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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The use of krypton as a tracer to quantify reaeration in surface waters

Murphy, J. L. January 2003 (has links)
No description available.
2

Legacy of historic mining and water quality in a heavily mined Scottish river catchment

Haunch, Simon January 2013 (has links)
Mine abandonment and the discharge of contaminated mine water is recognised globally as a major source of surface water and groundwater pollution. Contamination generally arises from the oxidation of sulphide minerals, principally pyrite, by the mining process, and the subsequent chemical reactions can lead to the discharge of mineralised, often acidic, iron, and sulphate rich waters. In many historically mined river catchments, mine water discharge is the main cause of poor water quality. Within the UK, managing the legacy of abandoned mines is one of the principal challenges presented by modern environmental legislation, particularly the EU Water Framework Directive, a challenge that is exacerbated by the diverse and widespread nature of historical mining. The impact and hazard associated with abandoned mining in one of the UK’s most intensively mined regions, the Almond River Catchment, Scotland, was examined via: 1) a detailed GIS mapping and investigation of historical mining processes in the catchment, 2) mine site discharge sampling, 3) detailed site investigations, 4) geochemical modelling of four mine waste sites and 5) analysis of temporal and spatial river water quality in the catchment. The results are then brought together to produce a catchment scale mine water hazard map. Mapping has identified over 300 mine sites in the catchment including coal, oil shale and ironstone mine wastes and flooded coal and oil shale mines. The historical development of oil shale retort methods has been shown to have an impact on potential hazard. Sampling of discharge waters from the different mining activities, in conjunction with detailed mineralogical analysis and geochemical modelling at the four mine waste sites has characterised the main hazards. Ironstone and pyrite bearing coal mine wastes discharge waters with highly elevated Fe and sulphate concentrations, up to 160mgl-1 and 1900mgl-1 respectively, due to extensive pyrite oxidation and acid generating salt dissolution (principally jarosite). Coal mine wastes show variable mineralogy, due to the diverse nature of coal bearing strata, and discharge waters with variable chemistry. Oil Shale mine wastes are generally depleted in pyrite due to historic processing and discharge low sulphate waters with moderately elevated Fe concentrations, up to 5mgl-1. Flooded coal mines discharge sulphate dominant alkaline waters, due to the availability of carbonate minerals in the mine complex, with elevated Fe concentrations, up to 50mgl-1, while flooded oil shale mines discharge waters with moderately elevated Fe concentrations, up to 4mgl-1, due to lower pyrite content in mine strata and reduced availability of oxygen related to mine abandonment age. Once in the surface water environment iron and sulphate display significant concentration-flow dependence: iron increases at high flows due to the re-suspension of river bed iron precipitates (Fe(OH)3); sulphate concentrations decrease with increased flow as a result of dilution. Further examination of iron and sulphate loading at low flows indicates a close correlation of iron and sulphate with mined areas; cumulative low flow load calculations indicate that coal and oil shale mining regions contribute 0.21 and 0.31 g/s of iron, respectively, to the main Almond tributary. Decreases in iron loading on river sections demonstrate the deposition and diffuse storage of iron within the river channel. This river bed iron is re-suspended with increased flow resulting in significant transport of diffuse iron downstream with load values of up to 50 g/s iron. Based on this hazard classification, a catchment scale mine water hazard map has been developed. The map allows the prioritisation of actions for future mine water management.
3

Vliv chemických zdrojů znečištění na jakost povrchových vod v povodí Horní Vltavy

NEKOLNÝ, Tomáš January 2019 (has links)
The diploma thesis is focused on the issue of surface water pollution, which is one of the biggest problems of the contemporary world. The pollution of watercourses and reservoirs worsens the quality of aquatic ecosystems as well as ecosystems in their surroundings. The typical sources of surface water pollution include especially point sources (human settlements, industrial sites) and land resources (agriculture). While the point sources of pollution can be monitored, the situation is far more complicated for the field sources. In agricultural farming, the fertilizer residues, pesticides and other substances come into the groundwater and the surface water. The aim of this work is to find out the quality of surface water in the measuring profiles (river Malše), to find out the hydrological situation during the year and to evaluate the impact of chemical pollution sources influencing the quality of the surface water in the river basin.
4

