Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / Este trabalho de pesquisa descreve dois estudos de caso de métodos quimiométricos empregados para a quantificação de hidrocarbonetos policíclicos aromáticos HPAs (naftaleno, fluoreno, fenantreno e fluoranteno) em água potável usando espectroscopia de fluorescência molecular e a classificação e caracterização de sucos de uva e seus parâmetros de qualidade através de espectroscopia de infravermelho próximo. O objetivo do primeiro estudo é a aplicação combinada de métodos quimiométricos de segunda ordem (N-PLS, U-PLS, U-PLS/RBL e PARAFAC) e espectrofluorimetria para determinação direta de HPAs em água potável, visando contribuir para o conhecimento do potencial destas metodologias como alternativa viável para a determinação tradicional por cromatografia univariada. O segundo estudo de caso destinado à classificação e determinação de parâmetros de qualidade de sucos de uva, densidade relativa e teor de sólidos solúveis totais, foi medida por espectroscopia de infravermelho próximo e métodos quimiométricos. Diversos métodos quimiométricos, tais como HCA, PLS-DA, SVM-DA e SIMCA foram investigados para a classificação amostras de sucos de uva ao mesmo tempo que métodos de calibração multivariada de primeira ordem, tais como PLS, iPLS e SVM-LS foram usadas para a predição dos parâmetros de qualidade. O princípio orientador para o desenvolvimento dos estudos aqui descritos foi a necessidade de metodologias analíticas com custo, tempo de execução e facilidade de operação melhores e menor produção de resíduos do que os métodos atualmente utilizados para a quantificação de HPAs, em água de torneira, e classificação e caracterização das amostras de suco de uva e seus parâmetros de qualidade / This research work describes two studies of chemometric methods employed for the quantification of polycyclic aromatic hydrocarbons PAHs (naphthalene, fluorene, phenanthrene and fluoranthene) in tap water using molecular fluorescence technique, and the classification and characterization of grape juice and its quality parameters by near infrared spectroscopy. The goal of the first study is the combined application of the second-order chemometric methods (N-PLS, U-PLS, U-PLS/RBL, PARAFAC) and spectrofluorimetry technique for direct determination of HPAs in tap water, aiming to contribute for the growth of knowledge about the potential of these methodologies as viable alternatives to the traditional univariate chromatographic determination. The second study aimed at the classification and determination of grape juice quality parameters, as relative density and total soluble solids, were measured with the aid of near infrared spectroscopy and chemometric methods. Several chemometric methods, such as HCA, PLS-DA, SVM-DA, SIMCA, were investigated for the classification of grape juice samples as the same time first-order multivariate calibration methods, such as PLS, iPLS, SVM-LS, were used for prediction of quality parameters. The guiding principle for the development of the studies herein described was the need for analytical methodologies with cost, execution time, ease of operation, and residue output better or lower than present day methods employed for the quantification of PAHs in tap water and the classification and characterization of grape juice sample and its quality parameters

Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / Este trabalho de pesquisa descreve dois estudos de caso de métodos quimiométricos empregados para a quantificação de hidrocarbonetos policíclicos aromáticos HPAs (naftaleno, fluoreno, fenantreno e fluoranteno) em água potável usando espectroscopia de fluorescência molecular e a classificação e caracterização de sucos de uva e seus parâmetros de qualidade através de espectroscopia de infravermelho próximo. O objetivo do primeiro estudo é a aplicação combinada de métodos quimiométricos de segunda ordem (N-PLS, U-PLS, U-PLS/RBL e PARAFAC) e espectrofluorimetria para determinação direta de HPAs em água potável, visando contribuir para o conhecimento do potencial destas metodologias como alternativa viável para a determinação tradicional por cromatografia univariada. O segundo estudo de caso destinado à classificação e determinação de parâmetros de qualidade de sucos de uva, densidade relativa e teor de sólidos solúveis totais, foi medida por espectroscopia de infravermelho próximo e métodos quimiométricos. Diversos métodos quimiométricos, tais como HCA, PLS-DA, SVM-DA e SIMCA foram investigados para a classificação amostras de sucos de uva ao mesmo tempo que métodos de calibração multivariada de primeira ordem, tais como PLS, iPLS e SVM-LS foram usadas para a predição dos parâmetros de qualidade. O princípio orientador para o desenvolvimento dos estudos aqui descritos foi a necessidade de metodologias analíticas com custo, tempo de execução e facilidade de operação melhores e menor produção de resíduos do que os métodos atualmente utilizados para a quantificação de HPAs, em água de torneira, e classificação e caracterização das amostras de suco de uva e seus parâmetros de qualidade / This research work describes two studies of chemometric methods employed for the quantification of polycyclic aromatic hydrocarbons PAHs (naphthalene, fluorene, phenanthrene and fluoranthene) in tap water using molecular fluorescence technique, and the classification and characterization of grape juice and its quality parameters by near infrared spectroscopy. The goal of the first study is the combined application of the second-order chemometric methods (N-PLS, U-PLS, U-PLS/RBL, PARAFAC) and spectrofluorimetry technique for direct determination of HPAs in tap water, aiming to contribute for the growth of knowledge about the potential of these methodologies as viable alternatives to the traditional univariate chromatographic determination. The second study aimed at the classification and determination of grape juice quality parameters, as relative density and total soluble solids, were measured with the aid of near infrared spectroscopy and chemometric methods. Several chemometric methods, such as HCA, PLS-DA, SVM-DA, SIMCA, were investigated for the classification of grape juice samples as the same time first-order multivariate calibration methods, such as PLS, iPLS, SVM-LS, were used for prediction of quality parameters. The guiding principle for the development of the studies herein described was the need for analytical methodologies with cost, execution time, ease of operation, and residue output better or lower than present day methods employed for the quantification of PAHs in tap water and the classification and characterization of grape juice sample and its quality parameters

