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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Estudo da degradação do trimetoprim e do sulfametoxazol utilizando peróxido de hidrogênio (H2O2) eletrogerado por eletrodos de difusão gasosa (EDG) / Study of degradation of trimethoprim and sulfamethoxazole using hydrogen peroxide (H2O2) eletrogenerated by gas diffusion electrodes

Fernando Lindo Silva 25 February 2013 (has links)
Atualmente a classe dos antibióticos se destaca pelo grande consumo e também pelo risco à saúde quando administrado de forma equivocada, esse aumento deve-se ao destaque cada vez maior da indústria de produtos farmacêuticos. Outra questão a ser levantada é a contaminação do meio ambiente por essa classe substâncias, pois após o uso pelo ser humano ocorre a eliminação natural de parte da concentração administrada, assim sendo liberadas nos esgotos e, posteriormente, contaminando os corpos d\'água, a fauna e flora local. Assim, foi proposto um métodos diferente para a degradação desses compostos, utilizando a eletrodos de difusão gasosa (EDG) capazes de gerar peróxido de hidrogênio in situ e em meio ácido, precursores dos radicais hidroxila, responsáveis pela degradação. Foram estudados EDG\'s não catalisados e catalisados, com diferentes porcentagens de ftalocianina de ferro II, com relação à quantidade de peróxido produzido, melhor potencial de produção e cinética do processo. Os resultados revelaram que a incorporação de 0,5% de Ft-Fe no eletrodo apresentou os melhores resultados. Esse eletrodo foi escolhido então para realizar as degradações dos antibióticos sulfametoxazol e trimetoprim. Na célula eletroquímica utilizou-se o processo Fenton, as reações ocorreram em uma faixa de potencial (-0,4 V ≤ E ≤ -1,4 V) e no reator foi utilizado um potencial fixo (-1,75 V) mas utilizando processos de Fenton e Foto-Fenton. As amostras degradadas foram avaliadas por técnicas analíticas de espectroscopia no ultravioleta (UV), cromatografia líquida de alta eficiência (HPLC) e teor de carbono orgânico total (TOC). Os resultados mostraram que, na célula eletroquímica, o melhor potencial de degradação foi de -1,1 V, com uma taxa de redução de 25,5% para o trimetoprim e 96,0% do sulfametoxazol e uma diminuição do teor de carbono orgânico total de 10,4%. Para o reator o melhor resultado foi obtido para o processo de Foto-Fenton onde houve uma redução de 16,9% do teor de carbono orgânico total e uma redução de 99,7% do sulfametoxazol e 11,3% do trimetoprim, em um potencial de -1,75 V. Considerando a formação de subprodutos foi elaborada uma rota de degradação com os possíveis compostos formados. / Currently the class of antibiotics is notable for the large consumption and also the risk to health when administered in error, this increase is due to the growing prominence of the pharmaceutical industry. Another issue to be addressed is the environmental contamination by substances that class, because after use by humans part of the concentration administered is naturally eliminated, thus being released into sewers and subsequently contaminating water bodies, the local fauna and flora. Thus, different methods has been proposed for the degradation of these compounds, using gas diffusion electrodes (GDE) capable of generating hydrogen peroxide in situ and in acid medium, precursors of hydroxyl radicals, responsible for degradation. We studied GDE\'s not catalyzed and catalyzed with different percentages of iron phthalocyanine II, with respect to the amount of peroxide produced better yield potential and kinetic process. The results revealed that the incorporation of 0.5% of Ft-Fe in the electrode showed the best results. This electrode was then chosen to perform the degradation of the antibiotic sulfamethoxazole and trimethoprim. In the electrochemical cell used in the Fenton process, the reactions occurred in a potential range (-0.4 V ≤ E ≤ -1.4 V) and in the reactor was used a fixed potential (-1.75 V) but using Fenton and photo-Fenton processes. Degraded samples were analyzed by analytical techniques, ultraviolet spectroscopy (UV), high performance liquid chromatography (HPLC) and total organic carbon content (TOC). The results showed that in the electrochemical cell, the best degradation potential was -1.1 V, with a reduction rate of 25.5% for trimethoprim and 96.0% for sulfamethoxazole and a decreased carbon content total of 10.4%. For the reactor the best result was obtained for the photo-Fenton process where there was a reduction of 16.9% of the total organic carbon content and a reduction of 99.7% of sulfamethoxazole and 11.3% of trimethoprim, in a potential of -1.75 V. Considering the formation of byproducts was drafted a route with the possible degradation compounds formed.
72

