Fossas e tanques sépticos são sistemas de pequeno porte utilizados para tratamento parcial do esgoto sanitário produzido nas áreas urbana e rural, quando não beneficiados por sistema de esgotamento sanitário. Tal utilização se justifica principalmente por ser tecnologia que não exige muita dedicação operacional e ser de simples implantação. Apesar da vasta utilização dessas unidades no Brasil, há pouca informação sobre a caracterização, as condições de coleta, transporte, tratamento e destino final de resíduo (lodo) produzido nesses sistemas. Nesse sentido, o presente trabalho tem como objetivo a caracterização do lodo produzido nessas unidades; e, também, a concepção, o desenvolvimento e a avaliação de uma unidade piloto para pré-tratamento de lodo de fossas e tanques sépticos. Essa unidade, constituída por grade, desarenador e flotador, foi instalada no Campus da Universidade de São Paulo, junto da Estação de Tratamento de Esgoto do Campus - área 1, e vista à remoção de sólidos grosseiros, areia e materiais flutuantes, antes de seu lançamento na Estação de Tratamento de Esgoto do Campus. Foi feita a caracterização do lodo de tanques sépticos coletado in situ e do lodo proveniente dos caminhões limpa-fossas, descarregando em tanque pulmão de 15000 litros. A caracterização do lodo proveniente dos caminhões limpa-fossas foi realizada em duas campanhas (coletas), sendo uma feita na primeira visita ao local pré-definido, e outra realizada aproximadamente seis meses após a primeira coleta. Com intuito de aprimorar o método de análise das amostras do lodo in situ, com finalidade de melhor fragmentar o material particulado, foi testado o uso de ultrassom. Também, foi realizada a caracterização do lodo de fossas e tanques sépticos na Central de Recebimento de Resíduos na cidade de Campinas-SP - SANASA - Sociedade de Abastecimento de Água e Saneamento AS. Para tanto, foram coletadas amostras compostas de lodo descarregado por 24 caminhões. Foi feito teste complementar, com a finalidade de estudar a degradação do lodo flotado por processos anaeróbio e aeróbio. Mediante essas caracterizações pode-se constatar a grande heterogeneidade da composição do lodo e a elevada carga orgânica, que devem ser ponderados com relação a impactos no meio ambiente e em Estações de Tratamento de Esgoto. Contudo, nota-se a importância do pré-tratamento desse lodo antes de ser lançado em ETEs. A unidade piloto foi operada com diferentes taxas de aplicação superficial (80; 110; 140 e 200 \'M POT.3\'/\'M POT.2\'.dia), quando foram obtidas remoções de 91,7% de sólidos suspensos; 89,3% de DQO e 81,9% de óleos e graxas. Pelos resultados obtidos foi demonstrada a eficiência do sistema de flotação na remoção de óleos e graxas e dos sólidos suspensos. A digestão aeróbia do lodo flotado mostrou-se eficiente quando foi aplicado inócuo com período de aeração superior a 20 dias, sendo que foram obtidas eficiências de 88,3% e 90% para remoção de DQO e de óleos e graxas, respectivamente. / Septic tanks are small structures used for partial treatment of wastewater produced from urban and rural areas. It utilization is justify mainly by simplicity of construction and for being a technology that requires low operational dedication. Although it is a technology vastly used in Brazil, there is not much information about the characteristics of the waste dumped in there, and the conditions of collection, transport, and final destination of the sludge generated in the system. The objective of this research was characterize the sludge originated from septic tanks and to design, construct and evaluate a treatment unit model to be used for prior treatment of the sludge generated in those septic tanks. This unit, composed by a sieve, a degritter, and a flotation device, was assembled in the São Paulo University Campus, near the area 1 from the campus Wasterwater Treatment Plant (WWTP). It had the purpose to remove har solid particle, sand and the floating material before their entry in the Wasterwater Treatment Plant. Was made to characterize the sludge septic tank collected in situ and the sludge originated from the Septic Pumper Truck, unloaded into a tank of 15000 L. Furthermore, the characterization of the sludge originated from the Septic Pumper Truck was performed twice, once in the material collected in the first visit to the defined location and the other in the material collected about six months after the first collection. The use of ultrasound was tested to ameliorate the fragmentation of the particulate material and to improve the method of analysis of the sludge in situ. Additionally, it was characterized the sludge from septic tanks in the Waste Reception Center from the city of Campinas, São Paulo State - SANASA - Society of Water Supply and Sanitation in composite samples collected from 24 trucks during the unloading. Septic Pumper Truck in th Waste Receptation Center. A complementing test was performed in order to text the degradation of the floated sludge by anaerobic and aerobic processes. The characterizations revealed a great heterogeneity in the composition of the sludge and the high organic content, which should be taken in consideration regarding the impacts in the environment and in the WWTP. This underlines the importance of treatment of the sludge prior to discharging into the WWTP. The pilot plant was managed to work at different rates of surface sludge application (80, 110, 140 and 200 \'M POT.3\'/\'M POT.2\'.day). The 110 \'M POT.3\'/\'M POT.2\'.day rate displayed the highest efficiency with the removal of 91.7% of suspended solids, 89.3% of the chemical oxygen demand, and 81 9% of oils and waxes. The results showed the efficiency of the flotation system in the removal of suspended solids, oil and greases. The aerobic digestion of the floated material was efficient when it received inoculation with aeration period greater than 20 days, which allowed CDO the removal of 88.3% and 90% of oil and greases.

