received wide attention throughout the world. Within this research study, a subsurface upflow wetland system (SUW), including four parallel SUW (three planted versus one unplanted), were constructed as a key component of the septic tank system receiving 454 liters per day (120 GPD) influent using the green sorption media along with selected plant species. It was proved effective in removing both nutrients and pathogens. During a one month test run, the planted wetlands achieved a removal efficiency of 84.2%, 97.3 %, 98.93 % and 99.92%, compared to the control wetland, 10.5%, 85.7 %, 99.74 % and 100.0 %, in total nitrogen (TN), total phosphorus (TP), fecal coli and E.Coli, respectively. Denitrification was proved to be the dominant pathway for removing N as evidenced by the mass balance and real-time PCR analyses. A simplified compartmental dynamics simulation model of constructed subsurface upflow wetlands was also developed to provide a dependable reference and tool for design of constructed subsurface upflow wetland.
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