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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.
311

Comportamento de filtros rápidos de camada profunda no tratamento de águas de abastecimento mediante o emprego de polímeros como auxiliares de filtração. / Behavior of deep bed rapid filters treating public water supplies through the use of polymers as filter aids.

Sergio Brasil Abreu 26 June 2009 (has links)
O projeto consistiu em avaliar o emprego de polímeros catiônicos e aniônicos de diferentes pesos moleculares como auxiliares de filtração no tratamento de águas de abastecimento proveniente de mananciais com alto grau de eutrofização com vistas a possibilitar a otimização da remoção de material particulado e minimização da evolução da perda de carga. O aparato experimental é composto, principalmente, por 4 filtros em escala piloto de alta taxa do tipo camada profunda e fluxo descendente por gravidade operados em paralelo. Os filtros possuem 5 m de altura e diâmetro interno de 150 mm. O procedimento experimental foi dividido em três etapas, execução de ensaios de fluidificação e expansão do leito dos filtros e utilização de polímeros catiônicos e de polímero aniônico como auxiliares de filtração. A primeira etapa teve como objetivo definir parâmetros de dimensionamento do sistema de lavagem em contra-corrente com ar e água e nas duas etapas seguintes foram realizados os ensaios de filtração a uma taxa de 500 m³/m²/dia, com a utilização dos polímeros com três dosagens diferentes. Os polímeros utilizados foram CA-2577, CA-2581, CD-2592 e N1986. Estes possuem estrutura e pesos moleculares variáveis, de forma que o trabalho tivesse uma maior amplitude. Os valores médios de turbidez, para a primeira etapa dos ensaios de filtração, foram de 2,36 ± 0,28 UNT e 1,12 ± 0,21 UNT para água bruta e decantada, respectivamente, 0,26 ± 0,07 UNT para o filtro F1 com antracito, 0,25 ± 0,08 UNT para o filtro F3 com antracito e adição de polímero, 0,29 ± 0,08 UNT para o filtro F2 com areia e 0,26 ± 0,08 UNT para o filtro F4 com areia e adição de polímero. Para a segunda etapa dos ensaios de filtração os valores médios de turbidez foram de 2,03 ± 0,36 UNT para água bruta, 0,80 ± 0,21 UNT para água decantada, 0,09 ± 0,03 UNT para o filtro F1, sem adição de polímero, e 0,15 ± 0,04, 0,16 ± 0,03 e 0,10 ± 0,04 UNT para os filtros F2, F3 e F4, respectivamente, todos com adição de polímero. Os resultados experimentais possibilitaram concluir que a adoção do antracito como material filtrante do tipo camada única e profunda apresenta a vantagem de permitir uma menor velocidade ascensional de água de lavagem para uma determinada expansão quando comparado a um filtro de areia de idêntica granulometria. A aplicação dos polímeros catiônicos e do polímero aniônico como auxiliares de filtração não proporcionou para nenhuma dosagem utilizada melhora significativa no comportamento dos filtros. Uma eventual melhora ou piora foi insignificante e estava ligada à qualidade da água decantada. No que diz respeito à perda de carga, os filtros com antracito tiveram carreiras de filtração mais longas quando comparados com os de areia, independente da utilização dos polímeros. / The project was to evaluate the use of anionic and cationic polymers of different molecular weights as filter aids to treat drinking water treatment of surface water sources with high degree of eutrophication, particularly with regard to particulate matter removal optimization and head loss rate minimization. The experimental apparatus was composed of four pilot scale, deep bed, down flow rapid gravity filters, operated in parallel. The filter columns were 5 m high, had inner diameter of 150 mm. The experimental procedure was divided in three stages, conduction of media fluidization and media expansion tests and cationic and anionic polymers application as filter aid. The first stage aims was to define design parameters for the filter backwashing system with water and air and in the two next phases the tests were conducted at a filtration rate of 500 m³/m²/day, with the use of polymers with three different dosages. The polymers tested were CA- 2577, CA-2581, CD-2592 and N1986. They have different structure and molecular weights, thus making wider the array of possibilities tested. The average values of turbidity, for the first stage of testing filtration, were 2.36 ± 0.28 and 1.12 ± 0.21 NTU for raw and settled water, respectively, 0.26 ± 0.07 NTU to the filter F1 with anthracite, 0.25 ± 0.08 NTU for the filter F3 with anthracite and addition of polymer, 0.29 ± 0.08 NTU for the filter F2 with sand and 0.26 ± 0.08 NTU for the filter F4 with sand and the addition of polymer. For the second stage of testing of the filter values of turbidity were 2.03 ± 0.36 NTU for raw water, 0.80 ± 0.21 NTU for settled water, 0.09 ± 0.03 for the filter F1, without the addition of polymer, and 0.15 ± 0.04, 0.16 ± 0.03 and 0.10 ± 0.04 NTU for filters F2, F3 and F4, respectively, all with the addition of polymer. The experimental results led us to conclusion that the adoption of anthracite as single media in deep bed filtration presents the advantage of a lower ascent backwash water velocity for any given bed expansion as compared to deep bed filtration through sand with the same granulometric characteristic. Application of cationic and anionic polymers as filter aids did not lead to any significant improvement in the behavior of pilot scale filters, regardless of applied polymer dosage. Any eventual improvement or worsening was not significant and was closely related to the settled water quality. Regarding the head loss, the filters with anthracite had longer filtration careers when compared to sand, regardless the use of polymers.
312

