Orientador: José Roberto Guimarães / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-23T01:48:16Z (GMT). No. of bitstreams: 1 Silva_CaioAlexandreAugustoRodriguesda_D.pdf: 5160272 bytes, checksum: ae6b16aeb8851a3f7a722c3a4fb1e054 (MD5) Previous issue date: 2013 / Resumo: Nesse trabalho foi avaliada a degradação de flumequina (500 ?g L-1) por processo físico (fotólise-UV254), químico (peroxidação-H2O2) e oxidativos avançados (fotoperoxidação-UV/H2O2, fotocatálise heterogênea-UV/TiO2, reagente de Fenton-Fe(II)/H2O2, foto-Fenton-UV/Fe(II)/H2O2, eletroquímico e foto-eletroquímico) em um reator fotoquímico de recirculação em batelada. Os processos UV/H2O2 (CH2O2 inicial = 1,0 mmol L-1) e a fotocatálise (CTiO2 suspensão = 0,62 mmol L-1) foram os processos mais eficientes, reduzindo cerca de 85% da flumequina em 15 min de reação. A fotólise provocou a degradação da flumequina em 91,2% em 60 min de ensaio, enquanto que o processo foto-Fenton 94%, quando usados 10,0 e 0,25 mmol L-1 de H2O2 e Fe(II), respectivamente. Por outro lado, a peroxidação (CH2O2 = 1,0 mmol L-1) e o reagente de Fenton (CFe(II) = 2,0 mmol L-1 e CH2O2 = 0,5 mmol L-1) não atingiram mais de 10% e 40 % de degradação, respectivamente, após 60 min de reação. Os processos eletroquímico e foto-químico atingiram aproximadamente 82 e 85% de degradação da flumequina, após 60 min de reação quando aplicado 45 mA cm-2. A diminuição da atividade antimicrobiana das soluções submetidas aos processos oxidativos avançados foi proporcional à concentração residual da flumequina na solução. Não foi observada atividade antimicrobiana residual nas soluções submetidas aos seguintes processos oxidativos avançados e condições: UV/ H2O2 (CH2O2 = 1,0 mmol L-1, 30 min de reação), UV/TiO2 (CTiO2 = 0,62 mmol L-1, 30 min de reação), foto-Fenton (CFe(II) = 0,25 mmol L-1 e CH2O2 = 10 mmol L-1, 60 min de reação) e foto-eletroquímico (45 mA cm-2 e 60 min de reação). Os intermediários formados foram monitorados em 10, 15 e 30 min de reação nos processos oxidativos avançados e fotólise, e foi observado que os intermediários propostos possuíam uma atividade antimicrobiana menor que a flumequina. A eficiência dos processos UV/ H2O2 e UV/TiO2 (1,0 mmol L-1 e 0,62 mmol L-1 de H2O2 e TiO2) foi próximo a 100%, removendo totalmente a atividade antimicrobiana da solução / Abstract: This work evaluated the degradation of flumequine (500 ?g L-1) by physical process (photolysis-UV254), chemical process (H2O2 - peroxidation) and advanced oxidation processes (photoperoxidation - UV/H2O2, heterogeneous photocatalysis - UV/TiO2, Fenton's reagent - Fe(II)/H2O2, photo-Fenton - UV/Fe(II)/H2O2) in a batch-recirculation photochemical reactor. The processes UV/H2O2 (CH2O2 = 1.0 mmol L-1) and photocatalysis (CTiO2 suspension = 0.62 mmol L-1) are the most efficient ones, reducing about 85% of the flumequine in 15 min of reaction time. The photolysis caused 91.2% of flumequine degradation after 60 min of assay, while the photo-Fenton process degraded 94% of the drug when used 10.0 and 0.25 mmol L-1 of H2O2 and Fe(II), respectively. Moreover, peroxidation (CH2O2 = 1,0 mmol L-1) and Fenton's reagent (CFe(II) = 2.0 mmol L-1 and CH2O2 = 0.5 mmol L-1) did not achieve more than 10% and 40% degradation, respectively, after 60 min of reaction. Eletrochemical and photo-eletrochemical processes degraded