ABSTRACT Influence of fenugreek gum on bread and in vitro physiological effects Keisha T. Roberts Advisors: University of Guelph Dr. S.W. Cui Professor T.E. Graham This thesis examined the effect of fenugreek gum, from Canadian grown fenugreek on bread quality, when substituted for wheat flour at 5 % and 10 %, and the in vitro physiological effects of these breads, based on models of acute and long - term feeding. Study I determined bread could be produced with 10 % fenugreek gum, while maintaining quality parameters of volume and texture, comparable to a control. This was accomplished through the development of a novel bread production method, using the lamination procedure for puff pastry production. The behavior of fenugreek gum and starch (wheat flour) was determined by rapid visco analysis (RVA), farinograph and dynamic rheological measurement, while scanning electron microscopy of bread found fenugreek gum could be identified within the bread matrix. Study 2 in vitro starch digestion found fenugreek gum at 5 % and 10 % reduced glucose liberated from bread, with 10 % fenugreek gum causing a reduction of over 30 %. RVA of fenugreek breads highlighted differences in viscosity between breads and wheat flour substituted with the gum. This was substantial as viscosity measurements by RVA are conducted on raw ingredients and not the food as consumed, which reflects the possible reduction in viscosity with food processing. This study also determined extruding fenugreek gum may have caused morphological changes to the gum, which may possibly contribute to attenuation of glucose liberated in vitro. Study 3 evaluated the accumulation of short chain fatty acids (SCFA) from the fermentation of three substrates: Extruded fenugreek gum, bread with 10 % extruded gum and control bread, based on fecal microbiota from three donors. SCFA profiles varied with substrates and donors, with fenugreek gum having the highest accumulation of SCFA after 12 hours. Donors were a caucuasian Canadian, a black Jamaican and a black Trinidadian who was the only donor culturally exposed to fenugreek. This Trinidadian’s SCFA profiles were consistently higher for fenugreek gum than the other donors. These studies collectively showed fenugreek gum, though viscous could be successfully incorporated into bread and have potential as a functional food and nutraceutical.

Anaerobic digestion (AD) is becoming a widely adopted technology for conversion of organic waste and nutrient-rich fertiliser production due to its cost-effectiveness and sustainability. In this study, a batch experiment was conducted using five different types of food waste and cow dung (CD). No significant difference was observed among the four substrates that produced the highest methane (P<0.05). Based on the batch experiment results, two substrates were selected for semi-continuous digestion and the highest methane yield (67%) was obtained from co-digestion (CO). PCR-DGGE results revealed higher bacterial and archaeal diversity indices in CO as compared to mono-digestion of CD and mixed food waste. The high-throughput sequence analyses revealed that the Operational Taxonomic Units (OTUs) belonging to the phyla Bacteroidetes, followed by Firmicutes, Actinobacteria and Proteobacteria, were dominant in all treatments. The enhanced methane production in CO could be attributed to the neutral pH and partial shift of archaea from Methanosaeta to Methanosarcina. The digestate and fresh CD were screened for plant growth promoting bacteria (PGPB), nutrient and heavy metal content. The dung contained higher concentrations of heavy metals (P<0.05) and potential pathogens in comparison to the digestate. The use of digestate may, therefore, enhance soil fertility with minimal negative environmental effects. / School of Agriculture and Life Sciences / M. Sc. (Life Sciences)

La matière des eaux usées urbaines (ERU) subit des transformations au sein des filières « eau » et « boue » des stations d’épuration (STEP). Une fraction de la matière organique est systématiquement retrouvée en fin de traitement biologique sous forme particulaire et est, à ce titre, identifiée comme non biodégradable et notée XU. L’origine « exogène » i.e. provenant de l’ERU brute, ou « endogène », i.e, résidus générés par les processus microbiens, et la contribution quantitative des composés accumulés dans cette fraction XU ne sont pas identifiables simplement. Par ailleurs, si une faible bioaccessibilité et/ou une inadéquation entre leur nature chimique et le pool enzymatique présent peuvent être suspectées, les raisons de leur caractère réfractaire sont mal connues et constituent un frein pour optimiser la valorisation de la boue par digestion anaérobie. S’intéressant spécifiquement à la fraction organique réfractaire d’une boue d’épuration, ce travail de thèse s’est donc attaché à définir son origine, à quantifier sa proportion selon différentes conditions opératoires de STEP et à caractériser ses composés d’un point de vue physique et chimique. Une approche filière a tout d’abord été menée pour analyser la relation entre l’origine et la biodégradabilité d’une boue. Deux approches de caractérisation chimique ont été mises en œuvre : (i) Analyse directe de l’empreinte chimique globale par spectrophotométrie infrarouge (IR) en réflexion totale atténuée (ATR) ; (ii) Analyses moléculaires (fluorescence 2D et 3D, UV 210 et 280 nm, dosages biochimiques) de fractions solubilisées après déconstruction thermo-chimique de l’agrégat réfractaire. Associée à des analyses statistiques, l’utilisation de l’empreinte IR s’est révélée pertinente pour différencier chimiquement différentes matrices réfractaires et suivre l’évolution des empreintes au fil des unités de traitement d’épuration. Par ailleurs, l’utilisation combinée de techniques analytiques complémentaires a permis une caractérisation plus précise des familles de molécules impliquées. Enfin, l’empreinte IR s’est avéré un outil pertinent de caractérisation de l’effet d’un traitement thermique (60 à 95°C) ou chimique (hydrolyse acide et alcaline) sur la chimie de la fraction XU / Organic matter of urban wastewaters (WW) is modified all along the treatment units of a wastewater treatment plant (WWTP). A fraction of the