Pesticide Pollution In Surface And Ground Water Of An Agricultural Area, Kumluca, Turkey

Oztas, Nur Banu 01 September 2007 (has links) (PDF)
Concentrations of 17 organochlorine and 14 organophosphorus pesticides were measured in 27 ground and 11 surface water samples collected from a heavily agricultural area, Kumluca, in spring and fall seasons of 2005. The samples were preconcentrated by Solid Phase Extraction. GC-ECD and GC-NPD systems were used for quantitative determination of organochlorine and organophosphorus pesticides respectively. The quality check/quality assurance tests were performed by the analysis of field and laboratory blanks, standard reference materials, spiked control and sample matrices, surrogate standards, sampling and analysis replicates. It is observed that, sample matrix lowers average percent recoveries from 89% to 76%. The uncertainties of measurements were calculated to determine major factors affecting the analysis results. It was observed that uncertainty arising from extraction procedure was generally the highest. The most commonly observed pesticide was endosulfan (70%) and chlorpyriphos (53%) for organophosphorus and organochlorine pesticides. The highest average concentration was observed for heptachlor (26 ng/L) and fenamiphos (184 ng/L). Generally pesticides were detected more often in surface waters, where the concentrations were also higher. The concentrations of organophosphorus pesticides in spring, and organochlorine pesticides in fall season were higher. The high occurrences and detection of degradation products of chlorinated pesticides clearly indicate their intense use before 1980s. It is shown that, in Kumluca environment, degradation of these pesticides mostly occurs in surface waters. It is observed that agricultural activities affect water quality in the region. The total concentration limit (500ng/L) was exceeded for 27% of surface and 14% of ground water samples, at least once in both seasons. The legal limit for a single pesticide (100ng/L) was exceeded by 32 % of surface, 24 % of ground water samples.
5

Hodnocení vlivu krajinné struktury na znečištění povrchových vod v CHKO Křivoklátsko s využitím ArcSWAT / Impact assessment of landscape structure on surface water pollution in Krivoklatsko protected area using ArcSWAT

Hanzlová, Markéta January 2018 (has links)
The topic of thesis deals with a hydrological model SWAT used for impact assessment of landscape structure on surface water pollution in Krivoklatsko protected area. For this purpose using ArcSWAT in the ArcGIS environment there were built hydrological models of three watersheds of various landscape structure located in the area of interest. The measured data of nitrate were used for these models. Concentration of nitrates in the surface waters were simulated by using these models in the period from 2003 until mid-2014. The statistical evaluation of the models including actual landscape structure did not show satisfactory match of the simulated values with the measured values. Due to the uncertainties of the model, including insufficient quantity of measured nitrates, it was not possible to expect exact results. After validation of basic models, it was important to create new models that would include various scenarios of landscape structure organization. New versions represented changes in the use of land classified as arable land in pasture or mixed forests, in the area around the stream to 250 m and 500 m. Modelling of the impact of individual scenarios on the structure of the landscape structure on nitrate concentrations there was displayed a positive effect of grassing and afforestation of...
6

Razvoj inovativne optičke senzorske tehnologije za hemijsku analizu neorganskih polutanata u akvatičnom medijumu / Development of innovative optic sensor technology for chemical analysis of inorganic pollutants in aquatic medium

Obrovski Boris 03 July 2020 (has links)
<p>Osnovni cilj teze bio je razvoj nove i inovativne senzorske metode za merenje neorganskih parametara u površinskim vodama i vodama zatvorenih bazena. Kolorimetriski fiber-optički senzor (KFOS) je osposobljen za merenje pet parametara u površinskoj vodi (ortofosfata, ukupnog hlora, hroma (VI), nitrita i sulfata) i za merenje dva parametra u bazenskim vodama (rezidualnog hlora i ukupnog hlora). Pored prilagođavanja nove metode urađena je i analiza kvaliteta reke Dunav u Novom Sadu na osnovu čega su odabrani parametri za merenje sa KFOS metodom.</p> / <p>The main goal of the thesis was to develop a new and innovative sensor method for measuring inorganic parameters in surface waters and waters of indoor pools. The Colorimetric Fiber Optic Sensor (CFOS) is capable for measuring five parameters in surface water (orthophosphate, total chlorine, chromium (VI), nitrite and sulfate) and for measuring two parameters in pool water (residual chlorine and total chlorine). In addition to adjusting the new method, an analysis of the quality of the Danube River in Novi Sad was performed and based on which parameters for measuring with the KFOS method were selected.</p>
7

