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This report is the result of a bachelor thesis project executed at Luleå University of Technology(LTU). The purpose of the project was to investigate the possibility to use the metal powder wasteproducts from LKAB’s pelletizing process for additive manufacturing as this would meaneconomic benefits for the sake of LKAB as well as environmental benefits.Two different powders were used in the experiments and were referred to as crush and dust. Theexperiments were made through the selective laser melting (SLM) method with varying laserparameters to observe their effect. These included the laser power and laser speed. Scanningelectron microscope (SEM), Energy Dispersive X-Ray Spectroscopy (EDS) and opticalmicroscopy were used for the analysis of the samples.The analysis of the chemical compositions showed that the powders were inhomogeneous anddiffered from each other. The crush powder contained phosphor and carbon which was lacking inthe dust and also had higher amounts of silicon and potassium. In spite of the inhomogeneouspowder and getting some agglomerations of half-melted grains on the tracks, the tracks tended tobe mostly homogenous. It was also observed that the tracks have a higher amount of carboncompared to the powder which probably derives from the substrate plate.The adherence of the tracks was greatest at a laser power between 200-300 W and a laser scanningspeed 0.5-1.75 m/min.The metal powder waste products from LKAB’s pelletization process could likely be used inadditive manufacturing, however, more work is needed in order to ensure the obtained results andcontinue with further experiments.

Submitted to School of Chemical and Metallurgical Engineering, Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, South Africa June, 2016 / The main objective of this study is to produce biofuel from waste animal fat (collected from abattoirs) using the pyrolysis (thermal cracking) method. To achieve this goal, the study investigated the effects of temperature and heating rate on the yield and quality of the bio-oil produced. Also investigated was the effect of zeolite nano-catalyst(s) on the quality of the bio-oil produced. Animal waste fat (tallow) was pyrolyzed in a laboratory fixed bed reactor of volume 2200 cm3 at final temperatures (FT), 450oC, 500oC, 530oC and 580oC using heating rates (HR) of 4oC/min, 5oC/min and 6oC/min. The properties of the resultant bio-oils were tested and analyzed. The maximum bio-oil yield of 82.78 % was achieved at 530oC FT and 6oC /min HR while the highest calorific value, 52.41 MJ/kg, was recorded from the bio-oil produced at the FT of 580oC and 6oC/min HR. The molecular components of each of the bio-oil samples was analyzed using the Gas Chromatography – Molecular Spectrograph (GC-MS) which indicated the predominant presence of alkanes, alkenes, carboxylic acids and alkyl esters in the bio-oils produced without a catalyst. The introduction of zeolites in nano-form yielded relatively more cyclo-alkanes and aromatics. A maximum yield of 58% was recorded when 1% of the zeolite nano-catalyst was used to pyrolyse the tallow at 530oC FT and 6oC/min HR but with lots of coking and gas formation. The viscosity improved with a 35% reduction for the samples produced with 1% zeolites (C1 and C2). The viscosity of the bio-oil produced with 2% zeolites improved with a resultant 34% reduction in value. For pyrolysis done at 530oC FT and 6oC/min HR, the bio-oils with 1% (C1) and 2% zeolite (C3) resulted in a reduction in acid value of 32% and 30%, respectively. Acid value is the mass of potassium hydroxide (KOH) in milligrams that is required to neutralize one gram of chemical substance. / MT2016

