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O lixiviado gerado em aterro sanitário possui substâncias de difícil degradação e amônia, que dificulta o tratamento biológico. O tratamento do lixiviado gerado em aterros sanitários requer uma série de processos de elevado custo e, outras técnicas de tratamento têm sido investigadas no intuito de reduzir custos e aumentar a eficiência do tratamento. A evaporação do lixiviado é uma técnica que aproveita o gás de aterro como fonte de calor, e é utilizada na redução do volume a tratar; porém as emissões atmosféricas geradas durante essa evaporação indicam a presença de amônia, o que pode causar impactos negativos em torno do aterro. Desta forma, é importante a realização de estudos que aprimorem esta técnica, para que a evaporação torne-se ambientalmente e economicamente viável. A amônia presente em amostras com pH em torno de 8,0 e temperatura em torno de 25C, está na forma de íon amônio, o que favorece ao processo de troca iônica. A troca iônica é um processo que tem sido estudado por muitos pesquisadores e consiste na troca de um ou mais constituintes de uma fase fluida para a superfície de uma fase sólida (resinas poliméricas). Este trabalho apresenta a eficiência de quatro tipos diferentes de resinas poliméricas: Amberlyst 15 Wet, Lewatit VPOC 1800, Dowex Mac-3 e Purolite MN250 na remoção e posterior, recuperação do íon amônio presente nos vapores condensados da evaporação de lixiviados. A princípio foi investigado a quantidade e o momento em que o amônio é lançado durante o processo de evaporação. Em seguida, caracterizaram-se as resinas quanto à eficiência de remoção, o tempo de contato e a quantidade ideal da resina. Estão apresentadas neste estudo as isotermas de adsorção de Langmuir, Freundlich e Temkin em diferentes temperaturas (298-318 K) e as condições ideais do processo. Os resultados apontaram duas resinas com eficiência de remoção, em torno de 40%, para concentrações acima de 1000 mg dm-3 de amônio, utilizando 0,5 g de resina e um tempo de contato de 20 minutos. Diferentes modelos cinéticos foram aplicados: Pseudo-Primeira Ordem, Pseudo-Segunda Ordem, difusão intrapartícula, Elovich e o modelo cinético de difusão externa e os resultados discutidos. Foi possível tratar Através da condensação dos vapores emitidos durante a evaporação do lixiviado, foi possível tratar foi possível obter uma recuperação em torno de 70% do íon amônio contido no vapor condensado proveniente da evaporação do lixiviado. / The leachate generated at the landfill has substances are difficult to degrade and ammonia, which hinders the biological treatment. The treatment of the leachate generated in landfills requires a number of high-cost procedures and other treatment techniques have been investigated in order to reduce costs and increase the efficiency of treatment. Evaporation of leachate is a technique that takes advantage of landfill gas as a heat source , and is used in reducing the volume to be treated, but atmospheric emissions generated during this evaporation indicate the presence of ammonia, which can cause negative impact on the surrounding the landfill. Thus, it is important to conduct studies that will improve this technique, so that evaporation to become environmentally and economically viable. The present in samples with pH around 8.0 and temperature around 25 C, ammonia is in the form of ammonium ion, which favors the ion exchange process. Ion exchange is a process that has been studied by many researchers and consists of the exchange of one or more constituents of a fluid phase to the surface of a solid phase ( polymer resin ). This paper shows the efficiency of four different types of polymeric resins: Amberlyst 15 Wet, Lewatit VPOC 1800 Dowex Mac - 3 and Purolite MN250 removal and later, recovery of ammonium ion present in the vapor condensate evaporation of leachate. At first it was investigated how much and when ammonium is released during the evaporation process. Then, the resins were characterized as to the removal efficiency, the contact time and the optimum amount of the resin. Are presented in this study, adsorption isotherms of Langmuir, Freundlich and Temkin at different temperatures (298-318 K) and the optimal process conditions. The results showed two resins with removal efficiency of around 40% for concentrations above 1000 mg dm-3 ammonium, using 0.5 g of resin and a contact time of 20 minutes. Different kinetic models were applied: pseudo-first order , pseudo-second order, intraparticle diffusion and Elovich kinetic model of external diffusion and results discussed. It can be treated by the condensation of the vapors emitted during the evaporation of the leachate was possible to treat it was possible to obtain a recovery of around 70% of the ammonium ion contained in the condensed steam from the evaporation of leachate.