Increased leaching of metals as a result of foundation work / Ökad urlakning av metaller till följd av grundläggningsarbete

Mattisson, Emmy January 2018 (has links)
Heavy metal contamination in the environment is a global issue that is likely to increase in the future. This report investigates a construction area in which increased concentrations of the heavy metals cadmium, cobalt, copper, nickel and zinc and a decreased pH-value has been observed in the surface water recipient. The focus is on assessing contamination characteristics and identifying suitable remediation methods to avoid a river protected by environmental quality standards further downstream from getting contaminated. The bedrock in the area is sulphide containing and releases acidic leachate when oxidising, which is assumed to have occurred due to plane blasting and filling of residual rock. The contamination characteristics were assessed with the statistical methods modified double mass analysis and principal components analysis. A water balance was established to obtain the flowrates, discharge volumes and to determine the masses of the released metals in the surface water. Identification of suitable remediation methods was performed through a literature study of available remediation methods and using the findings of the assessments as basis. The results showed that there was a significant increase in metal concentrations and decrease in pH-value roughly around the same time as blasting and filling of residual rocks in the area was begun and that there were elevated levels of sulphide and sulphur, but they could not be specifically linked to any media. The yearly masses of metals released from the area into the surface water were between 77-98 % higher than allowed by the established guidelines. By separating the water assumed to carry the majority of the contaminants from the remaining natural water in the watershed, the volume that needs to be treated can be halved. As the contamination is so extensive, a mixture of remediation methods was proposed, including installing green roofs to decrease the runoff from the area, confining the crushed rock with bentonite and installing a filter for fast, efficient reduction. For long-term remediation, it is suggested to optimise the existing sedimentation basins and wetlands. The conclusions were that it will be very expensive to remediate the contamination, due to the extent and magnitude, and that handling sulphide containing bedrock for construction purposes should be legally regulated in order to avoid negative environmental and economic impacts. / Förorening av tungmetaller i naturen är ett globalt problem som troligtvis kommer öka i framtiden. Den här rapporten undersöker en byggarbetsplats där ökade koncentrationer av metallerna kadmium, kobolt, koppar, nickel och zink samt ett minskat pH-värde har observerats i ytvattenrecipienten. Fokus ligger på att analysera föroreningskaraktärer och identifiera lämpliga åtgärdsmetoder för att undvika att en å nedströms som är skyddad av miljökvalitetsnormer ska förorenas. Berggrunden i området är sulfidförande och släpper ut surt lakvatten när den oxiderar, vilket är antaget har hänt till följd av plansprängning och utfyllnad av överblivet bergmaterial. Föroreningskaraktärerna analyserades med de statistiska metoderna modified double mass analysis och principalkomponentsanalys. En vattenbalans etablerades för att ta fram flöden, volymer och för att bestämma massorna av de frigjorda metallerna i ytvattnet. Identifiering av lämpliga åtgärdsmetoder gjordes med en litteraturstudie av tillgängliga metoder som grund. Resultaten visade att det är en signifikant ökning av metallkoncentrationer och minskning i pH-värde runt samma tid som sprängning och utfyllning av bergmaterial påbörjades samt att det är förhöjda halter av sulfid och svavel, men de kunde inte bli associerade med ett specifikt media. De årliga massorna av frigjorda metaller som släpps ut från området i ytvattnet är mellan 77-98 % högre än tillåtet av de etablerade riktlinjerna. Genom att separera vattnet som kan antas innehålla majoriteten av föroreningarna från det naturliga vattenflödet i avrinningsområdet kan volymen som behöver renas halveras. Eftersom föroreningen är så omfattande föreslås en kombination av åtgärdsmetoder; installation av gröna tak för att minska avrinningen från området, inneslutning av utfyllnadsmaterialet med bentonit och installation av ett filter för snabb, effektiv reduktion. För mer långsiktig rening föreslås det att optimera de existerande sedimentationsdammarna och våtmarken. Slutsatsen är att det kommer bli väldigt dyrt att åtgärda föroreningen på grund av dess omfattning, och hantering av sulfidförande berg för exploateringssyfte borde vara lagstadgat för att undvika miljömässiga och ekonomiska kostnader.
8