Orientador: Carlos Renato Corso / Banca: Dejanira de Franceschi de Angelis / Banca: Silvana Perissatto Meneghin / Resumo: Os corantes têxteis são um dos principais poluentes descartados em corpos hídricos, e devido a sua toxicidade, são responsáveis por diversos impactos ambientais no ecossistema aquático. A quitosana é um biopolímero derivado da desacetilação da quitina derivada da casca de camarão, que é originária de um resíduo pesqueiro. A levedura Saccharomyces cerevisiae é um micro-organismo muito importante para a indústria brasileira, sendo utilizada em vários processos industriais, além de sua biomassa ser produzida em larga escala no Brasil. Desta forma o trabalho teve como objetivo analisar a aplicação do pó de quitosana e da biomassa de S. cerevisiae na adsorção do corante têxtil Acid Blue 161. Foram feitos testes variando o pH da solução, e utilizou-se os estudos cinéticos, isotermas e termodinâmica para se analisar os resultados e avaliar a interação adsorbato/adsorvente. Realizou-se analises em espectrofotômetro FT-IR para se confirmar os resultados obtidos nos modelos matemáticos. Os resultados mostraram que ambos os adsorventes respeitaram o modelo de pseudo-segunda ordem, porém pode-se constatar também a ocorrência de difusão intrapartícula em ambos materiais. A adsorção melhor se ajustou ao modelo de Freundlich em todos os pH testados para ambos os adsorventes, indicando a formação de múltiplas-camadas. Os estudos termodinâmicos confirmaram que a adsorção é uma reação endotérmica e espontânea, além de confirmar que a adsorção é influenciada pela temperatura. As analises em esp... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Textile dyes are one of the main pollutants discarded in water bodies, and due to their toxicity, are responsible for several environmental impacts on the aquatic ecosystem. Chitosan is a biopolymer derived from the deacetylation of chitin derived from shrimp bark, which originates from a fishery residue. The yeast Saccharomyces cerevisiae is a very important microorganism for the Brazilian industry, being used in several industrial processes, besides its biomass being produced in large scale in Brazil. The aim of this work was to analyze the application of chitosan powder and S. cerevisiae biomass in adsorption of Acid Blue 161 dye. Tests were performed by varying the pH of the solution, and kinetic, isothermal and thermodynamic studies were used to analyze the results and evaluate the adsorbate/adsorbent interaction. FT-IR spectrophotometer analyzes were performed to confirm the results obtained in mathematical models. The results showed that both adsorbents respected the pseudosecond order model, but also the occurrence of intraparticle diffusion in both materials. The adsorption best fit the Freundlich model at all pH tested for both adsorbents, indicating the formation of multiple layers. The thermodynamic studies confirmed that the adsorption is an endothermic and spontaneous reaction, besides confirming that the adsorption is influenced by the temperature. The FT-IR spectrometer analyzes confirmed that for both adsorbents is occurring chemisorption at acidic pH due to the protonation of the medium, already at the alkaline pH was occurring a physisorption. With this it can be concluded that the pH of the solution directly influences the adsorption process. The efficiency of the use of chitosan powder and S. cerevisiae as a possible adsorbent material of textile dyes was also verified, indicating that the protonation of the ... (Complete abstract click electronic access below) / Mestre

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Título original: Influência da associação de vinhaça e herbicida formulado com Tebutiurom na microbiologia e ecotoxicidade de solo cultivado com cana-de-açúcar em manejo convencional / Orientador: Ederio Dino Bidoia / Banca: Peterson Bueno de Moraes / Banca: Dejanira de Franceschi de Angelis / Resumo: A cana-de-açúcar é uma cultura de grande importância econômica para o país, servindo de matéria prima para produção de açúcar e álcool. A vinhaça é um importante subproduto da produção alcooleira utilizada na fertirrigação por ter matéria orgânica e nutrientes em sua composição. Em contrapartida, pelo seu pH ácido e alta carga orgânica, pode apresentar um grande potencial poluente. Dentre os herbicidas mais utilizados na cultura da cana-de-açúcar, destaca-se o tebutiurom que apresenta toxicidade moderada a extrema e alta persistência, podendo ocasionar impacto ambiental. Por este motivo, o presente trabalho teve por objetivo avaliar o efeito da aplicação de diferentes doses de tebutiurom associadas ou não à vinhaça em solo de manejo convencional na cultura da cana-de-açúcar em condições laboratoriais. Foram avaliadas a biodegradação mediante respirometria, a fitotoxicidade das amostras de solo utilizando sementes de alface, e a quantificação da comunidade bacteriana. As análises foram realizadas nos tempos inicial (t0) e final (t51) do experimento. Os resultados foram analisados estatisticamente utilizando teste de Tuckey a 5,0% de significância. Na biodegradação, as doses de tebutiurom não apresentaram efeito significativo na atividade microbiana dentre os tratamentos que receberam o mesmo volume de vinhaça. Entretanto, o herbicida proporcionou mudanças nas relações de significância entre outros tratamentos, sugerindo que a adição de tebutiurom ao solo causa pequena alteraçã... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Sugarcane is a crop of great economic importance for the country, serving as raw material for sugar and alcohol production. Vinasse is an important by-product of the alcoholic production, which it is used in fertirrigation by having organic matter and nutrients in its composition. On the other hand, by its pH acid and high organic load, it can present a great polluting potential. Among most commonly used herbicides in sugarcane crops, tebuthiuron exhibits moderate to extreme toxicity and high persistence, and may have an environmental impact. For this reason, the objective of this study was to evaluate the effect of the application of different doses of tebutiurom associated or not to vinasse in conventional management soil in sugarcane cultivation under laboratory conditions. Biodegradation through respirometry, phytotoxicity of soil samples using lettuce seeds, and quantification of the bacterial community were evaluated. The analyzes were performed at the initial (t0) and final (t51) times of the experiment. The results were statistically analyzed using the Tuckey test at 5.0% probability. The doses of tebutiurom had no significant effect on biodegradation among the treatments that received the same volume of vinasse. However, the herbicide provided changes in the significance relationships between other treatments, suggesting that the addition of tebutiurom to the soil causes a small change in soil microbiota metabolism. The higher volume of vinasse applied resulted in hi... (Complete abstract click electronic access below) / Mestre

Typescript (photocopy). / Digitized by Kansas Correctional Industries

This thesis aimed at investigating a process based on anaerobic mixed culture fermentation (AMCF) of organic waste to produce carboxylates, molecular hydrogen and ethanol. The novelty of this study was to estimate the potential production of these bulk chemicals from selected renewable feedstocks and to experimentally investigate their production from the AMCF of three distinct types of feedstock without physicochemical pre-treatment: grass, a lignocellulosic substrate; cheese whey, a lactose-rich residue; and fish processing wastewater, a complex effluent containing proteins and fats. The estimation showed that AMCF of a small fraction (less than 1.6%) of the selected feedstock would be required to suffice the current production of carboxylates from oil-based feedstock, whilst up to 51% of the feedstock would be needed to satisfy the current production of ethanol and molecular hydrogen. In the experiments with AMCF of grass, low organic loading rates and long solids retention times were required to increase the substrate conversion because of the hard-biodegradability found in the substrate without any physicochemical pre-treatment. For the AMCF of cheese whey, the production of carboxylates decreased the pH to low levels and consequently inhibited the fermentation. For the AMCF of fish processing wastewater, the feedstock showed high biodegradability with production of biogas under batch condition and stable production of carboxylates under semi-continuous condition. The release of ammonium during the degradation of proteins was considered one of the main factors to avoid the pH drop when carboxylates were produced throughout the fermentation. In conclusion, the study showed that the feedstock nature and the operating condition play a key role in how to drive the AMCF to the production of these chemicals and avoid methanogenesis. Whilst hydrolysis limits the fermentation for hardly biodegradable feedstock, volatile fatty acids formation and pH inhibit the AMCF of more easily biodegradable feedstock.