about 82% and 85%, respectively, after 60 min of reaction at 45 mA cm-2. The decrease of the solutions antimicrobial activity subjected to advanced oxidation processes was proportional to the residual concentration of flumequine in the solution. There was no residual antimicrobial activity in the solutions subjected to the following advanced oxidation processes and conditions: UV/H2O2 (CH2O2 = 1.0 mmol L-1, 30 min of reaction), UV/TiO2 (CTiO2 = 0.62 mmol L-1, 30 min of reaction), photo-Fenton (CFe(II) = 0.25 mmol L-1 and CH2O2 = 10 mmol L-1, 60 min of reaction) and photo-eletrochemical (45 mA cm-2, 60 min of reaction). The intermediates formed were monitored at 10, 15 and 30 min of reaction in photolysis and advanced oxidation processes, where it was observed that the proposed byproducts owned a lower antimicrobial activity than flumequine. The efficiency of the processes UV/H2O2 and UV/TiO2 (1.0 mmol L-1 and 0.62 mmol L-1 of H2O2 and TiO2, respectively) was close to 100%, entirely removing the antimicrobial activity of the solution / Doutorado / Saneamento e Ambiente / Doutor em Engenharia Civil

The presence of trace organic compounds (TOrCs) in wastewater effluent and surface waters has raised attention due to their health and environmental effects. Some TOrCs are naturally attenuated via biodegradation, photo-degradation and/or adsorption, but some persist in the environment as contaminants in surface and ground waters. Thus, it is crucially important to understand their transformation pathways and their mechanisms following their discharge into the environment. This work presents research in three parts: • The first part represents an investigation of photo-transformation of TOrCs (e.g., furfuryl alcohol, p-cresol, gemfibrozil) under UV254, UVA and natural sunlight, and involving reactive oxygen species including singlet oxygen, hydroxyl radicals, triplet excited states, and specific inorganic radicals that are created by effluent organic matter (EfOM). Singlet oxygen was the only ROS, generated from effluent organic matter (EfOM) that mainly contributed to the photo-transformation of these selected TOrCs. A comprehensive mechanism and complementary kinetic model were proposed to predict the trajectories of TOrC removals via reaction with singlet oxygen. Simulations built on predicted quantum efficiencies accounted for light shading and competitive effects. Agreement between measurements and simulations was excellent. • The second part of the dissertation summarizes expected removal efficiencies for fifty-five TOrCs in alternative engineered and natural treatment processes including conventional biological treatment, advanced oxidation processes (AOP), reverse osmosis (RO), granular activated carbon (GAC), and sunlight photolysis. • The last section of the dissertation follows the trajectories of a series of TOrCs and total estrogenic activity in the Santa Cruz River, following their discharge from a wastewater treatment plant in the Tucson area. The study suggests that some TOrCs tend to persist in the environment while others experience photo (or other) transformations that diminish their concentrations or activities with distance and time of travel in the river. The attenuation of estrogenic activity was dependent on sunlight and the presence of specific (unidentified) wastewater components.

