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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Efeito da carga orgânica volumétrica sobre a produção de biogás utilizando-se dejeto de suíno em diferentes configurações de reatores anaeróbios / Effect of organic loading rate on the biogas yield swine manure in different anaerobic reactors configurations

Lins, Marcos Araújo 13 July 2017 (has links)
Submitted by Neusa Fagundes (neusa.fagundes@unioeste.br) on 2018-02-09T18:33:17Z No. of bitstreams: 2 Marcos_Lins2017.pdf: 1306769 bytes, checksum: e562bcb30c504f3ac5e0a7e12446e473 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-02-09T18:33:17Z (GMT). No. of bitstreams: 2 Marcos_Lins2017.pdf: 1306769 bytes, checksum: e562bcb30c504f3ac5e0a7e12446e473 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-07-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The use of anaerobic reactors with energetic purposes is an effective decision-making to treat swine farming wastewater. But, the applied organic loading rate (OLR)must be correct, since itvaries according to the reactor configuration and other process conduction conditions, such as temperature. Thus, this trial aimed at showing the effect of OLR progression on biogas generation and quality of swine manure in anaerobic reactors as continuous stirred tank reactor (CSTR), covered lagoon digester (CLD) and upflow anaerobic sludge blanket (UASB).The experiment with CSTR reactor of 17-L useful volume, semicontinuously fed at 37 ± 1 °C, was divided into three phases. In the first phase, a constant OLR was applied with 1.0 g VS add L-1reactor d-1 until biogas productivity was stable. This occurred after the fortieth day of operation. In phase II, the OLR progressions had begun, starting with 2.0 g VS add. L-1reactor d-1 and after stabilizing biogas production rate, OLR was increased to 3.0 g VS add. L-1 reactor d-1. In phase III, OLR answers were 1.0, 1.9 and 0.7 g Vs add. L-1reactor d-1 and submitted in this order, according to the hydraulic retention time (HRT) in order to identify the relation among these variables. In the trial with CLD of 17-L useful volume, and semicontinuously fed, OLR answers were 0.3, 0.4 and 0.5 g VSadd. L-1reactor d-1, respectively. The experiment with theUASB reactor of 6.6-L useful volume, continuously fed at 37 ± 1 °C, was divided into two phases. In phase I, OLR answers were:1.5, 2.0, 2.5 and 3.0 g VSadd L-1reactor d-1. In phase II, OLR answers were 0.5, 0.7, 1.0, 1.4, 1.6, 2.2, 2.9 and 8.4 g VS add. L-1reactor d-1.For CSTR reactor, the best results of methane content and biogas production rate was in OLR 1.9 g VS add. L-1reactor d-1 and HRT of 15 days, with 53 ± 10% (v v-1) and 0.7 ± 0.1 LNbiogas L-1reactord-1, respectively. In the experiment with CLD reactor, the best results of methane content and biogas production rate was in OLR 0.5 g VS add L-1reactor d-1 and HRT of 34 days, with 61 ± 5% (v v-1) and 0.3 ± 0.1 LN biogas L-1reactor d-1, respectively. For the UASB reactor, the best result of methane content and biogas production rate was in OLR 2.9 g VS add. L-1reactor d-1 and HRT of 1.5 days, with 74 ± 1% (v v-1) and 1.6 ± 0,5 LN biogas L-1reactor d-1, respectively. This research aimed at understanding the effect of OLR progression on the biogas production rate up from DS, establishing a relation among other variables that affect this biofuel production, contributing with important information to choose the most available reactor configuration to be settled in a full scale. / O uso de reatores anaeróbios com finalidades energéticas é uma forma eficiente para o tratamento de efluentes da suinocultura, desde que seja aplicada a correta carga orgânica volumétrica (COV), que varia de acordo com a configuração do reator e demais condições de condução do processo, tais como a temperatura. Assim, o objetivo deste trabalho é demonstrar o efeito de progressão da COV sobre a geração e qualidade do biogás a partir de dejetos de suínos em reatores anaeróbios do tipo:Continuous stirred tank reactor (CSTR), biodigestor de lagoa coberta (BLC) e Upflow anaerobic sludge blanket (UASB). O experimento com o reator CSTR de 17 L de volume útil, alimentado de forma semicontínua a 37 ± 1°C foi dividido em três fases. Na fase I, foi submetida COV constante de 1,0 g SV adic L-1 reator d-1 até estabilização da produção de biogás, que ocorreu a partir do quadragésimo dia de operação. Na fase II, iniciaram-se as progressões de COV, começando com 2,0 g SV adic. L-1reator d-1 e após estabilização