This dissertation research represents efforts towards development of organic waste fueled bio-refineries, capable of achieving circular economy and resource recovery through conversion of the embedded chemical energy and nutrients present in the organic waste, into biochemical products of commercial value. The specific objectives were: 1. Evaluation of anaerobic fermentation derived volatile fatty acid as a recovery platform: Anaerobic fermentation of organic wastes is a cost and energy efficient way of recovering the inherent chemical energy potential associated with such waste streams. Additionally, since the carbon is recovered in the form of short chain volatile fatty acids (VFA), the high solubility in water results in fairly easy recovery and handling than the gas phase endpoints (methane, hydrogen). It also opens up the possibility to biologically or chemically redirect those VFA to high-value endpoints. Anaerobic fermentation of such streams to recover VFA also results in reducing the organic strength of the waste streams, thereby achieving waste treatment and sanitation in a far more sustainable manner than the existing practices of the organic waste management and wastewater treatment, which were inherently designed with the goal of removal of contaminants and are focused upon sequential removal of those undesirable ‘contaminants’ including carbon (energy), nitrogen and phosphorus. Therefore, the focus of this review was to evaluate the feasibility of anaerobic fermentation derived volatile fatty acids as a substrate for potential bio-conversion into products of high commercial value. The key advantage of such a pipeline would be to intrinsically couple applications such as sanitation or wastewater treatment with resource recovery in an energetically and economically neutral or positive manner. The pipeline consists of two major steps, namely (i) Production and recovery of carbon in the form of volatile fatty acids through anaerobic fermentation and, (ii) Biological or chemical conversion of VFA to other endpoints including but not limited to biofuels, bio-plastics, butanol, organic acids and solvents and dihydrogen. 2. Microbial conversion of synthetic and food waste-derived volatile fatty acids to lipids: Lipid accumulation in the oleaginous yeast Cryptococcus albidus was evaluated using mixtures of volatile fatty acids (VFA) as substrates. In general, batch growth under nitrogen limitation led to higher lipid accumulation using synthetic VFA. During batch growth, an initial COD:N ratio of 25:1 mg COD:mg-N led to maximum intracellular lipid accumulation (28.33±0.74% g/g dry cell weight), which is the maximum reported for C. albidus using VFA as the carbon source, without compromising growth kinetics. At this feed COD:N ratio, chemostat cultures fed with synthetic VFA yielded statistically similar intracellular lipid content as batch cultures (29.88±1.92%, g/g). However, batch cultures fed with VFA produced from the fermentation of food waste, yielded a lower lipid content (14.99±0.06%, g/g). The lipid composition obtained with synthetic and food-waste-derived VFA was similar to commercial biodiesel feedstock. We therefore demonstrate the feasibility of linking biochemical waste treatment and biofuel production using VFA as key intermediates. 3. Genome sequencing of oleaginous yeast Cryptococcus albidus and evaluation of its genetic and biotechnological potential: We reported the complete draft genome sequence of Cryptococcus albidus var. albidus, an oleaginous yeast, which can utilize various organic carbon sources for lipid synthesis. The basidiomycetous oleaginous yeast has been gaining popularity as a non-conventional yeast with the ability to metabolize and transform diverse organic substrates. The 24.8 Mb genome of C. albidus was sequenced and the metabolic reconstruction revealed that C. albidus contains several essential pathways for metabolism of various carbon sources (including glucose, sucrose, glycerol, acetic, propionic and butyric acids), accumulation of carbon compounds (tri-acyl glycerol (TAGs) and glycogen) and for assimilation of various nitrogen (ammonia, nitrate, nitrite, and urea) and sulfur sources (sulfate, sulfite, thiosulfate). It is also capable of secreting enzymes of industrial significance. Here, we presented a comprehensive overview of the biology and biotechnology of C. albidus, specifically focusing on its microbial physiology, metabolic pathways and its potential for production of commercially and industrially important chemicals. 4. Evaluation of the global transcriptomic and proteomic responses of the Cryptococcus albidus to nitrogen limitation: ‘Non-ideal’ carbon sources could be an ideal substrate for economically feasible lipid production by oleaginous yeast Cryptococcus albidus; however, there have been no studies thus far, on biochemical pathways governing its oleaginity and metabolism. Here, we report for the first time, a comprehensive account of the transcriptome and proteome level changes in continuous cultures of Cryptococcus albidus in response to nitrogen limitation. Proteome and differential gene expression data revealed a tight co-regulation of nitrogen and carbon metabolism, wherein nitrogen limitation resulted in a complete redistribution of carbon flux throughout the cellular processes, including nitrogenous compound recycling, autophagy and cessation of nucleic acid and ribosome biosynthesis. Lipid accumulation by C. albidus does not seem to involve transcriptional regulation but is a passive consequence of carbon flux redistribution during nitrogen limitation. This study therefore, provides a valuable resource to understand oleaginity and metabolism of alternate carbon sources by C. albidus and provides opportunities for metabolic re-engineering of its lipid production pathways. 5. Organic waste fueled biorefineries: future perspectives on production of chemicals of industrial significance from volatile fatty acids: The focus of this review was to propose alternate bio-based pipelines for recovery and conversion of organic waste streams into high value commercial products, using VFA as central precursors for further aerobic/anaerobic carbon cycling. Herein, we present various pathways, microorganisms, culture conditions and current status of bio-based production of certain building-block chemicals such as adipic acid, butanol, organic acids such as citric, malic and succinic acids. These chemicals have the highest potential to be economically produced from VFA since the pathways for their bioconversion either exist natively or have been metabolically engineered. Nevertheless further research would be needed to reduce the costs and enhance productivity. In conclusion, this dissertation represents the first attempt at a holistic evaluation of a VFA based resource recovery platform. In first phase, microbial conversion of volatile fatty acids into lipids by the yeast C. albidus was evaluated and nitrogen limitation was identified as the inducer of lipogenesis in C. albidus through operation of batch and chemostat cultures. Next, entire genome was sequenced and transcriptome and proteome level changes were evaluated in conjunction to understand the metabolic basis of nitrogen-mediated oleaginity in C. albidus. This genomic and the comparative transcriptome and proteome data is expected to help further elucidate factors driving lipid accumulation in C. albidus and contribute toward bioprocess development and optimization for engineered lipid production from ‘waste’ streams. Finally, the feasibility of microbial conversion of VFA into several other bio-based chemicals of commercial value was also evaluated.

