The nutrients available in urine make it a good resource as fertilizer. Limited availability of natural phosphorus (P) is compelling people to think about recovering and returning it back to the land from waste stream. Urine comprising the majority of nitrogen (N) and P among other household wastewater, if managed separately, will benefit human against expensive commercial fertilizers, and eventually will reduce environmental problems. Various reactive filter systems have been studied since late 90’s as a potential system to recover N & P from urine and wastewater as a whole. Most studies are however limited to the laboratory scale only. Optimization of such technologies is one of the prime focuses in this area of research. This thesis project used the combination of two sorptive reactive materials, namely mordenite and polonite, to remove NH4-N and PO4-P from the source separated human urine. This two months laboratory scale study recommends dilution and storage to be a minimum pretreatment for urine. However as the influent’s NH4-N concentration was extremely high, further dilution or other relevant pretreatment is recommended. In overall, mordenite materials performed better for NH4-N removal reaching as high as 79% whereas polonite materials showed better results for PO4-P removal and the efficiency was as high as 97%. The reduction in NH4-N might also be due to the conversion of nitrogen into other forms. Mordenite materials showed a good potential for PO4-P removal and was up to 88% efficient initially. Both materials did not show the tendency of breakthrough for PO4-P until the end. The salinity measured as electric conductivity was reduced by both materials until about initial half-time period of the experiment. Since mordenite was the first unit to face the highly concentrated urine, it got saturated earlier and started showing the fluctuations in reduction and release for nutrients. The results obtained in this study provide the positive scenario for it to be implemented in the full scale system. However more elaborated studies in full scale addressing the major limitation of this project needs to be done before introducing the system for public uses.

Le développement d’un procédé de polymérisation en émulsion est complexe de par la nature hétérogène de ce type de réaction. En outre, dans le cas de la polymérisation en émulsion du fluorure de vinylidène, la difficulté est d’autant plus accrue que le monomère est habituellement en phase gazeuse ou supercritique dans les conditions d’intérêt. Or la littérature manque d’informations concernant ce type de procédé de synthèse du PVDF sous une pression comprise entre 30 bar et 90 bar.Ainsi cette thèse a pour objectif de contribuer à une meilleure compréhension des mécanismes cinétiques et de stabilisation intervenants dans la polymérisation radicalaire en émulsion du VDF dans des conditions supercritiques et, plus particulièrement, de fournir des données expérimentales nécessaires à l’élaboration de futurs modèles.Avant même d’entreprendre les études expérimentales, cette thèse s’intéresse d’abord aux aspects d’installation et d’automatisation de l’unité de polymérisation ainsi qu’au démarrage et à l’optimisation du réacteur. Ensuite, plusieurs tests sont réalisés afin de comprendre certaines caractéristiques du latex produit ainsi que certaines propriétés du tensioactif fluoré. Une nouvelle méthode a spécialement été développée afin de suivre le phénomène de coagulation des particules de polymère.Finalement des réactions sont réalisées par lot et en semi-continu et une étude paramétrique des conditions opératoires et de la composition des réactifs est effectuée afin d’évaluer leur impact sur l’évolution de la polymérisation en émulsion. Notamment, le profil de vitesse de polymérisation est obtenu par calorimétrie, à partir d’une approche pratique fondée sur un estimateur d’état en cascade, ainsi que sur la mesure de la consommation de monomère, et sur l’analyse gravimétrique réalisée par prélèvement / The heterogeneous nature of the conventional emulsion polymerization can render the process quite complex. In the case of the emulsion polymerisation of vinylidene fluoride (VDF), the situation is more complicated than for the majority of industrial processes because the monomer is typically either a gas or a supercritical fluid under the polymerization conditions of interest. Given the relatively high pressure required for this process (30bar <P< 90bar), there is a lack of information in the open literature about the VDF emulsion polymerization process.In this sense, this thesis is a contribution to the understanding of the kinetic and stabilization mechanisms that intervene in the free radical emulsion polymerization of vinylidene fluoride (VDF) under supercritical conditions, and more particularly, to the generation of relevant experimental data that can be used for future model developments.Prior to the experimental studies of VDF emulsion polymerization, issues that ranged from the installation and automation of the polymerization unit to the start-up and optimization of the reactor were covered. Later, different tests were performed in order to understand some important features of the produced latex as well as some properties of the fluorinated surfactant. Additionally, a new method to monitor the coagulation phenomena on polymer particles was developed.Finally, reactions were performed using batch and semi-batch mode. The impact of certain compositional changes and reaction conditions on the evolution of the emulsion polymerization was studied. A practical approach was implemented to follow the rate of polymerization using reaction calorimetry. Simultaneous estimations of the evolution of overall heat transfer coefficient and heat of reaction were determined using a high-gain nonlinear cascade state estimator

