As an effort to gain a better understanding of the processes that enable and sustain coal bed methanogenesis in the western Powder River Basin, a steady-state groundwater flow model using MODFLOW 2005 was constructed. The model covers the middle Tongue River Watershed of north-central Wyoming and southeastern Montana and is comprised of five heterogeneous layers. The model is designed to determine the location of recharge and quantify the volume and velocity of groundwater fluxes to, from and within methanogenic coal beds. Analysis of the model's results indicate a groundwater regime dominated by horizontal flow, with little hydrologic connection between the methanogenic coal beds and the near-surface aquifers and streams. The model predicts only 3.88 cubic feet per seconds (cfs) or 2.17 percent of the total steady state flux within the modeled domain percolates downward to potentially reach the methanogenic coal beds. Most of this downward flux is predicted to occur at the base of the Bighorn Mountains. Additionally, the model predicts that the transit time to and resultant groundwater age within the methanogenic coal beds in the study area is on the order of thousands of years (predicted minimum age of 8,967 years).

No description available.

Densification of tailings slurries to mature fine tailings (MFT) is important in the oil sands industry for tailings inventory reduction, pore water recovery and tailings reclamation. The cause of methane release from the tailings pond of Shell Albian Sands (Albian) and the effects this process has on densification of Albian tailings was investigated. Citrate, added to tailings with polyacrylamide and hydrocarbon-diluent, was identified as the methanogenic substrate. Bacterial and Archaeal 16S rRNA gene sequences in Albian MFT were dominated by matches to Rhodoferax, some Clostridia and sulfate-reducing bacteria, and acetoclastic methanogens. Citrate-, diluent-, and polyacrylamide-amendments to Albian MFT did not cause a microbial shift over a 10-month laboratory incubation period. A potential pathway for microbial methane production in Albian MFT is proposed. Methane production and release from citrate-amended Albian MFT correlated to accelerated densification. Though diluent and polyacrylamide did not affect methanogenesis, they potentially affect gas bubble formation and release. / Microbiology and Biotechnology

En rapport avec la transition énergétique, d’importantes capacités de stockage énergétique sont nécessaires pour intégrer la forte variation de la production énergétique au travers des centrales éoliennes et photovoltaïques. La transformation de l’énergie électrique en énergie chimique sous forme d’hydrogène est l’une des possibles techniques. La technologie de stockage de l’hydrogène souterrain, selon laquelle l’hydrogène est stocké dans les formations souterraines semblables au stockage du gaz naturel est actuellement un axe de recherche de plusieurs états européens. Par comparaison au stockage du gaz naturel dans les formations souterraines et qui est établie depuis de nombreuses années, l'hydrogène a montré des différences significatives dans son comportement hydrodynamique et biochimique. Ces aspects ont été étudiés dans la présente thèse en utilisant différentes approches analytiques et numériques / In the context of energy revolution large quantities of storage capacity are required for the integration of strongly fluctuating energy production from wind and solar power plants. The conversion of electrical energy into chemical energy in the form of hydrogen is one of the technical possibilities. The technology of underground hydrogen storage (UHS), where hydrogen is stored in subsurface formations similar to the storage of natural gas, is currently in the exploratory focus of several European countries. Compared to the storage of natural gas in subsurface formations, which is established since many years, hydrogen shown some significant differences in its hydrodynamic and bio-chemical behavior. These aspects were investigated in the present thesis by different analytical and numerical approaches

La production croissante de déchets alimentaires dans le monde et des nouvelles réglementations internationales exigent le développement de nouveaux procédés pour le traitement de ce type de déchets. Parmi toutes les possibilités existantes, les procédés anaérobies représentent une approche durable qui permet le traitement et la valorisation de ces déchets. Ce doctorat vise à comprendre les processus biochimiques régissant la digestion anaérobie des déchets alimentaires, en fournissant des éléments pour le développement de procédés applicables à l'échelle industrielle.Dans un premier temps, un screening a été effectué pour élucider les paramètres principaux affectant la digestion anaérobie des déchets alimentaires, en évaluant différentes charges de