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Dissertations / Theses on the topic 'Pollutants detection'
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1
Agboola, Bolade Oyeyinka. "Catalytic activities of Metallophthalocyanines towards detection and transformation of pollutants /." Thesis, Rhodes University, 2007. http://eprints.ru.ac.za/873/.
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Russell, Ingrid Margaret. "The development of an immobilised-enzyme bioprobe for the detection of phenolic pollutants in water." Thesis, Rhodes University, 1999. http://hdl.handle.net/10962/d1006211.
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The possibility of developing an immobilised-enzyme bioprobe, based on mushroom polyphenol oxidase, for the purely biological detection and quantification of phenolic pollutants in water was investigated. Polyphenol oxidase catalyses the bioconversion of many phenolic compounds into quinone-related coloured products. Thus, in an immobilised form, the enzyme serves as a visible indicator of the presence and concentration of phenolic pollutants in water. The objective of this research was to develop a portable, disposable bioprobe incorporating polyphenol oxidase for this purpose. The intensity of the colour changes produced by the enzyme on reaction with p-cresol, p-chlorophenol and phenol was found to increase proportionally with increasing concentrations of these substrates in solution. Immobilisation of the enzyme on various supports did not appear to significantly affect the catalytic activity of the enzyme. The enzyme was immobilised by adsorption and cross-linking on polyethersulphone, nitrocellulose and nylon membranes with the production of various colour ranges on reaction with the phenolic substrates. The most successful immobilisation of the enzyme, in terms of quantity and distribution of enzyme immobilised and colour production, was obtained with the enzyme immobilised by adsorption on nylon membranes in the presence of 3-methyl-2-benzothiazolinone hydrazone (MBTH). The enzyme, immobilised using this method, produced ranges of maroon colours in phenolic solutions and orange colours in cresylic solutions. The colour intensities produced were found to increase proportionally with increasing substrate concentration after 5 minutes exposure to the substrates. The bioprobe had a broad substrate specificity and was sensitive to substrate concentrations down to 0.05 mg/L. The enzyme activity of the bioprobe was not significantly affected in a pH range from 4 to 10 and in a temperature range from 5-25⁰C. The bioprobe activity was not affected by various concentrations of salt and metal ions and the bioprobe was able to detect and semi-quantify phenolic substrates in industrial effluent samples. These features of the bioprobe indicate that the commercialisation of such a bioprobe is feasible and this technology has been patented (Patent No. SA 97/0227).KMBT_363
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Meadows, Jane M. "Conditional sensitive whole cell biosensors for detection of pollutants in the natural environment." Thesis, University of Liverpool, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250276.
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LUDMERCZKI, ROBERT. "Carbon-based nanostructures in hybrid materials for detection and removal of water pollutants." Doctoral thesis, Università degli Studi di Cagliari, 2020. http://hdl.handle.net/11584/294538.
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The thesis is mainly focused on the better understanding of carbon dots (C-dots) formation in bottom-up syntheses, by identifying the key chemical processes and correlating them to the observed fluorescence. Therefore, several types of C-dots were studied, by systematically varying the used (molecular) precursor ratios and reaction times. Selected samples were surface functionalized by organosilanes to reveal the role of the C-dots surface functional groups in the overall photoluminescence. As better understanding of the ongoing processes finally achieved, the synthesized C-dots were applied in photocatalysis experiments by combining them with titania and an appropriate C-dot was tested as a nitrite ion sensor.
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Zhang, Haitao. "Development and application of the microanalytical systems for water pollutants determination." Thesis, Cachan, Ecole normale supérieure, 2013. http://www.theses.fr/2013DENS0032.
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Cette thèse concerne la détection des métaux lourds dans l’environnement et en particulier dans les eaux de surface et les sous-produits de désinfection de l’eau potable. Les deux catégories de contaminations ont des propriétés différentes de sorte que deux méthodes correspondantes ont été dévéloppées : l’une est basée sur des capteurs moléculaires fluorescents mis en oeuvre dans un micro-dispositif, l’autre est basée sur une détection électrochimique. Deux capteurs moléculaires fluorescents, Rhod-5N et DPPS-PEG, et plusieurs dispositifs microfluidiques ont été fabriqués et appliqués pour la détection des ions de métaux lourds, Cd (II) et Hg (II),dans les eaux de surface. Une nouveau circuit en PMMA est fabriqué par ablation laser femtoseconde et testé pour la détection de Cd2+ avec le Rhod-5N. De plus, des améliorations de la performance des circuits microfluidiques ont été faites. Une nouvelle méthode de détermination sensible de cinq acides haloacétiques (AHAs) dans les d'eaux a été développée. Elle est basée sur l'extraction électromembranaire (EME) avant électrophorèse capillaire avec détection de conductivité sans contact à couplage capacitif (CE-C4D)This thesis is aimed at environmental contaminations detection, mainly heavy metal ions in surface water and disinfection by-products (DBPs) in drinking water. The two categories of contaminations have different properties so that two correspondent methods were developed: one is based on fluorescent molecular sensors in a microfabricated device, the other one is based on conductive detection. Two fluorescent molecular sensors, Rhod-5N and DPPS-PEG, and several microfluidic devices were developed and applied for heavy metal ions Cd (II) and Hg (II) detection in surface water. A new microchip made of PMMA was fabricated by femtosecond laser ablation and tested for Cd (II) sensing based on a fluorescent molecular sensor Rhod-5N. Further more, some improvements of the performance of microfluidic chips were made. A novel method for sensitive determination of five priority haloacetic acids (HAAs) in water systems has been developed based on electromembrane extraction (EME) prior to capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-C4D)
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Oxspring, Darren A. "The detection and determination of selected organic pollutants by modern instrumental techniques of analysis." Thesis, University of Ulster, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241679.
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Bishop, Christopher. "Innovative sensors using nitride semiconductor materials for the detection of exhaust gases and water pollutants." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/54898.
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Microsensor technologies based on nitride semiconductor materials were developed as
options for improved exhaust gas sensors in diesel exhaust systems. The main goals were to develop new sensors that can meet the requirements given by Peugeot PSA to meet upcoming EU emissions regulations for NO, NO2, and NH3 detection. Two different sensor technologies were developed based on Schottky junction and high electron mobility transistor (HEMT) devices. Novel materials such as BGaN and BGaN/GaN superlattice structures are explored. For each device, a comprehensive analytical model is developed and simulations are carried out to optimize and design the sensor devices. Materials growth is then conducted for the different semiconductor layers, followed by materials characterizations to ensure high quality materials. Device prototypes are fabricated using various materials and functional layer designs. For device testing, an experimental setup is developed. Our experimental results show excellent sensitivity; we also report selectivity between NO and NO2 for the first time for these types of devices. Finally, we modify our devices for other sensing applications such as the detection of other harmful gases and pollutants in liquid environments.
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Abboo, Sagaran. "Phenolic compounds in water and the implications for rapid detection of indicator micro-organisms using ß-D-Galactosidase and ß-D-Glucuronidase." Thesis, Rhodes University, 2009. http://hdl.handle.net/10962/d1004037.
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Faecal contamination in water is detected using appropriate microbial models such as total coliforms, faecal coliforms and E. coli. Βeta-D-Galactosidase (β-GAL) and Beta-D-glucuronidase (β-GUD) are two marker enzymes that are used to test for the presence of total coliforms and E. coli in water samples, respectively. Various assay methods have been developed using chromogenic and fluorogenic substrates. In this study, the chromogenic substrates chlorophenol red β-D-galactopyranoside (CPRG) for β-GAL and p-nitrophenyl-β-D-galactopyranoside (PNPG) for β-GUD were used. Potential problems associated with this approach include interference from other organisms present in the environment (e.g. plants, algae and other bacteria), as well as the presence of certain chemicals, such as phenolic compounds in water. Phenolic compounds are present in the aquatic environment due to their extensive industrial applications. The USA Enviromental Protection Agency (EPA) lists 11 Priority Pollutant Phenols (PPP) due to their high level of toxicity. This study investigated the interfering effects of the eleven PPP found in water on the enzyme activities of both the β-GAL and β-GUD enzyme assays. The presence of these PPP in the β-GAL and β-GUD enzyme assays showed that over and underestimation of activity may occur due to inhibition or activation of these enzymes. Three types of inhibition to enzyme activities were identified from double reciprocal Lineweaver-Burk plots. The inhibition constants (Ki) were determined for all inhibitory phenolic compounds from appropriate secondary plots. Furthermore, this study presented a validated reverse phase high performance liquid chromatography (RP-HPLC) method, developed for the simultaneous detection, separation and determination of all eleven phenolic compounds found in the environment. This method demonstrated good linearity, reproducibility, accuracy and sensitivity. Environmental water samples were collected from rivers, streams, industrial sites and wastewater treatment plant effluent. These samples were extracted and concentrated using a solid phase extraction (SPE) procedure prior to analysis employing the newly developed HPLC method in this study. Seasonal variations on the presence of the PPP in the environment were observed at certain collection sites. The concentrations found were between 0.033 μg/ml for 2,4-dinitrophenol in a running stream to 0.890 mg/ml for pentachlorophenol from an tannery industrial site. These concentrations of phenolic compounds found in these environments were able to interfere with the β-GAL and β-GUD enzyme assays.