Pour les distributeurs d’eau, l’utilisation de chlore permet d’assurer la qualité bactériologique de l’eau, de l’usine de traitement au robinet du consommateur. Cependant, la flaveur chlore constitue une des plaintes les plus importantes adressée à l’encontre de l’eau du robinet et constitue donc un enjeu majeur de satisfaction des consommateurs. Dans ce contexte, l’objectif des travaux engagés dans cette thèse a été de mettre en évidence des moyens potentiels de neutralisation sensorielle de la flaveur chlore dans l’eau. Néanmoins, les mécanismes impliqués dans la perception de cette flaveur étant largement méconnu, notre première étape a consisté à préciser la nature de ces mécanismes. Nos résultats ont ainsi mis en évidence que l’acide hypochloreux sous sa forme associée, qui est le stimulus supposé de la flaveur chlore dans l’eau, active le système olfactif à faibles concentrations et le système trigéminal à partir de 4 mg/L. De plus, nous avons observé que la consommation d’eau du robinet ne semble pas liée à la sensibilité au chlore mais plutôt à la représentation qu’ont les consommateurs de l’eau du robinet. Dans un deuxième temps, nous avons exploré le rôle de la matrice de l’eau dans la perception de la flaveur chlore. Nous avons d’abord montré que les variations de molarité et de composition en cations de l’eau modulent le goût de l’eau. Nous avons ensuite mis en évidence une modulation de l’intensité chlorée en fonction de la matrice minérale de l’eau. Cependant, nos données suggèrent l’existence de mécanismes multiples, physicochimiques, physiologiques en bouche et sensoriels, susceptibles de moduler la perception de la flaveur chlore. Enfin, nous avons exploré les interactions perceptives entre un arôme supposé neutralisant et ajouté à l’eau de boisson et la flaveur chlore. Nos résultats montrent que l’ajout d’un arôme à un niveau péri-liminaire augmente la perception de la flaveur chlore et diminue l’acceptabilité des consommateurs. A plus forte concentrations, certains arômes semblent capables de diminuer la perception du chlore, mais ces conditions sont incompatibles avec les contraintes liées à l’eau de distribution / For water suppliers, using chlorine is necessary to ensure water bacteriological quality from the treatment plant to the consumers’ tap. However, chlorine flavour is one of the most common reasons advocated for choosing tap water alternatives as drinking water. As a consequence, the putative link between chlorine flavour perception and tap water consumption is an issue in drinking water habits studies. Since the sensory mechanisms involved in chlorine flavour perception remained largely unknown, the main objective of this thesis work was to first highlight those mechanisms and then to identify potential lever chlorine flavour sensory neutralisation.In a first step, we demonstrated that hypochlorous acid associated, which is likelyresponsible of chlorine flavour in tap water, could activate the olfactory system at low concentrations and the trigeminal system for concentrations up to 4 mg/L Cl2. Additionally, our results suggested that tap water consumption does not seem to be related to sensitivity to chlorine flavour but rather to consumers’ tap water representation.In a second stage, we explored the impact of water mineral matrix on chlorine flavour perception. We demonstrated first that water molarity and cationic content variations modulate drinking water taste. We also evidenced that chlorine flavour intensity is modulated according to water composition. Nevertheless, our data suggest that physico-chemical, in- mouth physiological and sensory mechanisms are likely involved in such modulation.In the last part of the Thesis work, we investigate the putative influence of aroma perceptionon chlorine flavour. Our results showed that beyond chemical reactions between hypochlorous acid and odorants, aromas at peri-threshold concentration enhance chlorine flavour and decrease tap water acceptability

The Peace River Valley (British Columbia, Canada) is an area of intensive unconventional oil and gas (UOG) exploitation, an activity that can release contaminants with possible adverse effects on the fetus. My project aimed to estimate the importance of this exposure. For this aim, we 1) measured concentrations of 21 trace elements in tap water and biological (hair, urine, nails) samples from 85 pregnant women in this region; 2) compared them with those from the general population and health-based guidance values; 3) assessed their correlations between matrices; and 4) evaluated their associations with the density and proximity of UOG wells (i.e., wells within radii of 2.5 km, 5 km, 10 km, and with all wells in British Columbia around residences). Spearman's rank correlation and multiple linear regression analyses adjusted covariates were performed. Our results showed higher urinary and hair levels of certain trace elements compared to reference populations (e.g., Co, Ba, Sr, Mn, V, Ga). Concentrations in tap water correlated strongest with concentrations in hair, followed by nails and urine. Positive (e.g., Al, Mn, Cu, Ga, Cd, Ba, Cr, Sr, U) and negative (e.g., Fe) associations were observed between the density and proximity of UOG wells and the concentrations of certain trace elements in tap water, hair, and nails. Our results suggest that pregnant women living in an active area of UOG exploitation are likely to be more exposed to certain trace elements than the general population, but the association with density and proximity to wells remains uncertain. / La vallée de la rivière de la Paix (Colombie-Britannique, Canada) est une zone d’exploitation de pétrole et de gaz naturel par méthodes non-conventionnelles (PGNNC), une activité qui est susceptible de libérer des contaminants avec des effets nocifs possibles sur le foetus. Mon projet visait à estimer l’importance de cette exposition. À cette fin, nous avons 1) mesuré les concentrations de 21 éléments traces dans des échantillons de cheveux, d'ongles, d'urine et d'eau du robinet de 85 femmes enceintes de cette région, 2) comparé celles-ci avec celles de la population générale et des valeurs-guides, 3) évalué leur corrélation entre matrices et 4) évalué leur association avec la densité et proximité des puits (mesures pour des rayons de 2,5 km, 5 km, 10 km, et sans limite autour des résidences). Des analyses de corrélation de Spearman et de régression linéaire multiple ajustées pour certaines variables ont été effectuées. Les concentrations urinaires et capillaires étaient plus élevées pour certains éléments traces par rapport aux populations de référence (p. ex. Co, Ba, Sr, Mn, V, Ga). Les concentrations dans l'eau du robinet étaient plus fortement corrélées avec les concentrations dans les cheveux, suivis des ongles et de l'urine. Des associations positives (p. ex. Al, Mn, Cu, Ga, Cd, Ba, Cr, Sr, U) et négatives (p. ex. Fe) ont été observées entre la densité/proximité des puits de PGNNC et les concentrations de certains éléments traces dans les échantillons d'eau, de cheveux et d’ongles. Nos résultats portent à croire que les femmes enceintes vivant dans une zone active de PGNNC sont susceptibles d’être plus exposées à certains éléments traces que la population générale, mais le lien avec la densité et la proximité des puits demeure incertain.