substrat, teneurs en matière sèche, proportions de co-digestion et des inocula microbiens de différentes origines. Après avoir conclu l'importance cruciale de l'inoculum utilisé et de la charge du substrat, différentes stratégies de stabilisation des procédés de méthanisation ont été testées à l'aide de réacteurs discontinus consécutifs. Ce travail a permis de confirmer l'effet positif de la supplémentation des oligoéléments et à identifier le principal verrou: l'accumulation d'acide propionique. Dans le but de trouver une solution, deux expériences ont été axées sur l'évaluation de la capacité des matériaux conducteurs à base de carbone à résoudre ce problème. Le dosage de ces matériaux favorisait la cinétique de la digestion, améliorant significativement les productions volumétriques du méthane.Cette thèse fournit des connaissances nouvelles, à la fois sur les principaux mécanismes régissant la digestion anaérobie des déchets alimentaires et sur les implications qu'elles présentent pour la valorisation de ces déchets. En outre, des solutions possibles pour lever les verrous opérationnels ont été développés, permettant de fournir des recommandations pour l’implantation d’un procédé de digestion à l’échelle industrielle. / The increasing production of food waste worldwide and new international regulations call for the development of novel processes for the treatment of this waste. Among all the existing possibilities, anaerobic processes represent a sustainable-modern approach that allows waste treatment and valorization. This PhD thesis aims at understanding the biochemical processes governing anaerobic digestion of food waste, eventually providing a stable process applicable at industrial scale.As a first step, a screening was performed to elucidate the main parameter affecting anaerobic digestion of food waste, evaluating different substrate loads, solid contents, co-digestion proportions and microbial inocula from different origins. After concluding the critical importance of the inoculum used and the substrate load, different strategies for process stabilization for methane production were tested using consecutive batch reactors. This served for confirming the positive effect of supplementation of trace elements and to identify the main issue that was found: accumulation of propionic acid. Aiming at finding a solution, the final experiments were focused on assessing the capability of carbon-based conductive materials to solve this problem. The dosing of these materials favored the digestion kinetics, improving greatly the methane volumetric productivities.This thesis provides novel insights, both on the main mechanisms governing food waste anaerobic digestion and on the implications that they present for the valorization of this waste. In addition, potential solutions for the complications found are given, aiding to the development of a feasible industrial digestion process.

abstract: Microbial electrochemical cells (MXCs) offer an alternative to methane production in anaerobic water treatment and the recapture of energy in waste waters. MXCs use anode respiring bacteria (ARB) to oxidize organic compounds and generate electrical current. In both anaerobic digestion and MXCs, an anaerobic food web connects the metabolisms of different microorganisms, using hydrolysis, fermentation and either methanogenesis or anode respiration to break down organic compounds, convert them to acetate and hydrogen, and then convert those intermediates into either methane or current. In this dissertation, understanding and managing the interactions among fermenters, methanogens, and ARB were critical to making developments in MXCs. Deep sequencing technologies were used in order to identify key community members, understand their role in the community, and identify selective pressures that drove the structure of microbial communities. This work goes from developing ARB communities by finding and using the best partners to managing ARB communities with undesirable partners. First, the foundation of MXCs, namely the ARB they rely on, was expanded by identifying novel ARB, the genus Geoalkalibacter, and demonstrating the presence of ARB in 7 out of 13 different environmental samples. Second, a new microbial community which converted butyrate to electricity at ~70% Coulombic efficiency was assembled and demonstrated that mixed communities can be used to assemble efficient ARB communities. Third, varying the concentrations of sugars and ethanol fed to methanogenic communities showed how increasing ED concentration drove decreases in methane production and increases in both fatty acids and the propionate producing genera Bacteroides and Clostridium. Finally, methanogenic batch cultures, fed glucose and sucrose, and exposed to 0.15 – 6 g N-NH4+ L-1 showed that increased NH4+ inhibited methane production, drove fatty acid and lactate production, and enriched Lactobacillales (up to 40% abundance) above 4 g N-NH4+ L-1. Further, 4 g N-NH4+ L-1 improved Coulombic efficiencies in MXCs fed with glucose and sucrose, and showed that MXC communities, especially the biofilm, are more resilient to high NH4+ than comparable methanogenic communities. These developments offer new opportunities for MXC applications, guidance for efficient operation of MXCs, and insights into fermentative microbial communities. / Dissertation/Thesis / Doctoral Dissertation Biological Design 2015

CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior / O presente estudo teve o objetivo de avaliar o uso de reatores biolÃgicos, sob condiÃÃes anaerÃbias e microaerÃbias, como opÃÃo de biorremediaÃÃo ex situ de Ãguas contaminadas com BTEX. Inicialmente, foi desenvolvido, otimizado e validado um mÃtodo analÃtico para a detecÃÃo e quantificaÃÃo de BTEX em Ãguas e efluentes, o qual consistia em extraÃÃo por headspace seguida de cromatografia gasosa com detecÃÃo por fotoionizaÃÃo. Posteriormente, foram conduzidos experimentos em fluxo contÃnuo em dois reatores anaerÃbios mesofÃlicos (27 ÂC) â um deles operado sob condiÃÃes metanogÃnicas e, em seguida, sob condiÃÃes microaerÃbias, e o outro, apenas sob condiÃÃes sulfetogÃnicas â a fim de verificar a melhor condiÃÃo operacional para a remoÃÃo de BTEX. Os reatores foram alimentados com Ãgua contaminada com BTEX (~3 mgÂL-1 de cada composto) e etanol (co-substrato), e, dependendo da condiÃÃo redox avaliada, investigou-se o efeito de diferentes parÃmetros operacionais, tais como tempo de detenÃÃo hidrÃulica (24, 36 e 48 h), recirculaÃÃo de efluente, concentraÃÃo de co-substrato, relaÃÃo DQO/SO4 2- e microaeraÃÃo, no desempenho de remoÃÃo de BTEX. AlÃm disso, o reator metanogÃnico sob condiÃÃes microaerÃbias foi submetido a simulaÃÃes de choques de carga e de ausÃncia desses compostos, e de falhas operacionais, como desligamento do sistema e desligamento da microaeraÃÃo, para verificaÃÃo de sua robustez. Sob condiÃÃes metanogÃnicas, dependendo do composto, as eficiÃncias de remoÃÃo variaram de 38 a 97%. PorÃm, o aumento da carga aplicada de BTEX, em consequÃncia da reduÃÃo do tempo de detenÃÃo hidrÃulica de 48 para 24 h, parece ter afetado negativamente o processo de remoÃÃo. Ainda sob condiÃÃes metanogÃnicas, tambÃm se verificou o efeito da recirculaÃÃo de efluente na remoÃÃo de BTEX para altas e baixas concentraÃÃes de co-substrato (etanol). Quando altas concentraÃÃes de etanol foram utilizadas, o impacto da recirculaÃÃo de efluente nÃo foi evidente, jà que, provavelmente, a elevada produÃÃo de biogÃs teria sido suficiente para garantir uma transferÃncia de massa efetiva. Sob condiÃÃes sulfetogÃnicas, a adiÃÃo de sulfato em diversas relaÃÃes DQO/SO4 2- nÃo alterou a remoÃÃo de BTEX, sugerindo que as bactÃrias redutoras de sulfato nÃo estariam diretamente relacionadas à ativaÃÃo inicial dos compostos aromÃticos. Sob condiÃÃes microaerÃbias, elevadas eficiÃncias de remoÃÃo de BTEX foram alcanÃadas (> 90%). à provÃvel que a adiÃÃo de baixas concentraÃÃes de oxigÃnio tenha facilitado a ativaÃÃo inicial dos compostos BTEX, a qual à considerada a etapa limitante do processo de degradaÃÃo anaerÃbia, principalmente para o benzeno. Ainda, constatou-se que a presenÃa de altas concentraÃÃes de etanol afetou negativamente a remoÃÃo de BTEX, notadamente para o benzeno, sob as diferentes condiÃÃes redox testadas, jà que à um substrato preferencialmente degradÃvel em relaÃÃo aos compostos aromÃticos. Finalmente, com relaÃÃo à robustez do reator metanogÃnico sob condiÃÃes microaerÃbias, o sistema conseguiu lidar com os choques de carga de BTEX embora choques consecutivos tenham aumentado seu tempo de recuperaÃÃo. O perÃodo de ausÃncia de BTEX parece ter prejudicado a microbiota do reator, pois a qualidade do efluente deteriorou-se consideravelmente apÃs reintroduÃÃo dos compostos. O desligamento da microaeraÃÃo impactou negativamente a remoÃÃo de BTEX, mas o sistema recuperou-se rapidamente apÃs restabelecimento das condiÃÃes microaerÃbias. / The present study aimed to evaluate the use of biological reactors under anaerobic and microaerobic conditions, as an option of ex situ bioremediation of BTEX-contaminated waters. Initially, an analytical method for BTEX detection and quantification in waters and wastewaters, which consisted of headspace extraction followed by gas chromatography with detection by photoionization, was developed, optimized and validated. Subsequently, continuous-flow experiments were conducted in two mesophilic (27 ÂC) anaerobic reactors â one of them operated under methanogenic conditions and, afterwards, under microaerobic conditions, and the other one only under sulfidogenic conditions â a in order to determine the best operational condition for BTEX removal. The reactors were fed with water contaminated with BTEX (~3 mgÂL-1 of each