DEVELOPMENT OF A CHEMICAL FINGERPRINT FOR DETECTING UNTREATED HUMAN SEWAGE POLLUTION IN SURFACE WATER

Pais Goyache, Irene January 2015 (has links)
Untreated human sewage pollution in surface water is of concern because it contributes to the degradation of aquatic ecosystems and it could be a potential hazard to human health. Also, any pollution of surface water, which ultimately supplies drinking water, may affect the drinking water quality. Improper operation and maintenance of separate storm sewer systems are prominent contributors of untreated sewage to source waters, resulting from illicit connections, leakage of sewers, or cross-connections. This thesis studied anthropogenic markers to track untreated sewage in an urban watershed with separate storm sewer system, under dry weather conditions. The main feature of these chemical markers is their degradation behavior at municipal wastewater treatment plants: some markers are completely removed (labile markers), whereas others show only partial or no removal at all (conservative markers). A set of ubiquitous chemical markers with practical analytical detection limits was selected to exploit the labile vs conservative distinction, and determine if untreated human sewage was discharged from stormwater outfalls. The presence of labile markers alone was not enough to confirm the occurrence of untreated sewage in stormwater outfalls. The concentration ratios between labile and conservative markers from several chemical groups (pharmaceuticals and personal care products, over-the-counter medications, artificial sweeteners, and human metabolites) created a chemical fingerprint of untreated sewage, and it was statistically demonstrated to track untreated human sewage in local stormwater outfalls. / Civil Engineering
9

The Detection of Amazonian Manatees (Trichechus inunguis) Using Side-Scan Sonar and the Effect of Oil Activities on Their Habitats in Eastern Ecuador

Brice, Caitlin E. 01 May 2014 (has links)
Substantial hunting pressure and habitat destruction caused by oil extraction has critically endangered the Amazonian manatee in Ecuador. The current population status is unknown because an effective method to observe them in the wild has yet to be developed. This study explored whether the Amazonian manatee persists or has been extirpated in the eastern Ecuadorian Amazon utilizing side-scan sonar to increase odds of detection. Spatial differences in probability of detection were quantified if manatees were observed. The level of chemical contamination was determined and compared spatially and temporally against historical data. Data were collected using opportunistic transect surveys and grab sampling of surface water in Yasuni National Park, Lagartococha, and Cuyabeno Wildlife Reserve. Surveys confirmed that the manatee population is extant. Manatees were encountered more often in Cuyabeno Wildlife Reserve than in Lagartococha and Yasuni. Side-scan sonar detected more manatees than previously reported in 1996-1999. Side-scan sonar is a viable method for detection of manatees in the Ecuadorian Amazon system and resulted in greater detection as a function of effort. All future population studies should incorporate side-scan sonar. Lead, arsenic, mercury, polynuclear aromatic hydrocarbons [PAHs], and volatile organic compounds [VOCs] were not detected in the waters of the study region. High total petroleum hydrocarbon [TPH] levels were measured in 7 samples from Yasuni National Park. The concentrations of TPH were higher in Yasuni National Park than in Lagartococha and Cuyabeno. TPHs were detected only in the study region with a recent oil spill; there was no evidence that TPHs were higher near oil production wells and pipelines. The concentrations of TPH were significantly different than those measured in 1998 (z =3.01710, p=0.0026). A dedicated study should be performed to develop a protocol for monitoring persistent oil contaminants in the Ecuadorian Amazon and determine their sink.
10