Ocorrência de antibióticos e estudo de resistência microbiana em sistemas aquaculturais do Rio Paraná, Reservatório de Ilha Solteira, na região de Santa Fé do Sul, estado de São Paulo / Occurrence of antibiotics and antimicrobial resistance study in aquaculture systems in Paraná River, Ilha Solteira reservoir, in Santa Fé do Sul area, Sao Paulo state

Sérgio Henrique Monteiro 06 June 2014 (has links)
A aquicultura teve um aumento significativo em todo o mundo nos últimos anos. Muitas classes de antimicrobianos são usadas na aquicultura para o tratamento de infecções causadas por bactérias patogênicas. Entretanto, a contaminação do ambiente, do alimento e a ocorrência de resistência microbiana decorrentes da intensa utilização dos antimicrobianos são motivos de preocupação. Com o objetivo de se saber a ocorrência de antimicrobianos e possíveis formação de resistência microbiana em pisciculturas paulistas, um método rápido, sensível e simples de extração em fase sólida acoplada à cromatografia líquida e espectrometria de massas sequencial (SPE-LC-MS/MS), foi desenvolvido e validado para a determinação simultânea de 12 antimicrobianos (oxitetraciclina, tetraciclina, clortetraciclina, ciprofloxacina, enrofloxacina, sarafloxacina, norfloxacina, florfenicol, cloranfenicol, sulfatizol, sulfadimetoxina e sulfametazina) em água superficial e sedimento. Outro método, utilizando LC-MS/MS, foi elaborado para a determinação dos antimicrobianos em peixes. Paralelamente, também, foi avaliada a seleção de resistência microbiana dessas classes de antimicrobianos em peixe. Os antimicrobianos foram extraídos do sedimento com acetonitrila e tampão citrato, a fase orgânica foi eliminada e a purificação do extrato realizada com cartuchos SPE Strata SAX 500 mg Phenomenex. Os extratos de sedimento e as amostras de água (sem pré-tratamento) foram injetadas em um sistema analítico, pela primeira vez utilizado no Brasil, que consistia em uma pré-concentração com um amostrador automático equipado com um loop de 900 ?L, uma válvula usada para alternar entre os modos de carregamento ou eluição, duas bombas e um sistema de MS/MS. Os extratos de peixe foram purificados por filtração utilizando cartuchos Captiva ND. Sulfadimetoxina-d6 foi utilizado como padrão interno para aferir a precisão dos resultados. Os métodos desenvolvidos foram validados baseados na decisão da União Europeia 2002/657/CE. As amostras foram coletadas de 4 pisciculturas localizadas na represa da usina hidrelétrica de Ilha Solteira, Brasil. Foram feitas 4 amostragens no período de abril de 2013 a janeiro de 2014, totalizando 144 amostras de água, 144 de sedimento e 126 amostras de peixe. Resíduos de oxitetraciclina, tetraciclina e clortetraciclina foram encontrados em sedimentos e oxitetraciclina, tetraciclina e florfenicol foram identificados nas amostras de água e peixe; à medida que aumentava a distância dos tanques e o tamanho do peixe as quantidades encontradas nas amostras diminuíam. Isolou-se bactérias resistentes a quinolonas, tetraciclinas, sulfonamidas em 36 cepas e o índice de resistência múltipla a antibióticos (MAR), variou entre 0 e 0,86, ou seja, cepas sensíveis a 100% dos antimicrobianos testados e outras resistentes a 86%. De acordo com os resultados encontrados considera-se que ações mais restritivas são necessárias quanto ao uso intensivo de antibióticos na produção de peixes / The aquiculture has had a sharp increase worldwide in the last years. Many classes of antibiotics have been used in aquaculture to treat infections caused by a number of pathogenic bacteria. However, environmental and food contamination and bacterial resistance are the main concerns arisen by these intense uses. In order to know the occurrence of antibiotics and possible antimicrobial resistance in fish farms in São Paulo, a fast, sensitive, and simple on-line solid phase extraction to liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) was developed and validated for simultaneous assessment of 12 drugs (chloramphenicol, florfenicol, oxytetracycline, tetracycline, chlortetracycline, sulfadimethoxine, sulfathiazole, sulfamethazine, enrofloxacin, ciprofloxacin, norfloxacin, and sarafloxacin) in surface water and sediment. Another method using LC-MS/MS was elaborated to determine antibiotics in fish. In parallel, the selection of antimicrobial resistance of these classes of antibiotics in fish was evaluated. The antibiotics were extracted from sediment with acetonitrile and citric buffer, the organic phase was eliminated and the clean-up was made by Strata SAX 500 mg of Phenomenex. The water phase of sediment and water samples (without pre-treatment) was injected in the analytical system, which consisted of a pre-concentration with an automated liquid sampler fitted with a 900 ?L injection loop; a valve is used to switch between the load or elution modes, a pair of pumps and a MS/MS system, it is the first time that this system is used in Brazil. The fish extracts were cleaned by filtration by Captiva cartridges. Sulfadimethoxine-d6 was used as an internal standard to obtain more reliable results. The developed method was validated based in the European Union Decision 2002/657/EC. The samples were collected from 4 fish farms located in Ilha Solteira hydroelectric dam, Brazil. Four sampling were made in the period April/2013 until January/2014, totalizing 144 samples of water and sediment and 126 fish samples. Residues of oxytetracycline, tetracycline and chlortetracycline, were found in sediment and oxytetracycline, tetracycline, and florfenicol have been identified in water and fish samples, with increasing distance from the tanks and the size of the fishs the quantities of residue found in the samples decreased. Bacteria were resistant to quinolones, tetracyclines, sulfonamides in 36 strains and the multiple antibiotic resistance index (MAR) values ranged between 0 and 0.86, that is, strains with a sensitivity of 100% to the tested antimicrobials and others resistant of 86% to the tested antimicrobials. According to the results it is believed that more stringent measures are needed concerning the intensive use of antibiotics in fish production
313