compound) and ethanol (co-substrate), and, depending on the redox condition evaluated, the effect of some operational parameters, such as hydraulic retention time (24, 36 and 48 h), effluent recirculation, co-substrate concentration, DQO/SO4 2- ratio and microaeration, was investigated in BTEX removal performance. Furthermore, the methanogenic reactor under microaerobic conditions was submitted to simulated situations of shock loading and absence of these compounds, and operational failures, such as system and microaeration shutdown to assess its robustness. Under methanogenic conditions, depending on the compound, removal efficiencies ranged from 38 to 97%. However, the increase of applied BTEX load, as a consequence of hydraulic detention time reduction from 48 to 24 h, seems to have adversely affected the removal process. Moreover, under methanogenic conditions, the effluent recirculation effect on BTEX removal was also assessed when high and low co-substrate (ethanol) concentrations were applied. For high ethanol concentrations, the impact of effluent recirculation was not evident since, probably, the high biogas production would have been sufficient to ensure effective mass transfer. Under sulfidogenic conditions, sulfate addition at different DQO/SO4 2- ratios did not change BTEX removal, which suggests sulfate-reducing bacteria would not be directly related to initial activation of aromatic compounds. Under microaerobic conditions, high BTEX removal efficiencies were achieved (> 90%). It is likely the addition of low oxygen concentrations has facilitated the initial activation of BTEX compounds, which is considered the limiting step of the anaerobic degradation process, mainly for benzene. Furthermore, the presence of high ethanol concentrations negatively affected BTEX removal, particularly for benzene, under the different redox conditions tested, since it is a preferentially degradable substrate when compared to the aromatic compounds. Finally, regarding the methanogenic reactor robustness under microaerobic conditions, the system could cope with BTEX load shocks although consecutive shocks have increased its recovery time. The period of BTEX absence seems to have negatively affected the reactor microbiota because the effluent quality deteriorated considerably after compounds reintroduction. The microaeration shutdown also negatively impacted the removal of BTEX, but the system recovered quickly after microaerobic conditions reestablishment.

O sedimento marinho da Península Antártica representa uma área sensível a mudanças ambientais. No entanto, pouco se conhece sobre as comunidades microbianas que habitam esse ecossistema, incluindo a sua diversidade, distribuição e variações temporais. O objetivo foi determinar a estrutura das comunidades microbianas nos sedimentos marinhos da Baía do Almirantado, Ilha Rei George, Península Antártica. Sedimentos da Baía apresentam uma predominância dos Filos Proteobacteria, Firmicutes e Actinobacteria. Análise temporal revelou que comunidades microbianas em sedimentos próximos à estação Ferraz são mais estáveis quando comparadas aos sedimentos em áreas de menor atividade antrópica. No gradiente de profundidade foi observado que a estrutura de comunidade não mudou, indicando tolerância a variações de pressão hidrostática. Organismos heterotróficos dos gêneros Psychrobacter, Psychromonas e Loktanella foram os mais abundantes, sugerindo uma alta concentração de matéria orgânica disponível. O enriquecimento de culturas metanogênicas produziu até 1,70 mmol de CH4 após 120 dias de incubação. Este estudo sugere que as condições dos sedimentos favorecem organismos psicrofílicos de metabolismo heterotrófico. / Marine sediment of the Antarctic Peninsula is a susceptible area to environmental changes. However, little is known about the microbial communities inhabiting this ecosystem, including its diversity, distribution and variations over time. The aim of this study was to determine the structure of microbial communities present in marine sediments of Admiralty Bay, King George Island, on the Antarctic Peninsula. Sediments from Admiralty Bay shown a predominance of the Proteobacteria, Firmicutes, and Actinobacteria phyla. Temporal analysis revealed that microbial communities in sediment, near Ferraz station, are more stable compared to that in the sediments in areas of lower human activity. No variation on the community structure was observed in depth gradient, indicating tolerance to hydrostatic pressure variations. Heterotrophic organisms of the genera Psychrobacter, Psychromonas and Loktanella were the most abundant, suggesting a high concentration of organic matter in the sediment. Enrichment of methanogenic cultures enrichment yielded 1.70 mmol of CH4. This study suggests that conditions in sediments favoring metabolism of heterotrophic and psychrophilic organisms.