organic matter systematically remains at the end of biological treatment, mainly aggregated in particulate form. It is thus classified as refractory organics, noticed XU. The “exogenous” origin (e.g. originated from the urban WW) or “endogenous” one (e.g. residues produced by the microbial processes) and the quantitative contribution of compounds accumulated into the XU fraction are difficult to identify. Limited bioaccessibility and/or inappropriate chemical characteristics can be suspected. However, the reasons of their non-biodegradability are not clearly identified that limits an optimal valorization of sewage sludge by anaerobic digestion (AD). Focusing specifically on the refractory COD fraction of sewage sludge, this research work attempts to define its origin, to quantify its proportion depending on the applied operating conditions in the WWTP and to characterize the physical and chemical properties of its different compounds.A first approach is carried out to analyze the relationship between the WWTP operating conditions and the biodegradability of various sludges. The scientific approach is based on (1) the use of sludges of contrasted composition (fed with raw wastewater, or pre-settled WW, diluted primary sludge or synthetic influent, and produced with a solid retention time in the range of 2 and 70 days), and, on (2) the comparative analysis of physical, biological and chemical characteristics for refractory matrices resulting from their ultimate anaerobic digestion. Refractory COD fractionations are estimated comparing experimental and ASM1 predicted data. While 85% of anaerobic refractory organic matter remain aggregated, two characterization approaches were applied: (i) direct analysis (on unmodified particulate matter) of the global chemical fingerprint by infrared spectroscopy (IR) on attenuated total reflexion (ATR); (ii) molecular analysis (fluorescence 2D and 3D, UV 210 and 280 nm, biochemical assays) of solubilized fractions obtained by thermo-chemical solubilisation of the refractory aggregate.Combined with statistical tools (Hierarchical Ascendant Classification, HAC and Principal Component Analysis, PCA), infrared fingerprints appear relevant to chemically discriminate refractory residues of the selected sludges and hence to follow the evolution of the chemistry of matrices along the treatments chains. Main factors involved in the chemical fingerprint of XU are highlighted. For example the major effect of the chemistry of exogenic refractory compounds (XU,inf) on the XU chemical fingerprint is shown. In addition, our work underlines the interest of using complementary analytical techniques to get a more accurate chemical characterization of the molecules involved in the ultimate refractory matrices. For example, a significant contribution of proteins and humics on the chemistry of refractory aggregate could be observed with a clear contribution of bacterial compounds to protein refractory fraction.Finally, the infrared fingerprint was used to characterize the effect of heat treatments (60-95°C) or chemical treatments (acid and alkaline hydrolysis) on the chemistry of XU. In perspective, this approach could be extended to other treatments (e.g. high temperature, ozonation, enzymatic hydrolysis) to assess their effects and to define their optimal operating point for degradation of refractory compounds. Furthermore, the possibility to discriminate chemical fingerprints of different refractory residues could also be exploited. Acquiring spectral data banks could better define the scope of application of treatment units combined with the anaerobic digestion of sewage sludge.

Fossas e tanques sépticos são sistemas de pequeno porte utilizados para tratamento parcial do esgoto sanitário produzido nas áreas urbana e rural, quando não beneficiados por sistema de esgotamento sanitário. Tal utilização se justifica principalmente por ser tecnologia que não exige muita dedicação operacional e ser de simples implantação. Apesar da vasta utilização dessas unidades no Brasil, há pouca informação sobre a caracterização, as condições de coleta, transporte, tratamento e destino final de resíduo (lodo) produzido nesses sistemas. Nesse sentido, o presente trabalho tem como objetivo a caracterização do lodo produzido nessas unidades; e, também, a concepção, o desenvolvimento e a avaliação de uma unidade piloto para pré-tratamento de lodo de fossas e tanques sépticos. Essa unidade, constituída por grade, desarenador e flotador, foi instalada no Campus da Universidade de São Paulo, junto da Estação de Tratamento de Esgoto do Campus - área 1, e vista à remoção de sólidos grosseiros, areia e materiais flutuantes, antes de seu lançamento na Estação de Tratamento de Esgoto do Campus. Foi feita a caracterização do lodo de tanques sépticos coletado in situ e do lodo proveniente dos caminhões limpa-fossas, descarregando em tanque pulmão de 15000 litros. A caracterização do lodo proveniente dos caminhões limpa-fossas foi realizada em duas campanhas (coletas), sendo uma feita na primeira visita ao local pré-definido, e outra realizada aproximadamente seis meses após a primeira coleta. Com intuito de aprimorar o método de análise das amostras do lodo in situ, com finalidade de melhor fragmentar o material particulado, foi testado o uso de ultrassom. Também, foi realizada a caracterização do lodo de fossas e tanques sépticos na Central de Recebimento de Resíduos na cidade de Campinas-SP - SANASA - Sociedade de Abastecimento de Água e Saneamento AS. Para tanto, foram coletadas amostras compostas de lodo descarregado por 24 caminhões. Foi feito teste complementar, com a finalidade de estudar a degradação do lodo flotado por processos anaeróbio e aeróbio. Mediante essas caracterizações pode-se constatar a grande heterogeneidade da composição do lodo e a elevada carga orgânica, que devem ser ponderados com relação a impactos no meio ambiente e em Estações de Tratamento de Esgoto. Contudo, nota-se a importância do pré-tratamento desse lodo antes de ser lançado em ETEs. A unidade piloto foi operada com diferentes taxas de aplicação superficial (80; 110; 140 e 200 \'M POT.3\'/\'M POT.2\'.dia), quando foram obtidas remoções de 91,7% de sólidos suspensos; 89,3% de DQO e 