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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.
21

Synthesis of smart nanomaterials for preconcentration and detection of E.coli in water

Mahlangu, Thembisile Patience 06 1900 (has links)
It is common knowledge that water is one of the basic needs for human beings. However, the consumption of contaminated water can lead to waterborne diseases and fatalities. It is, therefore imperative to constantly monitor the quality of potable water. There are numerous technologies used for water quality monitoring. These technologies are relatively effective however these tests are expensive and complex to use, which then require experienced technicians to operate them. Other tests are not rapid, making consumers of water susceptible to waterborne diseases. In this study, dye-doped, surface functionalized silica nanoparticles (SiNPs) and surface-functionalized magnetic nanocomposites (MNCs) were proposed as materials that can be applied in order to reduce the time taken to get results as well as to make the processes less complex and portable. The aim of this study was to synthesize and characterize surface functionalized dye-doped SiNPs and surface functionalized MNCs for detection and preconcentration of in water. Additionally, proof of concept had to be shown using the synthesized materials. SiNPs were the materials of choice due to their easily functionalized surfaces and their strong optical properties. SiNPs are photostable and they do not leach in solution due to the inert nature of the silica matrix in aqueous media. MNCs were chosen as materials of choice for preconcentration of E. coli in water because they are easy to synthesize and they can be applied in various biological applications due to their functional groups. SiNPs were synthesized using the water-in-oil microemulsion. The SiNPs were further functionalized with amine and carboxyl groups and avidin. Thereafter, they were bioconjugated with biotinylated anti-E. coli antibodies. The pure and surface functionalized SiNPs were characterized using ATR-FTIR spectroscopy, FE-SEM, HR-TEM, Zeta Sizer, UV-vis spectroscopy and spectrofluorometry. The application of the dye—doped surface functionalized SiNPs in E. coli detection was characterized using the fluorescence plate reader. The SiNPs were spherical and uniform in size. They increased in size as they were being functionalized, ranging from 21.20 nm to 75.06 nm. The SiNPs were successfully functionalized with amine and carboxyl groups as well as with avidin and antibodies. Two methods were investigated for carboxyl group attachment (direct and indirect attachment) and the direct attachment method yielded the best results with a surface charge of -31.9 mV compared to -23.3 mV of the indirect method. The dye loading was found to be 1% after particle synthesis. The optical properties of the Ru(Bpy) dye were enhanced 3 fold when they were encapsulated in the Si matrix. The SiNPs were binding to the E. coli cells and enabled detection. MNCs were synthesized through in-situ polymerization. The MNCs were characterized using ATR-FTIR spectroscopy, SEM, TEM and XRD. The MNCs were successfully functionalized with carboxyl groups. The increase in size of the nanocomposites as seen in SEM images proved that the Fe3O4 was successfully encapsulated in the polymer matrix. The MNCs were proven to be magnetic by a simple magnetism test whereby they were separated in an aqueous solution using an external magnetic field. The antibody-labelled MNCs were binding to the E. coli cells as shown in TEM images. E. coli cells were removed from water at varying concentrations of 1x106 CFU/mL to 1x109 CFU/mL at 10 mL volumes. This study has demonstrated that dye-doped SiNPs amplify the signal of E. coli cells using fluorescence. The study has also demonstrated that the MNCs can be applied in sample preconcentration and enrichment for E. coli detection. However, further studies should investigate and optimize the combination of the two techniques in a point of use device for water quality testing of 100 mL-samples as per the requirement of the SANS 241 standard. / Civil and Chemical Engineering / M. Tech. (Chemical Engineering)
22

Synthesis of smart nanomaterials for preconcentration and detection of E.coli in water