O objetivo do presente estudo foi identificar entre 10 óleos essenciais, os dois com maior capacidade mitigadora das emissões de metano proveniente da fermentação in vitro da microbiota ruminal de bovinos da raça Nelore (Etapa I), e o subsequente impacto da adoção destes dois óleos essenciais como estratégia nutricional para mitigação das emissões de metano in vivo por bovinos Nelore (Etapa II). Na primeira etapa, pela técnica de produção de gases in vitro foram avaliados a produção de gases acumulada, a degradabilidade, o fator de partição, a concentração de nitrogênio amoniacal, a produção de ácidos graxos de cadeia curta e a produção de metano com o uso dos óleos essenciais extraídos das seguintes plantas: anis estrelado (Illicium verum), citronela (Cymbopogon winterianus), cravo botão (Eugenia caryophyllus), eucalipto staigeriana (Eucalyptus staigeriana), eucalipto globulus (Eucalyptus globulus), gengibre (Zingiber officinale), ho wood (Cinnamomum camphora), melaleuca (Melaleuca alternifolia), orégano (Origanum vulgare) e tomilho branco (Thymus vulgaris). Todos os óleos essenciais foram testados em quatro doses; 0, 50, 250 e 500 mg/l de meio de incubação. O delineamento experimental foi em blocos casualizados, com quatro blocos, 10 tratamentos, quatro doses e duas réplicas dentro de cada bloco. Os procedimentos estatísticos foram obtidos com auxílio do programa SAS 9.3. Os resultados foram submetidos a análise de variância e regressão, com graus de liberdade desdobrados em efeitos linear e quadrático. A produção de gases acumulada sofreu efeito linear negativo (P<0,05) com o aumento dos níveis de inclusão dos óleos essenciais de citronela, ho wood, orégano e tomilho. A degradabilidade do substrato, a produção total de ácidos graxos de cadeia curta e a concentração de nitrogênio amoniacal não foram afetadas (P>0,05) por nenhum dos tratamentos. As menores produções líquidas de metano estiveram associadas às menores produções acumuladas de gases, nas quais os óleos essenciais de orégano e de tomilho tiveram maior poder mitigador de metano em doses acima de 250 mg/l. Esses mesmos óleos essenciais (tomilho e orégano) mostraram ser os mais promissores para o uso em dietas de bovinos por apresentarem as maiores eficiências na mitigação da produção de metano sem afetar a degradação do substrato, sugerindo provável efeito inibitório sobre a população de arqueias metanogênicas. Na etapa II, os óleos essenciais de orégano e de tomilho foram avaliados através de um delineamento experimental em quadrados latinos 3x3 replicados com três períodos de 21 dias cada, no qual seis bovinos da raça Nelore foram alimentados com dieta total composta de 70% silagem de milho e 30% concentrado a base de milho e farelo de soja. Os óleos essenciais foram inclusos na dieta na quantidade de 3 ml por kg de concentrado. Foram mensurados o consumo, a digestibilidade aparente total (da MS, da FDN e da FDA), os parâmetros ruminais (pH, concentração de nitrogênio amoniacal e de ácidos graxos de cadeia curta) e a emissão de metano (através da técnica do gás traçador SF6). As análises estatísticas foram realizadas com auxílio do programa SAS 9.3, utilizando o procedimento MIXED. O efeito de tratamento foi separado pelo