Estudo da degradação do trimetoprim e do sulfametoxazol utilizando peróxido de hidrogênio (H2O2) eletrogerado por eletrodos de difusão gasosa (EDG) / Study of degradation of trimethoprim and sulfamethoxazole using hydrogen peroxide (H2O2) eletrogenerated by gas diffusion electrodes

Silva, Fernando Lindo 25 February 2013 (has links)
Atualmente a classe dos antibióticos se destaca pelo grande consumo e também pelo risco à saúde quando administrado de forma equivocada, esse aumento deve-se ao destaque cada vez maior da indústria de produtos farmacêuticos. Outra questão a ser levantada é a contaminação do meio ambiente por essa classe substâncias, pois após o uso pelo ser humano ocorre a eliminação natural de parte da concentração administrada, assim sendo liberadas nos esgotos e, posteriormente, contaminando os corpos d\'água, a fauna e flora local. Assim, foi proposto um métodos diferente para a degradação desses compostos, utilizando a eletrodos de difusão gasosa (EDG) capazes de gerar peróxido de hidrogênio in situ e em meio ácido, precursores dos radicais hidroxila, responsáveis pela degradação. Foram estudados EDG\'s não catalisados e catalisados, com diferentes porcentagens de ftalocianina de ferro II, com relação à quantidade de peróxido produzido, melhor potencial de produção e cinética do processo. Os resultados revelaram que a incorporação de 0,5% de Ft-Fe no eletrodo apresentou os melhores resultados. Esse eletrodo foi escolhido então para realizar as degradações dos antibióticos sulfametoxazol e trimetoprim. Na célula eletroquímica utilizou-se o processo Fenton, as reações ocorreram em uma faixa de potencial (-0,4 V ≤ E ≤ -1,4 V) e no reator foi utilizado um potencial fixo (-1,75 V) mas utilizando processos de Fenton e Foto-Fenton. As amostras degradadas foram avaliadas por técnicas analíticas de espectroscopia no ultravioleta (UV), cromatografia líquida de alta eficiência (HPLC) e teor de carbono orgânico total (TOC). Os resultados mostraram que, na célula eletroquímica, o melhor potencial de degradação foi de -1,1 V, com uma taxa de redução de 25,5% para o trimetoprim e 96,0% do sulfametoxazol e uma diminuição do teor de carbono orgânico total de 10,4%. Para o reator o melhor resultado foi obtido para o processo de Foto-Fenton onde houve uma redução de 16,9% do teor de carbono orgânico total e uma redução de 99,7% do sulfametoxazol e 11,3% do trimetoprim, em um potencial de -1,75 V. Considerando a formação de subprodutos foi elaborada uma rota de degradação com os possíveis compostos formados. / Currently the class of antibiotics is notable for the large consumption and also the risk to health when administered in error, this increase is due to the growing prominence of the pharmaceutical industry. Another issue to be addressed is the environmental contamination by substances that class, because after use by humans part of the concentration administered is naturally eliminated, thus being released into sewers and subsequently contaminating water bodies, the local fauna and flora. Thus, different methods has been proposed for the degradation of these compounds, using gas diffusion electrodes (GDE) capable of generating hydrogen peroxide in situ and in acid medium, precursors of hydroxyl radicals, responsible for degradation. We studied GDE\'s not catalyzed and catalyzed with different percentages of iron phthalocyanine II, with respect to the amount of peroxide produced better yield potential and kinetic process. The results revealed that the incorporation of 0.5% of Ft-Fe in the electrode showed the best results. This electrode was then chosen to perform the degradation of the antibiotic sulfamethoxazole and trimethoprim. In the electrochemical cell used in the Fenton process, the reactions occurred in a potential range (-0.4 V ≤ E ≤ -1.4 V) and in the reactor was used a fixed potential (-1.75 V) but using Fenton and photo-Fenton processes. Degraded samples were analyzed by analytical techniques, ultraviolet spectroscopy (UV), high performance liquid chromatography (HPLC) and total organic carbon content (TOC). The results showed that in the electrochemical cell, the best degradation potential was -1.1 V, with a reduction rate of 25.5% for trimethoprim and 96.0% for sulfamethoxazole and a decreased carbon content total of 10.4%. For the reactor the best result was obtained for the photo-Fenton process where there was a reduction of 16.9% of the total organic carbon content and a reduction of 99.7% of sulfamethoxazole and 11.3% of trimethoprim, in a potential of -1.75 V. Considering the formation of byproducts was drafted a route with the possible degradation compounds formed.
73

Estudo da degradação da enrofloxacina em solução aquosa por meio de processos foto-oxidativos. / Study of degradation of enrofloration solution through process photo-oxidative.

