Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 5 uppsatser.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-08-26T23:16:09Z No. of bitstreams: 1 MonickarlaTeixeiraPegadoDaSilva_DISSERT.pdf: 2972749 bytes, checksum: 333ef217ee5461818b38fff8de7cfdeb (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-08-31T00:12:48Z (GMT) No. of bitstreams: 1 MonickarlaTeixeiraPegadoDaSilva_DISSERT.pdf: 2972749 bytes, checksum: 333ef217ee5461818b38fff8de7cfdeb (MD5) / Made available in DSpace on 2016-08-31T00:12:48Z (GMT). No. of bitstreams: 1 MonickarlaTeixeiraPegadoDaSilva_DISSERT.pdf: 2972749 bytes, checksum: 333ef217ee5461818b38fff8de7cfdeb (MD5) Previous issue date: 2016-02-23 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Suportes catal?ticos ? base de ?xido de alum?nio foram sintetizados pelo m?todo e esferas h?bridas utilizando carboximetilcelulose (CMC) como precursor org?nico (template) e nitrato de alum?nio como precursor inorg?nico. As caracteriza??es foram realizadas por an?lises de termogravimetria (TG), difra??o de raios-X (DRX), espectroscopia no infravermelho por transformada de fourier (FTIR), microscopia eletr?nica de varredura (MEV) e fisissor??o N2. Os materiais sintetizados foram testados na rea??o de convers?o do glicerol em fase g?s. Os estudos da s?ntese indicaram que as caracter?sticas do biopol?mero (grau de substitui??o e de polimeriza??o) influenciam diretamente no valor m?ximo da rela??o entre o precursor org?nico e inorg?nico para a forma??o das esferas h?bridas. As propriedades f?sico-qu?micas do material final (cristalinidade, porosidade, ?rea espec?fica e morfologia) mostraram uma depend?ncia direta com as propriedades do biopol?mero (grau de substitui??o e de polimeriza??o), indicando a versatilidade desta rota s?ntese. Os espectros de FTIR confirmaram a forma??o de um material h?brido quando se compara o espectro da CMC pura com os s?lidos obtidos ap?s a secagem. Os resultados de DRX mostraram um perfil de material amorfo para algumas amostras. Para alguns s?lidos foi poss?vel identificar a forma??o de uma fase cristalina relacionada com a alumina hidratada, ?xido de alum?nio e ?xido de cobre. As imagens obtidas por MEV indicaram a forma??o de um material com morfologia semelhante a uma esponja ap?s a calcina??o, caracter?stico de um s?lido altamente poroso. O perfil de adsor??o/dessor??o de N2 confirma a forma??o de materiais contendo micro-mesoporos com uma ?rea espec?fica entre 50-162 m2.g-1 para os suportes e 112-303 m2.g-1 para os catalisadores com cobre, indicando um aumento ?rea ap?s a adi??o do Cu por impregna??o devido a redissolu??o e recristaliza??o da fase alumina. Testes catal?ticos indicaram que os ?xidos s?o ativos e seletivos para a convers?o do glicerol (92-15%) a bioprodutos de alto maior valor agregado, confirmando a viabilidade do m?todo de s?ntese. / Catalytic supports based on aluminum oxide were synthesized by the method of hybrid spheres using carboxymethylcellulose (CMC) as organic precursor (template) and aluminum nitrate as inorganic precursor. The characterizations were performed by thermal chemical analysis (TGA), X-Ray diffraction (XRD), fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and N2 physisorption. The study of synthesis indicated that the characteristics of the biopolymer (degree of substitution and polymerization) directly influence on the maximum value of the ratio between the organic and inorganic precursor for the formation of hybrid spheres. The physicochemical properties of the final material (crystallinity, porosity, surface area and morphology) showed a direct dependence on the biopolymer properties (degree of substitution and polymerization), indicating the versatility of this synthesis route. The FTIR spectra confirm the formation of a hybrid material when comparing the pure CMC spectrum with the obtained solids after drying. The XRD results show a profile of amorphous and crystalline material for the different samples. For some solids were possible to identify the formation of a crystalline phase related to the hydrated alumina, aluminium oxide and copper oxide. The images obtained by SEM analysis showed the formation of a material with sponge-like morphology after calcination, characteristic of highly porous solid. The N2 adsorption/desorption isotherm profile confirms the formation of micro-mesoporous materials with a specific surface area between 50-162 m2.g-1 for the supports and 112-303 m2.g-1 for the copper-based catalysts, indicating an increase in the area after the addition of Cu by impregnation due to redissolution and recrystallization of alumina phase. Catalytic tests were tested in the glycerol conversion reaction (92-15%) to added value products in order to confirm their real viability.