teste de Tukey a 5% de probabilidade. A inclusão dos óleos essenciais de orégano ou de tomilho na dosagem avaliada in vivo, não foi suficiente para promover mudanças significativas (P>0,05) em nenhum dos parâmetros avaliados. / The objective of this study was to identify two out of 10 essential oils with the greatest capacity to mitigate methane emissions through an in vitro fermentation assay using ruminal microorganisms of Nellore cattle (Step I), and the subsequent impact of the use of these two essential oils as a nutritional strategy to mitigate methane emissions in vivo trial with Nellore cattle (Step II). In the step 1, it was evaluated through in vitro gas production technique the accumulated gas production, degradability, partitioning factor, ammoniacal nitrogen concentration, short chain fatty acid production and methane production, with the use of essential oils extracted from the following plants: anise (Illicium verum), citronella (Cymbopogon winterianus), clove (Eugenia caryophyllus), eucalyptus staigeriana (Eucalyptus staigeriana), eucalyptus globulus (Eucalytus globulus), ginger (Zingiber officinale), melaleuca (Melaleuca alternifolia), oregano (Origanum vulgare) and white thyme (Thymus vulgaris). All essential oils were tested in four doses; 0, 50, 250 and 500 mg / l of incubation solution. The experimental design was in randomized blocks, with four blocks, 10 treatments, four doses and two replicates within each block. The statistical procedures were done with the help of the SAS 9.3 program. The results were analyzed by analysis of variance and regression, with degrees of freedom unfolded in linear and quadratic. Accumulated gas production had a linear negative effect (P <0.05) with increasing the inclusion level of the essential oils of citronella, ho wood, oregano and thyme. Substrate degradability, total short chain fatty acid production and ammoniacal nitrogen concentration were not affected (P> 0.05) by treatments. The lower liquid methane yields were associated with lower accumulated gas production, in which oregano and thyme essential oils were the more potent at doses greater than 250 mg / l. These essential oils (thyme and oregano) were the most promising for use in cattle diets because they were the most effective for methane mitigation without affecting substrate degradation, suggesting a probable inhibitory effect on the methanogenic arqueas. In step II, the essential oils of oregano and thyme were evaluated through an experimental design in replicate 3x3 Latin squares with three periods of 21 days each, in which six Nellore cattle were distributed in the control, oregano oil and thyme oil treatments, were fed a total diet composed of 70% corn silage and 30% of concentrate based on ground corn and soybean meal. The essential oils were included in the diet 3 ml per kg of concentrate. Intake, total apparent digestibility (DM, NDF and ADF), ruminal parameters (pH, concentration of ammoniacal nitrogen and short chain fatty acids) and methane emission (through SF6 tracer gas) were measured. The inclusion of the essential oils of oregano or thyme in the dosage evaluated was not sufficient to promote significant changes (P> 0.05) in any of the outcomes evaluated.