Dias, Meriellen 19 April 2013 (has links)
As tecnologias utilizadas em estações de tratamento de água e efluentes não são eficientes para a remoção total de resíduos farmacêuticos e os efeitos dessas substâncias sobre o meio ambiente e a saúde humana ainda não são bem conhecidos. No presente trabalho, estudou-se a degradação do antibiótico enrofloxacina (ENRO) por fotólise e pelo processo H2O2/UV na presença de compostos bio-orgânicos (BOS), que têm se apresentado como interessantes promotores da oxidação de poluentes. Os experimentos foram realizados em um reator fotoquímico tubular de imersão com fonte radiante (lâmpada de xenônio) concêntrica, operado em batelada com recirculação. Utilizaram-se concentrações iniciais de ENRO e de BOS iguais a 50 mg L-1 e 20 mg L-1, respectivamente. Para todos os pH mantidos constantes (3, 5, 7 ou 9), a solução foi irradiada por 240 minutos. Os resultados indicam que o antibiótico não sofreu hidrólise em qualquer dos pH estudados em um período de 24 horas. Por sua vez, a fotólise da enrofloxacina mostrou-se eficiente somente na presença do composto bioorgânico CVT 230 (BOS C), com remoção de ENRO de quase 90% em meio neutro (pH 7). Resultados da literatura, associados a experimento realizado em meio anóxico, sugerem a participação de oxigênio singlete como principal espécie oxidante da enrofloxacina. Por outro lado, a degradação da ENRO pelo processo H2O2/UV apresentou remoção máxima do fármaco de 48% em pH 7, o que sugere que a ação de oxigênio singlete e/ou radicais hidroxila não foi eficaz na presença de peróxido de hidrogênio. Portanto, o BOS C pode ser empregado como promotor no tratamento de águas e efluentes aquosos contaminados com enrofloxacina sob baixas potências radiantes ou em sistemas irradiados por luz solar. / The technologies used in water and wastewater treatment plants are not efficient for the total removal of pharmaceutical compounds whose effect to the environment and to human health are still not well known. In this work, the degradation of the antibiotic enrofloxacin (ENRO) was studied by photolysis and by the H2O2/UV process in the presence of bio-organic substances (BOS), which have been identified as interesting promoters of pollutant oxidation. The experiments were carried out in a tubular immersion photochemical reactor equipped with a concentric radiant source (xenon lamp), and operated in batch mode with recirculation. Initial ENRO and BOS concentrations of 50 mg L-1 and 20 mg L-1 were used, respectively. The solution was irradiated for 240 minutes for all pH studied at constant values (3, 5, 7, and 9). The results show that the antibiotic did not undergo hydrolysis at any pH after 24 hours. The photolysis of enrofloxacin showed to be efficient only in the presence of the bio-organic substance CVT 230 (BOS C), with almost 90% ENRO removal in neutral solution (pH 7). Results from the literature, associated with an experiment carried out in anoxic conditions, suggest singlet oxygen as the main species responsible for enrofloxacin oxidation. On the other hand, ENRO degradation by the H2O2/UV process showed a maximum removal of 48% at pH 7, suggesting that the action of singlet oxygen and/or hydroxyl radicals was not effective in the presence of hydrogen peroxide. BOS C can therefore be used as an efficient promoter for the treatment of enrofloxacin-containing water and wastewater under low irradiant power or in solar-irradiated systems.
74

Étude de la régénération d’adsorbants par oxydation indirecte / Study of the regeneration of adsorbents by indirect oxidation

