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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.
261

État de la contamination des eaux du département de la Dordogne par les résidus de médicaments / State of water contamination by pharmaceutical compounds in the french area of Dordogne

Idder, Salima 11 December 2012 (has links)
Le début du 21e siècle a vu naître un intérêt croissant pour la problématique des résidus de médicaments dans les milieux aquatiques. L’apparition de nouvelles technologies analytiques permettant la détection et la quantification de molécules à l’état d’ultra-traces a fortement contribué à cette expansion. Ces améliorations technologiques ont permis la recherche et la quantification de nombreux xénobiotiques dans les différents compartiments aquatiques. Depuis une quinzaine d’années, l’attention des équipes de recherche s’est ainsi portée sur les résidus de médicaments à usage humain ou vétérinaire. La faune et la flore aquatiques sont ainsi exposées à des mélanges de composés certes à très faibles doses (souvent de l’ordre de quelques ng à quelques centaines de ng) mais en continu et les effets de cette exposition sont très peu documentés. Ces contaminants font partie des polluants émergents et il n’existe actuellement pasde réglementation en Europe concernant leur présence dans l’environnement. La contamination des milieux aquatiques par les résidus de médicaments à usage humain est souvent le signe d’une urbanisation importante et les cours d’eau soumis à de fortes pressions domestiques sont des sitesd’étude privilégiés. Néanmoins, les données concernant les milieux ruraux sont encoreparcellaires bien qu’ils représentent les quatre cinquièmes du territoire français. Les travaux de cette thèse ont pour objectif premier d’établir un état des lieux des ressources en eau d’un territoire à dominante rurale, le département de la Dordogne. Pour répondre à cette problématique, la recherche de résidus de médicaments s'est orientée sur une liste de 40 molécules comprenant des hypolipidémiants, des antibiotiques, des béta-bloquants, des anti-inflammatoires non stéroïdiens, des anticancéreux, etc. Une méthode chromatographique multi-résidus (pré-concentration en ligne - LC-MS/MS) a été développée et validée pour les eaux de surface. En accord avec la Directive européenne Cadre sur l'Eau (DCE), des sites ont été échantillonnés tous les mois pendant un an (2011) sur six cours d'eau majeurs du département de la Dordogne de manière à déterminer leur état écologique (physico-chimique et biologique).Parallèlement, la caractérisation des résidus de médicaments a été réalisée sur ces mêmes échantillons. Les différentes campagnes de mesure ont permis d'identifier les principales zones impactées par les composés pharmaceutiques et ont également montré des corrélations linéaires avec d'autres paramètres (ions ammonium, phosphore, etc.).Suite aux premiers résultats obtenus lors de l'état des lieux du département de laDordogne, une étude complémentaire focalisée sur la présence des résidus de médicaments dansl'Isle a été menée en parallèle. Elle a permis de caractériser les voies d’introduction des résidus de médicaments et mieux comprendre l’impact de la ville de Périgueux sur l’Isle. Ainsi, un des objectifs a été de caractériser la présence de composés pharmaceutiques dans cette rivière et de comprendre l’origine de ces molécules par l’identification des effluents domestiques des stationsd’épuration présentes dans la zone urbaine. / The beginning of the 21th century saw a growing interest for pharmaceuticals in aquaticsystems. The development of new analytical technologies allowing detection and quantification ofcompounds at ultra-trace levels mostly contributed to this expansion. These technologicalimprovements allowed to evidence and quantify many xenobiotics in various aquaticcompartments. Since about fifteen years, research teams focused their attention to human orveterinary pharmaceuticals. These contaminants are among emerging pollutants and no regulationexists in Europe concerning their presence in the environment. The presence of few tenths ofpharmaceuticals has been demonstrated. Living organisms in aquatic bodies are thereforeexposed to mixtures of compounds certainly at low doses (often between few ng and fewhundreds of ng) but continuously and the effects of this exposure are few documented. Thecontamination of aquatic systems by pharmaceuticals is usually the sign of an importanturbanization and streams with strong domestic pressures are often chosen as sampling sites inscientific studies. Nevertheless, the data concerning rural areas are still scarce although theyrepresent four fifth of the French territory.This work aims to establish a current situation of water resources of a rural territory, theDordogne administrative department. The occurrence of 40 pharmaceuticals including lipidregulators, antibiotics, β-blockers, non-steroidal anti-inflammatories, anticancer drugs, etc inseveral streams has studied with a multi-residue analytical method involving an on-linepreconcentration, a chromatographic separation followed by tandem MS/MS detection. Themethod has been validated for surface waters according to COFRAC requirements.Many sites were sampled every month during one year (2011) on six major streams of theDordogne department. The various campaigns allowed identifying the main areas contaminatedby pharmaceuticals and some linear correlations with other parameters (ammonium ion,phosphorus, etc.) have been evidenced.Beside the results obtained over all the Dordogne department, a focus on the presence ofpharmaceuticals in Isle river, around Périgueux, the main urban area of Dordogne, was led. Thissurvey allowed characterizing the introduction ways of pharmaceuticals and better understandingthe impact of the city of Périgueux on the river Isle.
262