da produtividade de biogás, a COV foi elevada para 3,0 g SV adic. L-1 reator d-1. Na fase III, as COV 1,0, 1,9 e 0,7 g SV adic. L-1reator d-1, submetidas nesta ordem, foram controladas pelo tempo de retenção de hidráulica (TRH), com o objetivo de identificar a relação entre essas variáveis. No experimento com o BLC de 17 L de volume útil, alimentado de forma semicontínua, foram submetidas as COV 0,3, 0,4 e 0,5 g SV adic L-1 reator d-1, respectivamente. O experimento com o reator UASB de 6,6 L de volume útil, alimentado de forma contínua a 37 ± 1°C, foi dividido em duas fases. Na fase I,foram submetidas as COV: 1,5, 2,0, 2,5 e 3,0 g SV adic L-1 reator d-1. Na fase II, foram submetidas as COV: 0,5, 0,7, 1,0, 1,4, 1,6, 2,2, 2,9 e 8,4 g SV adic L-1 reator d-1. Para reator CSTR, os melhores resultados de teor de metano e produtividade de biogás foram na COV de 1,9 g SV adic L-1 reator d-1 e TRH de 15 dias, com 53 ± 10% (v v-1) e 0,7 ± 0,1 LN biogás L-1 reator d-1, respectivamente. No experimento com o BLC, os melhores resultados de teor de metano e produtividade de biogás foram na COV 0,5 g SV adic L-1 reator d-1 e TRH de 34 dias, com 61 ± 5% (v v-1) e 0,3 ± 0,1 LN biogás L-1reator d-1, respectivamente. Para reator UASB, os melhores resultados de teor de metano e produtividade de biogás foram na COV 2,9 g sv adic L-1 reator d-1 e TRH de 1,5 dias, com 74 ± 1% (v v-1) e 1,6 ± 0,5 LN biogásL-1reator d-1, respectivamente. Esta pesquisa possibilitou compreender o efeito da progressão de COV sobre a produção de biogás a partir de DS, estabelecer relação com outras variáveis que afetam a produção deste biocombustível e contribuir com informações importantes para a escolha da configuração de reator, mais adequada para a implantação em escala real.
22

Influence de différents facteurs opérationnels sur la structure des communautés microbiennes impliquées dans le processus de digestion anaérobie / Influence of shifts in various operational parameters on the structure of the microbial communities involved in the anaerobic digestion process

Goux, Xavier 18 December 2015 (has links)
Le processus de digestion anaérobie conduit à la production de biométhane, un vecteur flexible d’énergie renouvelable. L’amélioration du rendement de ce processus est souvent évoquée comme dépendante de la compréhension approfondie de la structure et de la dynamique des communautés microbiennes qui y sont impliquées. L’objectif de la thèse a été de caractériser les communautés microbiennes impliquées dans le processus de digestion anaérobie et de déterminer l’influence de facteurs opérationnels sur leurs dynamiques. Nous nous sommes en particulier intéressés à l’augmentation du taux de charge organique, le type de digesteurs anaérobies (réacteur continu perpétuellement mélangé vs réacteur anaérobie à chicane), mais aussi à la phase de démarrage d’un digesteur de ferme avec une montée en température. En absence de conditions contraignantes, nous avons observé l’installation de populations méthanogènes les mieux adaptées à la production de biogaz dans les réacteurs étudiés et la mise en place de communautés microbiennes similaires entre réacteurs réplicats. Cependant, des changements au niveau opérationnel ont conduit au développement de communautés divergentes en termes de structure. En effet, en présence d’un environnement déterministe, la plupart des bactéries et archées impliquées en digestion anaérobie ont montré une redondance fonctionnelle à la perturbation. Toutefois, certaines populations bactériennes dominantes ont également pu montrer des phénomènes de résistance, en termes de présence et d’abondance, à l’évolution des conditions environnementales. Au cours de nos études, les différentes communautés s’installant dans les digesteurs étudiés ont également montré des aptitudes variables pour la production de biogaz. De plus, des corrélations entre les communautés bactériennes, archées et eucaryotes ont aussi été démontrées, soulignant le rôle non négligeable des eucaryotes dans le processus de digestion anaérobie et l’installation de communautés microbiennes dominantes et spécifiques à la production de biogaz. Ainsi, les changements au sein de la communauté microbienne résultant de la modification progressive de facteurs opérationnels, et ce bien avant l’apparition des premiers symptômes d’inhibition de la production de biogaz, pourraient permettre le développement d’indicateurs microbiens de l’état du processus de digestion anaérobie et donc la mise en place d’une gestion