<p>Significant seasonal changes in chemical and microbiological water quality can occur in buildings at different fixture locations due to temperature and time dependent reaction rates. Here, a series of calibrated plumbing hydraulic-water quality models were developed for the extensively monitored Retrofitted Net-zero Energy, Water & Waste (ReNEWW) house in West Lafayette, Indiana USA. Knowledge gaps that inhibited higher resolution water quality modeling were also identified. The eight new models predict the absolute level of free chlorine, total trihalomethanes (TTHM), Cu (Copper), Fe (Iron), Pb (lead), NO₃^–(nitrate-nitrogen), heterotrophic plate count (HPC), and <i>Legionella spp.</i> concentration at each fixture for plumbing use, operational characteristics, and design layouts of the plumbing system. Model development revealed that the carrying capacity to describe Legionella spp. growth (and other organisms) under water usage and plumbing design conditions is lacking in the literature. This information needed for higher resolution modeling. Reducing building water use by 25% prompted increased absolute concentrations of HPC and Legionella, each increasing by a factor of about 10⁵. When the service line length was increased, Legionella spp. concentrations increased by up to 10⁶gene copies /L in the Summer season. The proposed modeling framework can be used to support better planning, design, analysis, and operational decision-making.</p>

<p>Cilj ove doktorske disertacija&nbsp; bio je razvoj&nbsp; novih, osetljivih, selektivnih i ekonomski<br />isplativih&nbsp; voltametrijskih&nbsp; radnih&nbsp; elektroda&nbsp; za&nbsp; praćenje&nbsp; odabranih&nbsp; analita&nbsp; kako&nbsp; u<br />laboratorijskim tako i pri terenskim uslovima.&nbsp; Ispitivana je&nbsp; mogućnost primene&nbsp; ovih&nbsp; radnih&nbsp; elektroda&nbsp; primenom&nbsp; voltametrijskih&nbsp; metoda&nbsp; kako&nbsp; u&nbsp; model&nbsp; rastvorima&nbsp; tako&nbsp; i&nbsp; u&nbsp; pojedinim realnim sistemima. SW-ASV&nbsp; zasnovana&nbsp; na&nbsp; elektrodama&nbsp; od&nbsp; staklastog&nbsp; ugljenika&nbsp; povr&scaron;inski modifikovanim&nbsp; Bi-MWCNT&nbsp; i&nbsp; BiOCl-MWCNT&nbsp; je&nbsp; primenjena&nbsp; za&nbsp; određivanje&nbsp; jona&nbsp; Pb(II)&nbsp; i Cd(II)&nbsp; pri&nbsp; optimizovanim&nbsp; uslovima&nbsp; merenja.&nbsp; Određivanje&nbsp; ciljnih&nbsp; jona&nbsp; vr&scaron;eno&nbsp; je&nbsp; pri&nbsp; radnom potencijalu&nbsp; od&nbsp; -1,2&nbsp; V&nbsp; (izmeren&nbsp; u&nbsp; odnosu&nbsp; na&nbsp; zasićenu&nbsp; kalomelovu&nbsp; elektrodu)&nbsp; i&nbsp; vremenu<br />elektrodepozicije jona&nbsp; od 120 s. Sva merenja su izvr&scaron;ena u rastvoru acetatnog pufera čija je pH-vrednost iznosila&nbsp; 4,0. Primenjeni koncentracioni opseg ciljnih analita iznosio je&nbsp; od 5 do 50&nbsp; &mu;g&nbsp; dm ^-3 .&nbsp; Primenom&nbsp; ovog&nbsp; tipa&nbsp; elektrode&nbsp; dobijene&nbsp; su&nbsp; vrednosti&nbsp; granice&nbsp; detekcije&nbsp; za&nbsp; jone Pb(II) i Cd(II) 0,57&nbsp; &mu;g dm ^-3i 1,2 &mu;g dm^-3 , redom. Dobijena RSD iznosila je manje od 10% za oba&nbsp; jona.&nbsp; Ova&nbsp; metoda&nbsp; je&nbsp; primenjena&nbsp; i&nbsp; za&nbsp; određivanje&nbsp; ciljnih&nbsp; jona&nbsp; u&nbsp; realnom&nbsp; uzorku&nbsp; porne vode&nbsp; sedimenta&nbsp; a&nbsp; rezultati&nbsp; dobijeni&nbsp; optimizovanom&nbsp; voltametrijskom&nbsp; metodom&nbsp; su&nbsp; u&nbsp; dobroj saglasnosti sa rezultatima koji su dobijeni primenom komparativne GFAAS metode. Bizmut oksihlorid-vi&scaron;ezidne ugljenične nanocevi kompozitni materijal je primenjen za povr&scaron;insko&nbsp; modifikovanje&nbsp; elektrode&nbsp; od&nbsp; staklastog&nbsp; ugljenika&nbsp; za&nbsp; brzo&nbsp; i&nbsp; jednostavno voltametrijsko&nbsp; određivanje&nbsp; tragova&nbsp; Zn(II)-jona&nbsp; primenom&nbsp; SW-ASV&nbsp; metode.&nbsp; BiOClMWCNT/GCE je pokazala linearan analitički odgovor u&nbsp; osegu koncentracija od&nbsp; 2,50 do&nbsp; 80,0 &mu;g&nbsp; dm ^-3sa dobijenom vredno&scaron;ću GD 0,75 &mu;g&nbsp; dm^-3pri akumulacionom vremenu od&nbsp; 120 s&nbsp; i potencijalu&nbsp; elektrodepozicije&nbsp; -1,40&nbsp; V&nbsp; u&nbsp; odnosu&nbsp; na&nbsp; ZKE.&nbsp; Merenja&nbsp; su&nbsp; vr&scaron;ena&nbsp; u&nbsp; acetatnom puferu pH 4,5. Dobijena RSD iznosila je 4,8 %. Upoređene su performanse novodizajnirane BiOCl-MWCNT/GCE elektrode&nbsp; i&nbsp; tradicionalne elektrode na bazi bizmut filma (BiF/GCE), MWCNT/GCE,&nbsp; BiF-MWCNT/GCE&nbsp; i&nbsp; nemodifikovane&nbsp; GC&nbsp; elektrode.&nbsp; Novodizajnirana elektroda je primenjena za&nbsp; detekciju&nbsp; i određivanje&nbsp; Zn(II)-jona&nbsp; u realnim&nbsp; uzorcima kao &scaron;to su<br />dijetetski&nbsp; suplement&nbsp; i&nbsp; pekarski&nbsp; kvasac.&nbsp; Dobijeni&nbsp; rezultati&nbsp; su&nbsp; uporedivi&nbsp; sa&nbsp; deklarisanom vredno&scaron;ću&nbsp; u&nbsp; slučaju&nbsp; dijetetskog&nbsp; suplementa&nbsp; a&nbsp; u&nbsp; slučaju&nbsp; pekarskog&nbsp; kvasca&nbsp; sa&nbsp; rezultatima dobijenih komparativnom FAAS .