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-07-20T22:04:59Z No. of bitstreams: 1 MoacirBispoRamos_TESE.pdf: 16232608 bytes, checksum: 452eef16e8cb0bb6456bb9da73f46508 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-07-21T21:33:32Z (GMT) No. of bitstreams: 1 MoacirBispoRamos_TESE.pdf: 16232608 bytes, checksum: 452eef16e8cb0bb6456bb9da73f46508 (MD5) / Made available in DSpace on 2016-07-21T21:33:32Z (GMT). No. of bitstreams: 1 MoacirBispoRamos_TESE.pdf: 16232608 bytes, checksum: 452eef16e8cb0bb6456bb9da73f46508 (MD5) Previous issue date: 2015-12-07 / O presente trabalho prop?e a modifica??o do revestimento de eletrodos de baixo hidrog?nio, propiciando uma alternativa para execu??o de soldagem com o AWS E-7018 sem precisar resseca-los, reduzindo por conseguinte os custos financeiros e o tempo de fabrica??o de soldas estruturais de alta resist?ncia. As soldas deste estudo foram produzidas a partir de eletrodos com revestimento b?sico (higrosc?picos) - processo manual - pintados com tinta spray de alum?nio para altas temperaturas ou revestidos com filmes finos de PVC e de papel alum?nio (99,9%), comumente utilizados para prote??o de alimentos. A premissa b?sica ?, que estabelecendo uma barreira entre a atmosfera e o revestimento do eletrodo, poder-se-? diminuir os efeitos da alta higroscopicidade apresentada pelo revestimento, minimizando assim, a principal fonte de fornecimento de hidrog?nio ? po?a de fus?o durante a soldagem, tamb?m ? esperado, que a adi??o de novos materiais no revestimento ? po?a de fus?o, provoque altera??es metal?rgicas no metal depositado e consequentemente altera??es nas propriedades mec?nicas. Mensurar o hidrog?nio dissolvido no metal depositado ap?s soldado com os eletrodos modificados, avaliar a influencia dessas modifica??es nas microestruturas produzidas, nas propriedades mec?nicas da solda resultante e comparar esses resultados obtidos com procedimentos de soldagem padr?o normatizados e com os novos eletrodos imperme?veis recentemente desenvolvidos, balizou o estudo. Os resultados obtidos, na maioria das amostras soldadas com eletrodos modificados, apresentaram aumento significativo da resist?ncia mec?nica e de tenacidade, justificados pelo aumento percentual de ferrita acicular no metal depositado, sem, contudo, eleva??o significativa da dureza, quando comparados com a soldagem com eletrodo AWS E-7018 da forma tradicional. O hidrog?nio difus?vel nos eletrodos modificados manteve-se dentro do estabelecido pelos c?digos internacionais. / This paper suggests modifications in coating of electrodes providing an alternative for execution of welding with low hydrogen electrode AWS E7018 without having to dry it, reducing thus the cost and time of manufacturing of high resistance welds. The welds in this research were developed with basic coated electrodes (hygroscopic) ? SMAW process ? externally painted with aluminum spray paint for high temperatures or wrapped with thin plastic films (PVC) and aluminum foil films used commonly for food protection. The basic premise is that establishing a barrier between the atmosphere and the electrode coating could reduce the effects of high hygroscopicity presented by coatings of low hydrogen, minimizing this way the main source of supply of hydrogen to the fusion pool during welding. It is also expected that the addition of new materials from the electrode coating to the fusion pool would induce metallurgical changes in the deposited metal and, as a consequence, modifications in its mechanical properties. This research dealt with measuring the dissolved hydrogen in the deposited metal after welding with modified electrodes, evaluating the influence of these changes in the produced microstructures and in the mechanical properties of the resulting weld, and comparing the obtained results with the standard welding procedures and with the recently developed waterproof electrodes. The results obtained in most samples welded with modified electrodes showed increased mechanical resistance and increased tenacity due to the increased percentage of acicular ferrite in metal deposited without significant elevation of hardness, when compared with the traditional welding with AWS E7018 electrode and with ELBR?S BRH4R waterproof electrode. The diffusing hydrogen measured in the modified electrodes was kept inside the parameters defined by international codes.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-02-15T11:17:50Z No. of bitstreams: 1 CiceroLeonardoPereiraDeSouza_DISSERT.pdf: 12093980 bytes, checksum: 07b7fe22cb40d5bdd02b643fb06ab78a (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-02-16T11:10:32Z (GMT) No. of bitstreams: 1 CiceroLeonardoPereiraDeSouza_DISSERT.pdf: 12093980 bytes, checksum: 07b7fe22cb40d5bdd02b643fb06ab78a (MD5) / Made available in DSpace on 2018-02-16T11:10:32Z (GMT). No. of bitstreams: 1 CiceroLeonardoPereiraDeSouza_DISSERT.pdf: 12093980 bytes, checksum: 07b7fe22cb40d5bdd02b643fb06ab78a (MD5) Previous issue date: 2017-03-10 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A soldagem a arco el?trico por eletrodo revestido (SMAW) ? uma das mais antigas t?cnicas de soldagem e a primeira a ser utilizada industrialmente em grande escala. Durante o s?culo XX a soldagem SMAW foi a mais usada como t?cnica de uni?o permanente de metais, sendo at? hoje, mesmo com coexist?ncia de diversas outras t?cnicas, uma das que possuem maior utiliza??o no mercado brasileiro. Nesse tipo de soldagem uma das maiores preocupa??es ? o cuidado no armazenamento do eletrodo, pois o mesmo n?o pode ficar exposto a atmosfera ambiente, j? que absorveria umidade, que ? danoso para a qualidade da solda. A umidade introduz na zona fundida o hidrog?nio que pode levar ao surgimento de trincas a frio. A solu??o normalmente usada ? a da ressecagem em temperaturas at? 450? C, acompanhada de armazenamento em estufas, pr?tica que gera custos adicionais para um projeto de fabrica??o. Nesse contexto o presente trabalho teve a inten??o de caracterizar a zona fundida de soldas feitas com eletrodos revestidos E7018 encobertos com filmes de alum?nio e PVC, aplicados com o intuito de resguarda-los contra a umidade ambiente, diminuindo custos e tempo com secagem, tamb?m variando o valor de aporte t?rmico utilizado durante a soldagem. Essa atual