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Dale, Olivia R. "Detection, diversity, and activity on anaerobic ammonium oxidizing bacteria (Anammox) in the Cape Fear River Estuary /." Electronic version (PDF), 2007. http://dl.uncw.edu/etd/2007-1/r1/daleo/oliviadale.pdf.
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Guijarro, Řezníček Christian [Verfasser], and Stefan [Akademischer Betreuer] Wölfl. "Detection of pollutants in aquatic media using a cell-based sensor / Christian Guijarro Řezníček ; Betreuer: Stefan Wölfl." Heidelberg : Universitätsbibliothek Heidelberg, 2016. http://d-nb.info/1180735102/34.
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Wällstedt, Elin. "Development and preliminary evaluation of novel materials for selective detection of oseltamivir in waste water." Thesis, Linnéuniversitetet, Institutionen för biologi och miljö (BOM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-90571.
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This project aims to investigate whether it is possible to detect consentrations down to 0,3 µg/L of oseltamirir in waste water by Quartz Crystal Microbalance. The risks linked to this contaminant could be not only environmental, scientists have found that infuence recistence can propagate due to contaminats of this kind. Cases similar to the bird- and swine-flu could occure if the drug spreads through animals and mutate. Four systems of different character was synthesised. As a result it was found that MAA functional monomer systems probably was interfering with charges within it’s own nanowires. Reference systems could not detect 0,01 mg/mL and HEMA polymer surfaces was the only reliable system, pH of 5,1. Lowest limit of detection (LOD) was found in Molecular Imprinted Polymer nanowires (MIP Nw) at 0,01 mg/mL and could be scaled down to 0,1 mg/L with increased loop size (injection at 10x that of 0,01 mg/mL at about 500 µL and a halved flow rate.) An alternative could be nano structuring such as ”polystyrene balls” that possibly could be able to achieve surfaces with even more binding sites needed to detect the lowest limit at 0,3 µg/L.
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Young, Sarah Jane. "The detection of organic aqueous pollutants using inhibition of enzyme activity : a model system based on lactate dehydrogenase and pentachlorophenol." Thesis, University of the West of England, Bristol, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311878.
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Sioud, Salim. "Improvement of the detection of organic environmental pollutants and comprehension of the gas-phase chemical ionization mechanism using dopant-aided vacuum ultraviolet photoionization high- resolution mass spectrometry." Electronic Thesis or Diss., Sorbonne université, 2023. http://www.theses.fr/2023SORUS527.
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Des méthodes analytiques innovantes sont nécessaires pour surveiller ces polluants organiques en réponse au changement climatique. La spectrométrie de masse haute résolution couplée à la photoionisation à pression atmosphérique (APPI-HRMS) associée à la chromatographie liquide ultra-performante (UHPLC) est un outil de pointe pour l'analyse des molécules aromatiques apolaires. En effet, des mélanges multicomposants et un nouveau système de délivrance de dopants (tête d'impression piézoélectrique) ont été développés pour les applications APPI afin d'améliorer les performances d'ionisation et de détection des HAP en spectrométrie de masse à photoionisation à pression atmosphérique.Cela nous a permis de séparer et de détecter 14 des 18 HAP etudiés à de faibles concentrations en pg/µl avec des précisions de masse élevées de ≤4 ppm en 5 minutes. De plus, ces innovations ont amélioré de 2 à 10 fois les limites de détection et de quantification (LOD et LOQ) des HAP testés. Dans un second temps, afin de comprendre les mécanismes d'ionisation détaillés conduisant à la formation de cations radicaux ([M]+•), et a la formation d'ions [M–H]+ pour une classe de dérivés de TPD-N-substitués, de multiples études expérimentales ont été investiguées. Ainsi, un seul type de cation radicalaire, [M]+•, a été observé pour les HAP en utilisant des dopants multicomposants à base d'éthanol. D'autre part, les ions [M–H]+ pour les dérivés N-alkyl-TPD ont été observés en plus grande abondance dans les conditions APPI. De plus, le dopant de type benzène halogéné et la longueur de la chaîne alkyle (CnH2n+1), avec n ≥4, ont influencé la formation des ions [M–H]+Innovative analytical methods are needed to monitor these organic pollutants in response to climate change. High-resolution mass spectrometry coupled with atmospheric pressure photoionization (APPI-HRMS) associated with ultra-performance liquid chromatography (UHPLC) is a state-of-the-art tool for the analysis of non-polar aromatic molecules. Indeed, multicomponent mixtures and new dopant delivery system (piezoelectric printhead) have been developed for APPI applications to improve the ionization and detection performance of PAHs during atmospheric pressure photoionization mass spectrometry. This allowed us to separate and detect 14 of the 18 studied PAHs at low pg/µl concentrations with high mass accuracies of ≤4 ppm in 5 minutes. In addition, these innovations improved the limits of detection and quantification (LOD and LOQ) of the PAHs tested by 2 to 10 times. Secondly, in order to understand the detailed ionization mechanisms leading to the formation of radical cations ([M]+•), and to the formation of [M–H]+ ions for a class of derivatives of TPD- N-substituted, multiple experimental studies have been investigated. Thus, only one radical cation type, [M]+•, was observed for PAHs using ethanol-based multicomponent dopants. On the other hand, [M–H]+ ions for N-alkyl-TPD derivatives were observed in greater abundance under APPI conditions. In addition, the halogenated benzene-type dopant and the length of the alkyl chain (CnH2n+1), with n ≥4, influenced the formation of [M–H]+ ions
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Olvera, Vargas Hugo. "Study on the fate of pharmaceuticals in aqueous media : synthesis, characterization and detection of biotic and abiotic transformation products using electrochemical advanced oxidation processes and bioconversions." Thesis, Paris Est, 2014. http://www.theses.fr/2014PEST1179/document.
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La pollution des eaux superficielles et souterraines par des composés organiques est bien connue comme une préoccupation majeure de l'environnement dans de nombreux pays. Si les polluants prioritaires sont actuellement surveillés par la directive cadre européenne sur l'eau, il est désormais urgent de prendre en considération les nouveaux polluants dérivés de principes actifs des produits pharmaceutiques et d'identifier leurs produits de transformation à risque. Ce travail de thèse propose une étude globale sur l'état et l'avenir des produis pharmaceutiques dans l'environnement, sur l'exemple de deux pharmaceutiques choisis, dans le cadre de cette importante problématique environnementale. Nous avons donc appliqué les procédés électrochimiques d'oxydation avancée, électro-Fenton (EF), oxydation anodique(OA) et photoélectro-Fenton solaire (PEFS), ainsi que le couplage électro-Fenton/traitement biologique pour une élimination effective des polluants médicamenteux furosémide et ranitidine. Les résultats obtenus confirment l'efficacité de ces technologies électrochimiques pour la minéralisation quasi-totale des produits pharmaceutiques étudiés. En outre, l'utilisation du pré-traitement par EF suivi d'un procédé biologique confirme la capacité de l'EF de transformer les polluants organiques en produits biodégradables qui peuvent être consommés par des microorganismes lors d'un traitement biologique, démontrant ainsi l'applicabilité potentiel de cette technique combinée, en termes d'une consommation énergétique réduite. L'identification des produits de transformation (PTs) des pharmaceutiques étudiés par voie électrochimique (électro-oxydation) et biologique (bioconversion) a été effectuée par différentes techniques d'analyse physico-chimiques. La biotransformation du FRSM a conduit à la formation de trois PT principales; saluamide, pyridinium et un dérivé céto-alcool. Les deux premiers ont aussi été détectés lors du traitement électrochimique, ce qui suggère la probabilité de les trouver dans l'environnement comme les produits de transformation les plus plausibles par des différentes conditions de dégradation. Les tests de toxicité basés sur l'inhibition de la bioluminescence des bactéries marines Vibrio fischeri ont montré que certains PT formés lors de traitement électrochimiques sont plus toxique que la molécule mère, car une augmentation de la toxicité globale de la solution a été observée au début des électrolyses. Néanmoins, la toxicité de la solution est complètement éliminée à la fin des traitements électrochimiques, ce qui indique l'efficacité de ces technologies aussi pour la détoxification des solutions des médicaments traités. Par conséquent, cette étude constitue une contribution importante à l'évaluation des risques environnementaux des produits pharmaceutiquesThe present project contributes with valuable data for a better fundamental understanding on the fate of pharmaceutical residues in the environment, dealing with the main challenges concerning this increasingly worrying environmental issue. The used Electrochemical Advanced Oxidation Processes (EAOPs), electro-Fenton (EF) and anodic oxidation (AO), showed to be a very efficient alternative for the mineralization of acid solutions of the pharmaceuticals RNTD and FRSM, attaining almost complete mineralization of the drugs after 6h of electrolysis. A comparative study on the mineralization of RNTD solutions by EF and SPEF processes in a 2.5 L capacity pre-pilot flow plant demonstrates the higher oxidation capacity of SPEF, achieving very good mineralization rates, thus evidencing the potentiality of this technology at greater scale for the treatment of wastewaters containing pharmaceutical products. The application of an EF pre-treatment coupled with a biological process for the degradation of both drugs was conducted. EF pre-pretreatment was capable of enhancing the solution biodegradability envisaging a biological treatment, which efficiently removed the short-chain carboxylic acids that had been formerly generated during the pre-applied electrolysis. In this way, the combination of both processes was confirmed as a very promising technology for the treatment of pharmaceuticals-containing wastewater. Several transformation products (TPs) were detected and identified during the electrochemical oxidation of the studied drugs. Toxicity tests based on the bioluminescence of the marine bacteria V. fischeri. evidenced the toxicity some of these oxidation by-products, since the toxicity of the solution increased on the first stages of the electrolysis. However, the abatement of the toxicity in the final stages of the electrochemical treatments, demonstrated the effectiveness of these technologies for both the mineralization and detoxification of the RNTD and FRSM solutions. The use of the fungi Cunninghanella echinulate for the bioconversion of FRSM led to the formation of three main bio-transofrmation products: the previously identified saluamide and pyridinium, and the new detected keto-alcohol derivate. These TPs were generated by both, biological and electrochemical approches, evidencing their high probability to be found in environmental compartments as the most likely TPs of FRSM by different oxidation conditions. This study is thus presented as a very useful alternative for the assessment of the fate of pharmaceutical residues in the environment
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Olvera, Vargas Hugo. "Study on the fate of pharmaceuticals in aqueous media : synthesis, characterization and detection of biotic and abiotic transformation products using electrochemical advanced oxidation processes and bioconversions." Electronic Thesis or Diss., Paris Est, 2014. http://www.theses.fr/2014PEST1179.