<br />Elektroda od ugljenične paste je povr&scaron;inski modifikovana pripremljenim kompozitom<br />koji je&nbsp; izgrađen od vi&scaron;ezidnih ugljeničnih nanocevi i čestica&nbsp; Sb₂O_3.&nbsp; Kompozitni&nbsp; materijal&nbsp; je okarakterisan&nbsp; primenom&nbsp; TEM,&nbsp; EDS&nbsp; i&nbsp; XRD&nbsp; mernih&nbsp; tehnika.&nbsp; Sb₂O₃-MWCNT/CPE&nbsp; je okarakterisana primenom ciklične voltametrije a merenja su vr&scaron;ena u rastvoru hlorovodonične kiseline&nbsp; (pH&nbsp; 2,0).&nbsp; Primenom&nbsp; SW-ASV&nbsp; metode&nbsp; ova&nbsp; radna&nbsp; elektroda&nbsp; je&nbsp; upotrebljena&nbsp; za određivanje&nbsp; jona Pb(II) i Cd(II)&nbsp; u&nbsp; koncentracionom opsegu 2,0-40,0&nbsp; &mu;g&nbsp; dm&nbsp; ^-3za&nbsp; Pb(II)-jon&nbsp; i 2,0-40,0&nbsp; &mu;g&nbsp; dm ^-3 za&nbsp; Cd(II)-jon&nbsp; pri&nbsp; čemu&nbsp; su&nbsp; dobijene&nbsp; dobre&nbsp; linearne&nbsp; zavisnosti&nbsp; za&nbsp; oba&nbsp; ciljna jona.&nbsp; Optimalna&nbsp; procedura&nbsp; uključuje&nbsp; primenu&nbsp; Sb2O3-MWCNT/CPE&nbsp; u&nbsp; 0,01&nbsp; mol dm ^-3<br />hlorovodoničnoj kiselini uz vreme elektrodepozicije jona iz rastvora od 120&nbsp; s&nbsp; na&nbsp; potencijaluod&nbsp; -1,2&nbsp; V,&nbsp; pri&nbsp; čemu&nbsp; su&nbsp; dobijene&nbsp; vrednosti&nbsp; za&nbsp; GD&nbsp; 1,1&nbsp; &mu;g&nbsp; dm ^-3 Cd(II)&nbsp; i&nbsp; 1,6&nbsp; &mu;g&nbsp; dm ^-3 Pb(II). Optimizovana&nbsp; metoda&nbsp; zasnovana&nbsp; na&nbsp; ovom&nbsp; tipu&nbsp; voltametrijskog&nbsp; senzora&nbsp; je&nbsp; uspe&scaron;no primenjena&nbsp; za&nbsp; određivanje&nbsp; jona&nbsp; Cd(II)&nbsp; u&nbsp; obogaćenom&nbsp; uzorku&nbsp; česmenske&nbsp; vode,&nbsp; gde&nbsp; su&nbsp; se dobijene vrednosti u&nbsp; saglasnosti sa očekivanom. Elektroda od ugljenične paste povr&scaron;inski je&nbsp; modifikovana primenom&nbsp; Sb₂O₃-MWCNT nanokompozitnog&nbsp; materijala&nbsp; i&nbsp; primenjena&nbsp; za&nbsp; direktno&nbsp; voltametrijsko&nbsp; određivanje imidakloprida&nbsp; u&nbsp; model&nbsp; rastvorima.&nbsp; U&nbsp; cilju&nbsp; postizanja&nbsp; &scaron;to&nbsp; boljih&nbsp; analitičkih&nbsp; performansi optimizovani su eksperimentalni uslovi merenja kao &scaron;to su pH-vrednost rastvora pomoćnog elektrolita&nbsp; i&nbsp; kondicioniranje&nbsp; povr&scaron;ine&nbsp; voltametrijskog&nbsp; senzora.&nbsp; Kao&nbsp; optimalna&nbsp; pH-vrednost pomoćnog elektolita (Britton-Robinsonovog pufera) odabrana je pH 7,0, a ponavljanje ciklusa cikliranja najmanje 4 puta povoljno utiče na stabilnost&nbsp; voltametrijskih signala. Optimizovana metoda primenjena je za SW direktno katodno određivanje imidakloprida u koncentracionom intervalu od 1,41 do 32,77 &mu;g cm ^-3 uz dobijeni korelacioni faktor od 0,9995. Na osnovu dobijenih rezultata može se zaključiti da su razvijene analitičke metode pre svega&nbsp; osetljive,&nbsp; selektivne,&nbsp; reproduktivne&nbsp; i&nbsp;&nbsp; jednostavne&nbsp; &scaron;to&nbsp; omogućava&nbsp; njihovu&nbsp; primenu&nbsp; za veliki broj uzoraka.&nbsp; Merenjima u model i realnim rastvorima dokazana je mogućnost njihove primene&nbsp; u&nbsp;&nbsp; komplikovanim&nbsp; matriksima,&nbsp; pri&nbsp; različitim&nbsp; pH&nbsp; vredostima&nbsp; pri&nbsp; čemu&nbsp; su&nbsp; dobijeni<br />rezultati koji su u saglasnosti sa rezultatima primenjenih komparativnih metoda. Naravno, za dobijanje&nbsp; reprezentativnih&nbsp; rezultata&nbsp; neohodno&nbsp; je&nbsp; izvr&scaron;iti&nbsp; optimizaciju&nbsp; uslova&nbsp; merenja&nbsp; &scaron;to podrazumeva sam odabir supstrat-elektrode, odabir povr&scaron;inskog modifikatora i optimizaciju eksperimentalnih uslova merenja.</p> / <p>The&nbsp; aim of this&nbsp; Ph.D. thesis&nbsp; was the development of new, sensitive, selective and economically&nbsp; viable&nbsp; voltametric&nbsp; working&nbsp; electrode&nbsp; for&nbsp; continuous&nbsp; monitoring&nbsp; of&nbsp; different target&nbsp; analytes.&nbsp; The&nbsp; use&nbsp; of&nbsp; these&nbsp; advantaged&nbsp; working&nbsp; electrodes&nbsp; was&nbsp; investigated&nbsp; using voltametric methods both in model solutions and in certain real systems.SW-ASV&nbsp; based on glassy carbon&nbsp; electrode surface modified with&nbsp; Bi- MWCNT and BiOCl-MWCNT&nbsp; were&nbsp; applied&nbsp; for&nbsp; determination&nbsp; of&nbsp; Pb(II)&nbsp; and&nbsp; Cd(II)&nbsp; ions.&nbsp; Voltametric determination&nbsp; of&nbsp; Pb(II)&nbsp; and&nbsp; Cd(II)&nbsp; ions&nbsp; was&nbsp; performed&nbsp; at&nbsp; working&nbsp; potential&nbsp; of&nbsp; -1.2&nbsp; V (measured against the saturated calomel electrode) and time of electrodeposition of 120 s. All measurements were performed in acetate buffer solution pH 4.0. Concentration range of targetanalites were&nbsp; 5-50 &mu;g&nbsp; dm -3 . Using this type of electrode,&nbsp; obtained&nbsp; detection limits for&nbsp; Pb(II) and Cd(II) ions&nbsp; were&nbsp; 0.57&nbsp; &mu;g&nbsp; dm -3 and 1.2&nbsp; &mu;g&nbsp; dm -3 , respectively, with RSD lower than 10%.This&nbsp; method&nbsp; was&nbsp; applied&nbsp; for&nbsp; target&nbsp; ions&nbsp; determination&nbsp; in&nbsp; sediment&nbsp; pore&nbsp; water&nbsp; sample,&nbsp; and obtained results are comparable with those who are obtained using GFAAS method. Bismuth oxychloride-multiwalled carbon nanotubes composite material was applied for&nbsp; surface&nbsp; modification&nbsp; of&nbsp; the&nbsp; glass-carbon&nbsp; electrode&nbsp; for&nbsp; quick&nbsp; and&nbsp; simple&nbsp; voltametric determination&nbsp; of&nbsp; Zn(II)&nbsp; ions&nbsp; using&nbsp; the&nbsp; SW-ASV&nbsp; method.