O lixiviado gerado em aterro sanitário possui substâncias de difícil degradação e amônia, que dificulta o tratamento biológico. O tratamento do lixiviado gerado em aterros sanitários requer uma série de processos de elevado custo e, outras técnicas de tratamento têm sido investigadas no intuito de reduzir custos e aumentar a eficiência do tratamento. A evaporação do lixiviado é uma técnica que aproveita o gás de aterro como fonte de calor, e é utilizada na redução do volume a tratar; porém as emissões atmosféricas geradas durante essa evaporação indicam a presença de amônia, o que pode causar impactos negativos em torno do aterro. Desta forma, é importante a realização de estudos que aprimorem esta técnica, para que a evaporação torne-se ambientalmente e economicamente viável. A amônia presente em amostras com pH em torno de 8,0 e temperatura em torno de 25C, está na forma de íon amônio, o que favorece ao processo de troca iônica. A troca iônica é um processo que tem sido estudado por muitos pesquisadores e consiste na troca de um ou mais constituintes de uma fase fluida para a superfície de uma fase sólida (resinas poliméricas). Este trabalho apresenta a eficiência de quatro tipos diferentes de resinas poliméricas: Amberlyst 15 Wet, Lewatit VPOC 1800, Dowex Mac-3 e Purolite MN250 na remoção e posterior, recuperação do íon amônio presente nos vapores condensados da evaporação de lixiviados. A princípio foi investigado a quantidade e o momento em que o amônio é lançado durante o processo de evaporação. Em seguida, caracterizaram-se as resinas quanto à eficiência de remoção, o tempo de contato e a quantidade ideal da resina. Estão apresentadas neste estudo as isotermas de adsorção de Langmuir, Freundlich e Temkin em diferentes temperaturas (298-318 K) e as condições ideais do processo. Os resultados apontaram duas resinas com eficiência de remoção, em torno de 40%, para concentrações acima de 1000 mg dm-3 de amônio, utilizando 0,5 g de resina e um tempo de contato de 20 minutos. Diferentes modelos cinéticos foram aplicados: Pseudo-Primeira Ordem, Pseudo-Segunda Ordem, difusão intrapartícula, Elovich e o modelo cinético de difusão externa e os resultados discutidos. Foi possível tratar Através da condensação dos vapores emitidos durante a evaporação do lixiviado, foi possível tratar foi possível obter uma recuperação em torno de 70% do íon amônio contido no vapor condensado proveniente da evaporação do lixiviado. / The leachate generated at the landfill has substances are difficult to degrade and ammonia, which hinders the biological treatment. The treatment of the leachate generated in landfills requires a number of high-cost procedures and other treatment techniques have been investigated in order to reduce costs and increase the efficiency of treatment. Evaporation of leachate is a technique that takes advantage of landfill gas as a heat source , and is used in reducing the volume to be treated, but atmospheric emissions generated during this evaporation indicate the presence of ammonia, which can cause negative impact on the surrounding the landfill. Thus, it is important to conduct studies that will improve this technique, so that evaporation to become environmentally and economically viable. The present in samples with pH around 8.0 and temperature around 25 C, ammonia is in the form of ammonium ion, which favors the ion exchange process. Ion exchange is a process that has been studied by many researchers and consists of the exchange of one or more constituents of a fluid phase to the surface of a solid phase ( polymer resin ). This paper shows the efficiency of four different types of polymeric resins: Amberlyst 15 Wet, Lewatit VPOC 1800 Dowex Mac - 3 and Purolite MN250 removal and later, recovery of ammonium ion present in the vapor condensate evaporation of leachate. At first it was investigated how much and when ammonium is released during the evaporation process. Then, the resins were characterized as to the removal efficiency, the contact time and the optimum amount of the resin. Are presented in this study, adsorption isotherms of Langmuir, Freundlich and Temkin at different temperatures (298-318 K) and the optimal process conditions. The results showed two resins with removal efficiency of around 40% for concentrations above 1000 mg dm-3 ammonium, using 0.5 g of resin and a contact time of 20 minutes. Different kinetic models were applied: pseudo-first order , pseudo-second order, intraparticle diffusion and Elovich kinetic model of external diffusion and results discussed. It can be treated by the condensation of the vapors emitted during the evaporation of the leachate was possible to treat it was possible to obtain a recovery of around 70% of the ammonium ion contained in the condensed steam from the evaporation of leachate.