Mahlangu, Thembisile Patience 06 1900 (has links)
It is common knowledge that water is one of the basic needs for human beings. However, the consumption of contaminated water can lead to waterborne diseases and fatalities. It is, therefore imperative to constantly monitor the quality of potable water. There are numerous technologies used for water quality monitoring. These technologies are relatively effective however these tests are expensive and complex to use, which then require experienced technicians to operate them. Other tests are not rapid, making consumers of water susceptible to waterborne diseases. In this study, dye-doped, surface functionalized silica nanoparticles (SiNPs) and surface-functionalized magnetic nanocomposites (MNCs) were proposed as materials that can be applied in order to reduce the time taken to get results as well as to make the processes less complex and portable. The aim of this study was to synthesize and characterize surface functionalized dye-doped SiNPs and surface functionalized MNCs for detection and preconcentration of in water. Additionally, proof of concept had to be shown using the synthesized materials. SiNPs were the materials of choice due to their easily functionalized surfaces and their strong optical properties. SiNPs are photostable and they do not leach in solution due to the inert nature of the silica matrix in aqueous media. MNCs were chosen as materials of choice for preconcentration of E. coli in water because they are easy to synthesize and they can be applied in various biological applications due to their functional groups. SiNPs were synthesized using the water-in-oil microemulsion. The SiNPs were further functionalized with amine and carboxyl groups and avidin. Thereafter, they were bioconjugated with biotinylated anti-E. coli antibodies. The pure and surface functionalized SiNPs were characterized using ATR-FTIR spectroscopy, FE-SEM, HR-TEM, Zeta Sizer, UV-vis spectroscopy and spectrofluorometry. The application of the dye—doped surface functionalized SiNPs in E. coli detection was characterized using the fluorescence plate reader. The SiNPs were spherical and uniform in size. They increased in size as they were being functionalized, ranging from 21.20 nm to 75.06 nm. The SiNPs were successfully functionalized with amine and carboxyl groups as well as with avidin and antibodies. Two methods were investigated for carboxyl group attachment (direct and indirect attachment) and the direct attachment method yielded the best results with a surface charge of -31.9 mV compared to -23.3 mV of the indirect method. The dye loading was found to be 1% after particle synthesis. The optical properties of the Ru(Bpy) dye were enhanced 3 fold when they were encapsulated in the Si matrix. The SiNPs were binding to the E. coli cells and enabled detection. MNCs were synthesized through in-situ polymerization. The MNCs were characterized using ATR-FTIR spectroscopy, SEM, TEM and XRD. The MNCs were successfully functionalized with carboxyl groups. The increase in size of the nanocomposites as seen in SEM images proved that the Fe3O4 was successfully encapsulated in the polymer matrix. The MNCs were proven to be magnetic by a simple magnetism test whereby they were separated in an aqueous solution using an external magnetic field. The antibody-labelled MNCs were binding to the E. coli cells as shown in TEM images. E. coli cells were removed from water at varying concentrations of 1x106 CFU/mL to 1x109 CFU/mL at 10 mL volumes. This study has demonstrated that dye-doped SiNPs amplify the signal of E. coli cells using fluorescence. The study has also demonstrated that the MNCs can be applied in sample preconcentration and enrichment for E. coli detection. However, further studies should investigate and optimize the combination of the two techniques in a point of use device for water quality testing of 100 mL-samples as per the requirement of the SANS 241 standard. / Civil and Chemical Engineering / M. Tech. (Chemical Engineering)
23