81,9% de óleos e graxas. Pelos resultados obtidos foi demonstrada a eficiência do sistema de flotação na remoção de óleos e graxas e dos sólidos suspensos. A digestão aeróbia do lodo flotado mostrou-se eficiente quando foi aplicado inócuo com período de aeração superior a 20 dias, sendo que foram obtidas eficiências de 88,3% e 90% para remoção de DQO e de óleos e graxas, respectivamente. / Septic tanks are small structures used for partial treatment of wastewater produced from urban and rural areas. It utilization is justify mainly by simplicity of construction and for being a technology that requires low operational dedication. Although it is a technology vastly used in Brazil, there is not much information about the characteristics of the waste dumped in there, and the conditions of collection, transport, and final destination of the sludge generated in the system. The objective of this research was characterize the sludge originated from septic tanks and to design, construct and evaluate a treatment unit model to be used for prior treatment of the sludge generated in those septic tanks. This unit, composed by a sieve, a degritter, and a flotation device, was assembled in the São Paulo University Campus, near the area 1 from the campus Wasterwater Treatment Plant (WWTP). It had the purpose to remove har solid particle, sand and the floating material before their entry in the Wasterwater Treatment Plant. Was made to characterize the sludge septic tank collected in situ and the sludge originated from the Septic Pumper Truck, unloaded into a tank of 15000 L. Furthermore, the characterization of the sludge originated from the Septic Pumper Truck was performed twice, once in the material collected in the first visit to the defined location and the other in the material collected about six months after the first collection. The use of ultrasound was tested to ameliorate the fragmentation of the particulate material and to improve the method of analysis of the sludge in situ. Additionally, it was characterized the sludge from septic tanks in the Waste Reception Center from the city of Campinas, São Paulo State - SANASA - Society of Water Supply and Sanitation in composite samples collected from 24 trucks during the unloading. Septic Pumper Truck in th Waste Receptation Center. A complementing test was performed in order to text the degradation of the floated sludge by anaerobic and aerobic processes. The characterizations revealed a great heterogeneity in the composition of the sludge and the high organic content, which should be taken in consideration regarding the impacts in the environment and in the WWTP. This underlines the importance of treatment of the sludge prior to discharging into the WWTP. The pilot plant was managed to work at different rates of surface sludge application (80, 110, 140 and 200 \'M POT.3\'/\'M POT.2\'.day). The 110 \'M POT.3\'/\'M POT.2\'.day rate displayed the highest efficiency with the removal of 91.7% of suspended solids, 89.3% of the chemical oxygen demand, and 81 9% of oils and waxes. The results showed the efficiency of the flotation system in the removal of suspended solids, oil and greases. The aerobic digestion of the floated material was efficient when it received inoculation with aeration period greater than 20 days, which allowed CDO the removal of 88.3% and 90% of oil and greases.

A Política Nacional de Resíduos Sólidos, instituída pela Lei Federal 12.305 em agosto de 2010 e regulamentada pelo Decreto 7.404, em 23 de dezembro de 2010, estabeleceu um novo paradigma na gestão e gerenciamento dos resíduos sólidos no Brasil. Entre as mudanças apresentadas, uma das mais relevantes é a que prioriza o não aterramento da fração orgânica e a recuperação energética dos resíduos. Por esse motivo, a busca por novas tecnologias para o tratamento desses resíduos tem sido intensificada nos últimos anos. Nesse contexto, o objetivo deste trabalho busca avaliar o potencial de se realizar estratégias para aclimatação de lodos anaeróbios em possíveis inoculações de biometanizadores alimentados com fração orgânica dos resíduos sólidos urbanos (FORSU). Foram analisados dois diferentes lodos, esses em função da decomposição e estabilização da FORSU por meio de ensaios de biodegradabilidade anaeróbia. O primeiro, lodo ETE (LE), foi coletado de um reator UASB, utilizado para tratamento de esgoto sanitário doméstico, já o segundo, lodo Aterro (LA), foi coletado de uma lagoa de acúmulo de lixiviados em um aterro sanitário desativado. Para os ensaios, utilizaram-se frascos Duran® de 250 mL, incubados a 35°C, considerando-se a co-digestão nas seguintes relações resíduo/inóculo (R0/I0): 1/16, 1/8, 1/4, 1/2 e 1/1 gSTVresíduo.gSTVinóculo-1. As estratégias de aclimatação consistiram em manter o inóculo para as próximas bateladas, bem como, dobrar as relações (R0/I0) com sucessivas alimentações realizadas em três bateladas sequenciais. Para que fossem possíveis o controle e a verificação do processo ao longo das bateladas, foram realizadas análises físico-químicas, microbiológicas, cinéticas e de atividade metanogênica específica (AME). Os inóculos adaptaram-se de imediato à FORSU, tendo sido verificada produção crescente de metano já nos primeiros dias dos testes. Os melhores resultados do potencial bioquímico de metano foram obtidos pelas menores relações (R0/I0) para ambos os inóculos. As maiores relações (R0/I0) influenciaram negativamente o desempenho do processo de biometanização para o inóculo LE, verificada pelas menores taxas máximas de rendimento de metano e maiores fase lag. Para o inóculo LA, ao final do processo de aclimatação foi verificado maior índice de diversidade para o Domínio Archaea, corroborando com os resultados obtidos pela quantidade de micro-organismos metanogênicos. Essas verificações se deram por meio de análises de microscopia óptica e pelos maiores valores obtidos nos testes de AME. Destarte, conclui-se que a estratégia de aclimatação se utilizando das menores relações (R0/I0): 1/16, 1/8 e 1/4 para o inóculo LA, possui o maior potencial, sendo esse na inoculação em maiores relações (R0/I0) na partida de biometanizadores alimentados com fração orgânica dos resíduos sólidos urbanos, logo, garantindo-se efetividade no processo. / The