Block copolymers have been extensively applied in diverse fields including packaging, electrolytes, delivery devices, and biosensors. Multiple investigations have been carried out on polymeric materials for cargo delivery purpose to understand how they behave over time. Block copolymer micelles (BCMs) have demonstrated superiority to deliver cargo, especially in drug delivery due to their encapsulation of hydrophobic agents. This dissertation will mainly study BCMs for potential applications in cargo delivery. Methods to study BCMs, including NMR spectroscopy, relaxometry and diffusometry, can provide valuable molecular information, such as chemical structure, translational motion, inter- or intramolecular interaction, dynamics, and exchange kinetics. Therefore, this dissertation describes applications of versatile NMR methods to reveal the fundamental behaviors of block copolymer self-assemblies, such as their dynamic stability, cargo partitioning, polymer chain exchange, and chain distribution in solution. We have investigated two BCM systems. Poly(ethylene oxide)-b-(ε-caprolactone) (PEO-PCL) is a model system to study BCM dynamic stability. PEO-PCL can self-assemble into spherical micelles at 1% w/v in D2O-THF-d8 mixed solvents. We used NMR diffusometry to quantify diffusion coefficients and populations of micelles and unimers (i.e. free polymer chains in solution) over a range of temperature (21 – 50 °C) and solvent composition (10 – 100 vol % THF-d8). By mapping the micelle-unimer coexistence phase diagrams, we are able to enhance our ability to understand and design micelle structure and dynamics. Moreover, we can also probe the chain exchange kinetics between micelles using a new technique we developed – time-resolved NMR spin-lattice relaxation (T1) or TR-NMR. This technique is an analog to time-resolved small-angle neutron scattering (TR-SANS), which can monitor specific signal intensity changes caused after mixing of isotope-labeled micelle solutions. A second system, Pluronic® F127 (PEO99PPO69PEO99) is a test system to study BCM structure and dynamic changes upon drug uptake. Pluronic® F127 is a commercial copolymer that can solubilize different hydrophobic drugs in micelles. We successfully encapsulated three model drugs into Pluronic® F127 BCMs and investigated the effects of polymer concentration and drug composition on drug partitioning fractions. Also, we proposed to design and synthesize a series of block copolymers with varied glass transition temperatures in core-forming blocks. Using NMR diffusometry, we have measured the existing unimer concentrations in micellar solutions and correlated these results with chain mobility and internal chemical composition. Lastly, we have extended our expertise in NMR and polymers into the study of ion-containing polymer systems (polyelectrolytes). A critical problem in polymer science is the inability to reliably measure the molecular weight of polyelectrolytes. We are developing methods to solve this problem by using NMR diffusometry, rheology, scattering, and scaling theories to accomplish general molecular weight measurements for polyelectrolytes. In short, this dissertation describes studies to provide more perspectives on structural and dynamic properties at various time and length scales for polymeric materials. NMR measurements, in combination with many other advanced techniques, have given us a better picture of soft matter behaviors and provided guidance for synthesis and processing efforts, especially in block copolymer micelles for delivery purposes. / Doctor of Philosophy / Block copolymers have been extensively applied in diverse fields in packaging, electrolytes and nano-scale drug delivery carriers. In the area of cancer treatment, only a limited number of drug nanocarriers have been approved for clinical applications. Therefore, it is very important to understand the principles behind drug delivery for targeted purposes. There have been many studies on polymeric delivery carriers but their behaviors have not been completely understood. Therefore, we have tremendous interest in unraveling the mysteries in those polymeric systems. Among a multitude of techniques to study block copolymer materials, the NMR method serves as a potent tool for its non-destructive, chemical-specific and isotope-selective merits. NMR can provide basic information about block copolymer self-assembly and other polymeric properties, such as chemical structure, molecular interactions and diffusion coefficients of species of interests. Chapters 3, 4, 5, 6, and 7 have investigated different classes of polymeric materials, mainly block copolymer micelles, for their structure and stability, exchange kinetics of polymer chains or cargo, and translational properties. Greater understanding about the fundamental properties of these polymeric systems, is essential for enabling new applications and new research areas.