investiga??o d? continuidade ? pesquisa recente sobre a influ?ncia de tais filmes protetores na composi??o e, em especial, na microestrutura do metal de solda depositado, onde a quantifica??o dos constituintes e caracteriza??o microestrutural ocorreu atrav?s de um software para avalia??o de imagens. No presente caso, com a utiliza??o de um microsc?pio com emiss?o de campo, MEV-FEG, foram obtidas imagens com elevado contraste, que permitiram um levantamento detalhado dos tipos de constituintes presentes, assim como uma an?lise mais precisa de sua morfologia. Em particular foi poss?vel avaliar quantitativamente o efeito dos filmes protetores no tamanho de gr?o e na raz?o de aspecto do microconstituinte AF (ferrita acicular). Com base numa revis?o da literatura ? apresentada uma an?lise cr?tica acerca dos par?metros que tiveram maior relev?ncia na forma??o da microestrutura final e nas propriedades mec?nicas obtidas. Os resultados conduziram a constata??o de que para maiores valores de aporte t?rmico a microestrutura, em especial a ferrita acicular, tende a ser mais grosseira. Com a utiliza??o dos revestimentos de PVC e tinta de alum?nio obteve-se uma leve diminui??o nessa granulometria, j? que a microestrutura apresentou-se mais refinada do que com os eletrodos de refer?ncia (E7018 puro e BRH4R). / The shield metal arc welding (SMAW) is one of the oldest welding processes and the first one to be used in large industrial scale. During the XX century the SMAW was the most applied process for metal joining, remaining until nowadays as one of the most used in the Brazilian market. In this kind of welding one of the biggest problems is to avoid the hydrogen induced cold cracking, what imposes rigid requirements in the storing of the weld consumables. In order to avoid the humidity absorption, the consumables must be dried out in special ovens at temperatures in the order of 450 C, what implies in additional and higher manufacturing costs. In this context a recent research suggested modifications in coating of electrodes providing an alternative for execution of welding with low hydrogen electrode AWS E7018 without having to dry it, The welds were developed with basic coated electrodes (hygroscopic) externally painted with aluminum spray paint for high temperatures or wrapped with thin plastic films (PVC) and aluminum foil films. The induced metallurgical changes in the deposited metal, associated with the addition of new materials to the electrode coating, were investigated, wereby the microconstituents in the fusion zone were quantified using a software for image analysis. In the actual work, with the use of a field emission microscope, MEV-FEG, high contrast images could be obtained, this allowed a detailed characterization of the various microconstituents and a more precise description of their morphology. In special it was possible to evaluate the influence of the protective films in the grain size and aspect ratio of the microconstituent AF (acicular ferrite). On base of a literature review a critical analysis is presented, that embraces the effect of the more relevant parameters on the final microstructure and resulting mechanical properties. The results showed that for higher values of heat input the microstructure, especially the acicular ferrite, tends to be coarser. With the use of PVC coatings and aluminum paint, a slight reduction was achieved in this granulometry, since the microstructure was more refined than with reference electrodes (E7018 pure and BRH4R).

Made available in DSpace on 2015-12-04T11:45:28Z (GMT). No. of bitstreams: 1 Norberto_Giuntini.pdf: 3415741 bytes, checksum: 72c67797a89f14a5fc368022990ed41b (MD5) Previous issue date: 2003-06-03 / In 1990, Robert S. Kaplan and David P. Norton developed in United States of America, a new system as support for decision 1, denominated Balanced Scorecard. Even supposing it is not an innovation once it is based on knowledge and principles enclosed in theories previously developed, the Balanced Scorecard has organized some of these theoretical principles, having as objective a "Control Panel" construction to manager the Companies strategy by monitoring financial results, through performance operational indicators that influence these results, growing the analysis capability and organizational knowledge. The published books and articles about Balanced Scorecard2, simplify the methodology description for its implementation and relate some of success cases occurred in companies from United States of America. The Balanced Scorecard is coming to an experimental phase in order to verify its principles and concepts adherence. Many companies operating in Brazil are implanting and implementing it, without divulgating the facilities and difficulties to align the management practices to the strategy and budget, premise that constitute the differentiation for the system to support decision. With these circumstances, the objective for this work is to contribute with the scientific research, presenting the practical experience of one company in activity in the country, by the theoretical principles of Balanced Scorecard applied, divulgating the results obtained and if the company had to recover to improvisation and adaptation to fit the situation not contemplated in Kaplan and Norton methodology developed. The research was made by bibliographical study and empirical research, in order to transmit the concepts that fundaments the Balanced Scorecard utilization, such as not mystify the facility proclaimed