&nbsp; BiOCl-MWCNT/GCE&nbsp; showed&nbsp; a linear&nbsp; analytical&nbsp; response&nbsp; in&nbsp; a&nbsp;&nbsp; concentration&nbsp; from&nbsp; 2.50&nbsp; to&nbsp; 80.0&nbsp; &mu;g&nbsp; dm -3 with&nbsp; a&nbsp; value&nbsp; of detection limit 0.75 &mu;g dm -3 at a acumulation time of 120 s and an electrodeposition potential of&nbsp; -1.40 V vs. saturated&nbsp; calomel electrode.&nbsp; Measurements were carried out in acetate buffer pH 4.5. The obtained&nbsp; value of the RSD&nbsp; was&nbsp; 4.8%. The performance of the newly designed BiOCl-MWCNT/GCE&nbsp; electrode,&nbsp; traditional&nbsp; bismuth-based&nbsp; electrode&nbsp; (BiF/GCE), MWCNT/GCE,&nbsp; BiF-MWCNT/GCE&nbsp; and&nbsp; unmodified&nbsp; GC&nbsp; electrodes&nbsp; were&nbsp; compared.&nbsp; The applied electrode shows very good electroanalytic properties when determining this target ion. Obtained results are in good agreement with declared value in case of dietetic suplement, and in the brewer&rsquo;s yeast sample results were comparable with FAAS results. Carbon&nbsp; paste&nbsp; electrode&nbsp; surface&nbsp; modified&nbsp; with&nbsp; new&nbsp; composite&nbsp; material&nbsp; based&nbsp; on multiwalled carbon nanotubes and&nbsp; Sb2O3&nbsp; particles. The composite is characterized by TEM, EDS and&nbsp; XRD measurment. Sb2O3- MWCNT/CPE was characterized by cyclic voltammetry and measurements were carried out in a&nbsp; hydrochloric acid&nbsp; solution&nbsp; (pH 2.0). Using the SWASV&nbsp; method,&nbsp; this&nbsp; working&nbsp; electrode&nbsp; was&nbsp; used&nbsp; to&nbsp; determine&nbsp; Pb(II),&nbsp; Cd(II)&nbsp; ions&nbsp; in&nbsp; the concentration range&nbsp; from&nbsp; 2.0&nbsp; to 40.0&nbsp; &mu;g dm -3 for Pb(II) and 2.0-40.0&nbsp; &mu;g dm -3 for Cd(II) ions. Newly&nbsp; designed&nbsp; sensor&nbsp; showed&nbsp; good&nbsp; linear&nbsp; dependences&nbsp; for&nbsp; both&nbsp; target&nbsp; ions.&nbsp; The&nbsp; most optimal&nbsp; procedure&nbsp; involving&nbsp; application&nbsp; of&nbsp; Sb2O3-MWCNT/CPE&nbsp; in&nbsp;&nbsp; .01&nbsp; mol&nbsp; dm -3 hydrochloric&nbsp; acid,&nbsp; with&nbsp; electroposition&nbsp; time&nbsp; of&nbsp; target&nbsp; ions&nbsp; 120&nbsp; s&nbsp; at&nbsp; a&nbsp; electrodeposition potential&nbsp; of&nbsp; -1.2&nbsp; V.&nbsp; Obtained&nbsp;&nbsp; values&nbsp; of&nbsp;&nbsp;&nbsp; LOD&nbsp; 1,1&nbsp; &mu;g&nbsp; dm -3 for&nbsp; Cd(II)&nbsp; and&nbsp; for&nbsp; 1,6&nbsp; &mu;g&nbsp; dm -3 Pb(II)&nbsp; ions.&nbsp; An&nbsp; optimized&nbsp; method&nbsp; based&nbsp; on&nbsp; this&nbsp; type&nbsp; of&nbsp; voltametric&nbsp; sensor&nbsp; has&nbsp; been successfully&nbsp; applied&nbsp; for&nbsp; determination&nbsp; of&nbsp; Cd(II)&nbsp; ion&nbsp; in&nbsp; a&nbsp; spiked&nbsp; tap&nbsp; water&nbsp; sample.&nbsp; Results obtained during this measurment were in tune with expected results. CPE&nbsp; was&nbsp; surface&nbsp; modified&nbsp; using&nbsp; Sb2O3-MWCNT&nbsp; nanocomposite&nbsp; material&nbsp; and tested&nbsp; for&nbsp; direct&nbsp; voltametric&nbsp; determination&nbsp; of&nbsp; imidacloprid&nbsp; in&nbsp; model&nbsp; solutions.&nbsp; In&nbsp; order&nbsp; to achieve the best analytical performance, experimental conditions of measurement such as the pH value of the supporting electrolyte and conditioning of the voltametric sensor surface havebeen&nbsp; optimized.&nbsp; As&nbsp; an&nbsp; optimum&nbsp; pH&nbsp; value&nbsp; of&nbsp; the&nbsp; supporting&nbsp; electrolyte&nbsp; (Britton-Robinson buffer), a pH 7.0 was selected, and the repeating cycles of the cycling process at least 4 times favorably&nbsp; influenced&nbsp; the&nbsp; stability&nbsp; of&nbsp; the&nbsp; voltametric&nbsp; signals.&nbsp; The&nbsp; optimized&nbsp; method&nbsp; was applied for the SW direct cathodic determination&nbsp; of&nbsp; imidacloprid in the concentration range from 1.41 to 32.77 &mu;g cm -3&nbsp; with obtained correlation factor of 0.9995. Based on results it can be concluded that developed analytical methods are sensitive, selective, reproducibile and simple, which can enable their application for various number of samples. Measurements in the model and real solutions have demonstrated the possibility of their&nbsp; application&nbsp; in&nbsp; complicated&nbsp; matrices,&nbsp; at&nbsp; different&nbsp; pH,&nbsp; whereby&nbsp; obtained&nbsp; results&nbsp; are&nbsp; in accordance&nbsp; with&nbsp; the&nbsp; results&nbsp; of&nbsp; the&nbsp; applied&nbsp; comparative&nbsp; methods.&nbsp; For&nbsp; obtainig&nbsp; of representative&nbsp; results&nbsp; it&nbsp; is&nbsp; necessary&nbsp; to&nbsp; optimize&nbsp; conditions&nbsp; of&nbsp; measurment&nbsp; which&nbsp; include: selection of substrat electrode, surface modifier and optimization of experimental condition.</p>