Domergue, Lionel 11 July 2019 (has links)
Du fait du coût élevé de certains matériaux adsorbants d’intérêt pour le traitement de la micropollution organique, l’étude a porté sur la régénération de matériaux adsorbants de type zéolithes hydrophobes et monolithe de carbone dans le cas de l’adsorption du bisphénol A et du diclofénac comme micropolluants réfractaires. Des procédés d’oxydation avancée impliquant des espèces radicalaires HO• (réaction de Fenton, électro-Fenton) et SO₄• – (activation de persulfate par voie thermique) ont été utilisés pour assurer la régénération des matériaux par désorption et dégradation oxydative des polluants fixés. La production de radicaux HO• au sein de la phase aqueuse circulant au niveau de l’adsorbant n’est pas suffisamment efficace pour sa régénération. Il a donc été envisagé de générer les radicaux au plus près des molécules adsorbées. Au cours de ce travail, une méthode sensible d’analyse par polarographie de H₂O₂ a été développée et validée pour le suivi des expériences avec les procédés mettant en jeu la réaction de Fenton. Pour différentes zéolithes, le catalyseur de la réaction de Fenton à base de fer a été incorporé préalablement dans la zéolithe. Pour le monolithe de carbone, les propriétés de conduction du matériau ont été mises à profit en l’utilisant comme cathode pour l’application du procédé électro-Fenton permettant de produire les radicaux HO• directement au sein du matériau. Cela a conduit à améliorer les performances de la régénération avec toutefois une diminution de son efficacité au cours de cycles successifs adsorption/régénération. / The elimination of organic micropollutants often requires the use of adsorption processes among the water treatments. The aim of our study is to regenerate two expensive materials (hydrophobic zeolites and carbon monoliths) to increase their life expectancy and decrease their investing cost. Two organic contaminants were targeted : diclofenac and bisphenol A, which are refractory pollutants. Advanced oxidation processes involve radical species, HO• (Fenton and electro-Fenton reactions) and SO₄• – (thermal activation of persulfate ion). These oxidants were used to decompose the adsorbed pollutants and thus regenerate the adsorbents. The HO• production, within the core of aqueous phase, did not reach satisfactory regeneration, and a loss of adsorption capacity was observed. Furthermore, during this study, a sensitive polarographic analytical method was developed and validated for the quantification of H₂O₂ in the aqueous phase. This method was used to follow in situ the Fenton reaction. The location of the catalyst in a closer vicinity of the adsorbed species was then optimized and the iron catalyst was impregnated in the host, prior to the adsorption, on different types of hydrophobic zeolites. Concerning carbon monolith, the electro-Fenton process was carried out using the material as the cathode thanks to its electrical conductivity. Consequently, HO• are produced in the porosity of monolith. This latter property enhanced the degradation of adsorbed solutes. The overall performances were increased compared to the homogeneous Fenton process. Nonetheless, a decrease of the adsorption capacities with adsorption-regeneration cycles was observed.
75

Source Characterization and Pretreatment Evaluation of Pharmaceuticals and Personal Care Products in Healthcare Facility Wastewater

Nagarnaik, Pranav Mukund 2011 May 1900 (has links)
Healthcare facility wastewaters are a potentially important and under characterized source of pharmaceuticals and personal care products to the environment. In this study the composition and magnitude of pharmaceuticals and personal care products (PPCPs) released into a single municipality’s wastewater system from a hospital, a nursing care facility, an assisted living facility and an independent living facility are presented for 54 pharmaceuticals, 8 hormones and 31 Alkylphenol ethoxylates (APEOs). Chemical oxidation using molecular ozone and advanced oxidation processes (AOPs) (UV-hydrogen peroxide, Fenton’s Reagent, and Photo – Fenton’s Reagent) were screened and evaluated as potential treatment technologies for removal of APEOs in water and wastewater. In this research, APEOs were found to be dominant PPCP class out of 94 individual analytes measured, accounting for more than 65% of the total mass loading observed leaving the healthcare facility wastewater. Seventy one out of the total measured PPCPs were detected in wastewater from at least one of the facilities. Healthcare facility wastewater are the source of PPCPs to the environment; however, their contribution to the total magnitude of PPCPs in municipal wastewater and the surrounding environment will be determined by the relative flow contribution of wastewater released from the facility to the municipal sewer network. Molecular ozone and advanced oxidation processes were observed to remove APEOs from analyzed water matrices; however, understanding the product formation during the oxidation process is important before concluding a suitable treatment process. Molecular ozone reacted selectively with the double bond in the APEO while AOPs reaction was non selective oxidation. During the AOPs, OH· formation rate and scavenging rate constant of wastewater was found to be the factors governing the oxidation process. Thus, the research carried out informs a risk management decisions concerning the prevalence of PPCPs in the wastewater and use of oxidation systems as a treatment technologies for removal of PPCPs.
76