National Policy on Solid Waste, instituted by Federal Law 12,305 in august 2010 and regulated by Decree 7404, on december 23, 2010, established a new paradigm in the management of solid waste in Brazil. Among the changes presented, one of the most relevant is the one that prioritizes the non-grounding of the organic fraction and the energy recovery of the waste. For this reason, the search for new technologies for the treatment of this waste has been intensified in recent years. In this context, the objective of this work is to evaluate the potential of strategies for acclimatization of anaerobic sludge in possible inoculations of biomethanizers fed with organic fraction of municipal solid waste (OFMSW). Two different sludges were analyzed, as a function of the decomposition and stabilization of OFMSW by anaerobic biodegradability tests. The first, ETE sludge (LE), was collected from a UASB reactor, used to treat domestic sanitary sewage, while the second, Aterro sludge (LA) was collected from a pond of leachate accumulation in a deactivated landfill. For the tests, 250 ml Duran® flasks incubated at 35°C were used, considering co-digestion in the following residue/inoculum ratios (R0/I0): 1/16, 1/8, 1/4, 1/2 and 1/1 gSTVresidue.gSTVinoculum-1. The acclimation strategies consisted in maintaining the inoculum for the next batch, as well as doubling the ratios (R0/I0) with successive feedings performed in three sequential batches. In order to control and verify the process throughout the batch, physical-chemical, microbiological, kinetic and specific methanogenic activity (SMA) analyzes were performed. The inocula immediately adapted to OFMSW, and there was a growing production of methane already in the first days of the tests. The best results of the biochemical potential of methane were obtained by the lower ratios (R0/I0) for both inoculum. The higher ratios (R0/I0) negatively influenced the performance of the biomethanization process for the LE inoculum, verified by the lower maximum methane yield rates and higher lag phase. For the inoculum LA, at the end of the acclimation process, a higher diversity index was verified for the Archaea Domain, corroborating with the results obtained by a number of methanogenic microorganisms. These tests were carried out by means of optical microscopy and the highest values obtained in the SMA tests. Therefore, it is concluded that the acclimation strategy using the lowest ratios (R0/I0): 1/16, 1/8 and 1/4 for the inoculum LA, has the highest potential, being inoculated at higher rates (R0/I0) at the start of biomethanizers fed with organic fraction of municipal solid waste, thus, ensuring effectiveness in the process.

La bioconversion en méthane de biomasses lignocellulosiques est l’une des alternatives les plus prometteuses pour la production de méthane issu de la digestion anaérobie. Toutefois, les biomasses lignocellulosiques présentent des caractéristiques bio-physico-chimiques très variables en raison leur composition biochimique et de l’organisation structurale très diverses. Par ailleurs, leur faible biodégradabilité en conditions anaérobie nécessite de les prétraiter avant méthanisation pour optimiser la production de méthane. Ce travail vise à évaluer l’influence des caractéristiques d’une large gamme de substrats lignocellulosiques sur leur biodégradabilité anaérobie et les corrélations entre leurs caractéristiques bio-physico-chimiques et le potentiel biométhanogène, et d’étudier les effets du prétraitement fongique en présence de Ceriporiopsis subvermispora sur le potentiel biométhanogène de biomasses lignocellulosiques sélectionnées dans la présente étude et de caractériser les changements de leurs caractéristiques après le prétraitement fongique. La caractérisation de 36 biomasses lignocellulosiques représentatives d’une large gamme de gisements potentiellement mobilisables a permis de mettre en évidence les corrélations linéaires entre le potentiel biométhanogène des biomasses et certaines de leur caractéristiques bio-physico-chimiques, dont la teneur en lignine et la demande biochimique en oxygène. Les biomasses sylvicoles et agricoles ont montré des caractéristiques distinctes de la biodégradabilité aérobie et anaérobie. Les résultats de prétraitement fongique sur les 5 biomasses ont permis de mettre en évidence que le champignon de pourriture blanche Ceriporiopsis subvermispora réagit distinctement selon la biomasse prétraitée. Pour certaines biomasses, le prétraitement fongique conduit à augmenter significativement la production de méthane et la vitesse de bioconversion en méthane. Cette espèce présente la capacité de dégrader sélectivement la lignine sur certaines biomasses et, sur d’autres, celle de dégrader de manière non-sélective des polysaccharides et des lignines. De plus, pour les deux souches de Ceriporiopsis subvermispora testées, des métabolismes différents ont été mis en évidence sur une même biomasse. Les résultats de compositions et ceux de l’analyse structurale des biomasses (initiales, autoclavées, contrôles, et prétraitées par Ceriporiopsis subvermispora) ont montré que leur structure peut être modifiée sans toutefois observer une transformation significative de leur composition biochimique. / Bioconversion to methane lignocellulosic biomass is one of the most promising alternatives for the production of methane from anaerobic digestion. However, lignocellulosic biomass has various bio-physicochemical characteristics due to their biochemical composition and diverse structural organization. Moreover, their low biodegradability in anaerobic condition requires pretreatment before methanation to optimize methane production. This work aims to evaluate the influence of the characteristics of a wide range of lignocellulosic substrates on their anaerobic biodegradability and correlations between their bio-physical-chemical characteristics and biomethane potential, and study the effects of fungal pretreatment in the presence of Ceriporiopsis subvermispora on the biogas potential of lignocellulosic biomass selected in this study and characterize their changes of their characteristics before and after the fungal pretreatment. The characterization of 36 representative lignocellulosic