from its authors, from a field research done in Alcoa. The research was done based in two questionnaires, and one was constituted of 70 "opened" questions, applied in the Quality Manager, responsible to implanting and implementing the Balanced Scorecard in the company. The second questionnaire was constituted by 21 questions, tabulated in a scale like Likert, with eight levels, and it was applied in managers and users departments of Balanced Scorecard. Even though the Balance Scorecard theory establish facilities for its omplntation and implementation, the work hypothesis was confirmed, the implementation to the referred system needs adjustments and adaptations. These adjustment and adaptations are related to the people initiaves who are in the different hierarchical level to decide and the operate the actions to strategy and acquire knowledge to innovate the way of making the tasks. Other important factor is the difficult to measure objectively the strategy, throughout indicators inter-relation that mean the relation for cause and effect for these actions and iniciatives. Despite of adjustments and adaptations presented all long way, the Balanced Scorecard, constitute a recent tool, presenting evolution level, by the experiences acquired in companies that are adopting it. Even though presents difficulties in its implementation, the Balanced Scorecard represent a system for support decision to create and develop strategy management, doing its theoretic and practical principles an approach so actual related to the necessities established by the best practices to be observed in the Global World and in the Manager Accountancy / No ano de 1990, Robert S. Kaplan e David P. Norton desenvolveram, nos Estados Unidos da Am??rica, um sistema de suporte ?? decis??o, denominado Balanced Scorecard. Muito embora n??o seja inovador, por utilizar conhecimentos e princ??pios contidos em teorias desenvolvidas anteriormente, o Balanced Scorecard organizou alguns desses princ??pios te??ricos, tendo como objetivo a constru????o de um "painel de controle" para gerenciar a estrat??gia da empresa, monitorando os resultados financeiros, atrav??s do desempenho de indicadores operacionais que influenciam esses resultados, aumentando a capacidade de an??lise e aprendizado organizacional. Os livros e artigos sobre o Balanced Scorecard publicados simplificam a descri????o metodol??gica de sua implementa????o e relatam somente os casos de sucesso ocorridos em empresas estabelecidas nos Estados Unidos da Am??rica. O Balanced Scorecard est?? passando por uma fase experimental para a verifica????o da ader??ncia dos seus princ??pios e conceitos. V??rias empresas operando no Brasil est??o implantando-o e implementando-o, n??o divulgando as facilidades e dificuldades para alinhar as pr??ticas gerenciais ?? estrat??gia e ao or??amento, premissas que constituem diferenciais do referido sistema de suporte ?? decis??o. Diante de tais circunst??ncias, este trabalho, tem como objetivo contribuir com a pesquisa cient??fica, apresentando uma experi??ncia pr??tica de uma empresa em atividade no pa??s, quanto ?? aplica????o dos princ??pios te??ricos do Balanced Scorecard, divulgando os resultados obtidos e se a empresa teve que recorrer a improvisa????es ou adapta????es para fazer frente a situa????es n??o contempladas na metodologia desenvolvida por Kaplan & Norton. A pesquisa foi efetuada por meio de estudo bibliogr??fico e pesquisa emp??rica, procurando transmitir os conceitos que fundamentam a utiliza????o do Balanced Scorecard, bem como desmistificar a facilidade apregoada por seus autores, a partir de pesquisa de campo efetuada na unidade Po??os de Caldas da Alcoa. A pesquisa foi efetuada utilizando-se de dois question??rios, o primeiro constitu??do de 70 perguntas "abertas", aplicado na Gerencia de Qualidade, respons??vel pela implanta????o e implementa????o do Balanced Scorecard na empresa. O segundo question??rio, constitu??do de 21 perguntas, tabuladas numa escala tipo Likert, com oito n??veis, foi aplicado nas ger??ncias e departamentos usu??rias do Balanced Scorecard. Embora a teoria do Balanced Scorecard estabele??a facilidades para a sua implanta????o e implementa????o, a hip??tese do trabalho foi confirmada, na medida que a implementa????o do referido sistema de suporte ?? decis??o necessita de ajustes e adapta????es. Estes ajustes e adapta????es est??o relacionados ?? cultura, cren??as e valores, administra????o dos recursos dispon??veis e das iniciativas das pessoas que atuam nos diferentes n??veis hier??rquicos para decidir e operacionalizar as a????es voltadas ?? estrat??gia e adquirir o conhecimento para inovar a forma de fazer as tarefas. Outro fator importante consiste na dificuldade de se mensurar objetivamente a estrat??gia, atrav??s da inter-rela????o de indicadores que traduzam numa rela????o de causa e efeito essas a????es e iniciativas. Apesar dos ajustes e adapta????es apresentadas ao longo do trabalho, o Balanced Scorecard, constitui-se numa ferramenta recente, apresentando est??gio de evolu????o, em fun????o das experi??ncias adquiridas pelas organiza????es que o est??o utilizando. Embora apresente dificuldades na sua implementa????o, o Balanced Scorecard representa um sistema de suporte ?? decis??o para criar e desenvolver a gest??o estrat??gica, fazendo dos seus princ??pios te??ricos e pr??ticos, uma abordagem bastante atual relacionada ??s necessidades estabelecidas pela melhores pr??ticas a serem observadas no mundo globalizado e pela contabilidade gerencial.