A critical investigation into the effectiveness of soil and water remediation efforts in Steel Valley, Vanderbijlpark

Ahenkorah, Emmanuel 08 1900 (has links)
Post-remediation soil, ground and surface water monitoring is essential to assess the effectiveness of remediation efforts undertaken to eliminate or minimize the risk of pollution to human health and valuable ecosystems. In that regard, comparison of pollution levels pre- and post-remediation is an effective way of evaluating the effectiveness of the remediation techniques used. Thus, this study sought to measure concentrations of pollutants in the soil, ground and surface water post remediation in Steel Valley, Vanderbijlpark and compare them to concentration levels prior to remediation, as well as compare them to internationally accepted standards with respect to risk to humans and the environment. Water samples were collected from three locations within the study site, in both the dry and rainy seasons and their physio-chemical and organic properties were tested. Soil samples were collected from six different locations within the study site and analysed for metal concentrations. The data was compared against that of the Iron and Steel Corporation (ISCOR) Vanderbijlpark Environmental Master Plan (EMP), water and soil guidelines of the World Health Organization (WHO) as well as South African water and soil guidelines. The study found that groundwater is generally safe for domestic use but Aluminium (Al), Iron (Fe) and Manganese (Mn) concentrations were above South African water quality guideline levels – with their concentrations ranging from 0.54 to 0.91 mg/L, 1.01 to 1.86 mg/L and 0.24 to 0.53 mg/L respectively. There were no traces of organic pollution in the water samples. Soil samples had levels of Al ranging from 1106 mg/kg to 1 3621 mg/kg, Mn concentrations in the range of 202.8 to 966.4 mg/kg and Fe ranging from 1 1587 to 23 201 mg/kg. Thus, water and soil at the selected sites are safe in terms of physico-chemical and organic quality. Natural attenuation should be able, over time, to further reduce the levels of parameters that are currently above the target range. Thus, there has been considerable reduction in pollutant concentrations, but as this study was limited in scope, additional research is needed to verify the results. / Environmental Sciences / M. Sc. (Environmental Science)
314