microbiologique raisonnée des digesteurs anaérobies / The anaerobic digestion process leads to the production of biomethane, a versatile renewable energy vector. The dynamics and interactions between specific microbial groups are currently considered as key research subjects towards the improvement of the anaerobic digestion (AD) process. Indeed, deeper knowledge of the ecology of AD, the dynamics of the microbial populations and their structure could provide valuable information regarding unexplained and unpredictable failures or malfunctioning of the anaerobic digestion process. The aim of this work was to characterize the microbial communities involved in the AD process, and to study their responses due to the change of operational parameters such as an increase of the organic loading rate, the reactor type (completely stirred tank reactor vs anaerobic baffled reactor), or the start-up phase of a farm reactor with a shift from psychrophilic to mesophilic temperature range. While we observed the installation of similar microbial populations between replicated reactors under stable conditions, best adapted to biogas production, the microbial communities started to diverge once the operational parameters changed. Indeed, due to deterministic environment, most of bacteria and archaea showed redundant functional adaptation to the changing environmental conditions. However, some dominant bacterial populations were also resistant in terms of presence and abundance to the environmental change. The specific microbial communities established in our studied reactors showed also discrepancies in terms of biogas yields. Furthermore, correlations between the bacterial, archaeal and eukaryotic communities were pointed out, indicating the putative influence of eukaryotes on the anaerobic digestion process and the establishment of the other microbes having crucial functions during the anaerobic biomass digestion. Interestingly, shifts inside the anaerobic microbial community due to the gradual change of operational parameters, were detected prior to any biogas production inhibition, giving the opportunity for the development of potential early microbial indicators for assessing the AD process status and improving the microbial management of anaerobic reactors
23

Sustainability assessment of potential wastewater treatment techniques in Tupiza, Bolivia / Hållbarhetsanalys av potentiella lösningar för avloppsrening i Tupiza, Bolivia

Burström, Johanna January 2020 (has links)
Aiming for sustainable sanitation systems can provide benefits among a vast range of Sustainable Development Goals. In this study the sustainability of potential options for renovating or upgrading thewastewater treatment plant in Tupiza, a rapidly growing city in theSouthern highlands of Bolivia, was evaluated. The local context was characterized by increasing issues of flooding which in recent years has destroyed important wastewater treatment infrastructure and polluted sources of water for several downstream communities. Three system options consisting of different treatment technologies were evaluated against four criteria of sustainability; health,technical, environmental and financial and institutional. A "conventional" option consisting of waste stabilization ponds was compared against two more options with added steps of treatment, such as constructed wetlands, anaerobic reactors and alkaline and ammonia treatment of sludge. Social acceptance and demand of reuse of treated wastewater and sludge in agriculture was evaluated using qualitative research analysis. Results indicate that the systems with added treatment steps could help improve several areas of sustainability such as risks of disease transmission, space efficiency, treatment capacity and efficiency as well as enable safe reuse of sludge and wastewater in agriculture. Implementation of funding mechanisms covering the entire sanitation service chain as well as flood mitigation measures resulted essential in ensuring the long-term functionality of such improvements. This project was intended as a pre-study and identified several areas of future research including additional evaluation of nutrient content in effluent, investigation of a possible certification process for recycled byproducts from the wastewater treatment plant, risk assessment of floods of different magnitudes, evaluation of the long-term economic impact of having improved systems and evaluationof local institutional capacity surrounding the sanitation service chain