[pt] O potássio é um íon essencial para a nutrição de plantas, geralmente fornecido sob a forma de cloretos e sulfatos. De acordo com a disponibilidade e demanda brasileira de fertilizantes agrícolas, a importação de compostos portadores desse elemento químico é mandatória para atender a enorme demanda por esse nutriente. Assim, iniciativas que buscam fontes alternativas de potássio tornam-se cada vez mais interessantes e economicamente atraentes. Uma rota potencial está associada com a digestão com ácido sulfúrico de minerais portadores de glauconita e operações unitárias sequenciais para recuperar compostos de alumínio, ferro, magnésio e potássio. No contexto deste processo químico, o alúmen de potássio dodecahidrato aparece como um produto intermediário relevante que permite a recuperação seletiva de potássio e alumínio através de decomposição térmica seguida de solubilização em água e filtração. Com base no que foi dito, o presente trabalho investiga a cinética da decomposição do alúmen de potássio dodecahidratado sob condições não-redutoras e redutoras, e um novo modelo matemático é proposto para descrever a perda de massa ao longo do tempo. Uma abordagem estocástica, com o uso do método de otimização enxame de partículas, é empregada para estimar os parâmetros desconhecidos do modelo. As previsões do modelo são validadas por dados experimentais obtidos via análise termogravimétrica dinâmica em diferentes atmosferas de reação (inerte e oxidante), e com a presença ou não de agente redutor (finos de coque metalúrgico). Com os parâmetros do modelo validado, é possível usar o mesmo para monitorar as composições mássicas de todos os compostos presentes no meio assim como empregar o modelo futuramente para monitoramento online uma vez que sua simulação leva menos do que 1 s para simular 20 min de decomposição térmica. / [en] Potassium is an essential ion for plant nutrition, usually supplied in the form of chlorides and sulfates. According to Brazilian availability and demand of agriculture fertilizers, the importation of compounds carrying this chemical element is mandatory in order to fulfill the huge demand for this nutrient. So initiatives looking for alternative sources of potassium become increasingly interesting and economically attractive. A potential route is associated with the sulfuric digestion of glauconite-bearing greensands and sequential unit operations in order to recover aluminum, iron, magnesium and potassium compounds. In the context of this chemical process, the potassium alum dodecahydrate appears as a relevant intermediate product that allows the selective recovery of potassium and aluminum through thermal decomposition followed by solubilization in water and filtration. Based on what was said, the present work investigates the kinetics of potassium alum dodecahydrate decomposition under nonreductive and reductive conditions, and a novel mathematical model is proposed to describe the weight loss during time. A stochastic approach approach, using particle swarm optimization method, is employed to estimate the unknown model parameters. The model predictions are validated by experimental data obtained through dynamic thermogravimetric analysis at different reaction atmospheres (inert and oxidant), and with the presence or not of reducing agent (metallurgical coke breeze). With the validated model parameters, it is possible to use them to monitor the mass compositions of all compounds present in the process as well as to use the model for future online monitoring since its simulation takes less than 1 s to simulate 20 min of decomposition thermal.

Excess Fluoride in drinking water is a cause for concern in several countries in the world. Various techniques have been developed to mitigate the harmful effects of fluoride. In the present work, a combined alum and activated alumina (AA) process has been investigated. Tap water with sodium fluoride dissolved in it to produce a solution having a fluoride concentration of 5 mg/L was used as the feed. It was found that pretreatment with alum extends the time required for the regeneration of the AA column. The volume of water treated increased by 89% compared to AA process alone. Though the regeneration of the AA column has been well documented, subtle issues have ot been reported. The disposal of regeneration effluent is a concern in adsorption-based processes. This study aims to examine some of the issues involved in the regeneration of the AA column such as disposal of effluent, and the quantity of acid and alkali required. The regeneration effluent from the combined process, which had a fluoride concentration of 10-16 mg/L was treated in a solar still. The distillate from the still had a fluoride concentration of 2-3 mg/L, which is much lower than the concentration of the regeneration effluent. The cost of treatment decreased with each regeneration cycle and after four regenerations the cost was Rs 0.5/L of treated water. The volume of water treated after four regenerations was 307 L/Kg of AA. Studies were also done using field water from Banavara, Hassan district, Karnataka, which had a fluoride concentration of 3,0-3.5 mg/L. The combined process successfully produced treated water having an acceptable fluoride concentration. After one regeneration cycle, the operating cost was Rs. 1/L of treated water. Studies have also been conducted on a point-of-use water filter containing a bed of AA pellets. The filter was provided by an organization called TIDE. The present results appear to suggest that a column with a smaller diameter than the TIDE filter has a better removal capacity. Ceramic candles are widely used for water filtration as they are readily available and inexpensive. Hence they are suitable for household water treatment purposes. In the present work, ceramic candles have been impregnated with nano-size alumina and nano-size magnesium oxide and tested for their defluoridation capacity. The nanoparticles were generated in situ in the pores of the candle by solution combustion synthesis. It has been found the candle impregnated with nano-size magnesium oxide has a higher defluoridation capacity than nano-size alumina. Estimation of the particle size in the samples of treated water did not give conclusive evidence for the presence or absence of nanoparticles. The volume of water treated was low and the cost of treatment was high (Rs. 12/L for the candle impregnated with MgO). Hence such candles are unsuitable for defluoridation. Batch adsorption has been employed to measure the adsorption capacity of adsorbents. A model to capture the overall picture of the batch adsorption process, obtaining the kinetic and transport parameters involved has been developed. The mathematical model takes into account external mass transfer resistance, intraparticle diffusion, adsorption, and desorption. The equilibrium adsorption data was fitted using the Langmuir isotherm. The governing equations were solved using a finite difference technique known as the Laasonen method. The parameters were estimated by fitting two sets of data using a MATLAB function. The values estimated suggest that the adsorption process may not be diffusion-limited, in contrast to the assumption commonly used in the literature. The estimated parameter values were used to predict the concentration profiles for the other data sets. It was found that predicted and measured profiles agreed reasonably well.