Apport de la télédétection spatiale à haute résolution pour l’étude des cycles des eaux de surface et des matières particulaires en suspension le long du continuum bassin versant – océan côtier / Contribution of high resolution spatial remote sensing for the study of surface water cycles and suspended particulate matter along the watershed-coastal ocean continuum

Normandin, Cassandra 17 September 2019 (has links)
L’anticipation et l’adaptation de nos sociétés aux bouleversements résultants du changement climatique sont aujourd’hui des questions majeures guidant les activités humaines et l’action publique. Néanmoins, la prévision reste un défi essentiel en raison des fortes incertitudes existantes et il est primordial de continuer à progresser dans la compréhension des mécanismes à l’origine de ces bouleversements. Au sein du cycle hydrologique, le réservoir de surface (incluant les lacs, les rivières et les plaines d’inondation) occupe une place importante car il est l’une des principales ressources en eau des écosystèmes et des populations. Or, la dynamique des stocks d’eau de surface est toujours mal connue aux échelles régionale et globale, du fait de l’absence de mesures pluriannuelles d’extension et de hauteur d’eau des zones inondées, et de la prise en compte limitée de ces variables dans les modèles hydrologiques et hydrodynamiques. La télédétection spatiale offre désormais la possibilité d’effectuer un suivi des stocks d’eau de surface en utilisant la complémentarité entre l’imagerie multi-spectrale, permettant de cartographier les étendues inondées, et l’altimétrie radar fournissant des séries temporelles de hauteur d’eau des hydro-systèmes continentaux. L’objectif de ma thèse est de tirer le meilleur parti de la complémentarité entre les différents types d’observations spatiales pour évaluer les ressources en eau du réservoir de surface et mesurer la dynamique des transferts d’eau des continents aux océans, et son impact sur la zone côtière en utilisant les concentrations de matières en suspension comme traceur des masses d’eau. Depuis le milieu des années 1990, la multiplication des missions multi-spectrales à moyenne résolution (< 1 km de résolution spatiale) et des altimètres radars à haute précision (comprise entre 10 et 30 cm) permet de réaliser un suivi hebdomadaire à mensuel des volumes d’eau de surface dans les grands bassins fluviaux. / The anticipation and adaptation of our societies to the upheavals resulting from climate change are today major issues guiding human activities and public action. Nevertheless, the forecast remains a key challenge because of the strong uncertainties that exist and it is essential to continue to progress in understanding the mechanisms behind these upheavals. Within the hydrological cycle, the surface reservoir (including lakes, rivers and floodplains) occupies an important place as it is one of the main water resources of ecosystems and populations. However, the dynamics of surface water stocks are still poorly known at the regional and global scales, due to the absence of multi-year measures of extension and water depth of the flooded areas, and the limited consideration of these variables in hydrological and hydrodynamic models. Satellite remote sensing now offers the possibility of monitoring surface water stocks by using the complementarity between multispectral imagery, allowing to map flooded areas, and the radar altimetry providing time series of water depths of continental hydro systems. The aim of my thesis is to make the most of the complementarity between the different types of spatial observations to evaluate the water resources of the surface reservoir and to measure the dynamics of water transfers between land and ocean, and its impact on the coastal zone using suspended particulate matter as tracer of water bodies. Since the mid-1990s, the multiplication of multispectral missions with medium resolution (<1 km of spatial resolution) and high-precision radar altimeters (between 10 and 30 cm) makes it possible to carry out weekly-to-monthly monitoring of volumes surface water in large river basins.
315

Groundwater flow and contaminant transport in an alluvial aquifer: in-situ investigation and modelling of a brownfield with strong groundwater - surface water interactions