Full textAbstract:
La pollution des eaux superficielles et souterraines par des composés organiques est bien connue comme une préoccupation majeure de l'environnement dans de nombreux pays. Si les polluants prioritaires sont actuellement surveillés par la directive cadre européenne sur l'eau, il est désormais urgent de prendre en considération les nouveaux polluants dérivés de principes actifs des produits pharmaceutiques et d'identifier leurs produits de transformation à risque. Ce travail de thèse propose une étude globale sur l'état et l'avenir des produis pharmaceutiques dans l'environnement, sur l'exemple de deux pharmaceutiques choisis, dans le cadre de cette importante problématique environnementale. Nous avons donc appliqué les procédés électrochimiques d'oxydation avancée, électro-Fenton (EF), oxydation anodique(OA) et photoélectro-Fenton solaire (PEFS), ainsi que le couplage électro-Fenton/traitement biologique pour une élimination effective des polluants médicamenteux furosémide et ranitidine. Les résultats obtenus confirment l'efficacité de ces technologies électrochimiques pour la minéralisation quasi-totale des produits pharmaceutiques étudiés. En outre, l'utilisation du pré-traitement par EF suivi d'un procédé biologique confirme la capacité de l'EF de transformer les polluants organiques en produits biodégradables qui peuvent être consommés par des microorganismes lors d'un traitement biologique, démontrant ainsi l'applicabilité potentiel de cette technique combinée, en termes d'une consommation énergétique réduite. L'identification des produits de transformation (PTs) des pharmaceutiques étudiés par voie électrochimique (électro-oxydation) et biologique (bioconversion) a été effectuée par différentes techniques d'analyse physico-chimiques. La biotransformation du FRSM a conduit à la formation de trois PT principales; saluamide, pyridinium et un dérivé céto-alcool. Les deux premiers ont aussi été détectés lors du traitement électrochimique, ce qui suggère la probabilité de les trouver dans l'environnement comme les produits de transformation les plus plausibles par des différentes conditions de dégradation. Les tests de toxicité basés sur l'inhibition de la bioluminescence des bactéries marines Vibrio fischeri ont montré que certains PT formés lors de traitement électrochimiques sont plus toxique que la molécule mère, car une augmentation de la toxicité globale de la solution a été observée au début des électrolyses. Néanmoins, la toxicité de la solution est complètement éliminée à la fin des traitements électrochimiques, ce qui indique l'efficacité de ces technologies aussi pour la détoxification des solutions des médicaments traités. Par conséquent, cette étude constitue une contribution importante à l'évaluation des risques environnementaux des produits pharmaceutiquesThe present project contributes with valuable data for a better fundamental understanding on the fate of pharmaceutical residues in the environment, dealing with the main challenges concerning this increasingly worrying environmental issue. The used Electrochemical Advanced Oxidation Processes (EAOPs), electro-Fenton (EF) and anodic oxidation (AO), showed to be a very efficient alternative for the mineralization of acid solutions of the pharmaceuticals RNTD and FRSM, attaining almost complete mineralization of the drugs after 6h of electrolysis. A comparative study on the mineralization of RNTD solutions by EF and SPEF processes in a 2.5 L capacity pre-pilot flow plant demonstrates the higher oxidation capacity of SPEF, achieving very good mineralization rates, thus evidencing the potentiality of this technology at greater scale for the treatment of wastewaters containing pharmaceutical products. The application of an EF pre-treatment coupled with a biological process for the degradation of both drugs was conducted. EF pre-pretreatment was capable of enhancing the solution biodegradability envisaging a biological treatment, which efficiently removed the short-chain carboxylic acids that had been formerly generated during the pre-applied electrolysis. In this way, the combination of both processes was confirmed as a very promising technology for the treatment of pharmaceuticals-containing wastewater. Several transformation products (TPs) were detected and identified during the electrochemical oxidation of the studied drugs. Toxicity tests based on the bioluminescence of the marine bacteria V. fischeri. evidenced the toxicity some of these oxidation by-products, since the toxicity of the solution increased on the first stages of the electrolysis. However, the abatement of the toxicity in the final stages of the electrochemical treatments, demonstrated the effectiveness of these technologies for both the mineralization and detoxification of the RNTD and FRSM solutions. The use of the fungi Cunninghanella echinulate for the bioconversion of FRSM led to the formation of three main bio-transofrmation products: the previously identified saluamide and pyridinium, and the new detected keto-alcohol derivate. These TPs were generated by both, biological and electrochemical approches, evidencing their high probability to be found in environmental compartments as the most likely TPs of FRSM by different oxidation conditions. This study is thus presented as a very useful alternative for the assessment of the fate of pharmaceutical residues in the environment
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Newkirk, Scott Hunter. "Detection levels of drinking water contaminants using field portable ultraviolet and visible light (uv/vis) spectrophotometry /." Download the thesis in PDF, 2005. http://www.lrc.usuhs.mil/dissertations/pdf/NEWKIRK2005.pdf.
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Schiwy, Andreas Herbert [Verfasser], Henner [Akademischer Betreuer] Hollert, and Andreas [Akademischer Betreuer] Schäffer. "The nanotoxicology of a newly developed zero-valent iron nanomaterial for groundwater remediation and its remediation efficiency assessment combined with in vitro bioassays for detection of dioxin-like environmental pollutants / Andreas Herbert Schiwy ; Henner Hollert, Andreas Schäffer." Aachen : Universitätsbibliothek der RWTH Aachen, 2016. http://d-nb.info/1130792668/34.
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Wahman, Rofida Mostafa Ali [Verfasser], Thomas [Akademischer Betreuer] Letzel, Jörg E. [Gutachter] Drewes, Thomas [Gutachter] Letzel, and Peter [Gutachter] Schröder. "Pathway effect studies of different environmental pollutants on Lemna minor and Phragmites australis metabolism using polarity-extended chromatographic separation with mass spectrometric detection / Rofida Mostafa Ali Wahman ; Gutachter: Jörg E. Drewes, Thomas Letzel, Peter Schröder ; Betreuer: Thomas Letzel." München : Universitätsbibliothek der TU München, 2021. http://nbn-resolving.de/urn:nbn:de:bvb:91-diss-20210923-1615432-1-3.
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BARBIERI, CRISTINA B. "Caracterização de crime ambiental de poluição por meio de abordagem multiparamétrica e incorporando incerteza de amostragem." reponame:Repositório Institucional do IPEN, 2015. http://repositorio.ipen.br:8080/xmlui/handle/123456789/26391.
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Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2016-06-22T13:58:45Z
No. of bitstreams: 0Made available in DSpace on 2016-06-22T13:58:45Z (GMT). No. of bitstreams: 0
Tese (Doutorado em Tecnologia Nuclear)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Coelho, Lúcia Helena Gomes. "Desenvolvimento de métodos para coleta e determinação de poluentes em fase gasosa da atmosfera utilizando amostragem por difusão com membranas capilares microporosas." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/46/46133/tde-26042010-144931/.