Syfte: Rödfyr är gruvavfall från förbränning av alunskiffer. Materialet finns i naturen på många platser i Västra Götaland. Fram till 80-talet användes rödfyren som utfyllnadsmaterial men numera är användningen begränsad då materialet lakar tungmetaller. Mängden avfall som går till deponi skall minskas. Möjligheten att deponera rödfyrsmassor är därmed begränsad då områden med rödfyrshögar skall bebyggas. Syftet med denna studie är därför att öka kunskapen om hur rödfyrsmassor kan hanteras på ett miljömässigt och ekonomiskt sätt. Målet är att ge förslag på användningsområden och hanteringsmetoder för rödfyrsmassor för att bidra till bättre miljö och ekonomiska och förutsättningar. Genom att utreda vilka krav som ställs på användning av rödfyr, söktes svar på möjliga användningsområden och konstruktionslösningar för att minska lakningen. Denna studie är ett examensarbete som genomförts i samarbete med Skövde kommun. Metod: Valda metoder för datainsamling är litteraturstudie, dokumentanalys samt semi-strukturerade intervjuer. I litteraturstudien studerades litteratur om avfall, rödfyr, och efterbehandlingsmetoder. I dokumentanalysen studerades miljöutredningar för rödfyr för att erhålla kunskap om lakningen. Intervjuerna gav information om tillståndsmyndigheternas arbete med rödfyr, och sakkunnigas förslag på hur rödfyr bör användas och hanteras. Resultat: Studien visade att det finns andra användningsområden än deponi, samt att det finns metoder för att begränsa rödfyrens lakning. Det måste finnas kunskaper om hur rödfyrens spridning sker vid omröring och flytt. Att förhindra lakning kan uppnås genom att kapsla in rödfyren med hjälp av olika tätskikt. Detta innebär att rödfyren kan nyttjas som en resurs, ytor blir tillgängliga för exploatering, samt att rödfyren inte är tillgänglig för människor, och att lakningen till grundvattnet minskas. Konsekvenser: Rödfyr kan användas som utfyllnadsmaterial vid mindre känslig markanvändning, såsom industriområden och vägar. Detta är under förutsättning att övertäckning av massorna sker för att undvika lakning. Asfaltsytor, i kombination med ett tätskikt på ovansida, samt vertikala sidor, begränsar lakningen avsevärt. Överytan kan då utnyttjas för exploatering. Transportsträckan är ofta ekonomiskt avgörande för om rödfyren kan flyttas eller inte. Om rödfyren kan nyttjas för utfyllnadsändamål minskar kostnaden för inköp av material, och nya uttag av massor belastar inte miljön. Begränsningar: Den rödfyr som studerats är den som finns i Skövde Kommun. Studien bör dock kunna tillämpas på övriga länet. En begränsning är att intervjustudien inte genomfördes så omfattande. Ytterligare hade genomförande av skaktester i studien kunnat bidra med kunskap. På grund av den tid som krävs för detta var det ej möjligt. Dock erhölls bekräftande svar från de olika metoderna, och slutsatser kunde därmed trianguleras. / Purpose: Burnt alum shale is mining waste derived from combustion of the same rock. It exists in several places in Västra Götaland. Alum shale was previously used as filling but nowadays the use is limited thus the material is leaching heavy metals. The amount of waste normally put in landfills shall now be diminishing. Therefore the possibility to landfilling alum shale is limited. The purpose of this study is to increase the knowledge of how alum shale can be dealt with in an environmentally safe and economically beneficial way. The goal is to bring out suggestions for applications of use and ways of handling the excavations to contribute to a better environment and to achieve better financial conditions. By investigate what claims need to be achieved for the possibility of using Alum shale, useful areas of use and suitable management where brought forward. This study has been composed as a mean to get a bachelor degree in engineering, with the benefitial partner Skövde kommun. Method: Literature study, document analysis and interviews where used as research methods. Research on waste, alum shale and remediation techniques where studied in the literature study. In the document analysis, environmental study were analysed to retain knowledge of leachate. The interviews presented information of the authorities work with alum shale and experts’ suggestions of how alum shale can be used and handled. Findings: This study showed that there is other applications than landfills, and that there is methods to limit the leachate. If to be used, knowledge of the alum shale’s propensity of spreading due to stirring and relocation must be known. To inhibit leachate van be achieved by encapsulate the alum shale by waterproofing. This means that the alum shale can be used as a resource. Areas will be available for exploitation, it will not affect people in the surroundings, and the leachate to the groundwater will diminish. Implications: At minor sensitive land use, alum shale can be used as filling material, such as industrial areas and roads. This implicates waterproofing of the material. Asphalted surface, in combination of waterproofing the top surface and the vertical sides limits the leachate of metals considerably. The haul is often ruling the possibility to relocate the shale. If the alum shale, at disposal, could be used for filling purposes, the cost of purchasing new material, and outlet of new raw material does not need to burden the environment. Limitations: The alum shale studied is the one of Skövde County. The study should though be applicable to the whole of Västra Götaland. Not having the time to expand the interviews and include more people with research experience and expertise, is one of the limitations of this study. Also, carry out leachate tests could have contributed with more knowledge.