Batlle Aguilar, Jordi 19 September 2008 (has links)
The continuous demand on new residential and economic areas of the modern society has to face up with problems posed by polluted sites related to former industrial activities, typically located in suburbs areas. These sites, known as brownfields, are often located nearby navigable rivers to facilitate transport operations of industrial manufacturing, which increase their potential environmental threat due to the possible migration of pollutants in groundwater to surface water bodies through groundwater discharge. In this context, the objective of this research, performed in the scope of the FP6-IP AquaTerra project, was to contribute to a better assessment of the risk of groundwater contaminant dispersion for a brownfield located next to the Meuse River (Belgium), in a context where strong groundwater - surface water interactions prevail. The brownfield of interest corresponds to the site of the former coke factory of Flémalle. Resulting from industrial activities, soil and groundwater located in the alluvial aquifer are heavily contaminated with various types of organic (BTEX, PAHs, mineral oils...) and inorganic (As, Zn, Cd...) pollutants. To do so, detailed characterisation campaign was performed, consisting of, on the one hand, classical field experiments such as pumping tests, injection tests and tracer experiments; on the other hand, advanced and original field experiments such as detailed monitoring of groundwater - surface water interaction and dynamics, and the development and application of an innovative tracer technique, the Finite Volume Point Dilution Method (FVPDM), used to quantify and monitor groundwater fluxes. Monitoring and field works data was subsequently used to develop and calibrate a groundwater flow model using the finite difference code MODFLOW, with an automatic parameter estimation approach based on an original combined regional scale (zonation) and local scale (pilot points) approach. A transport model was also developed using MT3DMS and calibrated using tracer experiments performed in the brownfield. This groundwater flow and transport model was used to better quantify the dynamics of groundwater - surface water interactions and to model various scenarios of contaminant dispersion through the aquifer - river system. For these scenarios, benzene was considered because it is one of the main pollutants encountered in the site, its large solubility and mobility in groundwater and its acute toxicity. These scenarios were established considering various groundwater flow conditions (steady state vs. transient) and various hydrodispersive processes possibly affecting the mobility of benzene in groundwater, namely advection, hydrodynamic dispersion, sorption - desorption and, as evidenced by the research results of the University of Neuchâtel (Switzerland), benzene degradation under sulphate reducing conditions. These simulations indicate that benzene attenuation is mainly controlled by ongoing benzene degradation processes, aquifer heterogeneity and river stage fluctuations. Based on this analysis, the risk of benzene dispersion is low, and monitored natural attenuation (MNA) is a valuable option with (1) monitoring benzene at control planes downstream from the sources; (2) further investigation on risk of sulphate depletion in the alluvial aquifer; and (3) further investigation on mobilisation/immobilisation of heavy metals related to dynamics of organic pollutant plumes.
316

Basin-scale change in water availability and water quality under intensified irrigated agriculture

Törnqvist, Rebecka January 2013 (has links)
Changes in land use and water use can greatly impact the cycling of water and water-borne substances. Increased redistribution of river water to irrigated fields can cause enhanced evapotranspiration and decreased river discharge. Additionally, the water quality can be affected by the external input of fertilisers and pesticides, and by changed pollutant transport pathways in expansive irrigation canal systems. This thesis examines basin-scale changes in water use, river discharge, water quality and nitrogen (N) loading under conditions of intensified irrigated agriculture, using the Aral Sea drainage basin (ASDB) with its two large rivers Syr Darya and Amu Darya in Central Asia as study area. Results show that more efficient irrigation techniques could reduce outtake of river water to the cotton fields in the ASDB by about 10 km3/year, while the corresponding river water saving at the outlet would be 60% lower. The result illustrates the importance of accounting for return flows of irrigation water in basin-scale water saving assessments. Moreover, a decrease in riverine N concentrations at the outlet of the Amu Darya River Basin (ADRB) was observed during a 40-year period of increasing N fertiliser input. The decrease was identified to be primarily caused by increased recirculation of river water in the irrigation system, leading to increased flow-path lengths and enhanced N attenuation. Decreasing N loads were shown to be primarily related to reduced discharge. N export from the basin may further decrease due to projected discharge reductions related to climate change. Furthermore, nutrients and metals were occasionally found at concentrations above drinking water guideline values in surface waters in the ADRB. However, metal concentrations in groundwater in the lower ADRB were subject to orders of magnitude higher health hazards. Projected decrease in downstream surface water availability would thus imply decreased access to water suitable for drinking. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 4: Submitted. Paper 5: Manuscript.</p>
317

An Evaluation of Current Practices in Seepage Control

Boyer, D. G., Cluff, C. B. 06 May 1972 (has links)
From the Proceedings of the 1972 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - May 5-6, 1972, Prescott, Arizona / The need for increased control of seepage from both natural and artificial small ponds and lakes has become more apparent with the increased frequency of their construction and use on the farm, ranch, and in recreational urban use. Seepage control methods are also becoming more numerous. Unfortunately, comparisons as to effectiveness, longevity and costs are not readily available. This paper investigates some control techniques being used in this region and evaluated them according to the above criteria. Emphasis was on the use of available physiochemical methods other than rubber membranes and concrete liners. Examples of the types of controls in use include plastic, soil compaction aids, hydrophobic chemicals and monovalent cation applications, such as sodium chloride. Some examples of the use of these methods in Arizona are shown and the results of some field comparison tests conducted using 8 x 8 square foot double -ringed infiltrometers presented. Recommendations are made of additional research that should be undertaken to improve the technology of the control of seepage losses.
318