Μελέτη της επίδρασης του CO2 στην ποιότητα υπόγειων υδάτων, υπό συνθήκες ροής

Τερζή, Αικατερίνη 16 May 2014 (has links)
Η διαρροή αέριου CO2 προς υπερκείμενους ταμιευτήρες υπογείων υδάτων ως συνέπεια της δέσμευσης και αποθήκευσης του σε υπόγειους γεωλογικούς σχηματισμούς μπορεί να έχει αντίξοες συνέπειες στη ποιότητα του πόσιμου νερού. Μελέτες έχουν δείξει ότι υψηλά επίπεδα CO2 στο πόσιμο νερό ταμιευτήρων μπορεί να αυξήσει τις συγκεντρώσεις ιχνοστοιχείων μετάλλων σε ανεπιθύμητα επίπεδα. Η παρούσα εργασία αποτελεί μία μελέτη, υπό συνθήκες συνεχούς ροής, της επίδρασης της εισβολής CO2 σε ταμιευτήρες πόσιμου νερού λόγω πιθανών διαρροών από τους υπόγειους σχηματισμούς αποθήκευσης. Η ορυκτολογική σύσταση πυριτικής άμμου τροποποιήθηκε, με την ελεγχόμενη από το pH καθίζηση οχτώ μετάλλων (Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd). Διοξείδιο του άνθρακα και νερό διοχετεύονταν ταυτόχρονα σε μία στήλη γεμάτη με την τροποποιημένη άμμο, ενώ σε μία άλλη απαράλλακτη στήλη, διοχετευόταν μόνο νερό (πείραμα αναφοράς). Από τις εκροές των δύο στηλών συλλέγονταν δείγματα νερού και γινόταν μέτρηση των συγκεντρώσεων των μετάλλων με φασματοσκοπία ατομικής απορρόφησης (AAS). Το πείραμα διήρκεσε 2 μήνες. Η ορυκτολογική ανάλυση της άμμου πριν και μετά το τέλος των πειραμάτων έγινε με ηλεκτρονική μικροσκοπία σάρωσης και στοιχειακή ανάλυση μέσω φασματοσκοπίας διασποράς ενέργειας (SEM-EDS), φωτοηλεκτρική φασματοσκοπία ακτίνων Χ, (XPS)και ατομική απορρόφηση (AAS). Η διάλυση του CO2 στο νερό μείωσε το pH, αυξάνοντας τις συγκεντρώσεις των μετάλλων Mn, Co, Ni, Cu, Zn, στα δείγματα εκροής. Επιπλέον, οδήγησε σε μερική εκρόφηση του Cr, σε ολική εκρόφηση του Cd αλλά με πολύ γρήγορο ρυθμό σε σχέση με το πείραμα αναφοράς, ενώ δεν αποδεσμεύτηκε καθόλου ο Fe. Για να προσδιοριστεί η ευαισθησία του συντελεστή κατανομής κάθε μετάλλου στο pH, πραγματοποιήθηκαν συμπληρωματικά πειράματα διαλείποντος έργου και τα αποτελέσματα προσαρμόστηκαν σε ισόθερμες Freudlich. Για την ποσοτική ερμηνεία του πειράματος συνεχούς ροής, αναπτύχθηκε ένα δυναμικό μακροσκοπικό μοντέλο της διεργασίας με τη σύζευξη των φαινομένων μεταφοράς με τις αντιδράσεις διαλυτοποίησης του CO2 στο νερό και απελευθέρωσης των μετάλλων στην υδατική φάση. Αξίζει να σημειωθεί ότι η απελευθέρωση των μετάλλων στην υδατική φάση υπό συνθήκες ροής μοντελοποιήθηκε ως διεργασία εκρόφησης 2-θέσεων (ισορροπίας και μη ισορροπίας). Οι παράμετροι εκρόφησης των μετάλλων εκτιμήθηκαν με δυναμική προσαρμογή του μακροσκοπικού μοντέλου μεταφοράς/αντιδράσεων σε πειραματικές μετρήσεις της χρονικής μεταβολής της συγκέντρωσης των κατιόντων μετάλλων στην εκροή της στήλης. / Potential leakages of CO2 to shallow aquifers, as a result of its storage in underground reservoirs, could have adverse impacts on the groundwater quality. The mineralogical composition of well-sorted silica sand is modified by the pH-controlled precipitation of eight metals (Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd). Gas carbon dioxide and distilled, deaerated water are both injected in a fixed-bed column packed with the modified sand. In another identical column distilled and deaerated water is injected. Metal concentration in effluent by both columns is measured with atomic absorption spectroscopy (AAS). Mineralogical analysis of sand before and after the flow tests is done by Scanning Electron Microscopy – X-ray Energy Dispersive Spectroscopy (SEM-EDS), X-ray Photoelectron Spectroscopy (XPS), and AAS. Due to continuous CO2 dissolution, the pH is decreased and the release of Mn, Ni, Cu, Zn, Co is enhanced profoundly, the release of Cr increases moderately, the Cd dissolution accelerates, whereas Fe is strongly bonded as goethite and does not dissolve almost at all. To determine the sensitivity of partition coefficient for each metal with pH, batch experiments is done and the results were adjusted to isothermal Freudlich. The metal release from solid phase is modeled by a two-site desorption model (equilibrium and non-equilibrium), which is coupled with flow and mass-transfer processes. Inverse modeling of the flow test quantifies the dynamics of metal release in terms of equilibrium and kinetic desorption parameters, estimated under realistic flow conditions.
24

De l’acclimatation à l’adaptation : mécanismes évolutifs, conséquences populationnelles et implication en biosurveillance / From acclimation to adaptation : evolutionary mechanisms, populational consequences, and implications for biomonitoring