No description available.

Il apparaît au grand jour que de nombreuses substances telles que les perturbateurs endocriniens sont introduites quotidiennement dans l’environnement. Ces molécules organiques bien souvent d’origine anthropique peuvent être employées dans d’innombrables circonstances : pharmaceutique, médecine, agriculture, cosmétique, agroalimentaire pour citer quelques exemples. Parmi ce large panel de composés, se trouvent les hormones stéroïdiennes. Un certain nombre de maladies et de modifications aussi bien comportementales que physiologiques tant chez l’humain que sur la faune aquatique sont attribuées à l’usage et aux rejets chroniques de ces perturbateurs endocriniens. Il est donc indispensable de développer une approche portée sur la prévention et l’étude des niveaux de contamination selon un seul maître-mot : précaution. Dans ce contexte, ce projet de doctorat visait à développer de nouvelles méthodes de détection des hormones stéroïdiennes à niveau ultra-trace dans diverses matrices environnementales. La sélection des composés ciblés dans ce projet s’est basée sur la nouvelle liste de perturbateurs endocriniens prioritaires de l’agence de protection de l’environnement des États-Unis (US EPA), récemment élargie à d’autres classes de substances dont le bisphénol A. Les méthodes analytiques ont été développées non seulement dans l’eau du robinet (EPA 539), mais également dans d’autres matrices plus complexes (eaux de surface, eaux usées). Commune à l’ensemble des procédures testées, la phase de validation analytique a permis de vérifier la conformité avec les exigences de performance de l’EPA. La première méthode mise au point repose sur une pré-concentration rapide de l’échantillon par extraction sur phase solide en ligne (on-line SPE) couplée à la chromatographie liquide à ultra-haute performance (UHPLC) et à la spectrométrie de masse en tandem (MS/MS). La méthode validée présente de nombreux avantages—reproductibilité, automatisation, temps d’analyse minimal, logistique réduite et surtout des limites de détection de 0,10 ng·L-1 à 7,5 ng·L-1 selon les différentes matrices étudiées. Cette méthode apparaît particulièrement adaptée pour la détection des hormones dans les eaux usées, en lien avec les plus fortes concentrations attendues. Cependant, il est apparu pertinent d’améliorer encore la sensibilité des méthodes dans certains contextes, notamment dans le cadre des iv analyses d’eau de surface, compte tenu des critères de qualité applicables. La principale modification fut apportée au niveau de l’extraction et de la purification des échantillons. Amendée à la faveur des différentes matrices, l’étape d’extraction par SPE hors-ligne automatisée (off-line SPE) a permis d’atteindre des limites de détection adéquates variant de 0,010 ng·L-1 à 6,0 ng·L-1 dépendamment de la matrice et du composé. Un aspect original de cette étude a consisté à étudier de façon plus systématique les facteurs de robustesse de la méthode lorsque soumise à certaines variations, tant au niveau de l’analyse instrumentale (phases mobiles, volume d’injection) que des protocoles (emploi de différents agents de conservation, par exemple). L’analyse de la phase dissoute ne saurait être suffisante pour comprendre le devenir environnemental des perturbateurs endocriniens dans les milieux aquatiques, notamment leur distribution. Dans cette optique, la phase particulaire en suspension dans la colonne d’eau (SPM) fut également étudiée après optimisation et validation de la méthode d’extraction. Les limites de détection obtenues étaient comprises entre 0,10 ng/g et 3,0 ng/g, un degré de performance adéquat au regard des teneurs attendues dans l’environnement. De telles méthodes ne trouveraient pas de fondement si elles n’étaient pas employées à l’analyse d’échantillons réels. C’est pourquoi, pour chaque méthode développée, une série d’échantillons d’eau a été analysée pour toutes les matrices étudiées. La quantification des hormones stéroïdiennes a permis de rendre compte des niveaux de concentrations retrouvés dans l’environnement. Une étude saisonnière d’un cours d’eau a également été réalisée durant quatre saisons (hiver, printemps, été et automne) afin d’évaluer les éventuelles variations saisonnières en termes d’occurrence et de concentration. / It is now admitted that many substances such as endocrine disruptors are released daily into the environment. This process can be of natural origin but is predominantly linked to human activity. Endocrine disruptors originate from numerous fields: medicine, agriculture, cosmetics, and the food industry, to name a few. Steroid hormones belong to this wide array of compounds. A significant number of human diseases and behavioral and physiological changes in both humans and aquatic life have been attributed to the use and chronic release of these endocrine disruptors. The effects of such a cocktail of substances are difficult to understand and evaluate. To date, the synergistic mechanisms or the potential cumulative effects are not well