River-Aquifer Interaction in the Uppsala Esker - a Modelling Study of a Proposed Drinking Water Production site / Modellering av flödessamband mellan Uppsalaåsen och Dalälven norr om Älvkarleby, Sverige

Kjellander, Kalle January 2018 (has links)
The Swedish municipalities of Gävle and Älvkarleby need new sources of drinking water as the population grows. Gästrike vatten AB has employed the consultant firm Midvatten AB to assess the possibility of a new groundwater extraction site on the Uppsala esker between Älvkarleby and Skutskär in northern Uppland county. It has been observed that the natural recharge to the aquifer in the Uppsala esker might be too low to compensate for a future groundwater extraction and that there is a risk of induced infiltration from the river Dalälven if the water table is lowered. River water might bring organic contaminants into the aquifer and negatively affect the groundwater quality.A solution proposed by Midvatten is to infiltrate the esker with river water free from organic contaminants at infiltration sites. This artificial infiltration is estimated to create new groundwater to compensate for the extraction and stop river water from reaching the extraction wells. There is however, a need to estimate the magnitude of infiltrating river water when the infiltration sites are active.The aim of this study was to estimate the flow of water between the river and a section of the Uppsala esker for a test period during 2017, specifically, the infiltration from the river. In addition to this, changes in flow depending on proposed pumping and infiltration scenarios were modelled.A MODFLOW model was developed in the graphical user interface Groundwater Modeling System (GMS) and its performance was validated against observed aquifer head. The model could accurately represent the head close to the river but was less accurate with increasing distance from the river. Average infiltration from the river varied from 3 to 25 l s-1. The calculated infiltration depended on which extraction well or artificial infiltration site was active and the rate of flow.It was concluded that the distribution of hydraulic conductivity in the aquifer was not sufficiently detailed. A solution could have been to use stratigraphic data from borehole logs instead of a general quaternary deposits map as basis for the distribution of hydraulic conductivity. Artificial infiltration close to the river prevented large volumes of induced infiltration. The accuracy of the model could have been improved if the results were compared to other methods such as particle-tracking, tracer tests and with measurements of the streambed such as seepage meters. / Gävle och Älvkarlebys kommuner är i behov av nya grundvattentäkter för att kunna försörja invånarna med dricksvatten i framtiden. Ett område som är av intresse för de två kommunerna är ett grundvattenmagasin i Uppsalaåsen intill Dalälven mellan Älvkarleby och Skutskär. Vid ett dricksvattenuttag kan vattenbalansen i magasinet ändras. I magasinet uppskattas grundvattenbildningen vara för låg för att pumpa upp nog mycket vatten och bibehålla en stabil dricksvattenförsörjning. När uttaget av grundvatten är högre än grundvattenbildningen sänks grundvattenytan och vatten flödar från andra delar av magasinet eller älven för att kompensera. Älvvattnet bedöms ha en stark hydraulisk koppling med grundvattnet, vilket innebär att det finns en risk att älvvattnet infiltrerar i magasinet och sänker kvalitén på framtida dricksvatten.Konsultföretaget Midvatten AB har i uppdrag att bedöma möjligheten till ett framtida dricksvattenuttag. Midvatten har som lösning anlagt stationer med sprinklerinfiltration för att i framtiden kunna infiltrera avhumifierat älvvatten som på sikt omvandlas till grundvatten. Denna konstgjorda infiltration är också tänkt att hindra älvvatten från att ta sig in i magasinet genom att förse magasinet med den mängd vatten som går förlorad av dricksvattenuttag. Hur mycket älvvatten som tar sig in till grundvattenmagasinet och når brunnarna vid ett framtida uttag och konstgjord infiltration, är dock oklart.Syftet med denna studie var att uppskatta flödet mellan åsens grundvattenmagasin och Dalälven och specifikt infiltrationen av älvvatten. Detta gjordes genom att utveckla en digital MODFLOW-flödesmodell i programmet GMS. Modellen kunde, med hjälp av uppmätta vattennivåer i grundvattenmagasinet och älven, räkna ut hur mycket vatten som flödade in från älven (infiltrerade). Den uträknade infiltrationen låg i genomsnitt på 3-25 l s-1. Infiltrationsmängden berodde på vilken brunn som vattnet pumpades ur, hur mycket som pumpades ut och hur mycket artificiell infiltration som tillfördes i de tre infiltrationsområdena under en period av 2017. Modellen användes även till att uppskatta flödet från älven för 28 tilltänkta scenarier under 2017 med konstant pumpning och konstgjord infiltration i de olika brunnarna och infiltrationsstationerna.Resultaten visade att modellen kunde uppskatta grundvattenmagasinets vattennivåer nära älven men inte på längre avstånd ifrån älven. Detta berodde på att magasinets hydrauliska parametrar inte var korrekt fördelade. Fördelningen kunde ha förbättrats om de baserats på jordarter från borrprotokoll istället för en jordartskarta. Modellen visade att mycket lite älvvatten flödar in i akviferen om vatten artificiellt infiltreras nära älven. För att resultaten av den här studien ska bli tillförlitliga krävs det att resultaten jämförs med andra metoder som använder sig av förslagsvis partikelspårningsmodeller, spårämnesstudier eller flödesmätningar av flodbädden.
319