biomass of a wide range of potentially mobilized deposits allowed to highlight the linear correlations between biomethane potential of biomass and some of their bio-physical-chemical characteristics, of which the lignin content and biochemical oxygen demand. The forest and agricultural biomass exhibited distinct characteristics of the aerobic and anaerobic biodegradability. The results of fungal pretreatment of the 5 biomass indicated that the white rot fungus Ceriporiopsis subvermispora reacts distinctly depending on the pretreated biomass. For some biomass, fungal pretreatment leads to significant increase of methane production and the bioconversion rate of methane. This species presents the ability to selectively degrade lignin on some biomasses, in others, the ability to non-selectively degrade polysaccharides and lignins. In addition, for both strains of Ceriporiopsis subvermispora tested, different metabolisms were highlighted on the same biomass. The results of compositions and those of the structural analysis of biomass (initials, autoclaved, controls, and pretreated with Ceriporiopsis subvermispora) showed that their structure can be modified without observing a significant transformation of their biochemical composition.

Depuis le début des années 2000, la station d’épuration n’est plus seulement perçue comme une installation industrielle traitant les eaux résiduaires urbaines afin d’en minimiser leurs impacts sur le milieu naturel, mais aussi comme un moyen de récupérer des ressources : eau, nutriments, énergie. Ce travail de thèse traite de cette dernière ressource, l’énergie. Comment tendre vers la station d’épuration auto-suffisante en énergie, voire encore productrice d’énergie sans en affecter l’efficacité de traitement? A l’aide d’une filière de traitement ancienne revisitée : le procédé A/B (Adsorption/Bio-oxydation), le bilan énergétique de la station peut tendre vers la neutralité en réduisant les demandes liées à l’aération et en optimisant la production de biogaz. Ce travail de doctorat se concentre principalement sur la méthanisation des boues issues de ce procédé A/B afin d’en connaître leurs caractéristiques et leur digestibilité, de les comparer avec la digestion anaérobie de boues davantage connues et enfin d’utiliser ces résultats pour dresser le bilan énergétique du procédé A/B, ceci à partir des données récoltées sur un pilote de 50 m3/j installé sur la station d’épuration de Kranji à Singapour. Les boues A et B présentent respectivement les productions spécifiques de méthane respectives de 290 et 135 LCH4/kgMVentrante en conditions mésophiles. Le procédé A/B avec ses deux étages de boues activées permet de capter un maximum de carbone en première étape de traitement pour le transférer directement en digestion. En effet, la production totale de boues provient à 90% des boues A et seulement à 10% des boues B ce qui porte à 95% la production de méthane attribuée aux boues A. Ces résultats induisent une production d’énergie supérieure par rapport à une filière de traitement conventionnelle avec un seul étage de boues activées. Par ailleurs, ce procédé permet de diminuer les besoins en aération pour le traitement des pollutions carbonée et azotée, tout en gardant les mêmes efficacités de traitement. Il est ainsi possible de conclure que la filière de traitement des eaux usées en procédé A/B présente un degré d’efficacité énergétique proche de 300% (ratio entre l’énergie électrique produite à partir du biogaz et la consommation énergétique liée à l’aération), ce qui représente 73% d’auto-suffisance énergétique globale en considérant le cas de la station de Kranji en boues activées conventionnelles traitant les pollutions en carbone et en azote. / Since the early 2000’s, wastewater treatment plants (WWTP) have not been only seen as a mean to reduce the impact of the harmful emissions towards water bodies but also as a way to recover the resources contained in the raw wastewater: water, nutrients and energy. This doctorate seeks to study the latter one. How to tend to the energy self-sufficient or even energy positive WWTP without altering its treatment efficiencies? Using an old wastewater treatment process: the A/B process (Adsorption/Bio-oxidation) and state-of-the-art technologies, the energy autarky of a WWTP can become a reality by reducing its electricity consumption related to the aeration and by optimizing its energy production through anaerobic digestion. This work mainly focuses on the anaerobic digestion of the sludge produced by the A/B process. It aims at evaluating their characteristics and digestibility and thus at comparing these to the ones of better-known sludge such as primary, secondary and mixed sludge from a conventional wastewater treatment system. Eventually, these results with the addition of data collected on a 50 m3/d A/B process pilot plant on the Water Reclamation Plant of Kranji, Singapore, are used to draw the energy balance of the A/B process and to try to make a comparison to conventional systems. The A/B process produces the A and B sludge which respectively show specific methane productions of 290 and 135 LCH4/kgVSintroduced in mesophilic anaerobic digestion and can be considered quite similar to primary and secondary sludge respectively from conventional WWTPs. With its two stages of activated sludge, this process enables the early entrapment of carbon to be directly transferred to the digesters. Indeed, 90% of the sludge production comes from the A sludge in matter of Volatile Solids, which brings to 95% the biogas production to be ascribed to this sludge. Hence, the A/B process does produce more energy than a conventional single-stage activated sludge. It also reduces the aeration demand for the biological treatment of the carbon and nitrogen pollutions whilst complying with the same treatment performances. Drawing the energy balance of the A/B process leads to the conclusions that this process presents an energy efficiency of 300% by comparing only the electrical needs for the aeration (40-70% of the whole plant demand) and the electricity production from biogas generation, which, at the end, represents an energy self-sufficiency of 73% considering the Kranji conventional water reclamation plant.