Orientador: José Roberto Guimarães / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-24T08:56:07Z (GMT). No. of bitstreams: 1 Peres_MarcelaSouza_M.pdf: 1942738 bytes, checksum: e568a9f4c6bc9579df4ca7bc831e9085 (MD5) Previous issue date: 2014 / Resumo: A ofloxacina é um antimicrobiano de amplo espectro frequentemente encontrado em concentrações significativas em efluentes e águas superficiais. A contínua introdução deste fármaco no meio ambiente constitui um risco potencial em longo prazo para os organismos não alvos ou para a saúde humana. Neste estudo foi avaliada a degradação da ofloxacina pelos processos oxidativos avançados (POA) peroxidação assistida por radiação ultravioleta (UV/H2O2) e fotocatálise (UV/TiO2 e UV/TiO2/H2O2). Foi avaliada também a atividade antimicrobiana residual do fármaco, utilizando a bactéria E. coli, e a toxicidade aguda (Vibrio fischeri). A concentração de ofloxacina foi monitorada utilizando-se cromatografia líquida de alta eficiência (CLAE). Os resultados obtidos indicam que os POA aplicados foram eficientes para a degradação desse fármaco. O processo UV/H2O2 alcançou degradação de 99%, após 60 min de reação. Para o processo UV/TiO2, a eficiência de degradação obtida foi de 89,3% após 60 min e a adição de peróxido de hidrogênio elevou a eficiência para 97,8%. A atividade antimicrobiana do fármaco foi reduzida consideravelmente, alcançando 95% de remoção com a aplicação do UV/H2O2 e 96% utilizando o processo UV/TiO2/H2O2. A toxicidade das amostras não aumentou no decorrer da aplicação destes POA, indicando a potencial utilização destes processos para o tratamento de soluções aquosas contendo ofloxacina / Abstract: Ofloxacin is a broad-spectrum antimicrobial agent which is frequently found in significant concentrations in wastewater and surface water. Its continuous introduction into the environment constitutes a potential risk to non-target organisms or to human health. This study evaluated ofloxacin degradation by the UV/H2O2, UV/TiO2 and UV/TiO2/H2O2 advanced oxidation process (AOPs), residual antimicrobial activity (E. coli), and acute toxicity (Vibrio fischeri). Ofloxacin concentration was monitored with HPLC analyses. The results obtained shown that AOPs applied were efficient for ofloxacin degradation. For UV/H2O2, degradation efficiency was 99% in 60 min of reaction. For UV/TiO2, degradation efficiency was 89.3% in 60 min of reaction when applied 128 mg L-1 TiO2. The addition of 1.68 mmol L-1 of hydrogen peroxide increased the degradation to 97.8%. For both processes, the antimicrobial activity was considerably reduced throughout the reaction, reaching 95% removal when UV/H2O2 was applied and 96% using the UV/TiO2/H2O2 process. The toxicity of the samples did not increase during AOP application, indicating the potential use of these processes for the treatment of aqueous solutions containing ofloxacin / Mestrado / Saneamento e Ambiente / Mestra em Engenharia Civil

Wastewater reuse is very important in water resource management for both environmental and economic reasons. Unfortunately, wastewater from textile industries is difficult to treat by convectional wastewater treatment technologies. Now days, polluted water due to color from textile dyeing and finishing industries is burning issue for researchers. Textile or industrial wastewaters contain non-biodegradable organic compounds, which cannot be easily biodegraded because of their complex chemical structure. Dye wastewater discharged from textile wastewaters is one example of non-biodegradable organic compounds and it is difficult to remove dye effluent by convectional wastewater treatment methods. Therefore, this thesis deals about a review of advanced treatment technologies, which can de-colorize and remove non-biodegradable organic compounds from textile wastewater effluents. In addition to this, the potential and limitation of these advanced treatment methods are reviewed. Advanced treatment technologies reviewed in this paper are; Adsorption process, Membrane bioreactor (MBR) and advanced oxidation process (AOPs).

No description available.

No description available.