Made available in DSpace on 2014-12-17T15:01:54Z (GMT). No. of bitstreams: 1 KatiaRS_TESE.pdf: 3330352 bytes, checksum: a77bcf257b8b71b30d6dadf0de0d7fd4 (MD5) Previous issue date: 2012-03-30 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Among the waste generated in the petrochemical industry water associated with oil production is the most important. It is considered one of the great challenges due to the presence of considered toxic chemicals present in this composition. The presence of these substances difficult to reuse the water associated with the enhanced recovery processes, so that prior to their reuse or disposal, treatment is necessary. This paper aimed to study the removal efficiency of chemical species: Ba2+, Ni2+, Cd2+, Cu2+, Cr3+, Sr2+ and Zn2+, present in the composition of the water associated with oil production by electrocoagulation. The evaluation of removal of these chemical species was performed by laboratory tests using electrochemical batch reactors and continuous flow. Initial tests were performed with electrocoagulation of synthetic wastewater in batch reactor using iron electrode. Results of removal of Zn2+ and Ni2+ were 78 % and 59 % respectively. While the percentage of removed Ba2+ was 19 % by 30 minutes of treatment and by applying current of 1.10 A. The tests were performed on effluent batch reactor applying the electrochemical technique with stainless steel electrodes 304, the objective was to remove part of the dispersed oil and also of organic compounds in the effluent. Under the experimental conditions used, the maximum result was obtained TOG was 60 % and TOC was approximately 50 % compared to the initial concentration. In the experiments carried out in continuous reactor, with effluent semisynthetic, have been used electrodes of iron and aluminum and the results were 100 % removal of Cd2+, Cu2+, Cr3+ and Zn2+ and 77 % of Sr2+. These percentages were only attainable through the use of the iron electrode. However, when the electrode was replaced by aluminum, there was a reduction in the percentage of removal to 65 %, using the same flow rate and current. Therefore according to the results obtained using the iron electrode was more effective in removing these metals and the conditions of lower current and lower flow rate was satisfactory, as observed in the experimental design adopted / Dentre os res?duos gerados na ind?stria petroqu?mica a ?gua associada ? produ??o de petr?leo ? a mais importante. Ela ? considerada um dos grandes desafios devido ? presen?a de subst?ncias qu?micas consideradas t?xicas presente na sua composi??o. A presen?a dessas subst?ncias dificulta a reutiliza??o da ?gua associada nos processos de recupera??o avan?ada, fazendo com que antes da sua reutiliza??o ou descarte, seja necess?rio seu tratamento. Este trabalho teve como objetivo o estudo da efici?ncia de remo??o das esp?cies qu?micas: Ba2+, Ni2+, Cd2+, Cu2+, Cr3+, Sr2+e Zn2+, presentes na composi??o da ?gua associada ? produ??o de petr?leo por eletrocoagula??o. A avalia??o de remo??o dessas esp?cies qu?micas foi realizada por testes em laborat?rio utilizando reatores eletroqu?micos de batelada e de fluxo cont?nuo. Os testes iniciais da eletrocoagula??o foram realizados com efluente sint?tico em reator batelada utilizando eletrodo de ferro. Os resultados de remo??o de Zn2+ e de Ni2+ foram de 78% e 59%, respectivamente. Enquanto que o percentual removido de Ba2+ foi de 19%, em 30 minutos de tratamento, aplicando corrente de 1,10A. Os testes com efluente foram realizados em reator batelada aplicando a t?cnica eletroqu?mica com eletrodos de inox 304, o objetivo foi remover parte do ?leo disperso e tamb?m, de compostos org?nicos presentes no efluente. De acordo com as condi??es experimentais usadas, o resultado m?ximo obtido de TOG foi de 60% e de TOC foi aproximadamente de 50%, em rela??o ? concentra??o inicial. Para os experimentos realizados em reator cont?nuo, com efluente semi-sint?tico, foram usados eletrodos de ferro e de alum?nio e os resultados obtidos foram de 100% de remo??o de Cd2+, Cu2+, Cr3+ e Zn2+ e 77% de Sr2+. Esses percentuais s? foram poss?veis de alcan?ar mediante o uso do eletrodo de ferro. Entretanto quando esse eletrodo foi substitu?do pelo de alum?nio, ocorreu um decr?scimo no percentual de remo??o para 65%, utilizando-se a mesma vaz?o e corrente. Portanto segundo os resultados obtidos, a utiliza??o do eletrodo de ferro mostrou-se mais eficaz na remo??o desses metais e as condi??es de menor vaz?o e menor corrente foram satisfat?rias, conforme observado no planejamento fatorial adotado