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A tese enfatiza o desenvolvimento e aplicação de amostradores difusionais para pré-concentração de traços de poluentes gasosos e sua conjugação com técnicas de separação e determinação, especialmente, a eletroforese capilar. Foram implementadas novas aplicações para um amostrador com múltiplos filamentos microporosos de polipropileno, previamente desenvolvido pelo grupo de pesquisa, e para o novo dispositivo de coleta de dimensões reduzidas, composto por monofilamento microporoso de polipropileno (CMDS) com volume interno de 30 µL. Para o estabelecimento da vazão estável em 1,0 µL min-1 de fase aceptora pelo capilar poroso, recorreu-se à pressurização do reservatório com uma bomba pneumática de aquário e regulagem de vazão por um capilar de sílica fundida e uma válvula de agulha. Outra bomba pneumática foi utilizada para aspirar o fluxo de ar amostrado. As amostras foram coletadas seqüencialmente em frascos de 200 µL, mantidos sob temperatura reduzida em unidade de refrigeração do tipo Peltier acoplado ao amostrador. O CMDS monofilamentar, mais compacto e robusto, apresentou alta eficiência de coleta para a pré-concentração de formaldeído (CH2O), ácidos fórmico e acético e amônia da fase gasosa da atmosfera. Para as espécies com elevada constante de Henry, água deionizada serviu como fase aceptora, enquanto que para amônia, recorreu-se ao deslocamento do equilíbrio por um aceptor ácido, de modo a reter o analito na forma de NH4 +. A concentração das espécies em fase líquida foi determinada posteriormente por eletroforese capilar com detecção condutométrica sem contato (CE-C4D). Os limites de detecção, em fase líquida, para formiato, acetato, formaldeído (determinado na forma do aduto hidroximetanosulfonato HMS) e amônio foram estimados em 1,0, 1,5, 1,2 e 1,2 µmol L-1, respectivamente (equivalentes à 0,9, 3,0, 1,0 e 0,7 µg m-3 dessas espécies na atmosfera, respectivamente). Para a determinação de CH2O por injeção em fluxo (FIA) acoplada à detecção amperométrica em eletrodo de ouro platinizado, fez-se uso do coletor multifilamentar, por atender melhor à necessidade de volume de amostra. A interferência de espécies comumente presentes na atmosfera, como H2O2 e SO2, pôde ser contornada realizando coletas em presença de peróxido de hidrogênio para promover a oxidação do S(IV) à S(VI) e, posteriormente, destruindo o oxidante em reator contendo enzima catalase imobilizada. A determinação de CH2O foi implementada com sucesso por FIA com detecção por amperometria em eletrodo de ouro platinizado. Um CMDS portátil que funciona à pilha, próprio para amostragens em campo, foi desenvolvido utilizando, para o deslocamento do ar amostrado, uma bomba de pistão retirada de aparelho automático para medida de pressão arterial. O amostrador foi empregado na coleta de H2S, SO2 e alquil-mercaptanas em fase gasosa da atmosfera, utilizando fase aceptora alcalina para promover a desprotonação e conseqüente fixação das espécies em meio líquido. Os analitos foram determinados por CE-C4D ou por microextração em fase sólida (SPME) seguida de determinação por GC. O uso conjunto do antioxidante ascorbato para conservação das amostras e de etanol para fixação dos compostos voláteis em meio aquoso permitiu o estabelecimento de um protocolo completo para coleta e detecção dessas espécies reduzidas de enxofre, com sensibilidade suficiente para monitorar emissões de origem biogênica, o que foi exemplificado na prática coletando amostras próximo a um córrego contaminado com esgoto. A perfeita combinação do diminuto volume de fase aceptora do CMDS com a demanda de nanolitros de amostra da CE-C4D culminou com o desenvolvimento de um sistema de análise total (TAS) com gerenciamento de fluidos baseado em propulsão por bombas de aquário (de baixo custo e alta durabilidade) e válvulas solenóide de estrangulamento, controladas por computador. Como exemplo de aplicação inovador e bem sucedido do TAS desenvolveu-se a análise concomitante e em tempo quase real de ácidos fórmico e acético no ar, com freqüência de 10 pares de dados por hora. As vantagens do sistema CMDS-CE-C4D incluem simplicidade, versatilidade, consumo de reagentes e amostra e geração de resíduos minimizada, robustez e rapidez enquanto uma amostra é coletada, o eletroferograma da anterior é adquirido sem necessidade de bombas de alta pressão ou colunas dispendiosas como as requeridas para HPLCThe development and application of porous membrane diffusion samplers for fast and efficient pre-concentration of an array of trace air pollutants was emphasized in this thesis, in conjunction with compatible separation and determination techniques, especially capillary electrophoresis. New applications were found for a formerly developed diffusion scrubber based on a bundle of microporous hollow polypropylene capillary membranes and for a scaled down version with a single core capillary membrane diffusion scrubber (CMDS) comprising an internal volume of 30 µL, were used for sampling of the trace level pollutants to an adequate liquid acceptor. The low-flow of acceptor solution, 1.0 µL min-1, required by the CMDS was satisfied by pressurization of the reservoir with an aquarium pump combined with flow regulation by a silica capillary as hydrodynamic resistor and a needle valve. Another aquarium pump was used for the aspiration of the sampled air through the sampler. The low volumes collected in the CMDS were stored in 200 µL vials inserted in a cooling plate of a Peltier device. The robust and compact system was used for sampling of formaldehyde (CH2O), formic acid, acetic acid and ammonia in the gaseous phase of the atmosphere. For chemical species with high Henry´s constant, deionized water suffices as acceptor phase. Otherwise, equilibria displacement to a non-volatile ion, like NH4 + for NH3 sampling, promoted quantitative retention in the acceptor phase. The concentrations of the analytes in the liquid phase were determined by capillary electrophoresis with capacitively coupled contactless conductometric detection (CEC4D). The detection limits obtained in the liquid phase for formate, acetate, formaldehyde (in the form of the adduct hydroxymethanesulfonate HMS) and ammonium were 1,0, 1,5, 1,2 e 1,2 µmol L-1 respectively (what corresponds to 0,9, 3,0, 1,0 e 0,7 µg m-3 of the respective gaseous species in the air). The higher volume of acceptor phase provided by the sampler with a bundle of microporous membrane capillaries (~600 µL) are in tune with the needs of flow injection analysis (FIA), as demonstrated for amperometric detection of CH2O on a platinized gold electrode. The interferences from SO2 and H2O2 were overcome by adding H2O2 to the acceptor solution to promote the oxidation of S(IV) to S(VI) and destruction of the oxidant afterwards in a column with immobilized catalase enzyme. The aquarium pump used for gas aspiration was substituted to a piston pump, taken from arterial blood pressure meter fed with 8 V D.C., to turn possible field collections with the CMDS device. The system was used for the sampling of H2S, SO2 e alkyl-mercaptans in the gaseous phase of the atmosphere. To succeed on that, the samplings were performed in alkaline media to promote deprotonation of the species (and stabilization in non-volatile forms). The collected analytes were determined by CE-C4D or by solid phase microextraction (SPME) followed by GC analysis. The joint use of the antioxidant ascorbate for sample preservation and ethanol for fixation of the volatile compounds allowed the establishment of a complete protocol for sampling, storage and detection of the sulfur reduced species with enough sensitivity for monitoring biogenic emissions from waste discharge. Perfect matching of the low-volume characteristics of the CMDS device and the CE-C4D equipment led to the conception of a low-cost automatic CMDS-CE-C4D total analysis system (TAS) and its innovative and successful application to near-realtime simultaneous analysis of formic acid and acetic acid in air. During the evaluation of one sample, the TAS collects a new one, with valves, pumps and high voltage delivery under software control. Advantages include rapidity (10 data points per hour for each analyte), high preconcentration efficiency, simplicity and versatility, minimum sample and reagent consumption and residue generation (green analytical method), no need of costly high pressure pumps and separation columns like those used in HPLC
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Abbas, Khalid Khudhair. "Development of a Hybrid Multi-Functional Adsorbent-Solar-Photocatalyst for Detecting and Removing Toxic Heavy Metals and Refractory Pollutants from Water/Wastewater." Thesis, Curtin University, 2018. http://hdl.handle.net/20.500.11937/73520.
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In this thesis, treating portable water from hazardous pollutants such as dyes were studied by preparing TiO2/ZSM-5 mesoporous and modified RGO/TiO2/ZSM-5 mesoporous. Additionally, novel optical conjugated mesoporous adsorbents were prepared to treat portable water from heavy metal ions such as Hg2+ and Pb2+. Results show significant improvement over previous efforts by researchers. The work presented here has profound implications for future studies of wastewater treatment, and may one day help solve the problem of water scarcity.
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黃志偉 and Chi-wai Wong. "Analysis of trace ionic compounds and environmental pollutants in gas and liquid media by (A) Piezoelectric quartz crystal detector and (B)ultramicroelectrode." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B31239432.
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Wong, Chi-wai. "Analysis of trace ionic compounds and environmental pollutants in gas and liquid media by (A) Piezoelectric quartz crystal detector and (B) ultramicroelectrode /." Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B20577102.
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Baumgarten, Guilherme. "Développement et caractérisation d’une sonde RMN portable appliquée au suivi de la qualité de l’eau et à l’étude de la cinétique des réactions chimiques." Electronic Thesis or Diss., Strasbourg, 2024. http://www.theses.fr/2024STRAD014.