Potet, Marine 21 December 2017 (has links)
Le cadre réglementaire défini par la Directive Cadre sur l’Eau impose le développement de méthodologies fiables d’évaluation et/ou de caractérisation de l’état de santé des écosystèmes aquatiques. L’objectif de ce travail de thèse était d’identifier les rôles relatifs des paramètres des milieux aquatiques (température, cycle saisonnier, minéralisation), des caractéristiques des populations et des pressions anthropiques sur les réponses des biomarqueurs chez un organisme aquatique modèle, la moule zébrée (Dreissena polymorpha). Une espèce sœur, Dreissena rostriformis bugensis, arrivée plus récemment dans nos cours d’eau, a été suivie en parallèle et son potentiel en tant que biomoniteur a également été évalué. Pour cela, une batterie d’une douzaine de biomarqueurs sub-cellulaires a été mesurée dans différentes populations des deux espèces vivant dans des milieux contrastés, à différentes périodes de l’année, mais aussi lors de stress standardisés en laboratoire. Les biomarqueurs choisis correspondaient à différentes fonctions physiologiques et/ou antitoxiques, et des réponses à fortes pertinence écologiques, telles que la consommation d’oxygène ou l’activité de filtration, ont ponctuellement été suivies. Ces différents paramètres ont permis d’interroger les notions de sensibilité et de vulnérabilité des populations et de mieux comprendre les facteurs déterminant les réponses des biomarqueurs. Les différences inter-populationnelles montrent que l’accumulation des contaminants par les organismes et leurs réponses biologiques sont bien dépendantes de la qualité du biotope propre à chaque population, mais aussi de la saison, un facteur confondant qui doit donc être pris en compte lors de campagnes de biosurveillance. De fortes différences de réponse des biomarqueurs entre les deux espèces ont aussi été observées, aussi bien in situ que lors des expositions en laboratoire, soulignant la nécessité de bien différencier ces deux espèces, pourtant très proches. La nouvelle arrivée, D. r. bugensis, présente des réponses plus plastiques in situ, mais semble moins capable de gérer des stress aigus lors d’expositions en laboratoire. A l’inverse, D. polymorpha, arrivée il a 200 ans en France, semble mieux adaptée, avec une variabilité de réponse moins marquée et une meilleure tolérance aux contaminants. Ces travaux de thèse s’inscrivent dans le cadre de la convention BIOMICS, réalisée en collaboration avec l’ONEMA. Ils montrent que ces deux espèces sont aptes à nous renseigner sur l’état de contamination du milieu dans lequel elles vivent, même si les grilles d’interprétation peuvent être différentes de l’une à l’autre. Les variations des réponses des biomarqueurs au niveau sub-cellulaire témoignent de façon précoce de modifications de la qualité du milieu. Certains biomarqueurs semblent toutefois plus informatifs que d’autres, la batterie mesurée pourrait donc être réduite. A l’avenir, ces travaux permettront une meilleure lecture et interprétation des biomarqueurs mesurés dans des populations autochtones ou transplantées, et attestent de l’intérêt des biomarqueurs en tant qu’outils d’évaluation de la qualité des milieux aquatiques / The regulatory framework defined by the Water Framework Directive requires the development of reliable methodologies for assessing and / or characterizing the health status of aquatic ecosystems. The objective of this thesis was to identify the relative roles of environmental parameters (temperature, seasonal cycle, mineralization), population characteristics and anthropic pressures on biomarker responses in a model aquatic organism, the zebra mussel (Dreissena polymorpha). A sister species, Dreissena rostriformis bugensis, which invaded more recently our waterways, has been used in parallel and its potential as a biomonitor has also been evaluated. For this purpose, a battery of a dozen sub-cellular biomarkers was measured in different populations of the two species living in contrasting environments, at different times of the year, but also under laboratory stresses. The selected biomarkers corresponded to different physiological and / or antitoxic functions, and responses with high ecological relevance, such as oxygen consumption or filtration activity, were occasionally followed. These various parameters allowed to question the concepts of sensitivity and vulnerability of the populations and to understand the factors determining biomarker responses. Inter-population differences showed that the accumulation of contaminants by organisms and their biomarker responses depend on environmental quality at the originating site of each population, but also on the season, a confounding factor which must therefore be taken into account during biomonitoring programs. Strong differences in biomarker responses between the two species were also observed, both in situ and during laboratory experiments, emphasizing the need to differentiate the two species, so close they are. The recent invader, D. r. bugensis, presents more plastic responses in situ, but appears less able to manage acute stress in laboratory. Conversely, D. polymorpha, which is about 200 years old in France, appears to be better adapted, with less response variability and a better tolerance to contaminants. This thesis work is part of the BIOMICS convention, carried out in collaboration with ONEMA. It shows that these two species are able to inform about the contamination status of their environment. Variations in biomarker responses at the sub-cellular level indicate early changes in environmental quality. Some biomarkers, however, seem more informative than others do, so the measured battery could be reduced. In the future, this work will allow a better reading and interpretation of biomarkers measured in autochthonous or transplanted populations, and attest the value of biomarkers as tools for assessing aquatic environment quality
25

Traitement en ligne des eaux pluviales en zone urbaine dense. / Online storm-water treatment in dense urban area