Oxidation characteristics of fluorine-, nitrogen-, and sulfur-containing organic compounds by UV/O3

Chang, Ken-Lin 10 September 2007 (has links)
DMSO (dimethyl sulfoxide) is a liquid with a high boiling point (189 oC) that has been extensively utilized in various industries owing to its ability to dissolve various organic and inorganic compounds. DMSO is increasingly being adopted as a detergent or a photo-resistant stripping solvent in manufacturing semiconductors and liquid crystal displays (LCD). Therefore, DMSO is now a major component of wastewater. The biological treatment of DMSO-containing wastewater generates noxious DMS (dimethyl sulfide) and other compounds that may cause odor problems. Also having a high water solubility and a moderate boiling point (110 oC), tetrafluoro propanol (TFP) has been extensively applied in the manufacture of CD-R and DVD-R, due to its ability to dissolve organic dyes. The spin coating process produces a large amount of wastewater containing TFP. No reports have been written on the biodegradability of TFP to the authors¡¦ knowledge. Additionally, HMDS (hexamethyldisilazane) has been extensively used in life science microscopy and material science. For instance, the semiconductor industry employs HMDS to promote the adhesion of photo-resistant material to oxide(s). HMDS is classified as a carcinogen, and has an ammonia odor. Condensing incinerators have been found to be unsuitable for treating HMDS-containing waste gases, because of the formation of silicon dioxide, which blocks porous adsorbents. Biological treatment also appears to be unpromising due to its low water solubility and limited biodegradability. This investigation evaluates the feasibility, effectiveness and oxidation characteristics of aqueous DMSO, TFP and gaseous HMDS (hexamethyldisilazane) by UV/O3 processes. A reactor made entirely of acrylic plastic with an effective volume of 10 L was employed for the reactions. The tested VOCs concentrations were adjusted to 400¡V890mg/L and 772¡V887 mg/L for DMSO and TFP, respectively, and the gas (ozone-enriched air) flow rate was controlled at 3L/min. The effects of various solution pH values (acidic, alkaline, uncontrolled), solution temperatures (26 oC, 37 oC, 48 oC and 60 oC), and UV wavelengths (254 nm and 185+254 nm) on the removal of tested VOCs were studied . Additionally, the operation costs of treating DMSO and TFP by UV/O3 were estimated. Experimental results demonstrate that acidic conditions (pH = 3.6) favored the degradation of DMSO, and that the removal efficiency could reach 95% at a volumetric UV intensity P/V of 2.25 W/L and a reaction time of 120 min. However, alkaline conditions (pH = 9.5) favored the decomposition of TFP, with the removal efficiency reaching 95% at P/V = 2.5 W/L and a reaction time of 60 min. Both DMSO and TFP exhibited zero-order degradation kinetics when sufficient ozone was supplied. Raising the oxidation temperature did not increase the UV/O3 oxidation of TFP in the tested concentration and temperature ranges. Operation costs of the UV/O3 per unit volume of wastewater with DMSO or TFP are comparable to those of the methods described in the literature. For the gaseous HMDS oxidation, two batch reactors with effective volumes of 1.2 and 5.8 L were used employed with the decomposition occurred under UV (185+254 nm) irradiation and UV (254 nm)/O3 processes. Tests were performed with initial HMDS concentrations of 32¡V41mg/m3 under various initial ozone dosages (O3 (mg)/HMDS (mg) =1¡V5), atmospheres (N2, O2, and air), temperatures (28 oC, 46 oC, 65 oC and 80 oC), relative humilities (20%, 50%, 65% and 99%) and volumetric UV power inputs (0.87 W/L, 1.74 W/L, 4.07 W/L and 8.16 W/L) to assess their effects on the HMDS degradation rate. Results of this study demonstrate that the decomposition rates for the UV (185+254 nm) irradiation exceeded those for the UV (254 nm)/O3 process for all conditions. UV (185+254 nm) decompositions of HMDS displayed apparent first-order kinetics. A process with irradiation of UV (185+254 nm) to HMDS in air saturated with water at temperatures of 46¡V80 oC favors the HMDS degradation. With the above conditions and a P/V of around 8 W/L, k≈ 0.20 s−1, and over 90% of the initial HMDS was degraded in a time of 12s. The main mechanisms for the HMDS in wet air streams irradiated with UV (185+254 nm) were found to be caused by OH free radical oxidation produced from photolysis of water or O (1D) produced from photolysis of oxygen. Economic evaluation factors of UV (185+254 nm) and UV (254 nm)/O3 processes at various UV power inputs were also estimated.
77