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Submitted by Aelson Maciera (aelsoncm@terra.com.br) on 2017-03-22T19:16:28Z No. of bitstreams: 1 DissTTB.pdf: 2398693 bytes, checksum: 0a0148927746ba0af71705e6c51cb65e (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-03-22T19:21:20Z (GMT) No. of bitstreams: 1 DissTTB.pdf: 2398693 bytes, checksum: 0a0148927746ba0af71705e6c51cb65e (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-03-22T19:21:41Z (GMT) No. of bitstreams: 1 DissTTB.pdf: 2398693 bytes, checksum: 0a0148927746ba0af71705e6c51cb65e (MD5) / Made available in DSpace on 2017-03-22T19:26:28Z (GMT). No. of bitstreams: 1 DissTTB.pdf: 2398693 bytes, checksum: 0a0148927746ba0af71705e6c51cb65e (MD5) Previous issue date: 2016-02-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) / The production of biodegradable films based on renewable low cost resources has increased considerably. The research and development of new materials in this segment make possible to replace, even still partially, the synthetic plastics derived from petrol and to add value to agro-industrial waste and agricultural commodities. The fruit purees (or pulp) represent an alternative for obtaining these low-cost arrays. It can be obtained from the fruit itself or from its processing wastes. Amongst the suited fruits for this purpose is the papaya (Carica papaya), largely available. Brazil is the largest producer of this fruit and, due to its high perishability, is a rich source of waste material for pulp and edible film processing. Although the films prepared from fruit puree lacks in mechanical and permeability properties, such features may be minimized by the addition of nanofillers associated to film forming biopolymers. Thus, the evaluation of papaya puree, in over-ripe stage, as raw material for film processing using a Mathis System (in batch mode) with reinforced nanostructure was the main aim of this study. The films were characterized considering mechanical and thermal properties, permeability, colorimetric and antimicrobial activity. The best results were recorded to formulations in which the pectin was added at 0.5 % (w/v), increasing the maximum fracture strength (σmax), in 12 times when compared to neat puree films (control). The insertion of cellulose nanofibers and chitosan nanoparticles also promoted a σmax increasing, nevertheless in inferior proportion (6.2 and 5 times respectively). The presence of pectin also was positive in reducing the permeability rates (WVP) with values of 77.72 % lower than those measured to the control films. Concerning the colorimetric properties, the films with filler additions (chitosan nanoparticles with glycerol) suffered the greater color changes (ΔE). The addition of chitosan nanoparticles also speed the surface browning index (BI). Again the pectin acted positively in preserving the original color characteristics. The antimicrobial essays indicated that the chitosan in nanoparticle format inside the polymeric matrix did not present any antimicrobial activity. The over-ripe papaya pulp showed to be a raw material suitable for edible biodegradable film processing and the addition of nanofillers and pectin necessary to improve the barrier and mechanical properties and to preserve the original colorimetric features. / A produção de filmes biodegradáveis baseados em recursos renováveis, fazendo uso de matrizes biopoliméricas de baixo custo, vem aumentando consideravelmente. A pesquisa e o desenvolvimento de novos materiais neste segmento possibilitam a substituição, ainda que parcial, dos plásticos sintéticos derivados do petróleo, além de agregar valor a resíduos agroindustriais e commodities agrícolas. Os purês de frutas (ou polpa) representam uma alternativa viável para a obtenção destas matrizes, podendo ser empregados a própria fruta ou rejeitos provenientes de seu processamento. Dentre os frutos adequados para este fim está o mamão papaia (Carica papaya), fartamente disponível no país. O Brasil é seu maior produtor mundial e, devido à sua alta perecividade, é uma fonte rica de rejeitos adequados à produção de polpas e ao processamento de filmes comestíveis. Embora os filmes processados a partir de purê de frutas apresentem limitações mecânicas e de permeabilidade, estas características podem ser minimizadas pela formação de compósitos através da inserção de nanoestruturas de reforço e associação com outros biopolímeros com características filmogênicas. Assim, avaliar o uso de polpas de mamão papaia, em adiantado estado de maturação no processamento de filmes em Sistema Mathis (no modo batelada) e o efeito da inserção de estruturas de reforço, foram os principais objetivos deste trabalho. Os filmes foram caracterizados quanto às suas propriedades mecânicas, térmica, de permeabilidade, colorimétrica e antimicrobiana. Os melhores resultados foram obtidos para as composições em que a pectina foi adiciona em 0,5 % (m/v), elevando a tensão máxima de ruptura (σmax), em 12 vezes quando comparada aos filmes de polpa sem aditivos (controle). A adição de nanofibras de celulose e a nanopartículas de quitosana também melhoraram σmax, mas em valores inferiores (6,2 e 5 vezes respectivamente). A inserção da pectina também foi favorável na redução das taxas de permeabilidade (WVP) com valores 77,72 % inferiores aos filmes controle. Com relação às medidas colorimétricas, as maiores alterações registradas foram para os filmes processados com os reforços (quitosana em conjunto com o glicerol), os quais resultaram em uma maior variação total de cor (ΔE). A presença de nanopartículas de quitosana também acelerou o escurecimento superficial (IE). A adição de pectina nas formulações atuou positivamente na preservação das características colorimétricas iniciais. Os testes antimicrobianos indicaram que a quitosana na forma de nanopartículas inseridas na matriz biopolimérica não apresentou atividade antimicrobiana. A polpa de mamão papaia, na condição sobremadura, mostrou ser uma matéria-prima adequada ao processamento de filmes comestíveis biodegradáveis e a adição de nanoreforços e de pectina necessárias para a melhoria das propriedades mecânicas e de barreira e para a preservação das características colorimétricas iniciais dos filmes.