The photosynthetic water oxidation reaction is catalyzed by an inorganic Mn4OxCaClyHCO3-z cluster at the heart of the oxygen evolving complex (OEC) in photosystem II. In the absence of an atomic resolution crystal structure, the precise molecular organization of the OEC remains unresolved. Accordingly, the role of the protein and inorganic cofactors of PSII (Ca2+, HCO3- and Cl-) in the mechanism of O2-evolution await clarification. In this study, rapid 18O-isotope exchange measurements were applied to monitor the substrate-water binding kinetics as a function of the intermediate S-states of the catalytic site (i.e. S3, S2 and S1) in Triton X-100 solubilized membrane preparations that are enriched in photosystem II activity and are routinely used to evaluate cofactor requirements. Consistent with the previous determinations of the 18O exchange behavior in thylakoids, the initial 18O exchange measurements of native PSII membranes at m/e = 34 (which is sensitive to the 16O18O product) show that the ‘fast’ and ‘slowly’ exchanging substrate-waters are bound to the catalytic site in the S3 state, immediately prior to O2 release. Although the slowly exchanging water is bound throughout the entire S-state cycle, the kinetics of the fast exchanging water remains too fast in the S2, S1 [and S0] states to be resolved using the current instrumentation, and left open the possibility that the second substrate-water only binds to the active site after the formation of the S3 state. Presented is the first direct evidence to show that fast exchanging water is already bound to the OEC in the S2 state. Rapid 18O-isotope exchange measurements for Ex-depleted PSII (depleted of the 17- and 23-kDa extrinsic proteins) in the S2 state reveals a resolvable fast kinetic component of 34k2 = 120 ± 14 s-1. The slowing down of the fast phase kinetics is discussed in terms of increased water permeation and the effect on the local dielectric following removal of the extrinsic subunits. In addition, the first direct evidence to show the involvement of calcium in substrate-water binding is also presented. Strontium replacement of the OEC Ca2+-site reveals a factor of ~3-4 increase in the 18O exchange of the slowly exchanging water across the S3, S2 and S1 states while the kinetics of the fast exchanging water remain unchanged. Finally, a re-investigation of the proposed role for bicarbonate as an oxidizable electron donor to photosystem II was unable to discern any 18O enrichment of the photosynthetically evolved O2 in the presence of 18O-bicarbonate. A working model for O2-evolution in terms of these results is presented.

The field of molecular bioenergetics deals with the energy transduction in biological cells. In this project, respiration and more specifically proton and sodium pumping enzymes and their coupling to electron transfer have been in focus. First we have been interested in the Na+-pumping NADH:quinone reductase from Vibrio cholerae which is the entry site of electrons in the respiratory chain of several pathogens. The role of specific flavin cofactors and amino acids involved in Na+ transfer has been shown in a combined IR spectroscopic and electrochemical approach. The interaction between proteins, namely the cytochrome c552 and the CuA fragment from the terminal ba3 oxidase from the organism Thermus thermophilus was then investigated. Structural reorganization during electron transfer was revealed by IR spectroscopy. Finally, in the third part of the project the interaction within the bc1-aa3 supercomplex from the respiratory chain from Corynebacterium glutamicum was analyzed.

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Le domaine de la bioénergie moléculaire concerne le transfert et le stockage d’énergie dans les cellules biologiques. Ce projet s’articule autour de la respiration et plus précisément le mécanisme de pompage de sodium et de protons, et son couplage au transfert d’électrons. Premièrement, nous nous sommes intéressés au pompage d’ions sodium par la NADH : quinone oxidoreductase de la bactérie Vibrio cholerae. L’importance de flavines spécifiques et des résidus acides dans le transfert de sodium ont été démontrée. Par la suite, l’interaction entre protéines, notamment le cytochrome c552 et le fragment CuA de l’oxidase de type ba3 de l’organisme Thermus thermophilus a été étudié. Une réorganisation structurelle induit par le transfert d’électron a été démontrée par la spectroscopie IRTF différentielle. Enfin, dans la dernière partie de ce travail, l’interaction au sein du supercomplex bc1-aa3 de la chaîne respiratoire du Corynebacterium glutamicum a été analysée. / The field of molecular bioenergetics deals with the energy transduction in biological cells. In this project, respiration and more specifically proton and sodium pumping enzymes and their coupling to electron transfer have been in focus. First we have been interested in the Na+-pumping NADH:quinone reductase from Vibrio cholerae which is the entry site of electrons in the respiratory chain of several pathogens. The role of specific flavin cofactors and amino acids involved in Na+ transfer has been shown in a combined IR spectroscopic and electrochemical approach. The interaction between proteins, namely the cytochrome c552 and the CuA fragment from the terminal ba3 oxidase from the organism Thermus thermophilus was then investigated. Structural reorganization during electron transfer was revealed by IR spectroscopy. Finally, in the third part of the project the interaction within the bc1-aa3 supercomplex from the respiratory chain from Corynebacterium glutamicum was analyzed.