Degradation of hazardous organic compounds by using electro-fenton technology

Özcan, Ali 19 March 2010 (has links) (PDF)
In this thesis, a detailed investigation has been carried out on the use of electro-Fenton technique for the oxidation of the some persistent organic pollutants for the sake of water remediation. This technique produces *OH radicals electrocatalytically and uses them to oxidize the organic pollutants. The overall study can be divided into three parts. In the first part, the removal of selected synthetic dyes and pesticides from water was investigated by using carbon felt (CF) cathode. The oxidation kinetics of the synthetic dyes (Acid Orange 7 and Basic Blue 3) and pesticides (picloram, propham, azinphos-methyl and clopyralid) were determined. Mineralization kinetics of the related organic pollutants in aqueous medium was followed by total organic carbon and chemical oxygen demand analysis. The overall mineralization was obtained in all cases. Identification and quantification of the oxidation by-products of the given synthetic dyes and pesticides were performed by high performance liquid chromatography, gas chromatography-mass spectrometry, liquid chromatography-mass spectrometry and ion chromatography. These systematic analysis showed that the initial organic pollutants were converted into three intermediate forms; organic intermediates, short-chain aliphatic carboxylic acids and inorganic ions. Based on the intermediates identified, a plausible mineralization pathway was proposed for each dye and pesticide.In the second part of the study, the H2O2 production ability of carbon sponge (CS) as a novel cathode material for the electro-Fenton technique was investigated for the first time in the literature. The obtained results indicated that CS has a H2O2 production ability three times higher than the classical cathode CF.In the third and last part, the efficiency of boron doped diamond (BDD) as an anode in the electro-Fenton technique was investigated. Firstly, the oxidation and mineralization ability of BDD was tested for herbicide propham in anodic oxidation conditions. Then, the combination of CS and BDD electrode in the electro-Fenton technique was examined. The obtained results indicated that this combination allowed the most efficient results throughout the thesis. Moreover, the use of BDD anode in the electro-Fenton technique had considerable effect on the oxidation and mineralization of organics and especially carboxylic acids such as oxalic and oxamic acids which were highly resistant to mineralization in the case of Pt anode
78

Contribution à l’étude du traitement de résidus médicamenteux dans les milieux aqueux par plasmas non thermiques. Application au paracétamol et à l’ésoméprazole / Contribution to the study of pharmaceutical residues treatment in aqueous solution by non-thermal plasmas. Application to paracetamol and esomeprazole