Orientadores: Aline Carvalho da Costa, Rubens Maciel Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-10T20:20:17Z (GMT). No. of bitstreams: 1 Andrade_RafaelRamosde_M.pdf: 1587910 bytes, checksum: 8b9b9c8732f2cb239ee3db85845e7e92 (MD5) Previous issue date: 2007 / Resumo: Entre os principais problemas relacionados à produção de etanol está a falta de robustez da fermentação em presença de flutuações na qualidade de matéria-prima, o que leva a mudanças no comportamento cinético com impacto no rendimento, produtividade e conversão. Esta falta de robustez pode ser levada em conta através de ajustes operacionais e de controle, que pode ser melhorado com o uso de um modelo matemático preciso. Neste trabalho, um procedimento para o desenvolvimento de um modelo matemático robusto, valido em uma grande faixa de condição operacional foi estabelecido. Este modelo considera o efeito da temperatura na cinética. Experimentos foram executados em modo batelada. O microrganismo utilizado foi Saccharomyces cerevisiae e o meio de cultura, melaço de cana de açúcar. O objetivo foi avaliar a dificuldade em atualizar os parâmetros cinéticos quando se tem mudanças nas condições de fermentação. Rendimento e produtividade foram analisados como funções de temperatura e concentração inicial de substrato. Neste trabalho foi executada também a otimização dos parâmetros cinéticos no processo de fermentação alcoólica. Parâmetros cinéticos foram determinados como função da temperatura para fermentações em batelada na faixa de temperatura de 30 até 38oC. Baseado em dados experimentais, um modelo diferencial que consiste em expressões para taxa de crescimento celular, consumo de substrato e formação de produto foi proposto. O objetivo foi desenvolver um procedimento para atualizar os parâmetros cinéticos sempre que mudanças nas condições de fermentação ocorrerem. Mudanças em condições operacionais são muito comuns em plantas de fermentação alcoólica, elas ocorrem não somente devido a variações na qualidade da matéria-prima, mas também devido a variações nas leveduras dominantes no processo. Também, o processo de fermentação alcoólica é exotérmico e pequenos desvios na temperatura podem deslocar o processo da condição de operação ótima. Assim, está claro que a principal dificuldade nas técnicas baseadas em modelos para definição de estratégias operacionais, controle e otimização, é o problema de obter um modelo preciso / Abstract: Among the main current problems related to industrial ethanol production is the lack of robustness of the fermentation in presence of fluctuations in the quality of raw material, which leads to changes in the kinetic behavior with impact on yield, productivity and conversion. This lack of robustness can be taken into account through operational and control adjustments, which can be aided by the use of an accurate mathematical model. In this work, a procedure to develop a robust mathematical model, valid in a large range of operational conditions, was established. This model considers the effect of temperature on the kinetics. Experiments were performed in batch mode. The microorganism used was Saccharomyces cerevisiae and the culture media, sugar-cane molasses. The objective was to assess the difficulty in updating the kinetic parameters when there are changes in fermentation conditions. Yield and productivity were analyzed as functions of temperature and initial substrate concentration. In this work we perform kinetic parameters optimization in alcoholic fermentation process. Kinetic parameters were determined as functions of temperature from batch fermentations at temperatures from 30 to 38oC. Based on experimental data, a differential model consisting of rate expressions for cell growth, substrate consumption and product formation was proposed. The objective is to develop a procedure to update the kinetic parameters always that changes in fermentation conditions occur. The lack of robustness of the fermentation in the presence of fluctuations in the quality of the raw material, which leads to changes in the kinetic behavior with impact on yield, productivity and conversion, is among the main current problems related to the alcoholic fermentation process. Changes in the operational conditions are quite common in plants of alcoholic fermentation; they occur not only due to the variations in the quality of the raw material but also due to variations of dominant yeast in the process. Also, the alcoholic fermentation process is exothermic and small deviations in temperature can dislocate the process from optimal operational conditions. Thus, it is clear that the main difficulty in model-based techniques for definition of operational strategies, control and optimization, is the problem of obtaining an accurate model / Mestrado / Desenvolvimento de Processos Químicos / Mestre em Engenharia Química