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La spectroscopie de résonance magnétique nucléaire (RMN) est une technique amplement utilisée pour la détection et la quantification de composés chimiques avec un spectre d’application très large. Dans ce manuscrit, deux d’entre eux sont traités : la détection de polluants dans l'eau potable et la surveillance des réactions chimiques. Alors que les équipements de RMN de laboratoire présentent des résultats d'analyse très fiables, la RMN portable est un domaine de recherche en évolution avec de multiples défis technologiques et d’autres liés aux applications ciblées. Les dispositifs RMN portables émergents présentent cependant comme avantage évidente par rapport aux dispositifs classiques leur utilisation directe sur le terrain. Cela permet ainsi d’avoir des résultats d’analyses plus rapidement et de limiter les coûts de personnel et de consommables. Afin de concevoir des spectromètres RMN portables, on doit faire des compromis de conception, tout en étant capable de comprendre les enjeux liés à ces choix, afin que le produit final puisse toujours répondre aux exigences des applications concernées. Pour cela, nous proposons une chaîne d'outils de simulation RMN complète, capable de générer divers aboutissements correspondant à un spectromètre RMN réel. En outre, nous développons une preuve de concept de l’électronique de contrôle et d’acquisition basée sur des composants commerciaux disponibles et nous la validons sur notre prototype de spectromètre RMN portable. Finalement, ce prototype est utilisé pour évaluer le potentiel de la RMN portable pour les applications citées ci-dessus. Cette étude nous a permis d’identifier les limites du dispositif actuel et de proposer un cahier des charges visant son amélioration continueNuclear Magnetic Reaction (NMR) spectroscopy is a widely employed technique in the detection and quantification of chemical compounds, with a wide range of applications. In this manuscript, the focus is put on two of them: the detection of pollutants in drinking water and the monitoring of chemical reactions. While laboratory NMR equipment presents highly reliable analysis results, portable miniaturized NMR is an evolving research field with multiple technological and application-related challenges. Such emerging devices present however a clear advantage when compared to the classic, stablished ones: it can be used in the field, therefore saving time and limiting staff and consumables costs. In order to design NMR spectrometers to attain the desired portability and miniaturization, one has to compromise, however being able to understand what is at stake, so that the final product still meets the demands. For that, we propose a complete NMR simulation toolchain capable of generating diverse outcomes corresponding to a real NMR spectrometer. Furthermore, we develop a proof of concept for an electronic control and acquisition unit based on commercial-off-the-shelf components and validate it on a portable NMR spectrometer prototype. Finally, we use this prototype to assess the potential of portable miniaturized NMR for the targeted applications cited above. This study allowed us to identify the limits of our current prototypical device and to provide directions for its further improvement
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Šesták, Zbyněk. "Marketingová strategie vyvíjeného přípravku na detekci polutantů." Master's thesis, Vysoká škola ekonomická v Praze, 2012. http://www.nusl.cz/ntk/nusl-191559.
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The main objective of this thesis is to develop marketing strategy for pollutant detector in the development. The first part of the thesis focuses on the environmental issues, pollutant measuring technologies and on bioluminescence bacteria which are used in the detector. The detector is designed for companies which get in touch with selected dangerous elements (mercury, cadmium, lead, BTEX and PCBs) within their business activities. That is why the next part is about B2B specifics as companies are targeted customers. Various marketing theories are applied to set marketing strategy. It starts with situation analysis which involves PEST analysis, Porter's five forces analysis and SWOT analysis. Based on analyzed information and responses given in online questionnaire the perspective markets are identified, positioning set up, and product, price, distribution and communication policy specified.
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Boson, Jonas. "Improving accuracy of in situ gamma-ray spectrometry." Doctoral thesis, Umeå : Umeå University, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1805.
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Lepot, Mathieu. "Mesurage en continu des flux polluants en MES et DCO en réseau d'assainissement." Phd thesis, INSA de Lyon, 2012. http://tel.archives-ouvertes.fr/tel-00782324.
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Les débitmètres sont des technologies connues et fortement répandues mais pas exemptes d'erreurs, dont les causes peuvent être assez variées. Ces capteurs installés dans les systèmes d'assainissement ne sont de plus pas rigoureusement étalonnables in situ. Une méthode de vérification in situ des débitmètres, utilisable pour des pseudos étalonnages, est présentée. En effet, l'injection ponctuelle d'un traceur dans un écoulement permet de calculer le débit et son incertitude d'une manière indépendante des sondes en place. Cette méthodologie, en sept étapes, offre des résultats comparables à ceux fournis par des méthodes considérées comme des références (traçages aux sels et débitmètre électromagnétique). Des premiers essais en réseaux unitaires ont été réalisés pour la vérification de débitmètres (le long d'un collecteur du Grand Lyon) et pour le calage de courbes de tarages (sur le Syndicat Intercommunal d'Assainissement Grand Projet). Pour les mesures qualitatives des effluents, de nombreuses études antérieures ont montrées de bonnes corrélations entre les concentrations en polluants et les signaux fournis par des turbidimètres et des spectromètres UV/visible. Un pilote expérimental et des campagnes d'échantillonnages sur des effluents prétraités de la station d'épuration de Fontaines sur Saône ont été mis en place pour répondre aux objectifs suivants : i) concevoir et tester un site de mesure de nouvelle génération, ii) chercher des modèles de régressions entres différents capteurs (turbidimètres mono et bi-longueur(s) d'onde(s), conductimètre, pHmètre, spectromètre UV/visible, capteurs à micro-ondes) et les concentrations en polluants pour les échantillons de temps sec, de temps de pluie et la totalité, iii) caractériser la performance de ces modèles et iv) tester la robustesse des méthodes proposées sous des conditions atypiques mais susceptibles d'être rencontrées en réseau d'assainissement. Les résultats confirment les bonnes corrélations entre certains paramètres (turbidité, conductivité et spectre UV/visible) et les concentrations en polluants. Aucun capteur n'est le plus performant pour l'ensemble des polluants. La majorité des capteurs délivrent des estimations comparables aux incertitudes près mais ces estimations sont peu voire pas redondantes aux analyses effectuées sur les échantillons. La conception du banc (et les variations des matrices des eaux usées) et/ou les conditions expérimentales lors des tests de robustesse sont peut être en cause.
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Delmarre, David. "Incorporation de porphyrines dans les matrices sol-gel : études spectroscopiques et application à la détection de polluants." Cachan, Ecole normale supérieure, 1998. http://www.theses.fr/1998DENS0024.
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Le but de ce travail de thèse était de réaliser des capteurs de molécules polluantes à l'aide de porphyrines incorporées dans des matrices sol-gel. La première partie de ce travail a été consacrée a l'étude des interactions entre molécules sondes et environnement local en solution et en milieu sol-gel. Ceci a été réalisé à l'aide de porphyrines d'étain qui se sont révélés sensibles aux effets de solvant et au ph. Puis dans un second temps a l'aide de porphyrines non-métallées a cause de leur sensibilité aux variations de ph qui ont permis de calculer le ph à l'intérieur des matrices sol-gel. Une fois les interactions entre molécules sondes et matrice mieux comprises, la deuxième partie de cette thèse a consiste à étudier les interactions entre molécules sondes et polluants. Les études ont été menées dans un premier temps en solution puis en milieu sol-gel. La détection d'amine a pu être réalisée en utilisant une porphyrine de cobalt greffable. Le seuil de détection de la pyridine est de 100g/l. La deuxième partie a consisté à étudier la détection des sels de métaux lourds par des porphyrines non-métallées. Les matériaux sol-gel ne se sont pas révélés intéressants pour ce type de détection mais il a été montre que 90% des ions diffusent dans la matrice, cette propriété pourrait se révéler intéressante dans la purification de l'eau. Enfin une nouvelle structure permettant de limiter les interactions en ions et matrice semble être prometteuse pour la détection des ions métalliques.
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Li, Yueh-Fen. "Biological assays for the detection and measurement of environmental pollutants." 2006. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-1407200615085700.
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Li, Yueh-Fen, and 李悅芬. "Biological assays for the detection and measurement of environmental pollutants." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/69766803084412400787.