Bouarab, Amine 22 July 2014 (has links)
Les travaux décrits dans le présent rapport concernent l’étude d’un ouvrage de traitement en ligne des eaux pluviales issues d’un bassin versant fortement urbanisé. L’ouvrage Charles Keller, d’une capacité de 7000 m3, est conçu pour traiter les eaux pluviales issues du bassin versant de Boudonville, situé dans la Communauté Urbaine du Grand Nancy. L’ouvrage est installé à l’exutoire de bassin versant en aval d’autres ouvrages de stockage temporaires. Les eaux traitées par l’ouvrage Charles Keller sont ensuite renvoyées vers la Meurthe et les boues produites sont traitées au niveau de la station d’épuration du Grand Nancy à Maxéville. La stratégie adoptée dans ce travail a permis de d’aborder l’ouvrage sous plusieurs angles : 1) d’abord l’étude de l’ouvrage seul en se focalisant sur l’ensemble de ses composantes unitaires (dessableurs, chambre d’injection des réactifs, réacteurs et décanteurs) ; 2) la partie physico-chimique (non opérationnelle jusqu’à présent) a fait l’objet de plusieurs compagnes d’analyse à travers les essais en Jar test effectués au laboratoire sur des eaux issues du bassin versant de Boudonville dont les caractéristiques couvrent toute la gamme que l’ouvrage Charles Keller peut traiter ; 3) ensuite l’ouvrage a été resitué dans l’ensemble du système de gestion des eaux pluviales (bassin versant - ouvrage Charles Keller - station d’épuration) et son fonctionnement simulé. Plusieurs configurations ont été testées pour reproduire les conditions réelles de fonctionnement de l’ouvrage. Les résultats obtenus ont montré d’abord la complexité de faire fonctionner dans la pratique un tel ouvrage, notamment avec sa partie coagulation/floculation mais a fait également ressortir des défauts de conception. / An online urban storm-water treatment system has been studied in this work. This system is able to treat the runoff from a highly impervious watershed (Boudonville) in Greater Nancy (North-East of France). It has a capacity of 7000 cubic meters. Some storage tanks are existing in the watershed. The treated water is discharged into the Meurthe River, while the sludge is treated in the Greater Nancy wastewater treatment plant in Maxéville.The strategy adopted in this work allowed for the consideration of the treat ment system from several angles:• first of all, the system is analyzed through its elementary components (sand removal unit, reagents injection and reactors for flocculation-coagulation and clarifiers): this has been done by observing the variations in water quality at the different treatment levels with online instrumentation. This has been completed with an offline characterization.• the flocculation-coagulation section, which was not yet operational during our work, was studied in the laboratory by jar tests. The water to be treated was sampled from the Boudonville watershed to be close to the conditions that should be observed in the Charles Keller treatment system.• finally the stormwater treatment was simulated as part of a full storm-water management system (watershed-Charles Keller treatment system-wastewater treatment plant).• The results that were obtained showed in the one hand the complexity of using such a treatment system in real-life conditions, especially with a coagulation / flocculation part to it, which has some conceptual issues.
26

Influencia de processos naturais e tecnogenicos na qualidade de águas superficiais de Blumenau-SC

Percebon, Claudete Massuchin January 2003 (has links)
Apendices / Anexo / Orientador: André de Virmond Lima Bittencourt / Co-orientador: Ernani F. da Rosa Filho / Dissertaçao (mestrado) - Universidade Federal do Paraná / Resumo: Esse e um estudo sobre a qualidade das águas superficiais de Blumenau - SC, desenvolvido dentro de um programa de amostragens e analises que se estendeu por 24 meses, entre junho e 2000 a agosto de 2002. Fazem parte dessa avaliação os principais rios desse Município, a saber: o trecho do Itajai-Acu, que divide a cidade, e seus tributários. Na sua margem direita, o Garcia e o da Velha; e em sua margem esquerda: o do Testo, Itoupava e Fortaleza. Foram avaliados os resultados de 15 parâmetros fisicoquimicos diferentes, analisados nas águas desses rios. Fez-se o levantamento de informações da micro-região, como condições climáticas, topográficas, hidrográficas, geológicas, geomorfológicas, de uso do solo, do potencial poluidor das atividades econômicas locais, pedológicas e agropecuárias, entre outras. Foi confrontada a resposta de cada rio, segundo o resultado da qualidade de suas águas, aos fatores ambientais locais, esse foi um dos objetivos do presente estudo. O uso atual e futuro dessas águas superficiais, correspondentes a rede potamografica estudada, seja para abastecimento publico, seja com finalidades turísticas ou de preservação ambiental, foi a justificativa para o estudo. Como principais conclusões desse estudo tem-se: a temperatura se mostrou um parâmetro de controle muito importante na avaliação da qualidade das águas superficiais; a condutividade foi o parâmetro mais fiel a qualidade da águas; a presença de mata ciliar nos rios e cobertura vegetal nas micro-bacias estudadas se mostraram como fatores positivos na qualidade das águas; a chuva evidenciou arrastar nutrientes para os rios em áreas mais expostas; o substrato drenado apresentou significativa correlação com a presença de cor, baixo pH e sólidos totais em diferentes pontos estudados; a correlação entre os parâmetros e maior para águas de melhor qualidade; o método do IQA simplificado desenvolvido permitiu analisar a qualidade dos rios estudados. A metodologia desenvolvida nesse diagnostico, os mapas elaborados, as informações compiladas e as conclusões aqui apontadas, poderão ser uteis nos trabalhos de monitoramento e preservação da qualidade dos rios da área, ou servirem de apoio a outras pesquisas ou estudos correlatos desenvolvidos na região. Palavras-chave: Qualidade de Águas de Rios; Fatores Ambientais; Parâmetros Físicos, Químicos e Bacteriológicos. / Abstract: This is a study about Blumenau's, Santa Catarina State, surface water quality, using a sampling and analyses program extended for twenty-four months. Including in this assessment the main streams of municipal district area, such: the Itajai-Agu, on its portion, on the passage through Blumenau City, and its tributaries. On its right margin, the Garcia stream, and da Velha stream. On its left margin, the Testo stream, Itoupava stream and Fortaleza stream. Were evaluated fifteen physical-chemistry distinct parameters, developed on the waters from these streams. The micro-region knowledge like the climate conditions, the topography, the hydrology, the geology, the geomorphology, the soil use, the pollution potential from local economical and agricultural activities, and others aspects, was realized. The water quality answer to these subjects was pondered for each stream. It was developed a particular water quality index to evaluate the surface water studied. The head conclusions of this study was: the temperature was showed like a important control parameter on the superficial water evaluation; the parameter conductivity offers the better answer to the water quality; the riparian zone and basin vegetable coverage was positives aspects on superficial waters quality; the rain falls over exposed areas can to induce nutrients to the superficial waters; the answers of the subsurface drained on the streams waters can be watched in the pH, total solids and apparent color parameters; the best relationships between parameters was noted in the better quality waters; the simplified method of Water Quality Index allowed to define the studied streams quality.To know the local streams water quality and make the correlation with theirs environments is one of purposes of this work. The real and future use of regional surfaces waters was an apology of this study. The developed methodology used to this diagnosis, the maps elaborated, the data and conclusions here pointed, could be useful on the works to keeping and preserving regional waters rivers quality. Key-words: River Water Quality; Environmental Assessments; Physics, Chemicals and Bacteriological Parameters.
27