known. It remains essential to develop an approach focused on the prevention and the study of contamination levels with one key word in mind: precaution. In this context and aiming to detect steroid hormones in tap water, surface water and wastewater at trace levels, new analytical methods have been developed within the framework of this project. The first method developed is based on high performance liquid chromatography (HPLC) coupled with tandem mass spectrometry (MS / MS). LC-MS/MS hyphenation involved using an electrospray ionization source at atmospheric pressure with heating element (H-ESI). Pre-concentration and purification of the samples were executed by on-line solid phase extraction (on-line SPE). The validated method presents several advantages: reproducibility, automation, minimum analysis time, reduced logistics and above all, detection limits ranging from 0.10 ng·L-1 to 7.5 ng·L-1 considering the different matrices studied. The second approach proposed herein is based on the development of an analysis method allowing lower detection limits compared to the previous workflow. The same detection method was used, but a modification was made to the sample extraction and purification. Allowing for greater pre-concentration than online SPE, manual SPE (off-line SPE) was used in this method. Depending on the particular matrix, the extraction step allowed to reach adequate detection limits for the analysis of environmental aqueous samples: 0.010 ng·L-1 up vi to 6.0 ng·L-1 from the matrix-free sample to the most complex matrices. The use of an automated system also made it possible to make the extraction step robust and reproducible. The analysis of the dissolved phase of water samples cannot be sufficient to understand and comprehensively assess the contamination of aquatic environments. The particulate phase in suspension in the water column (SPM) was also studied. The extraction method was optimized and validated. Coupled with the previous method of analysis, it was possible to quantify the steroid hormones attached to suspended materials. The obtained detection limits ranged from 0.10 ng/g to 3.0 ng/g dry weight. For each developed method, dissolved phase samples were analyzed for all the studied matrices (tap water, surface water and wastewater). Quantification of steroid hormones allowed the comprehension of concentration levels found in the environment under usual discharge conditions in multiples matrices. A seasonal study of a watercourse was also carried out during the winter, spring, summer and fall seasons to observe possible seasonal variations in terms of occurrence and concentration.

Denna kandidatuppsats i miljöteknik består av en fältundersökning från Norrvatten, ett kommunalförbund ägt av 14 olika kommuner i norra Stockholms län. Uppsatsen innehåller en undersökning av möjliga relationer mellan olika klagomål på dricksvattnet från Görvälnverket, som lagrar och behandlar råvaran för framställning dricksvatten från Mälaren. De uppmätta parametrarna var definierade från litteratur inom ämnet. Indata består av det totala antalet inkomna klagomål, med ett särskilt fokus på dem med en eller flera överskridna parametrar. Vi analyserar kvantitén av klagomål per kommun, per capita och fördelningen av klagomål för olika kategorier och relevanta parametrar såväl som relationen till befolkningstätheten i regionen. Vi hittade att det är signifikanta kopplingar mellan vissa kategorier av klagomål, och framförallt att järn är den vanligaste parametern häri. Vi hittade också att klagomål per capita kan indikera ett samband med befolkningstätheten. Ytterligare ett konstaterande är att spolning är effektivt som åtgärd mot mikrobiologiska problem, medan det för vissa kemiska parametrar förvärrade situationen. / This bachelor thesis in environmental engineering consists of a case study from Norrvatten, a municipal federation owned by 14 different urban municipalities in the northern part of the Stockholm region. The essay contains an investigation of possible relations between the various complaints on the drinking water from Görvälnverket, which is storing and treating the source material for tap water production from Mälaren. The measured parameters were defined from literature in the field. The data sets consisted in the total quantity of the complaints, with a particular focus on the ones where one or several parameters were exceeded. We analyse the quantity of complaints per municipality, per capita and the distribution of complaints for various categories and relevant parameters as well as the relation to the population densities in the region. We found that there are significant connections between some classes of complaints, and in particular that iron is the most common parameter herein. We also found that complaints per capita may indicate a correlation with the population density. A further finding is that flushing is more efficient as a measure against microbiological issues, while it for some chemical parameters rather worsened the situations.