Baloul, Yasmine 30 January 2018 (has links)
De nombreuses molécules médicamenteuses ne sont pas traitées efficacement par les techniques classiques utilisées dans les stations d'épuration et s’accumulent dans les milieux naturels. L’objectif de cette thèse a été de développer un procédé d’oxydation avancée utilisant un plasma non thermique généré par décharge électrique pour le traitement de molécules médicamenteuses et d’identifier le schéma de dégradation d’une des molécules d’étude, à savoir le paracétamol. Les traitements ont été réalisés à l’aide de deux réacteurs : un réacteur multi-pointes avec le plasma au contact direct du liquide à traiter et un réacteur fil-cylindre avec le plasma en amont du liquide à traiter. Des taux de conversion supérieurs à 80% ont pu être obtenus avec des rendements énergétiques, qui peuvent atteindre 8g/kWh et 39 g/kWh pour le paracétamol et l’ésoméprazole, respectivement. La décharge électrique créée entre une pointe et le liquide a été caractérisée par la spectroscopie d’émission optique afin d’observer la présence des espèces oxydantes produites par le plasma et d’estimer la température du milieu faiblement ionisé. Les espèces produites dans le liquide lors de la dégradation du paracétamol et de l’ésoméprazole qui ont été identifiées par la technique HRMS, entre autres, sont principalement des acides carboxyliques ainsi que des produits azotés. L’identification des voies de production pour la formation des principaux produits ont été étudiés particulièrement à l’aide de nombreuses méthodes chimiques comme HPLC/MS, MS/MS, et de différents marquages de paracétamol. Il a été prouvé que les principaux acides carboxyliques produits proviennent de la rupture du cycle aromatique. En conclusion, cette étude nous a permis d’obtenir des rendements énergétiques de traitement des deux molécules d’étude comparables à ceux retrouvés en littérature, et surtout d’établir un chemin de dégradation du paracétamol. / Many drug molecules are not effectively treated by conventional techniques used in wastewater treatment plants and accumulate in natural environments. The objective of this thesis was to develop an advanced oxidation process using a non-thermal plasma generated by electric discharge for the treatment of drug molecules (paracetamol and esomeprazole). The NTP treatments were carried out using two reactors: a multiple needle-to-plate reactor with the plasma in direct contact with the liquid to be treated and a wire-cylinder reactor with the plasma up stream of the liquid to be treated. Conversion rates higher than 80% have been obtained with energy yields, which can reach 8 g/kWh and 39 g/kWh for paracetamol and esomeprazole, respectively. The electrical discharge created between the need leand the liquid has been characterized by optical emission spectroscopy to observe the presence of the oxidative species produced by the plasma and to estimate the temperature of the ionized medium. The species produced in the liquid during the degradation of paracetamol and esomeprazole have been identified by the HRMS technique. The produced species, are mainly carboxylic acids as well as nitrogen products. The identification of production pathways for the formation of the main products has been studied particularly using numerous chemical methods such as HPLC/MS, MS/MS, and different labelling of paracetamol. It has been proven that the main carboxylic acids produced come from the breaking of the aromatic ring. In conclusion, this study allowed us to obtain energy efficiencies of treatment of the two study molecules comparable to those found in literature, and especially to establish a pathways of degradation of paracetamol.
79

Avaliação dos tratamentos oxidativos avançados em água de lavagem de biodiesel e ensaios de fitoxicidade

Grangeiro, Rosa Virgínia Tavares 09 May 2014 (has links)
Made available in DSpace on 2015-05-14T13:21:37Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1224120 bytes, checksum: f64c0391dc1efdba15b19e77bab0b144 (MD5) Previous issue date: 2014-05-09 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Given the growing trend to explore biofuels as a renewable energy source with less environmental impact and considering thatthe transesterification by basic catalysis is the most used in the biodiesel purification, it becomes importantperform treatments order to reuse of wash water biodiesel. In this sense, the objective of this study was to apply and compare photolysis (UV) followed by advanced oxidation treatment; UV/H2O2; Fenton (Fe2+/H2O2) and photo-Fenton (Fe2+/UV/H2O2)as well as perform toxicity tests using seeds lettuce (Lactuca sativa) before and after treatment of effluents.washing water was collected in biodiesel industry located in Caetés - PE. Biodiesel obtained from cotton oil was washed sequentially with two portions of one hundred liters of water. It was found pH values of 3.8 and 3.4; The minimum turbidity of 158 NTU and a maximum of 7.369 and EC was 0.25 and 0.86, minimum of 160,000 and maximum of 184.000 mg.L-1 COD, BOD ranging 830 and 2,150 mg.L-1 and the content of oils and greases varied 2,852 and 21,761 mg.L-1, respectively for first and second washing water. After application of photolysis process, reduction occurred (82.6% and 72.5%) for the water turbidity resulting from two washes.For the first rinse water, UV/H2O treatment resulted in a reduction of turbidity (91.4%) and COD (70.4%). For water resulting from second wash, reduced turbidity (84%) and in COD (80%), determined by photo-Fenton process. Through toxicity tests using lettuce seeds, it was proven that the best IG% occurred in treatments photolysis (95.3%) and UV/H2O2 (92.8%) / Diante da crescente tendência de se explorar os biocombustíveis como a fonte de energia renovável e com menor impacto ambiental e considerando que a transesterificação pela catálise básica é a mais utilizada na purificação do biodiesel, torna-se relevante realizar tratamentos visando à reutilização da água de lavagem do biodiesel. Neste sentido, o objetivo deste trabalho foi aplicar e comparar aFotólise (UV)seguidados tratamentos oxidativos avançados; UV/H2O2; Fenton (Fe2+/H2O2) e foto-Fenton (Fe2+/UV/H2O2), bem como realizar ensaios de toxicidade usando sementes de alface (lactuca sativa), antes e após o tratamento dos efluentes. A água de lavagem foi coletada na usina de biodiesel localizada na cidade de Caetés PE. O biodiesel obtido a partir do óleo de algodão foi lavado, sequencialmente, com duas porções de cem litros de água. Foram encontrados valores de pH de 3,8 e 3,4; a turbidez apresentou valor mínimo de 158 e máximo de 7369 UNT; a CE foi de 0,25 e 0,86; o valor mínimo de 160.000 e máximo de 184.000 mg.L-1de DQO; a DBO variou de 830 a 2.150 mg.L-1 e o teor de óleos e graxas oscilaram de 2.852 a 21.761 mg.L-1, respectivamente, para água de primeira e segunda lavagem. Após a aplicação do processo por fotólise, ocorreu redução (82,6% e 72,5%) da turbidez para as águas resultantes das duaslavagens. Para a água da primeira lavagem, o tratamento por UV/H2O2 resultou na melhor redução da turbidez (91,4%) e DQO (70,4%). Para a água resultante da segunda lavagem a turbidez reduziu em (84%) e a DQO em (80%), determinadas pelo processo de foto-Fenton.Através dos testes de toxicidade utilizando sementes de alface, ficou comprovado que o melhor IG% ocorreu nos tratamentos por fotólise (95,3%) e UV/H2O2 (92,8%)
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Águas de processo da REPLAN = qualidade e aplicação de processos oxidativos avançados / Process water from a Petroleum Refinery (REPLAN) : quality and application of advanced oxidation process