Evaluating the Role of Biotic and Abiotic Ecosystem Components on the Retention and Removal of Ditch Nutrients in Ditches of Different Construction

Paull, Rachel May 12 August 2020 (has links)
No description available.
263

Nutrient and Contaminant Export Dynamics in a Larger-order Midwestern Watershed: Upper White River, Central Indiana, USA

Stouder, Michael David Wayne 15 October 2010 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The transport of excess nutrients, sediment, and other contaminants to surface waters has been shown to cause a number of environmental and human health concerns. An understanding of the export pathways that these contaminants follow to surrounding water bodies is crucial to the anticipation and management of peak concentration events. Several studies have demonstrated that the majority of annual contaminant loading in the Midwest occurs during periods of elevated discharge. However, many studies use a limited number of sampling points to determine concentration patterns, loadings, and fluxes which decreases accuracy. Through high-resolution storm sampling conducted in a 2945 km2 (1137 mi2) area of central Indiana’s Upper White River Watershed, this research has documented the complex concentration signals and fluxes associated with a suite of cations, nutrients, and contaminants and isolated their primary transport pathways. Additionally, by comparing the results of similar studies conducted on smaller areas within this watershed, differences in concentration patterns and fluxes, as they relate to drainage area, have also been documented. Similar to the results of previous studies, NO3- concentrations lacked a well-defined relationship relative to discharge and was attributed to primarily subsurface contribution. DOC was exported along a shallow, lateral subsurface pathway, TP and TSS via overland flow, and TKN through a combination of both. Near or in-channel scouring of sediment increased DOC, TKN, TP, and TSS concentrations during Storm 2. Atrazine export was attributed to a combination of overland and subsurface pathways. 2-MIB and geosmin derived from different sources and pathways despite being produced by similar organisms. 2-MIB concentration patterns were characterized by dilution of an in-stream source during Storm 1 and potential sediment export during Storm 2 while in-stream concentrations or a sediment source of geosmin was rapidly exhausted during Storm 1. Many of the concentration patterns were subject to an exaggerated averaging effect due to the mixing of several larger watersheds, especially during Storm 1. This research illustrates the need for high-frequency sampling to accurately quantify contaminant loads for total maximum daily load (TMDL) values, developing best management practices (BMPs), and confronting the challenges associated with modeling increasingly larger-scale watersheds.
264

The geochemical composition of the Scioto River, Ohio: influence of urbanization and seasonal changes in agricultural inputs

Wichterich, Connor M. 06 September 2022 (has links)
No description available.
265

WATER PROVISION FOR SMALL, ARID ISLANDS: FINDING SOLUTIONS FOR THE ISLANDS OF THE SOUTH AEGEAN SEA

VAMVAKIDOU, MARIA 01 July 2004 (has links)
No description available.
266

Water Quality Internship with the Ohio Environmental Protection Agency

Del Valle, Lemuel Alejandro 04 August 2016 (has links)
No description available.
267

Microbial Source Tracking: Watershed Scale Study of Pathogen Origin, Fate, and Transport in the Upper Sugar Creek Watershed, Northeast Ohio

Merrick, Natsuko N. 13 September 2010 (has links)
No description available.
268

Visualization, Characterization, and Analysis of Gold Nanoparticles Fate and Transport in Aqueous Porous Media Environment with Advanced Photonics Technique