Investigation of selected organic compounds on water quality along the Olifants river catchment

Mulanga, Tshimanga Christelle 06 1900 (has links)
Water is a crucial natural resource, indispensable to food production, life, the environment, power generation, industry, sanitation and hygiene. The presence of Organochlorine Pesticides (OCPs) in the environment is not wanted due to their negative effects on human beings and animals. As a result, there is a need to continuously monitor their presence in the environment. In this study, surface water samples were collected once a month during the dry season and during wet season from the selected five points along the Olifants River and stored at a temperature of < 50C before analysis. The OCPs were extracted with dichloromethane (DCM) using the Liquid-Liquid Extraction (LLE) method. After undertaking the sample through the clean- up process, the crude extracts obtained were put into the column chromatography and eluted with hexane, about 1.5 μL of the purified extracts were analysed by the Gas Chromatographic- Mass Spectrophotometer (GC/MS). The percentage recoveries, varied from 32- 116 % for p, p’-DDT and 4,4'-DDD respectively in triply spiked water samples. The standard deviation for most of the compounds is less than±0.04, with the exclusion of Heptachlor (±0.14). The seasonal variability of OCPs in water samples along Olifants River results show that in dry season, the Olifants River is mostly polluted at the Oxford site with (BHC-beta, Aldrin, Heptachlor-epoxide, Endosulfan-alpha and Endrin), at the Ga- Selati site with (Heptachlor-epoxide and Endrin) and at the Wolvekrans site with (Endosulfan-alpha), with Aldrin up to 834.20 ng/ L indicating the highest hazard toward the aquatic environment while in summer the Olifants River is mostly polluted at the Ga- selati site with BHC-beta and at the Waterval site with (Heptachlor and BHC-gamma) with BHC- gamma up to 560 ng/ L indicating the highest hazard toward the aquatic environment. The levels reached from the Olifants River catchment were meaningfully above the drinking water quality guidelines for organic chemical recommended by WHO, 2006 i.e. (BHC-gamma,DDT-44, Aldrin, dieldrin and Endrin are (2.0,1.0,0.03,0.03 and 0.6) respectively for the protection of the domestic use, aquatic ecology and agricultural use (irrigation and livestock watering) for compounds with local guideline values; while, the international water quality guidelines to protect the aquatic ecosystems are 0.00083 ng/mℓ (4,4’DDD), 0.00059 ng/mL (4,4’DDE), (4,4’DDT), 0.00021 ng/mL (heptachlor), 0.0092 ng/mℓ (α-HCH), 0.0186 ng/mL (γ- HCH), and chronic values are 0.056 ng/mL (ENDO I and II) and 0.0023 ng/mL endrin) (USEPA, 2002). Levels detected were significantly higher than some research studies conducted up to now in South African aquatic environments. These results confirm the contamination of the Olifants River catchment by the OCPs. / Water and Sanitation / M. Sc. (Environmental Science)
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Implementering av miljökvalitetsnormer för vatten i samband med miljökonsekvensbeskrivning / Implementation of Environmental Quality Standars for Water in Connection with Environmental Impact Assessment