in Tupiza. / Hållbara sanitetssystem för med sig många fördelar som kan främja majoriteten av de globala hållbarhetsmålen. I denna studie utreds hållbarheten i potentiella alternativ för renovering eller uppgradering av ett avloppsreningsverk i Tupiza, en snabbt växande stad i södra Bolivias högland. Den lokala kontexten präglades av en tilltagande översvämmningsproblematik som de senaste åren bidragit till förstörelse av central infrastruktur for avloppsvattenrening samt påföljande vattenföroreningar i samhällen nedströms reningsverket. Tre systemalternativ beståendes av olika reningstekniker utreddes utefter fyra hållbarhetskategorier; hälsa, teknologi, miljö samt finansiell/institutionell. Ett konventionellt alternativ som utgjordes av stabiliseringsdammar jämfördes mot två mer avancerade alternativ med ytterligare reningssteg såsom anlagd våtmark, anaerobiska reaktorer samt alkali- och ammoniakbehandling av slam. Social acceptans och efterfrågan för återanvändning av behandlat avloppsvatten och slam inom lantbruket utreddes i en kvalitativ forskningsstudie. Resultaten tyder på att system med fler reningssteg kan främja flera hållbarhetsområden såsom risk för överföring av sjukdomar, yteffektivitet, reningskapacitet och effektivitet samt möjliggöra säkert återanvändande av slam och avloppsvatten i jordbruket. Implementering av mekanismer för finansiering som täcker hela sanitetskedjan samt åtgärder mor översvämningar visade sig vara centrala för att säkerställa långsiktig funktion av sådana förbättringar. \\\\Det här projektet var menat som en förstudie och identifierade flertalet områden för vidare forskning såsom ytterligare utvärdering av näringsinnehåll i utgående vatten, utredning av möjlig certifieringsprocess för återvunna produkter från avloppsreningsverket, analys av översvämningsrisker av olika magnituder, utvärdering av den indirekta ekonomiska effekten av att ha system med fler reningssteg samt utvärdering av lokal institutionell kapacitet för hela servicekedjan för sanitet i Tupiza. / En este estudio se evaluó la sostenibilidad de opciones potenciales para renovar o mejorar la planta de tratamiento de aguas residuales de Tupiza, una ciudad de rápido crecimiento en las tierras altas del sur de Bolivia. En los últimos años, el contexto local se ha caracterizado por la ocurrencia de lluvias de mayor intensidad. Estas ocasionaron inundaciones que en efecto causaron daños importantes en la infraestructura de la planta de tratamiento de aguas residuales (PTAR). El deterioro de la infraestructura provocó el derrame de aguas residuales al río y la contaminación del agua en las comunidades ubicadas en la cuenca baja. Trés opciones de sistemas de tecnologías de tratamiento de aguas residuales para la renovación y/o mejoro de la planta de Tupiza fueron evaluadas considerando cuatro criterios de sostenibilidad: Salud, tecnolgía, ambiental y financiera/institucional. Por otra parte la aceptación social y demanda de reúso de aguas residuales y lodos tratados en la agricultura se evaluaron mediante un análisis de investigación cualitativa. La opción convencional que consiste en estanques de estabilización de desechos, se comparó con dos otras alternativas que incluyen pasos adicionales de tratamiento, como son humedales artificiales, reactores anaeróbicos y tratamiento de lodos con urea y cal. Los resultados indican que los sistemas de pasos adicionales de tratamiento podrían ayudar a mejorar diferentes aspectos de sostenibilidad, como los riesgos de transmisión de enfermedades, la eficiencia espacial,  la capacidad y eficiencia de tratamiento y la posibilidad de reutilización segura de lodos y aguas residuales en la agricultura. La implementación de mecanismos de financiación que cubren toda la cadena de servicios de saneamiento, así como las medidas de mitigacióin de inundaciones se mostraron esenciales para garantizar la funcionalidad a largo plazo de tales mejoras. La tesis es un estudio preliminar e identificó varias áreas de investigación futuras, la evaluación adicional del contenido de nutrientes en el efluente, la investigación de un posible proceso de certificación de subproductos reciclados de la PTAR, la evaluación de riesgos de inundaciones de diferentes magnitudes, la evaluación del impacto económico a largo plazo de la implementación de sistemas con pasos adicionales de tratamiento y la evaluación  de capacidad institucional local a lo largo de la cadena de servicios de sanemiento.

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