[ES] La Agenda 2030 para el Desarrollo Sostenible establece una serie de retos ambiciosos para la comunidad mundial denominados Objetivos de Desarrollo Sostenible (ODS). Entre ellos se encuentran retos específicos como el acceso al agua potable y al saneamiento y una mejor planificación de los recursos hídricos, además de objetivos dirigidos con el fin de combatir las desigualdades y la discriminación, entre los cuales se incluyen los siguientes objetivos generales "no dejar a nadie atrás" y "llegar primero a los más rezagados". Hasta la fecha, se ha demostrado que estos retos son difíciles de cumplir, en parte porque son complejos, pero también debido a la inercia política. Por otra parte, las potabilizadoras son capaces de suministrar agua segura para el consumo humano, sin embargo, es posible que su calidad se vea deteriorada a lo largo de su recorrido por el sistema de distribución antes su llegada al consumidor; si el abastecimiento de agua se ve restringido, las posibilidades de degradación de la calidad física, química y, sobre todo, microbiológica a nivel doméstico se incrementan, por ese motivo, para garantizar la calidad del agua se debe asegurar la integridad física, química y cualitativa del agua. Al aplicar los métodos de análisis de riesgos a los sistemas de agua potable para el consumo humano, se está desarrollando como una importante técnica de gestión preventiva, que ya está ofreciendo resultados muy significativos a la hora de anticiparse a eventuales situaciones de peligro, lo que permite intervenir con rapidez y evitar el impacto de los eventos de origen natural contra las infraestructuras y el agua para el consumo humano. En esta tesis se aborda la problemática de la seguridad del agua destinada al consumidor, identificando los fundamentos de la buena gobernanza y proponiendo un nuevo enfoque para llevar a cabo un análisis del riesgo a lo largo de la cadena del agua, integrando la modelización predictiva y las técnicas de árbol de eventos y de fallos. El estudio ha demostrado la gran capacidad del nuevo enfoque para reproducir escenarios reales y evaluar los niveles de ooquistes después del tratamiento, teniendo en cuenta la heterogeneidad de los aportes resultantes de diferentes niveles de ooquistes contenidos en las aguas superficiales, la eficiencia del tratamiento, los controles del proceso y los aportes de agua. El nuevo planteamiento también puede utilizarse para la evaluación de la exposición de otros agentes patógenos en el agua, y en todas las etapas de la cadena del agua, con el fin de evaluar el impacto real de las desviaciones o los fallos en las condiciones del proceso y los controles de seguridad sobre el riesgo para los consumidores provocado por los agentes patógenos. / [CA] L'Agenda 2030 per al desenvolupament Sostenible estableix una sèrie de reptes ambiciosos per a la comunitat mundial denominat Objectius de Desenvolupament Sostenible (ODS). Aquests inclouen reptes com l'accés a l'aigua, el sanejament segur i una millor gestió de l'aigua, igual que objectius per a afrontar la desigualtat i la discriminació incloent propòsits generals per a "no deixar a ningú arrere" i "arribar primer als més ressagats". Fins hui, s'ha demostrat que aquests reptes són difícils de complir, en part perquè són complexos però també a causa de la inèrcia política. D'altra banda, les plantes de tractament d'aigua potable poden proveir aigua segura per al consum humà, però la seua qualitat es pot alternar durant el pas pel Sistema de Distribució d'Aigua abans d'arribar al consumidor; si el proveïment d'aigua és restringit, la possibilitat de deterioració de la qualitat física, química i principalment microbiològica a nivell intradomiciliària s'incrementa havent-se de protegir la integritat física, hidràulica i de qualitat de l'aigua per a garantir l'assegurament del subministrament de l'aigua potable. L'aplicació dels mètodes d'anàlisi de risc aplicats als serveis d'aigua i sanejament s'està convertint en una estratègia imprescindible en la gestió preventiva, que comença a mostrar resultats importants en l'anticipació oportuna de desastres potencials, facilitant les accions anticipades per a enfrontar les amenaces previsibles per a mitigar els impactes dels esdeveniments naturals en la infraestructura d'aigua i sanejament. En aquesta tesi s'aborda la problemàtica de la seguretat de l'aigua destinada al consumidor, identificant els fonaments de la bona governança i proposant un nou enfocament per a dur a terme una anàlisi de risc al llarg de la cadena de l'aigua, integrant la modelització predictiva i les tècniques d'arbre d'esdeveniments i de fallades. L'estudi ha demostrat la gran capacitat del nou enfocament per a reproduir escenaris reals i avaluar els nivells d'ooquistes després del tractament, tenint en compte l'heterogeneïtat de les aportacions resultants de diferents nivells d'ooquistes continguts en les aigües superficials, l'eficiència del tractament, els controls del procés. L'eficiència de la planta, l'eficiència del tractament, els controls del procés i les aportacions d'aigua. El nou plantejament també pot utilitzar-se per a l'avaluació de l'exposició d'altres agents patògens en l'aigua i en totes les etapes de la cadena de l'aigua, amb la finalitat d'avaluar l'impacte real de les desviacions o les fallades en les condicions del procés i els controls de seguretat sobre el risc per als consumidors provocat per agents patògens. / [EN] The 2030 Agenda for Sustainable Development sets out a series of ambitious challenges for the global community. These Sustainable Development Goals (SDGs) include targets for access to safe water and sanitation and improved water management, as well as goals to tackle inequality and discrimination, including overarching proposals to "leave no one behind" and "reach the most disadvantaged first". To date, these are challenges that have proved difficult to meet, partly because they are complex, but also because of political inertia. On the other hand, drinking water treatment plants can provide safe water for human consumption, but its quality can be altered during its passage through the water distribution system before it reaches the consumer; if the water sup-ply is restricted, the possibility of physical, chemical and mainly microbiological quality detection at the household level increases, and the physical, hydraulic and quality integrity of the water must be protected to ensure the safety of the drinking water supply. The application of risk analysis methods applied to water and sanitation ser-vices is becoming an important preventive management strategy, which is be-ginning to show significant results in the timely anticipation of potential disas-ters, facilitating anticipatory actions to address foreseeable hazards and to mit-igate the impacts of natural events on water and sanitation infrastructure. This thesis addresses the issue of consumer water safety by identifying the fundamentals of good governance and proposing a new approach for conduct-ing risk analysis along the water chain, integrating predictive modelling and event and fault tree techniques. The study has demonstrated the high capacity of the new approach to reproduce real scenarios and to evaluate the levels of oocysts after treatment, taking into account the heterogeneity of the inputs resulting from different levels of oocysts contained in the surface water, the efficiency of the treatment, the process controls and the water in-puts. The new approach can also be used for exposure assessment of other pathogens in water, and at all stages of the water chain, to assess the real im-pact of deviations or failures in process conditions and safety controls on the risk to consumers from pathogens. / Kombo Mpindou, GOM. (2023). Aportación a la implantación del análisis de riesgo en los sistemas de distribución del agua: caso del Cryptosporidium para distintos niveles de desarrollo tecnológico en la potabilizadora [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/193340