Chan, Matthew Yunho 27 April 2017 (has links)
Increased proliferation of nanotechnology has led to concerns regarding its implication to the water environment. Gold nanoparticles (AuNP) were used as a model nanomaterial to investigate the fate and dynamics of nanoparticles in the complex water environment. A column study was performed to examine the fate and transport of gold nanoparticles with two different coatings in porous media. The resulting data suggested that gold nanoparticles aggregate significantly in the porespace of the column interior, a finding that is not predicted by traditional colloidal filtration theory or Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. Surface-enhanced Raman spectroscopy (SERS) was developed as a new technique to investigate AuNP aggregation in water with varying salt levels. The SERS technique proved valuable as an analytical technique, elucidating information about aggregation as well as AuNP surface interactions with dissolved halides in water. A thorough investigation examining Aunt aggregation with monovalent and divalent salts utilizing SERS, ultraviolet-visible light (UV-Vis) spectroscopy, and dynamic light scattering (DLS) was conducted. Each technique provided data describing different aspects of the dynamic behavior of AuNPs in complex water environments. Results suggest that in addition to attractive and repulsive interactions described by DLVO theory, chemical interactions between the AuNP surface and dissolved halides were also a significant driving force for aggregation and other transformative behaviors of AuNPs in water. The SERS technique developed in this work was shown to be a viable tool to help unveil the vastly complex dynamics of nanomaterial in the water environment. / Ph. D.
269

Développement de méthodes analytiques et devenir environnemental de multiples classes de contaminants pharmaceutiques

Vaudreuil, Marc-Antoine 09 1900 (has links)
La consommation des composés pharmaceutiques est en constante croissance à travers le monde et leur utilisation peut entraîner une accumulation dans l’environnement d’où leur désignation à titre de contaminants émergents. De nombreux groupes de recherche se penchent donc sur les questions de leurs effets sur des organismes vivants, sur la santé de certains écosystèmes ou encore sur l’efficacité de différents types de traitement des eaux usées. Or, peu de données sont disponibles quant aux concentrations présentes dans différentes matrices telles que les eaux usées ou l’eau de surface dans lesquelles elles sont déversées ou encore l’impact que peuvent avoir les hôpitaux sur l’occurrence des composés pharmaceutiques. La recherche dans ce domaine peut s’avérer un outil clé dans l’établissement de normes et de limites pour différents contaminants puisque celles-ci sont encore marginales dans la plupart des pays du monde, surtout au niveau des médicaments. Dans le cadre de cette thèse, différentes méthodes analytiques ont été développées pour faire l’analyse de classes ciblées de médicaments par chromatographie liquide couplée à la spectrométrie de masse afin de quantifier ceux-ci dans diverses matrices environnementales. Un des objectifs du présent ouvrage est donc de détailler les travaux de développement et de validation de méthodes analytiques robustes. Une première méthode d’extraction en phase solide en ligne avec la chromatographie liquide ultra-haute performance couplée à la spectrométrie de masse en tandem (SPE en ligne UPLC-MS/MS) a été développée afin de faire l’analyse de huit différentes classes de composés pharmaceutiques susceptibles d’être retrouvés dans les eaux usées. Afin de déterminer la distribution et l’adsorption des composés ciblés sur la phase solide de différentes matrices, une méthode d’extraction et de purification a également été optimisée de telle sorte que les extraits de matière particulaire et de sédiments soient compatibles avec cette méthode analytique. Ces méthodes ont été appliquées sur de nombreuses eaux usées d’hôpitaux et d’usine de traitement des eaux au Québec (Canada). Les produits de chimiothérapies présentent un défi analytique supplémentaire puisqu’ils sont polaires comparativement à la plupart des autres classes de composés pharmaceutiques. Il y a donc peu d’études sur la présence et le comportement de ces contaminants bien que ceux-ci présentent un risque écotoxicologique potentiellement important. Un deuxième objectif de cette thèse a donc été de comparer différentes alternatives pour la préconcentration et la séparation chromatographique, notamment la chromatographie à interaction hydrophile (HILIC). Celle-ci a mené à la validation de deux méthodes analytiques dont la sensibilité est de l’ordre des ng/L pour ces composés dans des eaux usées brutes. Ces méthodes de SPE en ligne UPLC-MS/MS ont été appliquées à de nombreux