Rôle des étangs de barrage à vocation piscicole dans la dynamique des micropolluants en têtes de bassins versants / Role of barrage fishponds in the dynamic of micropollutants in headwater streams

Gaillard, Juliette 16 December 2014 (has links)
En Lorraine, environ 7000 ha d’étangs sont exploités pour la production piscicole. Le présent travail a été consacré à la compréhension des mécanismes de transfert des micropolluants dans les étangs en mettant l'accent sur trois questions : (1) évaluer l'ampleur de la contamination métallique des étangs (n=45) ; (2) évaluer l'influence des étangs (n=3) sur les concentrations, le risque de toxicité et les flux de pesticides; (3) évaluer l'importance relative des voies de transfert des PCB vers le poisson. (1) Les enrichissements calculés soulignent des contaminations généralement faibles à modérés à l’exception des étangs localisés dans la Vôge et de deux étangs localisés dans la Woëvre. Cet enrichissement est plus prononcé pour le Cd et semble être lié à la richesse du sédiment en matière organique et carbonates (perte au feu). (2) Dans les cours d’eau de tête de bassin versant sur lesquels s’inscrivent ces trois étangs de barrage, les concentrations les plus élevées étaient généralement réduites de plus de 90% entre l'amont et l'aval de l'étang. Le risque de toxicité, évalué par la méthode de l'unité toxique, était atténué en aval des étangs. Lorsqu’on considère les flux de pesticides, les résultats obtenus suggèrent que, selon les substances considérées, les charges en pesticides sont réduites de 10 à 100% entre l'amont et l'aval de l'étang. (3) Les résultats montrent que le sédiment contaminé n’a pas d’impact sur la biodisponibilité orale des trois congénères de PCB chez la carpe commune. L’effet géosorbant du sédiment, qui explique son rôle de réservoir environnemental de PCB, paraît insuffisant dans les conditions du tractus digestif de la carpe commune, pour éviter un transfert vers le poisson / In the Lorraine Region, about 7,000 ha of ponds are exploited for fish production. The present work was dedicated to the understanding of micropollutants transfer mechanisms in freshwater fishponds focusing on three issues: (1) evaluate the extent of fishpond (n=45) exposure to trace metals (2) evaluate the influence of fishponds (n=3) on concentrations, potential toxicity and mass flows of pesticides; (3) evaluate the relative importance of transfer pathways of PCBs to fish. (1) The enrichments measured were generally low to moderate with the exception of the sites located in the Vôge and two sites located in the Woëvre. Enrichment was particularly high for Cd and seemed related to the loss of ignition. No relationship between enrichment and land use could however be observed. (2) High pesticide concentrations were generally reduced by more than 90% between upstream and downstream location. The risk of toxicity, evaluated under the toxic unit approach was attenuated downstream of the ponds. When considering the flow of pesticides, the results suggest that, depending on the substances in question, 10 to 100% of the loads of pesticides are retained in fishponds. (3) The oral transfer of polychlorinated biphenyls (PCBs 138, 153, and 180) from a contaminated sediment to a benthic fish (carp) was studied by the in vivo relative bioavailability method. The results show that the contaminated sediment has no effect on the oral bioavailability of the three PCB congeners in common carp. The geosorbing effect of sediment, which explains its role as an environmental reservoir of PCBs, seems insufficient under the conditions of the digestive tract of the common carp, to prevent transfer to fish
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Identification and quantification of selected pesticides in surface water in Southern Gauteng region