O Brasil é o segundo maior produtor de etanol do mundo. Na safra 2015/16, foram produzidos 30,4 bilhões de litros. Na produção de etanol realizada no Brasil é gerado grande volume de vinhaça, cerca de 10 a 13 litros desse resíduo por litro de etanol produzido. Isso significa uma produção anual de cerca de 300 bilhões de litros desse material residual. Em função disso e do risco de contaminação ambiental por esse material, há necessidade de reduzir o volume desse resíduo. Com isso minimizar o custo com a gestão desse passivo ambiental. Isso pode ser feito mediante a concentração da vinhaça. Além disso, o mercado de energia elétrica tem se apresentado com uma boa oportunidade para o setor sucroenergético. Por esses motivos, o objetivo deste projeto foi a produção de metano a partir do uso de vinhaça concentrada. Para tal, a vinhaça concentrada foi obtida em uma usina no Estado de São Paulo que utiliza concentrador de vinhaça de múltiplos efeitos. Utilizaram-se dois reatores (R1 e R2) do tipo UASB (reator anaeróbio de fluxo ascendente e manta de lodo) com capacidade para 50 L e volume reacional de 34,5 L cada. Os reatores foram operados à 38 ºC, com tempo de detenção hidráulica de 24 horas por 103 dias. O reator R1 recebeu cargas orgânicas volumétricas (COV) crescentes durante 9 fases (3,94; 3,5; 3,89; 4,66; 4,94; 5,33; 5,66; 6,08; 6,38 e 8,96 g DQO (L d)-1), com DQO afluente variando de 23.927 mg L-1 a 44.060 mgL-1. O reator R2 operou como tratamento controle, com COV variando entre 3,83 e 4,32 g DQO (L d)-1. A avaliação do processo de biodigestão anaeróbia foi realizada com base na produção de biogás, eficiência de remoção de DQO, pH, alcalinidade, concentração de ácidos voláteis totais (AVT), concentração de sólidos no lodo e atividade metanogênicas específica do lodo (AME). R1 mostrou-se mais eficiente, com pH e alcalinidade dentro da faixa ideal e efluente com menor concentração de AVT. O desempenho do processo mostrouse estável, atingindo eficiência máxima de remoção de DQO de 90% em R1. A maior produção volumétrica de biogás ocorreu concomitantemente com a maior produção específica de biogás, quando a DQO afluente foi de 42.003 mg L-1, a produção volumétrica de biogás foi de 135,24 L dia-1, e a produção de biogás em relação a DQO removida foi de 0,362 LbiogásgDQOremov-1. No fim do experimento, a AME de R1 foi de 1,19 gDQOCH4 gSTV.d-1, 40% superior a R2, que teve 0,85 gDQOCH4 gSTV.d-1. A alta eficiência de remoção de matéria orgânica e produção de biogás no reator alimentado com alta concentração de DQO foi obtida através da adaptação gradual do consórcio microbiano. / Brazil is the second largest producer of ethanol in the world. In the 2015/16 crop, 30.4 billion liters were produced. In Brazil\'s ethanol production, a large volume of vinasse is generated, about 10 to 13 liters of this residue per liter of ethanol produced. This means an annual output of about 300 billion liters of this waste material. Because of this and the risk of environmental contamination by this material, there is a need to reduce the volume of this waste. This will minimize the cost of managing this environmental liability. This can be done by concentrating the vinasse. In addition, the electricity market has presented itself with a good opportunity for the sugar-energy sector. For these reasons, the objective of this study was to produce methane from concentrated vinasse. For this purpose, concentrated vinasse was obtained from a mill that uses a multi-purpose vinasse concentrator in São Paulo State. Two reactors (R1 and R2) of UASB type (up-flow anaerobic sludge blanket) with capacity for 50 L and reactional volume of 34.5 L each one. The reactors were operated at 38 °C, with hydraulic retention time of 24 hours for 103 days. The reactor R1 received increasing organic load rate (OLR) during 9 phases (3.94, 3.5, 3.89, 4.66, 4.94, 5.33, 5.66, 6.08, 6.38 And 8.96 g COD (L d)-1), with affluent COD ranging from 23,927 mg L-1 to 44,060 mg L-1. The R2 reactor was operated as a control treatment, with OLR ranging from 3.83 to 4.32 g COD (L d)-1. The evaluation of the anaerobic biodigestion process was carried out based on biogas production, COD removal efficiency, pH, alkalinity, total volatile acid concentration (TVA), sludge solids concentration and sludge specific methanogenic activity (SMA). R1 showed to be more efficient, with pH and alkalinity within the ideal range and effluent with lower concentration of TVA. The process performance was stable, achieving maximum COD removal efficiency of 90% in R1. The higher volume of biogas production occurred concurrently with the higher specific biogas production, when the COD was 42.003 mg L-1, the volumetric biogas production was 135.24 L day-1, and the biogas production in relation to removed COD was 0.362 Lbiogas gCODremoved -1. At the end of the experiment, the SMA of R1 was 1.19 gCODCH4 gTVS.day-1, 40% higher than R2, which had 0.85 gCODCH4 gTVS.day-1. The high efficiency of organic matter removal and biogas production in the reactor fed with high COD concentration was obtained through the gradual adaptation of the microbial consortium.