échantillons d’effluents d’hôpitaux ainsi qu’à des usines de traitement des eaux usées au Québec (Canada). D’autre part, la méthode SPE en ligne UPLC-MS/MS pour l’analyse des multiples classes de composés pharmaceutiques a été validée pour l’eau de surface enfin d’atteindre un dernier objectif de cet ouvrage qui consiste à évaluer différentes sources de contamination de cette matrice à proximité de zones densément peuplées. Durant de larges campagnes d’échantillonnage sur le fleuve Saint-Laurent, échelonnées sur une période de cinq ans et ayant couvert une zone géographique de près de 700 km entre le Lac Ontario et l’estuaire, plus de 400 échantillons ont été prélevés et analysés. Parmi ceux-ci figurent des échantillons provenant de 56 rivières tributaires au fleuve prélevés afin de déterminer l’impact de celles-ci en termes de pollution en composés pharmaceutiques et de les comparer avec des points de rejet d’eau usée de villes telles que Montréal ou Québec. Enfin, ces mêmes méthodes ont été appliquées lors de projets en collaboration avec des chercheurs se penchant sur les effets écotoxicologiques des composés pharmaceutiques sur des organismes aquatiques dans des matrices d’eau de surface ainsi que pour de développement de technologies alternatives pour le traitement des eaux usées. / A constant increase in pharmaceutical compounds worldwide can accentuate problems related to these pollutants of emerging concern in environmental matrices. Therefore, many researchers are studying their effects on living organisms, the health of impacted ecosystems, and the efficiency of different types of wastewater treatment systems. However, there is a lack of available data on the occurrence and concentrations of pharmaceuticals in different matrices, such as wastewaters or receiving surface waters, and the relative importance of hospital effluents on the load of these contaminants. Research in this field can be a key tool on different drugs since only a few countries have implemented norms and guidance, especially for medications. As part of this thesis, different analytical methods have been developed for the analysis of selected drugs, and liquid chromatography coupled with mass spectrometry was used to quantify multi-class pharmaceuticals occurring in various environmental matrices. One objective of this manuscript is to develop and validate robust analytical methods. A first extraction method on-line with liquid chromatography coupled to tandem mass spectrometry (on-line SPE UPLC-MS/MS) was developed to analyze eight different pharmaceutical classes susceptible to be found in wastewaters. With the aim of evaluating the partitioning and adsorption of target compounds onto a solid phase, an extraction and purification method was optimized to ensure that particulate matter and sediment extracts were compatible with the analytical method. These optimized methods were then applied to several hospital effluents and wastewater treatment plants samples in the province of Quebec (Canada). Chemotherapy agents present an additional analytical challenge since these drugs are relatively polar compared with most of other pharmaceutical classes. This explains the low number of publications relating to their occurrence and behaviour even though they present a high ecotoxicological hazard. A second objective of this thesis was to compare different potential alternatives for enrichment and chromatographic separation of these pollutants, notably the use of hydrophilic interaction chromatography (HILIC). This work led to the validation of two analytical methods for which the sensitivity reached ng/L levels for these compounds in raw sewage. These methods were successfully applied to samples from numerous hospital effluents and wastewater treatment plants from the province of Quebec (Canada). Also, a multi-class pharmaceutical method was validated for surface water in order to achieve the last objective of this thesis which consisted in the determination of the different contamination sources of this matrix near densely populated areas. During major sampling campaigns on the Saint-Lawrence River, spanning over five years and covering a geographical area of approx. 700 km between Lake Ontario and the estuary, a total of more than 400 samples were collected and analyzed. Among those, 56 different rivers tributary to the Saint-Lawrence were sampled to establish the impact they may have on pharmaceutical pollution. Data were compared with wastewater rejection points from cities, such as Montreal and Quebec. Finally, these methods were applied in the context of collaboration projects with researchers focusing on measuring ecotoxicological effects of pharmaceutical compounds on living organisms in surface water matrices and on the development of alternative wastewater treatment technologies.
270