Bucibo, Malesole Nontutu Gadihele 07 1900 (has links)
Thesis (M. Tech. - Dept. of Chemistry, Faculty of Applied and Computer Sciences) -- Vaal University of Technology, 2010 / The increased production and application of pesticides for agricultural and non-agricultural purposes has caused the pollution of air, soil, ground and surface water. This has a negative impact on the environment as well as human health due to direct exposure or through residues in food and drinking water. The continuous monitoring of pesticides residues in environmental samples has great importance and demands high efficiency, unique selectivity and high sensitivity techniques. Gas chromatography and high performance liquid chromatography have been established for years as the techniques for the analysis of pesticides residues. The dissertation deals with the qualitative and quantitative determination of selected pesticides in the Southern Gauteng region using Liquid- liquid extraction solid-phase extraction, high performance liquid chromatography, gas chromatography equipped with electron capture detector and gas chromatography mass spectrometry. Liquid-liquid extraction and solid-phase extraction using dichloromethane, hexane and ethyl acetate as the extracting solvent were optimized and evaluated for the determination of pesticides in surface water in the Southern Gauteng region. From the developed method the techniques were applied to water samples taken from different rivers selected namely: Zuikerbosch, Rand Water barrage and Kliprivier for sampling. Dichloromethane was used as a solvent in this study since a recovery test was done between dichloromethane, Ethyl acetate and n-hexane. The percentage recovery test for 4,4-DDT, 4,4-DDE, 2,4-DDD and Endosulfan 1 & 2 ranged from 89.9% -97.3% for dichloromethane, 87.3%-96.8% for hexane 88.4%-97.1% for ethyl acetate. The extracts obtained were subjected to column chromatography for clean up. Thereafter 1µl of the cleaned extracts were injected into the Gas chromatography equipped with an electron capture detector. Organochlorines 4,4-DDT and its metabolites, Organophosphate Chlorypyriphos and carbamates were detected using Gas chromatography electron capture, Gas chromatography mass spectrometry and high performance liquid chromatography.
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Monitoring and modelling of pharmaceuticals in wastewater : Daily and hourly loads in both hospital and urban wastewater / Métrologie et modélisation de résidus de médicaments en eaux usées : Flux journaliers et horaires d'un bassin versant urbain et d'un hôpital

Pouzol, Tanguy 20 February 2018 (has links)
Les flux journaliers et horaires de 15 molécules pharmaceutiques à l'entrée d'une station d'épuration ont été mesurés sur 3 ans et modélisés à la fois pour un bassin urbain de 16 000 habitants et un hôpital de 450 lits. Certaines molécules ne sont jamais ou rarement quantifiées. Les flux journaliers vont de 0,6 à 564 g/jour en fonction de la molécule et de la campagne de mesure 24h. Aucune dynamique saisonnière ou hebdomadaire n’a été identifiées. La dynamique des flux horaires des médicaments se distingue des autres polluants et du débit des eaux usées. Les flux horaires mesurés sont sévèrement impactés par le comportement aléatoire des patients lorsque la masse journalière consommée est faible. Ainsi, la dynamique moyenne est difficile à identifier. L'hypothèse principale pour modéliser les flux de médicaments dans les eaux usées est qu'ils résultent des étapes suivantes: ventes ou distributions de médicaments, consommation humaine, métabolisme et excrétion. Les ventes de médicaments pour le bassin urbain et les distributions de l'hôpital ont été collectées à différentes échelles spatiales et temporelles (respectivement 1, 6 et 223 pharmacies et journalières, hebdomadaires et mensuelles). Les plus grandes échelles sont plus fiables pour estimer les niveaux de consommations mais la variabilité des plus petites est plus proche de la variabilité observée dans les mesures. Les quantités de médicaments vendus ou distribués vont de 0,4 à 1 600 patients théoriques par jour en moyenne. En associant les flux journaliers mesurés aux ventes ou aux distributions, aucune corrélation linéaire n'a été trouvée. Un modèle stochastique au pas de temps de la minute est proposé et appliqué aux deux sites. Il produit des résultats fiables et précis pour les flux quotidiens et horaires. Cependant, les résultats sont difficiles à interpréter lorsque seuls quelques patients consomment un médicament. De plus, le modèle ne reproduit pas la spécificité inhérente de l'hôpital. En outre, le modèle est également capable de prédire avec précision le débit des eaux usées domestiques d'un bassin versant urbain, tant pour les volumes quotidiens que pour leurs dynamiques. / Daily and hourly loads of 15 pharmaceutical molecules at the inlet of a wastewater treatment plant have been measured over 3 years and modelled for both an urban catchment of 16 000 inhabitants and a hospital of 450 beds. Some molecules are never or rarely quantified. Daily loads range from 0.6 to 564 g/day depending of the molecule and the 24 h measurement campaign. Seasonal or weekly patterns are not identified. Pharmaceuticals hourly loads dynamics are distinctive from one another and from wastewater flow. The measured hourly loads are severely impacted by the random behaviour of the patients when the daily mass consumed is low. Thus, the average dynamics is difficult to identify. The main hypothesis to model pharmaceuticals loads in wastewater is that they result from the following steps: pharmaceuticals sales or distributions, human consumption, metabolism and excretion. Pharmaceuticals sales for the urban catchment and distribution for the hospital have been collected at different space and timescales (respectively 1, 6 and 223 pharmacies and daily, weekly and monthly). Larger scales are more reliable for magnitude but the variability of the smaller ones is closer to the variability observed in the measurements. The quantities of pharmaceuticals sold or distributed range from 0.4 to 1 600 theoretical patients per day. Associating measured daily loads with sales or distributions, no linear correlation is found. A minute time step stochastic model is proposed and applied to both sites. It produces reliable and accurate results for both daily and hourly loads. However, results are difficult to interpret when only a few patients are consuming a pharmaceutical. Also, the model does not reproduce the inherent specificity of the hospital. In addition, the model is also able to predict the domestic wastewater flow of an urban catchment with great accuracy for both daily volumes and dynamics.
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Les bactériophages ARN F-spécifiques comme indicateurs du danger viral lié à la pollution fécale des matrices hydriques et alimentaires / F-specific RNA bacteriophages as indicators to assess viral hazard linked to fecal pollution of water and foodstuff