Título original: Estudos adsortivos do corante Acid Blue 25 pelos materiais sintetizados : esferas quartenária, esferas de quitosana e esferas com Saccharomyces cerevisiae imobilizada / Orientador: Renato Nallin Montagnolli / Coorientador: Ederio Dino Bidoia / Banca: Dejanira de Franceschi de Angelis / Banca: Roselena Faez / Resumo: O aumento da relação produção e consumo exigem uma maior exploração dos recursos naturais e com isso a indústria têxtil gera grandes quantidades de efluentes contendo resíduos de corantes que são descartados no ambiente. Por conseqüência gera poluição visual no corpo do rio, além de desequilíbrio na microbiota e macrobiota. A Saccharomyces cerevisiae é considerado um biocatalizador de baixo custo e não patogênico. A parede da S. cerevisiae é descrita como capaz de adsorver as moléculas de corante. Outro material com possíveis sítios de interação com o corante é a quitosana um biopolímero derivado da desacetilação da quitina de crustáceos um resíduo pesqueiro. Uma das vantagens do uso da quitosana é a possibilidade de introduzir grupos amino quaternário na cadeia do polímero que garantem aumentar a capacidade adsortiva. Esse trabalho propõe o uso da quitosana para sintetizar esferas de quitosana, quitosana com levedura e quitosana quaternária para o uso nos tratamentos adsortivos do corante têxtil Acid Blue 25. Foram feitos estudos cinéticos, isotermas, termodinâmica, comportamento reológico da matéria, FT-IR, MEV e toxicidade. Os resultados mostraram que os adsorventes respeitaram o modelo de pseudo-segunda ordem, porém pode-se constatar também a ocorrência de difusão intrapartícula nos materiais. A aplicação da esfera de quitosana quaternária produziu melhores resultados nos estudos adsortivos e se ajustou ao modelo de Freundlich em todos os pH. Os outros adsorventes de ajus... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The increased production and consumption ratio require a greater exploitation of the natural resources and thus the textile industry generates large amounts of effluents containing residues of dyes that are discarded in the environment. Consequently it generates visual pollution in the body of the river, besides imbalance in the microbiota and macrobiota. Saccharomyces cerevisiae is considered a low-cost, non-pathogenic biocatalyst. The S. cerevisiae wall is described as capable of adsorbing the dye molecules. Another material with possible sites of interaction with the dye is chitosan a biopolymer derived from the deacetylation of chitin from crustaceans a fishery residue. One of the advantages of the use of chitosan is the possibility of introducing groups of quaternary ammonium in the polymer chain that confirms to increase the adsorptive capacity. This study proposes the use of chitosan to synthesize beads of chitosan, chitosan with yeast and quaternary chitosan for use in adsorptive treatments of Acid Blue 25 dye. Kinetic studies, isotherms, thermodynamics, rheological behavior of matter, FT-IR, MEV and toxicity were performed. The results showed that the adsorbents indicated the pseudo-second order model, but also the occurrence of intraparticle diffusion in the materials. The quaternary chitosan beads obtained the best results in the adsorption studies and adjusted to the Freundlich model at all pH. The other adsorbents were adjusted in the Langmuir model in acid pH an... (Complete abstract click electronic access below) / Mestre