[en] REMOVAL OF MANGANESE BY CATALYTIC OXIDIZING PRECIPITATION USING H2O2 IN THE TREATMENT OF WATER FOR HUMAN CONSUMPTION / [pt] REMOÇÃO DE MANGANÊS POR PRECIPITAÇÃO OXIDANTE CATALÍTICA UTILIZANDO H2O2 NO TRATAMENTO DE ÁGUA PARA CONSUMO HUMANO

RAPHAEL BARRETO DE OLIVEIRA 14 May 2024 (has links)
[pt] Concentrações de manganês acima de 0.02 mg L(-1) são suficientes para promover alterações organolépticas na água. O impacto conhecido como água preta capaz de manchar roupas e utensílios é gerado pela oxidação espontânea do íon Mn(II) para Mn(IV) e sua consequente precipitação na forma de MnO2. Essa oxidação pode ocorrer por diferentes agentes oxidantes como cloro e o próprio oxigênio dissolvido. Nas estações de tratamento de água, a remoção desse contaminante se dá geralmente pela oxidação iniciando na etapa de pré oxidação e terminando na filtração. Os oxidantes mais utilizados são permanganato de potássio, cloro e ozônio. O presente trabalho visou estudar a eficiência na remoção de manganês com o agente oxidante peróxido de hidrogênio através do processo de adsorção e oxidação. A água utilizada para o trabalho foi preparada sinteticamente mimetizando propriedades da água natural. O sistema consiste do Fe(OH)3 sólido para promover a adsorção de manganês dissolvido e a ação de dois floculantes: FeSO4 e Fe2(SO4)3. Foram elaborados 4 grupos de experimentos de plano fatorial completo com 3 fatores e 2 níveis. Dois desses quatro grupos foram utilizando FeSO4 como floculante enquanto os outros dois grupos com o floculante Fe2(SO4)3. Para cada floculante, um grupo de plano fatorial completo possuiu concentrações iniciais de peróxido de hidrogênio iguais a 3.7 e 7.4 mg L(-1) enquanto o outro possuiu as concentrações iniciais iguais a 0 e 7.4 mg L(-1). O outro fator analisado foi o pH que em todos os quatro grupos apresentou os níveis 6 e 9. Foram obtidos dois tipos de resultados principais para cada experimento, sendo um deles a concentração de manganês através da técnica de ICP-OES e o outro a concentração residual de peróxido de hidrogênio pela técnica de reflectância. Todos os resultados passaram pela análise de variância para indicar quais fatores foram significativos seja para a remoção de manganês, seja para o consumo de peróxido de hidrogênio. O pH foi observado como fator significativo o que já era esperado pela revisão bibliográfica. O agente oxidante só foi observado como significativo no grupo com Fe(3+) e concentrações iniciais de H2O2 iguais a 0 e 7.4 mg L(-1) . Dos 30 experimentos elaborados, 8 terminaram com concentrações de Mn(2+) abaixo do limite legal 0.1 mg L(-1) (Portaria MS 888/2021). Desses 8 experimentos, 6 continham pelo menos um dos íons de ferro e todos apresentaram pH igual a 9. Um desses resultados foi sem a adição de agente oxidante ou de íons de ferro. Em pH 7.5 a [Mn] pode ser reduzida para 0.2 mg L(-1) com [H2O2] = 5.5 mg L(-1) e [Fe] = 7.5 mg L(-1) . Os íons de ferro aumentam o impacto gerado na remoção de manganês à medida em que o tempo de reação aumenta. / [en] Manganese concentrations above 0.02 mg L(-1) are sufficient to promote organoleptic changes in water. The impact known as black water is capable of staining clothes and utensils. It is generated by the spontaneous oxidation of Mn(II) to Mn(IV) and its consequent precipitation in the form of MnO2. Thisoxidation occurs by different oxidizing agents such as chlorine and dissolved oxygen. In water treatment plants, the removal of this contaminant generally occurs through oxidation, starting in the peroxidation stage and ending with filtration. The most used oxidants are potassium permanganate, chlorine, and ozone. The present work aims to study the efficiency in removing manganese withthe oxidizing agent hydrogen peroxide through the process of adsorption and oxidation. Water used in the present work was prepared trying to mimic natural water. The system consists of solid Fe(OH)3 responsible for the adsorption of dissolved manganese and two flocculants: FeSO4 and Fe2(SO4)3. Four complete factorial groups were created with 3 factors 2 levels each. Two of these groups are using FeSO4 as flocculant while the other two groups use the flocculant Fe2(SO4)3. For each flocculant, one factorial group has initial hydrogen peroxide concentrations equal to 3.7 and 7.4 mg L(-1) while the other group has initial concentrations equal to 0 and 7.4 mg L(-1). The last factor analyzed was the pH, which in all four groups presented levels 6 and 9. Two types of main results were obtained for each experiment, one being the concentration of manganese through ICP-OES technique and the other is concentration of residual hydrogen peroxideby the reflectance technique. All results underwent analysis of variance to indicate which factors were significant for both manganese removal and hydrogen peroxide consumption. The pH was observed to be a significant factor, which was expected from the literature review. The oxidizing agent was only observed assignificant in the group with Fe(3+) ion and initial concentrations of H2O2 equal to 0and 7.4 mg L(-1). Out of the 30 experiments, 8 showed Mn(2+) concentrations belowthe legal limit of 0.1 mg L(-1)(Brazilian Drinking water standard MS 888/2021). Of the 8 experiments, 6 contained at least one of the iron ions and all had a pH of 9. One of these results had no oxidizing agent nor iron ions. In pH 7.5, the [Mn] canachieve 0.2 mg L(-1) as long as [H2O2] = 5.5 mg L(-1) and [Fe] = 7.5 mg L(-1). Iron ions have their effects increased in the removal of manganese as the reaction advancesin time.

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