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碩士國立臺灣大學
生物環境系統工程學研究所
94
The environmental pollution threatens human health as well as wildlife in the past decades. As a result, it is necessary to develop sensitive, effective, and inexpensive methods which can efficiently monitor and determine the presence and amount of hazards in the environment. In this study, we report two biologically analytical methods to detect and measure the environmental pollutants. Firstly, we describe the construction and characterization of the fluorescent and the luminescent Escherichia coli whole-cell biosensors for the detection of bioavailable toluene and its related compounds. The biosensor strains Escherichia coli DH5α carrying pTOLGFP or pTOLLUX were developed based on the expression of reporter genes: gfp or luxCDABE under the control of the Pu promoter and xylR gene of Pseudomonas putita plasmid pWW0. To assess their applicability for analyzing environmentally relevant samples, the biosensor harboring pTOLLUX was field-tested on water and soil samples collected from toluene contaminated sites. Our results demonstrate that nonpathogenic bacterial biosensors developed in the present study is useful and applicable in determining the bioavailability of toluene and its related compounds with high sensitivity in environmental samples, and they suggest a potential for its inexpensive application in field-ready tests. Secondly, alterations of glutathione levels as well as the mRNA levels of HSP70 in tilapia fish were investigated under arsenite exposure. Tilapia fish were exposed to waterborne arsenite (0, 1, 2, and 4 ppm, respectively) for 1 day and 3 day exposure duration. After the treatment, arsenite concentrations in gill, intestine, liver, and muscle were measured by means of inductively coupled plasma (ICP). Meanwhile, the GSH contents in fish tissues were measured and the mRNA expression of HSP70 was analyzed with semi-quantitative RT-PCR. Our results indicate that HSP70 mRNA expression and GSH levels exhibited a correlation with the arsenite exposure condition as well as the arsenic accumulation, indicating their usefulness as the biomarker of arsenite exposure in tilapia. Furthermore, the bioaccumulations of arsenic differentially distributed in various fish tissues assist in providing information of bioavailability. We conclude that biological assays, such as bacterial biosensors and biomarker presented in this study, for detecting and determining the environmental contaminants can compensate the disadvantages of traditional analytical methods such as not capable to reflect the bioavailability and failing to show the effects of contaminants mixtures on organisms, and thus providing critical data that can be useful in risk assessment.
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Dai, Zi-Chi, and 戴子琪. "Fabrication of Nanomaterial Modified Electrodes for Electrochemical Detection of Environmental Hazardous Pollutants." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/s2x6dh.
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碩士國立臺北科技大學
化學工程研究所
104
In this work, we reported nanomaterials modified electrodes for electrochemical detection of environmental hazardous pollutants. First, we report a general and facile electrochemical synthesis strategy of Cu2O (nanocubes, nanosheets and nanoflower) nanostuctured materials deposited on glassy carbon electrodes (GCEs) surface for the electrochemical detection of .toxic 4-Nitrophenol (4-NP) sensor. Notably, the proposed sensor exhibits an excellent analytical parameters, such as widelinear range, high sensitivity with good detection limit, and the values are 0.006-2.72 mM, 197.7 µA mM -1 cm -2 and 0.5 µM, respectively. This result reveals that Cu2O modified GCE is more suitable for the detection of 4-NP due to its low cost with simple electrode preparation process and also successfully applied for the detection of 4-NP in various water samples with acceptable results, could act as practical platform in several industrial practical applications. Second, we report a highly sensitive electrochemical determination of nitrobenzene based on effect of β-Cyclodextrin (β-CD) entrapped graphene oxide (GO) composite modified screen printed carbon electrode. The GO/β-CD composite was prepared by a simple sonication of β-CD in aqueous solution of GO. The electrocatalytic activity of nitrobenzene shows higher in GO/β-CD composite with a lower overpotential compared with bare, GO and β-CD modified SPCEs. By applying Linear sweep voltammetry, the GO/β-CD modified SPCE detects the linear concentration range from 0.5µM to 96.5µM with a limit of detection of 0.184 µM. The GO/β-CD modified SPCE also exhibits high sensitivity, wide dynamic response range, the acceptable repeatability and long stability towards the determination of nitrobenzene. In addition, the developed sensor is thus promising for the determination of nitrobenzene in different water samples. Finally, we report a simple hydrothermal synthesis method for the fabrication of glucose-derived sheet like carbon-nickel oxide (GDC/NiO) nanocomposites using glucose as carbon precursor. Fascinatingly, we report a novel hydrazine and hydrogen peroxide (H2O2) sensor based on low-cost as-prepared sheet-like GDC/NiO nanocomposite. The sensitive and selective sensors were fabricated by GDC/NiO modified glassy carbon electrode (GCE) and ring-disc electrode by using cyclic voltammetry and amperometry (i-t) methods. Notably, the GDC/NiO-300℃ modified GCE exhibits with a well-resolved sharp peak at a very lower over oxidation potential of 0.13 V toward hydrazine and H2O2 oxidation. It is found that the resulting sensor shown excellent electrocatalytic performance toward hydrazine and H2O2 detection with wide linear ranges, lower detection limit, and ultra-high sensitivities. The results reveal that GDC/NiO nanocomposites could be used for the hydrazine and H2O2 detection with simplicity, low cost, repeatability and stability, meet as a practical platform for several industrial biosensing applications. All the reported materials are characterized by a variety of analytical and spectroscopic techniques such as SEM, XRD, FT-IR, UV-Vis, EIS and electrochemical methods.
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Bartie, Catheleen. "Evaluation of detection methods for Legionella in industrial cooling water systems." Thesis, 2002. http://hdl.handle.net/2263/29471.
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Please read the "Background" (p v) in the section 00front of this document Copyright 2002, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. Please cite as follows: Bartie, C 2002, The life and career of the South African dramatric soprano Marita Napier, DPhil thesis, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-11142007-125718 / >Thesis (DPhil (Microbiology))--University of Pretoria, 2007.
Microbiology and Plant Pathology
unrestricted
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Ndlovu, Thabile. "Electrochemical detection of organic and inorganic water pollutants using recompressed exfoliated graphite electrodes." Thesis, 2012. http://hdl.handle.net/10210/8091.
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Ph.D.This study explored the possible application of a relatively new electrode called exfoliated graphite electrode (EG electrode) in the electroanalysis of organic and inorganic water pollutants. This study also explored the applicability of this electrode in the removal of heavy metal pollutants in water. The EG material was successfully prepared by intercalating bisulphate ions into graphite flakes (>300 μm) followed by thermal shock at 800°C to obtain an exfoliated graphite. After compressing the EG at high pressure, the obtained circular sheets were used to fabricate electrodes. The electrochemical profiles of EG electrode and glassy carbon electrodes (GCE) were recorded and compared using cyclic voltammetryand square wave voltammetry in the presence of various supporting electrolytes and [Fe(CN)6]3-/4-, [Ru(NH3)6]2+/3+, ferrocene redox probes. In the supporting electrolytes (KCl, H2SO4, NaOH, tetrabutylammoniumtetraflouroborate, phosphate buffers), the potential windows of EG were found, in some cases, to be about 300 mV larger than that of GCE. The diffusion coefficients (cm2s-1) of the redox probes were calculated to be 3.638 x 10-6, 1.213 x 10-6 and 4.411 x 10-6 for [Fe(CN)6]3-/4-, [Ru(NH3)6]2+/3+ and ferrocene, respectively. These values are comparable to those obtained from GCE. Furthermore, EG was modified with various nanomaterials such as poly (propylene imine) dendrimer (PPI), gold nanoparticles, silver nanoparticles, dendrimer–gold nanoparticles composite, cobalt oxide and bismuth. The morphologies of the modified electrodes were studied using scanning electron microscopy and their electrochemical reactivities in the three redox probes were investigated. The current and the reversibility of redox probes were enhanced in the presence of modifiers in different degrees with dendrimer and gold nanoparticles having a favourable edge. The electrochemical determination of o-nitrophenol by square wave voltammetry using a nanocomposite of generation 2 poly(propyleneimine) dendrimer and gold nanoparticles modified GCEand EG electrode were compared. A characteristic reduction peak between -600 mV and -700 mV for o-nitrophenol was observed with enhanced current on both GCE and EG modified electrodes.
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Wang, Yen-Chun, and 王彥鈞. "The detection of association between meteorological factors, air pollutants and two heart diseases." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/10824286611169791131.
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碩士國立臺灣大學
流行病學與預防醫學研究所
100
As the public health issues shift from malnutrition and emerging infectious diseases to cardiovascular and cerebrovascular diseases, more and more researchers have focused on the investigation of the causal and risk factors of such diseases. For instance, a considerable amount of literature has indicated that meteorological factors and air pollutants may contribute to the risk of diseases. Funded by the Taiwan Central Weather Bureau, this study aims to develop a predictive model for the risk of disease based on specific populations and meteorological factors. The diseases of interest include Ischemic Heart Disease (IHD with ICD-9 coding 410-414) and Cerebrovascular Disease (CVD with ICD-9 coding 430-438) occurred in Taiwan. Our study population was selected from the National Health Insurance Research Database with an admission record of IHD or CVD between 2000 and 2009 and aged between 50 and 70. Exposure factors included the meteorological hourly data provided by the Taiwan Central Weather Bureau, and the environmental parameters downloaded from the Taiwan EPA air quality monitoring website.For areas with missing covariates, the ordinary Kriging method was applied for imputation. The results of this study provides a probabilistic measure for the risk of disease based on given meteorological and pollutant variables. In addition, such quantification can demonstrate the uncertainty in prediction, and offer risk information for the group of susceptible individuals for health management.
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Wang, Ya-Ling, and 王雅玲. "Multichannel piezoelectric crystal detection system with principal component analysis for air pollutants from PVC plants." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/83557960408760108025.