Made available in DSpace on 2014-12-17T15:01:57Z (GMT). No. of bitstreams: 1 MarcianoHLN.pdf: 1368494 bytes, checksum: bb70e8ef85120a42eab9a63074c5ba8a (MD5) Previous issue date: 2005-11-25 / Gallium is an important material used in the electronic industry whose demand in the world market is increasing in view of its potential applications. A selective technique is required to allow for the production of the metal, separated from aluminium. Due to the fact that microemulsions constitute an attractive alternative to metal extraction procedures, microemulsified systems have been employed as gallium-selective extraction agents. Two surfactants have been synthesized: sodium 12-N,N-diethylamino-9,10-dihydroxyestearate (AMINE) and saponified coconut oil (SCO), both produced from raw materials readily available in Northeastern Brazil. Also, the commercial extraction agent KELEX-100, conventionally used with the same purpose, has been used in this work for comparison. The optimization of the extraction process with microemulsions was carried out by investigating the influence of some parameters, namely the type of cosurfactant, the cosurfactant/surfactant (C/S) ratio, the pH and concentration of metals in the aqueous phase. Pseudoternary diagrams, which are representative of the microemulsified systems under study, have been constructed in order to establish the boundaries of the regions where the several Winsor systems are formed. An experimental planning methodology (Scheff? Net) has been used to optimize the extraction. The extraction percentage values were as high as 100% for gallium and 99.99% for aluminium for the system with KELEX-100; 96.6% for gallium and 98.8% for aluminium for the system containing AMINE; and 88% for gallium and 85% for aluminium for the system with SCO. The microemulsified system chosen for presenting the best results in gallium extraction was composed by SCO/isoamyl alcohol/kerosene/Bayer licquor with a C/S ratio of 28 and pH of the original aqueous phase of 6.0. The selectivity that has not been observed in the extraction stage was accomplished in the reextraction process using HCl. For the KELEX-100 system, gallium was reextracted at 100% with 6M HCl and aluminium was reextracted at 100% with 0.8M HCl. For the AMINE system, the reextraction percentages were also 100% for both metals, using 6M HCl for gallium and 0.5M HCl for aluminium. On the other hand, the reextraction percentages for the system with SCO were as high as 84% for gallium and 92% for aluminium, with HCl in the same concentrations as those used in the AMINE system. Finally, an optimized system was applied in the gallium extraction process employing a reciprocating perforated-plates extractor. As a result, the metal content was extracted at a recovery rate of 95% for gallium and 97% for aluminium / O g?lio ? um importante material utilizado na ind?stria eletr?nica, cuja demanda no mercado mundial est? crescendo em raz?o de suas aplica??es. A obten??o do metal necessita de um m?todo seletivo para separ?-lo do alum?nio. Sendo as microemuls?es uma alternativa atrativa para a extra??o de metais, decidiu-se utilizar sistemas microemulsionados como extratantes seletivos ao g?lio. Dois tensoativos foram sintetizados; o 12-N,Ndietil-amino-9,10-dihidroxiestearato de s?dio (AMINADO) e o ?leo de coco saponificado (OCS), obtidos de mat?rias-prima dispon?veis na regi?o Nordeste do Brasil. O extratante comercial KELEX-100, convencionalmente utilizado com essa mesma finalidade, foi usado neste trabalho para compara??o. A otimiza??o do processo de extra??o por microemuls?es foi realizada atrav?s do estudo da influ?ncia de par?metros, tais como: tipo de cotensoativo, raz?o C/T, pH e concentra??o de metais na fase aquosa. Os diagramas pseudotern?rios, representativos dos sistemas microemulsionados em estudo, foram estabelecidos no sentido de delimitar as regi?es de exist?ncia dos sistemas de Winsor. Uma metodologia de planejamento experimental (Rede Scheff?) foi usada para otimizar a extra??o. O percentual de extra??o atingiu valores de at? 100 % para o g?lio e 99,99% para o alum?nio para o sistema com o KELEX-100; 96,6 % para o g?lio e 98,8 % para o alum?nio no sistema contendo AMINADO; 88 % para o g?lio e 85 % para o alum?nio no sistema com OCS. O sistema microemulsionado selecionado por apresentar os melhores resultados na extra??o do g?lio foi composto de: OCS/?lcool isoam?lico/querosene/licor de Bayer a uma raz?o C/T igual a 28 e pH da fase aquosa igual a 6. A seletividade que faltou ? extra??o foi atingida na etapa de reextra??o utilizando-se solu??es de HCl. Para o sistema com o KELEX-100, reextraiu-se g?lio a 100% com HCl 6M e alum?nio a 100% com HCl 0,8M. No caso do sistema com AMINADO, os percentuais de reextra??o de ambos os metais tamb?m foram de 100%, usando-se HCl 6M para g?lio e HCl 0,5 M para o alum?nio. Por outro lado, para o sistema com OCS, os percentuais de reextra??o foram tais que 84% do g?lio e 92% do alum?nio foram recuperados com HCl nas mesmas concentra??es empregadas no caso do AMINADO. Um sistema otimizado foi, finalmente, aplicado na extra??o do g?lio em um extrator de pratos perfurados rec?procos (EPPR) e permitiu a extra??o deste metal com uma taxa de recupera??o de g?lio a 95% e alum?nio a 97%