Österberg, Nicole January 2018 (has links)
EU:s ramdirektiv för vatten kom år 2000 och har som uppgift att förbättra vattenkvaliteten inom unionen. Direktivet är rättsligt bindande för medlemsstaterna och har målet att samtliga vattenförekomster i EU ska nå minst god status. I arbetet med vattenförvaltningen används begreppen statusklassificering, som är ett mått på rådande vattenkvalitet i vattenförekomsten, och miljökvalitetsnormer, som den vattenkvaliteten vattenförekomsten ska ha vid en viss tidpunkt. Statusklassificeringen består av ekologisk och kemisk status. Ekologisk status bedöms utifrån kvalitetsfaktorer (exempelvis växtplankton, näringsämnen), som bedöms av parametrar (exempelvis biovolym, total fosfor), och kemisk status utifrån EU bestämda gränsvärden för prioriterade ämnen. 2015 kom Weserdomen, som är ett förhandsavgörande från EU-domstolen om tolkning av ramdirektivet för vatten, rörande medlemsstaternas skyldighet att inte lämna tillstånd till projekt som orsakar en försämring av status eller äventyrar miljökvalitetsnormen samt innebörden att en försämring av status föreligger då en kvalitetsfaktor ändras en statusklass. Weserdomen har förändrat rättsläget för miljökvalitetsnormerna och har i Sverige skapat stora osäkerheter vid tillstånd och miljökonsekvensbeskrivning (MKB), med behov av att på sikt förändra lagstiftningen. Syftet med examensarbete är att studera hur Mark- och miljööverdomstolen hanterat Weserdomen vid prövning samt hur miljökvalitetsnormerna för ytvatten bör hanteras i MKB för projekt. För att undersöka detta genomfördes en litteraturstudie, en rättsfallsstudie av Mark- och miljööverdomstolens domar samt en studie av detaljnivån på redovisningen av miljökvalitetsnormerna i MKB för projekt. Litteraturstudien visar att Weserdomen innebär ett skärpt rättsläge för miljökvalitetsnormerna, att ekologisk status har fått samma rättsverkan som kemisk status samt att svensk lagstiftning behöver anpassas till det nya rättsläget. Rättsfallsstudien visade att miljökvalitetsnormerna fått en viktig roll i tillståndsprövning och att bedömning av påverkan ska göras utifrån kvalitetsfaktorer och har stor betydelse vid prövning. Utifrån studien över detaljnivån i MKB ställs större krav på redovisning av påverkan på kvalitetsfaktornivå. Dock finns utrymme att förbättra motiveringen av relevanta och icke-relevanta kvalitetsfaktorer. / The EU Water Framework Directive came in the year 2000 and its aim is to improve the water quality within the union. The directive is legally binding for all member states and sets out to achieve good status for Europe’s all water bodies. In the work of water management are the following two terms commonly used, the concept of status classification, a measure of the water quality in a water body, and Environmental Quality Standards (EQS), the time when a certain water quality should be reached. The status classification consists of ecological quality and chemical quality. Ecological quality is assessed based on quality factors (e.g. phytoplankton, nutrients), which are assessed based on parameters (e.g. biovolume, total phosphorus), and chemical quality is assessed from an EU-defined limit value. In 2015 came the Weser ruling, a preliminary ruling by the European Court of Justice regarding interpretations in the Water Framework Directive. The Court found that the member states are required to not give permission to a project that could cause a deterioration of status or jeopardize current environmental quality standard in a water body. Regarding the interpretation of when a “deterioration of status” occurs, the Court found that it occurs when a quality factor is lowered by one statues class. The Weser ruling has changed the legal situation around the environmental quality standards, which in Sweden has led to major uncertainties among authorizations and Environmental Impact Assessment (EIA). In Sweden, an adjustment of the law is considered needed. This master thesis main purpose is to study how the Land and Environment Court of Appeal has dealt with the Weser ruling in trial and how Environmental Quality Standards for surface water should be managed in EIA for projects. The thesis consists of a literature study, a study of cases in the Land and Environment Court of Appeal and a study of the presentation of Environmental Quality Standards in EIA in projects. The study shows that the Weser ruling leads to a stronger interpretation of the Environmental Quality Standards, gives the ecological statuses the same legal value as chemical statues and lead to a need for adaption of the Swedish legalization to the new legal position. The case study shows that Environmental Quality Standards plays an important role during trial and that the impact assessment should be done on at the level of quality factors and is of great importance for the trial. The study of presentation in EIA shows higher demands on impact assessment at the level of quality factors, but still has room for improved motivation of relevant and non-relevant quality factors.

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