Hartard, Cédric 14 November 2017 (has links)
Les virus entériques sont à l’origine de pathologies liées au péril fécal et dans l’état actuel des connaissances, la recherche des indicateurs de pollution fécale conventionnels (i.e. Escherichia coli, entérocoques) peut s’avérer inefficace pour évaluer le danger viral. La définition d’autres indicateurs pour gérer le danger lié à la présence des virus entériques dans les matrices hydriques et alimentaires est aujourd’hui nécessaire. Parmi eux, les bactériophages ARN F-spécifiques (FRNAPH) présentent plusieurs intérêts. Ces virus d’origine entérique sont présents en quantité importante dans les eaux usées. Très proches des virus entériques en termes de structure, ces microorganismes présentent l’avantage d’être facilement cultivables. Ils sont enfin souvent étudiés pour déterminer l’origine d’une pollution fécale (i.e. humaine ou animale). Certaines limites leur sont cependant fréquemment associées, que ce soit en termes de corrélation avec les pathogènes entériques ou concernant leur potentiel pour discriminer l’origine d’une pollution. Dans ce contexte, l’objectif du travail présenté ici était de préciser l’intérêt des FRNAPH en tant qu’indicateurs de pollution fécale mais aussi en tant qu’indicateurs de pollution virale dans l’environnement et les coquillages. Ces travaux ont permis dans un premier temps d’améliorer la capacité des FRNAPH à identifier les contaminations d’origine humaine. Nos résultats soulignent par ailleurs la plus-value apportée par la recherche des FRNAPH en cas de pollution fécale massive, en particulier si on s’intéresse à la contamination des coquillages. En effet, contrairement aux indicateurs bactériens, l’accumulation des FRNAPH ainsi que leur persistance dans ces aliments est très comparable à celles des virus entériques (i.e. norovirus). Enfin, en utilisant des méthodes de détection comparables, une forte corrélation entre la présence des FRNAPH d’origine humaine et celle des norovirus a été observée dans les coquillages. Compte tenu de ces résultats, une méthode de détection assurant la détection sensible des FRNAPH infectieux d’origine humaine dans différents types de matrices hydriques ou alimentaires (e.g. eaux de surface, fruits de mer, fruits rouges, salades) est proposée pour améliorer la gestion du danger viral / Enteric viruses are a leading cause of fecal-oral route transmitted diseases and currently, conventional fecal indicator bacteria (i.e. Escherichia coli, enterococcus) fail to assess this kind of hazard. In this context, the use of more efficient indicators to assess the hazard linked to viruses in water or foodstuff is required. F-specific RNA bacteriophages (FRNAPH) present numerous benefits for this purpose. Of enteric origin, these viruses are found in high concentrations in wastewater. Sharing many structural similarities with pathogenic enteric viruses, FRNAPH are easily cultivable and their potential to track the origin of the pollution is also often investigated. However, some limits are still associated with these indicators, regarding to their ability to track the origin of the pollution or concerning the lack of correlation with pathogens. In this context, the aim of this work was to make clear the potential of FRNAPH as fecal and as viral indicators in environmental waters and shellfish. As a first step, their ability to track human pollution was optimized. In addition, our results underlined the gains bringing by FRNAPH detection, especially when focusing on shellfish microbiological quality management. Indeed, unlike fecal indicator bacteria, the accumulation of FRNAPH and their persistence in shellfish have been found to be close to that of enteric viruses (i.e. norovirus). Furthermore, when using comparable methods for their detection, high correlation was observed between human FRNAPH and norovirus in shellfish. Taking into account these observations, a sensitive method allowing the detection of infectious FRNAPH of human origin was developed to improve viral hazard management in water and food commodities (e.g. environmental waters, shellfish, soft fruits, leaf)

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