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碩士國立臺灣師範大學
化學研究所
90
Piezoelectric(PZ) quartz crystal is well-known to be sensitive to pressure exerted on its surface. The vibrational frequency of an oscillating piezoelectric quartz crystal decreases when a foreign substrance is adsorbed onto its surface. This phenomenon enables us to detect the characteristics of the substance. In this study, a multi-channel piezoelectric quartz crystal gas detection system with various organic material coated quartz crystals and a home-made computer interface for data processing were prepared and employed to detect various organic pollutants from PVC plants such as methanol, formic acid, propionaldehyde, carbon disulfide and N,N-dimethyl formamide. The principal component analysis (PCA) method was than applied to analyze the signals from each channel with each coating material, and the appropriate coating materials for organic pollutants were selected. After performing PCA assay, the data set obtained from 29 piezoelectric crystal sensors for 5 analytes and the first three factors of the reduced set explained 98.66﹪of the variation. Six representative coating materials such as C60/PPA, Polyethylene glycol, Nafion, Triphenyl phosphine, Cryptand-22 and Polyvinyl pyrrolidone were selected. Five vaporized organic pollutants, Methanol、Formic acid、Propionaldehyde、Carbon disulfide and N,N-Dimethyl formamide could be effectively distinguished from PCA Scores Map generated by employing factor 1(PRIN1) as the x-axis and factor 2(PRIN2) as the y-axis. Furthermore, since different evaporated organic molecules tend to have distinguishing profile discrimination maps, profile discrimination maps can be used as finger-prints for distinction. Effects of coating load, concentration and interference of water were also investigated and discussed. The result of multi-channel piezoelectric quartz crystal gas detection system showed the good detection limit, but the detection with some coating materials such as Polyvinyl pyrrolidone was found to be interfered by water. The relationship between concentration and profile discrimination maps of organic mixtures with methanol, carbon disulfide, propionaldehyde and N,N-dimethyl formamide detected by the six-channel piezoelectric detection system were also probed and discussed afterward in this study. By comparing the signal intensity of specific axis in profile discrimination maps of the organic mixtures, specific gases could be identified. The multichannel piezoelectric crystal detection system developed in this study can be potentially expected to be applied for organic pollutants from other polymer industrial plants.
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RUSTAMADI, SAPTO WIJANARKO, and SAPTO WIJANARKO RUSTAMADI. "Gold Nanoparticles Immobilized on Zinc Oxide Nanoparticles for Photodegradation and SERS Detection of Water Pollutants." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/nn6442.
Full textAbstract:
碩士國立臺灣科技大學
材料科學與工程系
106
Zinc oxide nanoparticles (ZnO NPs) were successfully synthesized by hydro thermal methods and then annealing at varied temperature (200, 300, 400, 500, 600 and 700oC). Furthermore, gold nanoparticles (Au NPs) were immobilized on the dimercaptosuccinic acid (DMSA) modified ZnO NPs (Au-ZnO NPs) for the photodegradation and surface enhanced Raman scattering (SERS) detection of the water pollutants, such as methylene blue. The effects of the particle size of ZnO NPs at varied annealing temperatures were investigated. The morphology of ZnO NPs and Au NPs were evaluated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It showed that ZnO NPs were spherical in shape with the diameter about 50 nm and Au NPs were spherical in shape with diameter about 10 nm. The optical properties of the ZnO NPs were characterized by UV-visible spectroscopy. XRD results revealed that the ZnO NPs are highly crystalline, showing the hexagonal wurtzite crystal structure. Au-ZnO NPs displays great characterizations in the photodegradation and SERS detection, which is potential to apply in the field of biomedical and water treatments and rapid detection.
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Wu, Zong-Han, and 吳宗翰. "Extraction, concentration and detection of metallic pollutants in environmental samples: (1) silver nanoparticles; (2) mercury ion." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/41744949872269018226.
Full textAbstract:
碩士國立中山大學
化學系研究所
99
I. Combined cloud point extraction and Tween 20-stabilized gold nanoparticles for colorimetric assay of silver nanoparticles in environmental water This study investigated a simple, sensitive and selective method for the colorimetric assay of silver nanoparticles (AgNPs) using Triton X-114-based cloud point extraction (CPE) as a preconcentration step and Tween 20-stabilized gold nanoparticles (Tween-AuNPs) as a colorimetric probe. After heating beyond the cloud point temperature of Triton X-114, a solution containing Triton X-114 micelles and AgNPs separated into a surfactant-rich phase (small volume) and a dilute aqueous phase. AgNPs partitioned into a Triton X-114-rich phase through a hydrophobic interaction between Triton X-114 micelles and AgNPs. After phase separation, the concentrated AgNPs oxidized to form Ag+ upon adding H2O2. The generated Ag+ triggered the aggregation of Tween 20-AuNPs in a high-ionic-strength solution because the reduction of Ag+ on the AuNP surface enabled Tween 20 (stabilizer) to be removed from the NP surface. The efficiency of Triton X-114-based CPE of the AgNPs was found to be iv insensitive to their size and coating type. Under optimal extraction and detection conditions, the selectivity of this method for AgNPs was considerably higher than for other nanomaterials. The minimum detectable concentrations for 7, 22, and 54 nm AgNPs were measured to be 0.1, 420, and 600 ng/mL, respectively. This method was successfully applied to the analysis of 7 nm AgNPs in drinking water, tap water and seawater. Keyword: silver nanoparticles, gold nanoparticles, cloud point extraction, Tween-20, colorimetric assay II. Functionalized silver nanoparticles as an extracting and preconcentrating agent for detection of mercury ions In this research we provided highly sensitive and selective for fluorescence assay of combined polythymine oligonucleotide (PolyT) with silver nanoparticles (AgNPs) as an extracting agent to detect mercury ion in environmental water. According to previous researches, PolyT will form a hairpin structure in the presence of Hg2+, this structure provide several 3-D grooves that the fluorescent dye can inlay with it. SYBR Green I (SG) is a staining dye for DNA, when binding with single strand DNA, it shows low fluorescence. On the contrast, SG inlay with grooves of hairpin structure, it shows v 11-fold of fluorescence signal. Hence, we used SG as a fluorescence probe for Hg2+. We modified thiol group at the 5’ of PolyT DNA, because of forming silver sulfur bond, PolyT will able to modified on the surface of AgNPs. PolyT33SH-AgNPs are the extracting and concentrating agent in Hg2+ solution, by the centrifugation, we collected the PolyT33SH-AgNPs. For the purpose of releasing PolyT from AgNPs’ surface, we adding H2O2 to oxidize the AgNPs into Ag+. By mixing buffer and SG into previous solution, mercury ion could be detected. In this study, we successfully detecting Hg2+ in the aqueous solution contained drinking water and tap water. The detection limit in drinking water is 20 pM, which is below Environmental Protection Agency limit for Hg2+ in drinkable water (10 nM), the linear range is from 50-600 pM. On the other hand, the detection limit in tap water is 50 pM, linear range is from 100-700 pM. Keyword: silver nanoparticles, mercury ion, PolyT, SYBR Green I, thymine
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Ghoor, Samira. "Pro-inflammatory cytokine expression as an indicator of bacterial pathogenicity in water." Thesis, 2010. http://hdl.handle.net/10210/3134.
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M. Tech.Background: Waterborne disease contributes significantly to the total global disease burden. Populations in rural areas of South Africa depend on untreated waters for consumption and sanitation. Contamination of public water supplies by harmful bacteria such as pathogenic E. coli poses a major risk for public health. Ingestion of these pathogenic microorganisms present in the contaminated and untreated waters could cause infection, leading to systemic inflammatory responses manifested by the production of various proinflammatory cytokines. To date, there is no human system test available to detect whether water, following ingestion, would cause disease (i.e. whether the water is infectious). The current water testing methods only test for the presence of indicator organisms, such as faecal coliforms, total coliforms, and Escherichia coli. A reliable in-vitro bioassay that could assess whether the water would cause an inflammatory response was investigated in this study. Objectives: Pro-inflammatory cytokines and whole-blood have been used in similar studies to detect the inflammatory responses following exposure to specific stimulants such as dust, lipopolysaccharide (LPS), E. coli and various others. It has been reported that larger numbers of these contaminants induced higher levels of pro-inflammatory cytokine expression. This implies that the pro-inflammatory cytokine expression could be used as a marker of infection since, inflammation occurs in response to infection. Successful infection is thus necessary for inflammation to occur, and high levels of pro-inflammatory cytokine expression confirm that infection has occurred. Thus if pro-inflammatory cytokines could serve as indicators for infection, these cytokines could be used as indicators for bacterial pathogenicity of water.
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Ntsendwana, Bulelwa. "Development of advanced carbon based composite electrodes for the detection and the degradation of organic pollutants in water via electrochemical/photoelectrochemical processes." Thesis, 2014. http://hdl.handle.net/10210/11379.
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Ph.D. (Chemistry)In this study, carbon based electrode materials such as glassy carbon, graphene, diamond and exfoliated graphite were explored as suitable electrode materials for electrochemical detection, electrochemical and photoelectrochemical degradation of organic water pollutants. Graphene modified glassy carbon electrode sensor was developed for bisphenol A. Cyclic voltammetry was used to study the electrochemical properties of the prepared graphene- modified glassy carbon electrode using potassium ferricyanide as a redox probe. The prepared graphene- modified glassy carbon electrode exhibited more facile electron kinetics and enhanced current of about 75% when compared to the unmodified glassy carbon electrode...