Gewässerbelastung mit endokrin wirksamen Substanzen

Levy, Gregor 21 March 2005 (has links)
In der vorliegenden Arbeit wurde untersucht, inwieweit die Reproduktionsbiologie von aquatischen Lebewesen durch die Gewässerbelastung mit endokrin wirksamen Substanzen (endocrine disruptors, ED) beeinflusst wird. Mit dem Amphib Xenopus laevis steht ein etabliertes Studienmodell zur Untersuchung der Wirkungen von ED auf die Reproduktionsbiologie zur Verfügung, das für die vorliegenden Studien modifiziert und erweitert sowie mit gewässeranalytischen Methoden verknüpft wurde. Die Gefährdung wasserlebender Tiere durch Gewässerbelastung mit ED kann erfasst werden, indem die Wirkung einer ausgewählten Einzelsubstanz auf die Reproduktionsbiologie untersucht wird. Anschließend erfolgt ein Nachweis der Substanz in Umweltproben. Durch Expositionsversuche, histologische Untersuchungen und Expressionsnachweis eines molekularen östrogenen Biomarkers konnte festgestellt werden, dass Bisphenol A (BPA) in Kaulquappen von Xenopus laevis verweiblichend wirkt und seine Effekte über eine Bindung an den Östrogenrezeptor vermittelt. Chemische Analysen während der Expositionsversuche zeigten, dass BPA von den Kaulquappen aufgenommen wird und dass eine geringe Abbaubarkeit der Substanz während eines Zeitraums von 48 Stunden besteht. Die Analyse von BPA in Wasserproben, die aus dem Fluss Alb oder aus Kläranlagenausläufen stammten, zeigte, dass BPA im Gewässer in relevanten Konzentrationen vorhanden ist und hauptsächlich durch eine Kläranlage in den Fluss eingeleitet wird. In einem Gewässer liegt allerdings ein Gemisch aus unterschiedlichen ED mit verschiedenen Wirkmechanismen vor. Die Gewässerbelastung mit endokrin wirksamen Substanzen kann weiterhin untersucht werden, indem Gewässerextrakte fraktioniert und in in vitro-Screeningmethoden getestet werden. Als Screeningmethoden dienten Rezeptorbindungsstudien an Östrogen- und Androgenrezeptoren sowie die Behandlung von Leberzellkulturen mit den Gewässerextrakten aus der Alb, um eine Regulation der Expression bestimmter Biomarkergene durch potenzielle ED nachzuweisen. Dazu wurde als neuer (anti)androgener und (anti)östrogener Biomarker das Retinol-binding Protein eingeführt. Die Untersuchung der Gewässerextrakte mit diesen Methoden zeigte, dass die Alb eine Belastung mit endokrin wirksamen Substanzen aufweist und dass hauptsächlich östrogen wirksame Substanzen vorkommen. Die Proben aus den Kläranlagenausläufen weisen die höchste endokrine Aktivität auf. / The present study examined the influence of endocrine active compounds (endocrine disruptors, ED), which are present in surface waters, on reproductive biology of aquatic organisms. The amphibian Xenopus laevis is a well-established model organism for the study of effects of ED on reproduction. It has been modified and broadened for the purpose of this study, and it was combined with chemical methods for water analyses. It is possible to assess water pollution with ED by detecting effects on repro-ductive biology of one particular substance, and then by looking for this substance in environmental water samples. We showed the feminizing potency of Bisphenol A (BPA) in conducting exposure experiments with tadpoles, in examining histological samples of gonads and in detecting the induction of the expression of a molecular estrogenic biomarker. BPA was recognized to mediate its effects via binding to the estrogen receptor. Moreover, analysis of BPA during exposure experiments revealed that BPA is taken up by tadpoles and is not readily degradable during a time period of 48 hours. Chemical analyses of environmental water samples from the river Alb or samples from sewage treatment works (STW) showed that BPA is released into the environment by STW effluents. In surface waters, there are different kinds of ED with different modes of action. Thus, it is another possibility to assess water pollution with ED by fractionating environmental water samples and by testing these fractions in rapid in vitro-screening methods. In the present work, receptor binding assays were carried out, both examining the binding to estrogen and androgen receptors. Furthermore, Xenopus laevis hepatocyte cultures were treated with fractions of environmental samples and biomarker expression was detected. A new biomarker to assess (anti)androgenic or (anti)estrogenic modes of action, respectively, was established. This new biomarker was the Retinol-binding Protein. The results obtained by these methods revealed that the river Alb is mainly polluted with estrogenic ED. Samples from STW effluents possessed the highest endocrine activity.

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