Heterogeneous photocatalysis is an advanced oxidation technology widely applied in environmental remediation processes. It is a relatively safe and affordable technology with a low impact on the environment and has found applications in a number of fields from chemical engineering, construction and microbiology to medicine. It is not catalysis in the real sense of the word as the photons which initiate the desired photocatalytic reaction are consumed in the process. The cost of these photons is by far the limiting economic factor in its application. From a technical standpoint, the inefficient use of the aforementioned photons during the photocatalytic reaction is responsible for the limited adoption of its application in industry. This inefficiency is characterised by low quantum yields or photonic efficiencies during its application. The mechanism of the technique of controlled periodic illumination which was previously proposed as a way of enhancing the low photonic efficiency of TiO2 photocatalysis has been investigated using a novel controlled experimental approach; the results showed no advantage of periodic illumination over continuous illumination at equivalent photon flux. When the technique of controlled periodic illumination is applied in a photocatalytic reaction where attraction between substrate molecules and catalyst surface is maximum and photo-oxidation by surface-trapped holes, {TiIVOH•}+ ads is predominant, photonic efficiency is significantly improved. For immobilized reactors which usually have a lower illuminated surface area per unit volume compared to suspended catalyst and mass transfer limitations, the photonic efficiency is even lower. A novel photocatalytic impeller reactor was designed to investigate photonic efficiency in gas–solid photocatalysis of aromatic volatile organic compounds. The results indicate photonic efficiency is a function of mass transfer and catalyst deactivation rate. The development of future reactors which can optimise the use of photons and maximize photonic efficiency is important for the widespread adoption of heterogeneous photocatalysis by industry.

Les procédés d’oxydation chimique sont utilisés pour traiter des effluents contenant des composés organiques non biodégradables. Or, la présence de sels diminue l’efficacité de ce traitement. Dans ce travail, nous étudions un procédé couplé, comprenant une étape de déminéralisation par électrodialyse associée à une étape de photo oxydation (photo-Fenton). Une eau synthétique, contenant du NaCl et du phénol, est utilisée comme modèle. Chaque opération est étudiée en couplant des outils expérimentaux et théoriques. Concernant l’électrodialyse, l’influence des variables opératoires, comme la composition initiale de l’eau à traiter et la densité de courant, sur le taux de déminéralisation et le rendement en phénol, est évaluée. Différents types d’expériences sont réalisées pour dissocier les contributions des divers phénomènes au transfert d’eau, de sel et de phénol. Dans des conditions standard, outre la diffusion, une contribution additionnelle au transfert de phénol, directement proportionnelle au transfert d’eau et donc à la migration des sels, est mise en évidence. Un modèle phénoménologique est proposé pour relier les flux aux forces agissantes et les paramètres caractéristiques sont déterminés en ajustant les résultats expérimentaux avec ceux du modèle. Le procédé d’oxydation photo chimique (Fenton) est ensuite étudié suivant une approche similaire. La sensibilité du procédé, caractérisé par une vitesse de dégradation, aux variables d’entrée est évaluée. En particulier, on montre une influence de la présence de sels. Eu égard à la complexité du système réactionnel, un modèle de type réseau de neurones est choisi pour modéliser la relation entre l’efficacité de l’oxydation aux conditions opératoires. Dans un dernier temps, un modèle hybride est proposé en intégrant les modèles développés pour les étapes d’électrodialyse et d’oxydation. Ce modèle est testé en discutant différentes configurations vis-à-vis de considérations énergétiques. Il sera utilisé pour étudier les configurations les plus adaptées vis-à-vis d’autres critères, comme la qualité de l’eau traitée par exemple. / Chemical oxidation processes can be used to treat industrial wastewater containing non-biodegradable organic compounds. However, the presence of dissolved salts may inhibit or retard the treatment process. In this work, a coupled process is studied including a desalination step by electrodialysis (ED) associated with an advanced oxidation process (photo-Fenton) with a synthetic wastewater containing NaCl and phenol. The experimental study concerning ED was carried out using a pilot plant. The influence of process variables, like the initial water composition and the electrical current intensity, on the demineralization factor was investigated. Experiments were also performed without electrical current application, in order to determine the unfavorable phenol transfer through the membranes due to diffusion. The phenol and salt concentration variations in the ED compartments were measured over time, using dedicated procedures and an experimental design to determine the global characteristic parameters. A phenomenological approach was used to relate the phenol, salt and water fluxes with the driving force (concentration and electric potential gradients). Under normal ED conditions, two contributions were pointed out for the phenol transport, i.e. Diffusion and convection, this latter coming from the water flux due to electroosmosis related to the migration of salts. The fitting of the parameters of the transport equations resulted in good agreement with the experimental results over the range of conditions investigated. Photo- enton oxidation process was studied in a laboratory batch reactor. As expected, the results confirm the negative effect of the salt concentration on the phenol removal efficiency by oxidation. This effect was not found to be linear concerning salt concentration and degradation rate. Due to the complexity of these reaction systems, a model based on artificial neural networks has been developed to fit the experimental data. This model describes the evolution of the pollutant concentration i.e. phenol, by means of a reaction rate, during irradiation time under various operating conditions.