La digestion anaérobie en voie sèche représente une opportunité de développement de la méthanisation sur le territoire français au vu des gisements agricoles disponibles sur le territoire. Toutefois, l’importance des verrous scientifiques et technologiques de par leur nombre et leur complexité rend cette technologie non mature et peu développée sur le territoire français. Dans ces travaux de thèse, il a été étudié dans un premier axe la mise au point de la détermination de la demande chimique en oxygène (DCO) pour des substrats solides avec un kit commercial rendant celle-ci utilisable sans dilution des déchets et utilisant une faible quantité de réactifs. Cette méthode est un outil de suivi des installations. Un deuxième axe d’étude qui s’est attaché à l’étude de la phase d’acidification, verrou majeur de la méthanisation phase sèche, a démontré l’impact de la conservation et de l’origine des inocula sur leur capacité à gérer une phase d’acidification en présence de déchets facilement hydrolysables. L’inoculum est un paramètre majeur de la méthanisation voie sèche et est pourtant peu étudié. Un troisième axe de cette thèse concerne l’étude des transferts hydriques sur des substrats d’origine agricole par une méthodologie de traçage et de modélisation via le modèle à deux régions d’eau mobile et immobile. L’évolution des transferts hydriques a été étudiée au cours de la digestion anaérobie de fumier bovin en digesteur 60 L montrant une diminution de la perméabilité du massif après le deuxième pic de production de méthane. Par conséquent, tout l’inoculum recirculé passe par les côtés et non au sein du massif solide. Deux fréquences de recirculation ont été testées permettant d’obtenir une amélioration de la production de méthane d’environ 20 %. La caractérisation des transferts hydriques obtenus pour ces deux modalités sont identiques après 32 jours de dégradation anaérobie. Le gain de méthane obtenu se fait donc jusqu’au deuxième pic de production de biogaz par la recirculation. Les bilans hydriques et massiques effectués sur ces digesteurs 60 L démontrent que 36 % de la matière organique sont retrouvés dans le digestat montrant un procédé non optimisé. Le quatrième axe d’étude a été de comprendre et d’étudier la dynamique des populations méthanogènes au sein de digesteurs de méthanisation voie sèche de 60 L selon deux configurations. Des expérimentations modulant l’immersion du massif solide ont conduit à obtenir une amélioration de 13 % de production de méthane pour la condition favorisant l’immersion. Cette augmentation de production de méthane est induite par une plus forte quantité de Methanosarcinaceae. La dynamique des populations méthanogènes a été étudiée dans la phase solide et liquide au cours de la digestion anaérobie montrant un transfert microbien de la phase liquide à solide pour un ordre des bactéries hydrogénotrophes, une hiérarchie de ces « hydrogénotrophes » dans le milieu et un fort développement des « acétotrophes » dans le milieu solide servant de support. Dans un cinquième axe, la mise en oeuvre de la tomographie électrique sur un digesteur de 30 m3 a permis de valider son utilisation pour localiser la phase liquide, les zones de potentiels méthane et les zones dégradées dans un container en fonction des protocoles de remplissage et de vidange du digesteur. Cette méthode est disponible pour localiser les zones mortes et donc pour optimiser le procédé de méthanisation en voie sèche type batch. A travers ces expérimentations menées à différentes échelles et avec différentes problématiques, des méthodologies ont été adaptées pour la compréhension des mécanismes et le suivi du procédé de méthanisation par voie sèche. / The dry anaerobic digestion (AD) process is an opportunity to develop the methanization in France. Agricultural waste is abundant in France. However, many scientific and technical locks are complex and must be solved to develop the dry anaerobic digestion process in France. In this work, the chemical oxygen demand (COD) method was adapted for solid waste no implying waste dilution or a high quantity of reagent. This COD method was available to monitor and manage the dry AD process. The study of acidification phase, a major lock of the dry AD process, showed that the storage condition and the origin of inoculum influence the capacity to manage this phase. The inoculum is a major parameter of the dry AD process. But, the inoculum is few studied.On another part of experiments concerned the water transfers studied on agricultural waste with a tracing method. The modeling of the elution curves to determine the diffusion and the convective transfers was made with a model with two Mobile-Immobile regions. The evolution of water transfers was studied during the AD cycle showing a decrease about the permeability of solid phase after the second peak of methane production. Thus, the inoculum passes on the board of solid phase. Two recirculations were tested allowing to obtain an improvement the methane production about 20 % after the AD cycle. The water transfers of these two recirculations modalities were identical after the AD cycle. The improvement of methane production occurred after the second peak of the methane production. Water and mass balances made showing that 36 % of organic matter was find in the digestat. Consequently, the process was not optimized. Others experiments modulating the immerged part of solid phase showed an improvement of the methane production about 13 % with the increasing of immerged part. This methane improvement was induced by the development of Methanosarcinaceae. The methanogens dynamics were studied in the liquid and solid phases during the AD process showing (i) a population transfer between the liquid phase to the solid phase, (ii) a hierarchy of hydrogenotrophs methanogens in the media, and (iii) a strong development of acetotrophs methanogens in the solid phase. In the final part, the electrical tomography was implemented in a dry AD batch at full scale (30 m3). This method was adapted to localize the liquid phase, the zones of methane potential and the degraded zones according to filling and the emptying protocols. This method can detect the “dead” zones of process in dry AD process.Though, experiments carried out at different scales and with different problematic and several methodologies were adapted to understand the dry AD process. Moreover, the optimization of dry AD process was finding to increase the methane production.