Gasparini, Mirthys Cozzett 18 August 2018 (has links)
Orientadores: José Roberto Guimarães, Carlos Gomes da Nave Mendes / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-18T03:12:06Z (GMT). No. of bitstreams: 1 Gasparini_MirthysCozzett_M.pdf: 1574617 bytes, checksum: 879f212f74e005fca5974d6f943a790e (MD5) Previous issue date: 2011 / Resumo: No presente trabalho foi realizada a caracterização de várias correntes de águas de processo da REPLAN (Refinaria de Paulínia), bem como a avaliação dos processos de fotólise (UV), peroxidação (H2O2), peroxidação assistida por radiação ultravioleta (H2O2/UV), reagente de Fenton (H2O2/Fe2+) e foto-Fenton (H2O2/Fe2+/UV) no tratamento de um dos efluentes, principalmente na degradação dos compostos orgânicos. Analisando-se os dados de caracterização dos diferentes efluentes foi possível sugerir alternativas de reuso no processo de refino, como também selecionar a corrente de água ácida retificada para aplicação dos processos físico-químicos de tratamento. A eficiência dos ensaios de tratabilidade foi baseada na redução da concentração do carbono orgânico dissolvido (COD). Dentre os processos estudados, os processos oxidativos avançados (POA) H2O2/UV e foto-Fenton apresentaram 95 % de eficiência após 150 minutos de ensaio. As condições ótimas foram obtidas na relação mássica COD: H2O2 de 1:7 para o processo peroxidação assistida por radiação UV, e de 1:5 e concentração de Fe2+ de 31 mg/L para o processo foto-Fenton. O efluente tratado pelo processo H2O2/UV poderia ser reutilizado como água de reposição no sistema de resfriamento, já que esta é responsável por 49 % do total de água utilizada na refinaria / Abstract: In the present study was performed the characterization of various process water from REPLAN (Paulínia Refinery) as well as an assessment of 5 processes to treat one of the effluents: photolysis (UV), peroxidation (H2O2), peroxidation assisted by ultraviolet radiation (H2O2/UV), Fenton reagent (H2O2/Fe2+) and photo-Fenton (H2O2/Fe2+/UV), in order to degrade the organic compounds. Effluents characterization results provided reuse possibilities in the process refining and also selected the stripped sour water stream for application of physical-chemical treatments. The processes efficiency was evaluated by the dissolved organic carbon (DOC) reduction. Among the processes studied, the advanced oxidation processes (AOPs) H2O2/UV and photo-Fenton reached 95 % efficiency after 150 minutes of reaction. The optimum conditions were obtained in a mass ratio COD: H2O2 of 1:7 for peroxidation assisted by UV radiation, and of 1:5 with 31 mg/L of Fe2+ for photo-Fenton. The effluent treated by AOP H2O2/UV could be reused as make-up water in cooling systems, since it is responsible for 49 % of the total water used in the refinery / Mestrado / Saneamento e Ambiente / Mestre em Engenharia Civil

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