L'adsorption sur charbon actif est une technique relativement répandue de post-traitement des effluents aqueux. Cependant il ne s'agit pas d'un traitement ultime, puisque les polluants restent concentrés sur la surface solide. Des techniques de régénération doivent donc être mises en œuvre. C'est dans ce contexte qu'ont été étudiés ici les procédés d'oxydation avancée Fenton et photo-Fenton, dont l'efficacité est reconnue pour éliminer la pollution organique. Plus précisément, l'objet de cette thèse est l'étude sur plusieurs cycles consécutifs de l'adsorption du phénol sur charbon actif et de la régénération in-situ de l'adsorbant par oxydation (photo)Fenton. Deux charbons actifs différents ont été étudiés : le premier à la fois micro et mésoporeux (PICA L27) et le second essentiellement microporeux (PICA S23). Deux séries d'expériences ont été ainsi réalisées : 1) d'abord en réacteur agité (adsorption et oxydation en mode batch), 2) puis dans des conditions plus proches du procédé réel, avec une adsorption continue en lit fixe, suivie de l'oxydation batch par recirculation du réactif Fenton au travers du lit saturé. Dans le premier cas, les effets de la concentration en Fe2+ et en H2O2 ont été analysés, montrant que les conditions optimales pour l'oxydation homogène du phénol (sans charbon) ne sont pas les meilleures pour la régénération du charbon saturé par le polluant : une réduction continue de la capacité d'adsorption du L27, de 100% à 23%, est observée après 3 oxydations, en raison de la consommation du charbon et de la diminution de sa surface spécifique. Par contre, une concentration plus élevée de Fe2+ et plus faible de H2O2 (2 fois la stœchiométrie) permettent de retrouver 50% de la capacité initiale d'adsorption pendant au moins 4 cycles consécutifs. Comme il a été vu dans des études précédentes utilisant l'oxydation à l'air (sous température et pression), l'efficacité de régénération est aussi bien plus faible pour le S23 (autour de 20%). Des résultats similaires ont été obtenus sur le réacteur à lit fixe avec recirculation. Durant l'oxydation, le taux de conversion du Carbone Organique Total en phase liquide a atteint à chaque fois une valeur limite, probablement du fait de la formation de complexes entre le fer et les acides carboxyliques produits. L'utilisation de l'irradiation UV, qui est connue pour décomposer ces complexes, a conduit à une minéralisation quasi-totale et a amélioré l'efficacité de régénération du charbon, jusqu'à 56% de la capacité initiale après 2 cycles (contre 40% pour l'oxydation Fenton simple) / Adsorption on activated carbon (AC) is a technique extensively applied for wastewater treatment. However adsorption alone is not an ultimate solution, since the pollutants are just immobilized on the carbon surface. There is thus a need for efficient regeneration techniques. In this context, Fenton and photo-Fenton oxidations, which are promising technologies to destroy organic pollution, have been tested to regenerate the AC. The purposes of this study are the adsorption of phenol on activated carbons and the consecutive in-situ regeneration of carbon by (photo-) Fenton oxidation. Two different operations have been carried out: 1) batch procedure in order to investigate the influence of Fe2+ and H2O2 concentrations; 2) continuous fixed bed adsorption, followed by a batch circulation of the Fenton’s reagent through the saturated AC bed, to examine the efficiency of the real process. Two different activated carbons have been also studied: a both micro- and mesoporous AC (PICA L27) and an only microporous one (PICA S23). In the batch reactor the best conditions found for pollutant mineralization in the