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Anil, Amith G. "Architecting and Developing Sensors for Environmental Monitoring." Thesis, 2021. https://etd.iisc.ac.in/handle/2005/5539.
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Pollution arising from inorganic and organic contaminants is a major environmental hazard that needs imperative attention. Anthropogenic and natural deposition of heavy metal ions constitute a significant component of this pollution. Selective, sensitive, and unambiguous detection of such pollutants is of prime importance in assessing environmental damage and controlling toxicity in biosystems. To this date, multifarious sensing systems and methodologies have been developed. Limited selectivity, sensitivity and environmental stability of these sensors continue to hinder their large-scale deployment. This works attempts to look at the problems of selectivity and sensitivity taking inspiration from natural processes like bioremediation and utilising data driven methods. Bioremediation is a potential, environmentally benign method for treating heavy metal polluted water. Bioremediation of hexavalent chromium, a carcinogenic pollutant, by Citrobacter freundii species of bacteria has been evaluated. Synchrotron based scanning transmission X-ray microscopy was utilised to analyse the process in an attempt to decipher the biosorption and bioreduction mechanism. Understanding this would assist in designing better selective sensors for Cr(VI). Bacteria derived carbon dots were synthesised from Citrobacter freundii bacterial cells following a green synthesis approach. The obtained carbon dots displayed fluorescence sensing with exceptional selectivity towards Cr(VI). The sensor performance and mechanism of Cr(VI) detection were thoroughly evaluated. In another work, a colorimetric sensor with high selectivity toward Cr(VI) was demonstrated and the sensor response was predicted using data driven methods. The computational method could simulate and predict sensor response at unknown concentrations in between known experimental concentrations. These predictions can generate sensor calibration scales with high accuracy, eliminating experimental and instrumental errors involved. Conjugated polymers have been studied as a potential class of materials for environmental sensors. Herein, the design, synthesis and sensing properties of a novel hexylthiophene conjugated polymer is reported for fluorescence detection of Fe(III) metal ions. Similarly, a nickel based organometallic complex was synthesised for detection of urea in real samples.CEFIPRA, UGC
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Hsuan, Shou-Hao, and 宣守昊. "A Feasibility Study on Air Pollutant Detection Using Unmanned Aerial Vehicles." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/aw8dd6.
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碩士國立臺北科技大學
機電整合研究所
105
The development of science and technology, air pollution is an important issue that can not be ignored. In the past, these detection methods are limited to detection mobility and sampling location. So it can’t provide real-time detection information. In order to monitor air pollutants more effectively, this study presents the conception of gas sensors installed on mobile vehicles. Used to provide a variety of air pollutants analysis data. In this study we select a NDIR sensor and a electrochemical sensor to detect CO2 and CO. Respectively, to design the experimental platform to simulate the impact of each move in the state. In Mode 1, the NDIR sensor is placed directly in a closed recirculation wind tunnel with a fixed CO2 concentration . In Mode 2, it will be added to the micro-aid auxiliary mouth intake. Both Model 1 and Mode 2 are evaluated using carbon dioxide at 30 km/h, 40 km/h, and 50 km/h. With Electrochemical sensor, Both Mode 1 and Mode 2 are each configured with a concentration of 30 ppm of carbon monoxide. Respectively, in the open wind tunnel and closed loop wind tunnel for testing. In Mode 3, N2 will be added to reduce the concentration after the stability test. Finally, the effects of the test sensors were also measured at 30 km / h, 40 km / h, 50 km / h. After the test of the NDIR sensor in the flow rate experiment, the values were compared within the NDIR sensor error range. Therefore, in the flow state does not have an impact on the NDIR sensor; After the test of the electrochemical sensors, the CO gas concentration increases with respect to the wind speed without wind speed, so the accuracy of the electrochemical sensor is affected by the wind speed.
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Chang, Ya-Han, and 張雅涵. "Constructing New Biological Detection System of Common Environmental Pollutant - Naphthalene by Genetic Engineering Technology." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/01066494750083927961.
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碩士大同大學
生物工程學系(所)
99
The polycyclic aromatic hydrocarbons (PAHs) are stable and difficult to degrade in the nature. Also, it has been currently recognized as the largest group of carcinogens. According to the latest regulation published by Environmental Protection Administration in 2001, the content of Naphthalene in groundwater has been definitely regulated. Besides, the overseas investigation of plants with organic pollutants in recent years have indicated that the detection of Naphthalene pollution is almost up to 50%. We cloned the ndo and gst promoter sequence from PP-23 strain and constructed into pBBR1 vector, which with lux gene as reporter fusion. These above-mentioned plasmids were named pBBR1-ndo-lux and pBBR1-gst-lux. In promoter sequence analysis, the similarity between ndo promoter and accession number AF010471 of Pseudomonase putida strain is 94%, gst promoter and accession number NC004999 of Pseudomonase putida strain is 91%. In addition, we transformed the pBBR1-ndo-lux and pBBR1-gst-lux into PP-23 strain and observed the expression of luciferase activity. We found the expression of strain containing pBBR1-ndo-lux plasmid increased as content of naphthalene. It took only 6.5 hours to complete the detection of naphthalene. This method is more efficient and better than others. Therefore, it might be the model and is potential to analyze other PAHs compounds.
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Jou, Wen Suiang, and 周文相. "A Study of Air Pollutants by PTV Thermal Desorption method and Sulfur-Selective Detector." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/07377851966991749042.
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(6863093), Li-Kai Lin. "Pollutant and Inflammation marker detection using low-cost and portable microfluidic platform, and flexible microelectronic platform." Thesis, 2019.
Find full textAbstract:
Existing methods for pathogen/pollutant detection or wound infection monitoring employ high-cost instruments that could only be operated by trained personnel, and costly device-based detection requires a time-consuming field-to-lab process. This expensive process with multiple prerequisites prolongs the time that patients must wait for a diagnosis. Therefore, improved methods for point-of-care biosensing are necessary. In this study, we aimed to develop a direct, easy-to-use, portable, low cost, highly sensitive and selective sensor platform with the goal of pollutant detection and wound infection/cancer migration monitoring. This study has two main parts, including microfluidic, electrical, and optical sensing platforms. The first part, including chapters 2, 3, and 4, focuses on Bisphenol A (BPA) lateral flow assay (LFA) detection; the second part, including chapter 5 focuses on the electrical sensing platform fabrication for one of the markers of inflammation, matrix metalloproteinases-9 (MMP-9), monitoring/detection. In chapters 2, 3, and 4, we found that the few lateral flow assays (LFAs) established for detecting the endocrine-disrupting chemical BPA have employed citrate-stabilized gold nanoparticles (GNPs), which have inevitable limitations and instability issues. To address these limitations, in chapter 2, a more stable and more sensitive biosensor is developed by designing strategies for modifying the surfaces of GNPs with polyethylene glycol and then testing their effectiveness and sensitivity toward BPA in an LFA. In chapter 3, we describe the development of a new range-extended bisphenol A (BPA) detection method that uses a surface enhanced Raman scattering lateral flow assay (SERS-LFA) binary system. In chapter 4, we examine advanced bisphenol A (BPA) lateral flow assays (LFAs) that use multiple nanosystems. The assays include three nanosystems, namely, gold nanostars, gold nanocubes, and gold nanorods, which are rarely applied in LFAs, compared with general gold nanoparticles. The developed LFAs show different performances in the detection of BPA. In chapter 5, a stable electrical sensing platform is developed for MMP-9 detection.
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Blašková, Marta. "Využití jednoduchého elektrochemického DNA biosenzoru při stanovení environmentálních polutantů a vyšetřování jejich interakce s DNA." Master's thesis, 2014. http://www.nusl.cz/ntk/nusl-333185.
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The interaction between three selected representatives of environmental pollutants - naphthalene, anthracene, and 2-aminoanthracene - and DNA was investigated using an electrochemical DNA biosensor based on a glassy carbon electrode (GCE) and low molecular weight DNA from salmon sperm (DNA/GCE). The interactions with DNA were monitored using square wave voltammetry (SWV) and electrochemical impedance spectroscopy (EIS). For naphthalene, there was no DNA damaging interaction observed. In the case of anthracene, the formation of an intercalation complex [DNA-anthracene] was observed. However, its formation does not cause DNA strand breaks. The formation of similar intercalation complex was observed for 2-aminoanthracene [DNA-2-aminoanthracene], where we suppose on the basis of the results obtained that the intercalation of 2-aminoanthracene into the DNA double helix induces a tension and subsequent formation of single-strand breaks, which cause that the fragments of DNA fall away from the electrode surface. The intercalative interaction of DNA with anthracene a 2-aminoanthracene was used in the development of electrochemical methods for determination of these compounds at the GCE and DNA/GCE. At the development of the methods, DC voltammetry (DCV) and differential pulse voltammetry (DPV) were used....