L'optimisation de la digestion anaérobie par voie sèche est actuellement limitée par un manque de connaissances fondamentales. En particulier, les effets des principaux paramètres de procédé sur la dynamique réactionnelle sont peu connus en digestion sèche : teneur en eau, propriétés du substrat ou taux d'inoculation. Ces conditions opératoires ont des conséquences importantes à l'échelle des micro-organismes par la modification des conditions environnementales locales. Si la relation entre les propriétés des substrats lignocellulosiques et l'activité de la biomasse microbienne est au cœur de la dynamique réactionnelle, elle reste très peu prise en compte lors de l'ajustement des conditions opératoires. Ce travail vise à comprendre l'impact des paramètres de procédé (teneur en eau, caractéristiques du substrat, taux d'inoculation) sur le développement, la structuration et l'activité des micro-organismes au cours de la digestion sèche de substrats lignocellulosiques, en vue de maitriser le procédé dans son ensemble. La stratégie retenue a consisté à suivre la dégradation de la paille de blé, modèle des résidus agricoles méthanisables, en réacteurs discontinus faiblement inoculés. Quatre séries d'expériences ont été mises en place pour : i) comprendre comment les paramètres de procédés impactent les réactions, ii) étudier le comportement métabolique des micro-organismes à faibles teneurs en eau, iii) déterminer comment les communautés microbiennes se spécialisent selon l'évolution des caractéristiques du substrat au cours de sa dégradation, et enfin iv) valider les résultats par un taux d'inoculation moins contraignant. Tout d'abord, le criblage des principaux paramètres de procédés (teneur en matières sèches, taille des particules et taux d'inoculation) a montré une évolution progressive de leurs effets au cours de l'avancement de la réaction, sur les processus de digestion. Ensuite, l‘étude de la fermentation en voie sèche a permis de montrer, qu'en présence d'eau libre, l'augmentation de la siccité n'impacte pas le métabolisme microbien, mais modifie les équilibres entre les communautés microbiennes. Le recours à un protocole de compartimentation de la biomasse microbienne spécialement développé dans cette thèse a mis en évidence une spécialisation forte et progressive des communautés microbiennes associées à l'hydrolyse du substrat, au cours de sa dégradation. Des observations par microscopie électronique à transmission indiquent que cette modification coïncide avec la dégradation progressive des tissus de la paille en fonction de leur degré de lignification. La mise en évidence de barrières physiques, récalcitrantes à la biodégradation et rarement décrites dans le contexte de la méthanisation, indique que l'accessibilité du substrat est le paramètre principal limitant la réaction. Ces informations suggèrent que le broyage du substrat est un prétraitement de choix en digestion sèche. Cependant, une dernière expérience a montré qu'en voie sèche, un broyage fin limite les gains de performances du procédé par une augmentation des risques d'acidification des digesteurs. / Nowadays, optimization of solid-state anaerobic digestion is limited by a lack of fundamental knowledge. In particular, the effects of the main process parameters, such as water content, substrate property or inoculation rate, on the reaction dynamics are poorly understood in solid-state anaerobic digestion. In fact, process parameters have consequences at microbial scale by the modification of the local environmental conditions. Nevertheless, even if the relationship between the lignocellulosic substrate characteristics and the microbial activity is a keystone of the reaction dynamics, it is rarely considered for the selection of operating conditions.This work aims to understand the influence of process parameters (total solid content, substrate characteristics, and inoculation ratio) on the microbial development, compartmentation and activity in order to optimize dry anaerobic digestion of lignocellulosic substrate. The selected strategy consisted in following wheat straw biodegradation, which is a model of agricultural wastes available for anaerobic digestion, in low inoculated batch reactors. Four series of experiment have been established to: i) understand the impact of process parameters on the reaction, ii) study the metabolic behavior of microorganisms face to low water content, iii) evaluate the relationship between substrate characteristics and modification of microbial communities and finally iv) validate results by less restricting inoculation rate.First, a screening of solid-state process parameters (total solid content, particle size and inoculation rate) showed a progressive change of their effect on digestion process during the reaction progress. Then, the study of dry fermentation indicated that, when water is free within the media, increasing total solid content has a low impact on the microbial metabolism, but modifies equilibriums between microbial communities. Based on a protocol developed to investigate the biomass compartmentation, we enlightened a strong and progressive specialization of the microbial communities associated to substrate hydrolysis during its biodegradation. Observations using transmission electronic microscopy indicated that this modification corresponds to a progressive degradation of the straw tissues depending on their lignification degree. Furthermore, the identification of physical barriers, rarely described in anaerobic digestion, suggests that substrate accessibility is the main parameter limiting the reaction. This information suggests that substrate milling can be theoretically a good pretreatment to improve dry anaerobic digestion. However, a last experiment showed that fine milling limits the process performances by a higher risk of acidification in digesters.