homogeneous Fenton system are not the best for AC regeneration: a continuous reduction of adsorption capacity of L27 is observed after 3 oxidations, due to the decrease of both AC weight and surface area. Higher concentration of Fe2+ and lower concentration of H2O2 (2 times the stoechiometry) lead to a 50% recovery of the initial adsorption capacity during at least 4 consecutive cycles for L27, while about 20% for S23. In the consecutive continuous adsorption/batch Fenton oxidation process, the regeneration efficiency reaches 30% to 40% for L27 after two cycles whatever the feed concentration and less than 10% for S23. A photo-Fenton test performed on L27 shows almost complete mineralization (contrary to dark Fenton) and further improves recovery of AC adsorption capacity although not complete (56% after two cycles)

L'installation de décharges sanitaires représente la seule méthode de stockage des déchets ménagers solides dans plusieurs pays. Les lixiviats générés à partir de ces décharges présentent une grande toxicité aigüe et chronique. Lorsqu'ils ne sont pas traités, ces lixiviats peuvent pénétrer dans la nappe phréatique ou contaminer les eaux de surface et donc contribuer à la pollution des eaux. Divers procédés biologiques ont été appliqués au traitement des lixiviats de décharge. Cependant, ces procédés sont relativement inefficaces pour le traitement des lixiviats à cause de la présence de composés bioréfractaires. Les procédés d'oxydation avancée représentent une excellente alternative pour le traitement des eaux polluées par les polluants toxiques et/ou persistants (biorfractaires). Dans ce travail, quelques procédés d'oxydation avancée (procédé Glidarc, électro-Fenton, oxydation anodique et photo-Fenton) ont été appliqués au traitement de deux molécules modèles appartenant chacune à une famille de polluants présents dans la matrice du lixiviat tunisien de la décharge contrôlée de Jebel Chakir (identifiée dans ce travail), à savoir, l'anhydride phtalique et le 8-hydroxyquinoléine sulfate. Pour ces deux molécules, une étude de la dégradation et la minéralisation a été réalisée en optimisant les paramètres expérimentaux. L'étude cinétique montre que la dégradation oxydative des deux polluants étudiés suit une cinétique de réaction du pseudo-premier ordre, avec des temps de dégradation assez courts. Par exemple, avec une anode de Pt, l'oxydation complète de l'anhydride phtalique a été achevée en moins de 15 min sous un courant appliqué de 2,88 mA cm-2. L'identification des intermédiaires aromatiques et carboxyliques à courte chaine carbonée a permis de proposer un mécanisme de dégradation de l'anhydride phtalique par les radicaux hydroxyles. Les valeurs des constantes de vitesse des réactions entre les •OH, et les deux polluants et leurs intermédiaires ont été déterminés par la technique de cinétique de compétition à l'aide d'un composé de référence ; l'acide 4-hydroxybenzoϊque. Le suivi de la toxicité lors du traitement de la solution de 8-HQS par la méthode Microtox®, (une méthode basée sur la mesure de la luminescence des bactéries marines Vibriofischeri) a montré la formation des intermédiaires plus toxiques que les molécules mères. Une comparaison des procédés d'oxydation avancée appliqués a été réalisée pour chacun des polluants. Enfin, différents procédés d'oxydation avancée (procédé Glidarc, électro-Fenton, oxydation anodique et photo-Fenton) ont été appliqués à la dépollution du lixiviat tunisien de Jebel Chakir. Une étude comparative a été réalisée afin d'évaluer le coût des procédés. L'ensemble des résultats obtenus confirme l'efficacité du procédé électro-Fenton pour la dépollution des lixiviats / Pas de résumé en anglais