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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.
431

Análise comparativa do desempenho de reator anaeróbio híbrido e reator de manto de lodo de fluxo ascendente (UASB) aplicados ao tratamento de esgoto sanitário

Hoyos, Nestor Leonel Muñoz January 2016 (has links)
O presente trabalho teve como objetivo principal avaliar a performance e a estabilidade operacional de uma nova configuração de um reator anaeróbio híbrido (RAH) que combina um filtro anaeróbio de fluxo descendente seguido de uma câmara de manta de lodo de fluxo ascendente comparativamente ao reator UASB nas mesmas condições operacionais aplicados ao tratamento de esgoto sanitário. A avaliação da eficiência de remoção de remoção da matéria orgânica e dos sólidos suspensos nos reatores piloto foi por meio de testes da DQO, DBO, sólidos em suspensão totais (SST) e dos sólidos em suspensão voláteis (SSV).Os reatores UASB e RAH foram operados por um período de 240 dias na fase 1 e 150 dias na fase 2 com vazão afluente de 1,6 m3/h e TDH de 11,8 h. O TDH médio na câmara de entrada do RAH foi de 2,7h e de 9,1h na câmara ascendente de manto de lodo. Os reatores piloto apresentaram capacidade de tratamento para suportar os choques de carga orgânica devido à variabilidade do esgoto bruto. A eficiência de remoção de matéria orgânica em termos de DQO foi de 66% e 59% para o UASB e RAH, a eficiência de remoção de SST atingiu valores de 65% e 63% respectivamente, aliás, o reator UASB apresentando valores superiores de desempenho operacional em quase todos os parâmetros de monitoramento dos processos de digestão anaeróbia os valores médios dos parâmetros DQO, DBO5, SST e SSV não tiveram diferenças estatisticamente significativas. O pH para os sistemas piloto esteve na faixa ideal para o desenvolvimento dos microorganismos anaeróbios (6,5 a 7,5) e a alcalinidade e os AGVs demonstraram estabilidade dos reatores, corroborados pela estabilidade do pH no interior de cada sistema. A velocidade ascensional na câmara de manta de lodo (0,45 m/h) não causou efeito adverso na qualidade do efluente em termos de SST, com valor médio de 39,8 mg/L, na mesma faixa observada no reator UASB (41,6 mg/L). Foi observada menor concentração de biomassa no reator RAH (distribuição vertical) comparativamente ao reator UASB segundo os perfis verticais de lodo, entretanto, este fato não comprometeu a sua eficiência de remoção de matéria orgânica e dos sólidos suspensos. A retirada do lodo de excesso dos sistemas piloto foi baseada na relação STV/ST para estimar a fração de biomassa, a freqüência do descarte foi de 1 vez por mês retirando o equivalente aos 10% do volume de lodo das tomadas que apresentaram uma fração de STV menor que 50%. É viável a implementação da turbidez como parâmetro de detenção de perdida de lodo no efluente dos reatores anaeróbios devido a que a turbidez e os SST apresentaram uma relação direta o que ajudaria a simplificar mecanismos de controle operacional para a toma de decisões nas estações de tratamento, sendo que a turbidez é um parâmetro de leitura rápida “in situ” e poderia advertir do excesso de lodo ao interior do reator. Foram empregados diferentes métodos titrimétricos para a determinação dos AGVs no efluente do RAH e UASB. Após análise dos resultados, recomenda-se o uso do método de KAPP e RIPLEY para a determinação dos AGVs pela simplicidade metodológica e pela rapidez na obtenção do resultado. / This study aimed to evaluate the performance and operational stability of a new configuration of a hybrid anaerobic reactor (RAH) combining an anaerobic filter downflow followed by a sludge blanket chamber upflow compared to UASB in same operating conditions applied to sewage treatment. The evaluation of organic matter removal and removal efficiency of suspended solids in the pilot reactor was by testing COD, BOD, total suspended solids (TSS) and volatile suspended solids (VSS). The RAH and UASB reactors were operated for a period of 240 days in the first phase and 150 days in phase 2 with the inlet flow of 1,6 m3/h and 11,8h TDH. The average TDH RAH in the inlet chamber was 2.7h and 9,1h in ascending chamber sludge blanket. Pilot reactors showed treatment capacity to support organic shock loads due to the variability of raw sewage. The organic matter removal efficiency in terms of COD was 66% and 59% for the UASB and RAH, the TSS removal efficiency reached values of 65% and 63% respectively, by the way, the UASB presenting performance values higher operational in almost all parameters of the monitoring anaerobic digestion processes mean values of the parameters COD, BOD5, TSS and VSS were not statistically significant differences. The pH for the pilot systems was in the ideal range for the development of anaerobic microorganisms (6,5 to 7,5) and alkalinity and Volatile Fatty Acids (VFA) demonstrated stability of reactors corroborated by the pH stability within each system. The upflow velocity in the sludge blanket chamber (0,45 m/h) caused no adverse effect on effluent quality in terms of TSS, with an average of 39,8 mg/L, in the same range observed in UASB (41,6 mg/L). It was observed lower concentration of biomass in the reactor RAH (vertical distribution) compared to UASB second vertical sludge profiles, however, this fact did not compromise its removal efficiency of organic matter and suspended solids. The withdrawal of the pilot systems excess sludge was based on TSV/TS ratio to estimate the biomass fraction, the frequency of disposal was 1 once a month by removing the equivalent of 10% of the outlets sludge volume that had a fraction of TSV less than 50%. The implementation of turbidity as sludge lost detention parameter is viable in the effluent of the anaerobic reactors due to turbidity and TSS showed a direct relationship which would help simplify operational control mechanisms for decision making in treatment plants, wherein the turbidity is a quick read parameter "in situ" and could warn of excess sludge inside the reactor. Different titrimetric methods were employed for the determination of VFA and the effluent from the UASB and RAH. After analyzing the results, we recommend the use of KAPP and RIPLEY method for the determination of VFA by methodological simplicity and speed in obtaining results.
432

Elimination des micropolluants aromatiques et persistants de boues de station d'épuration au cours de la digestion anaérobie assistée par électrolyse microbienne et matériaux conducteurs / Removal of persistent aromatic micropolluants from municipal sewage sludge in anaerobic digesters assisted by microbial electrolysis and conductive materials

Kronenberg, Izabel 29 March 2018 (has links)
L’élimination des micropolluants organiques est devenue aujourd’hui un objectif de santé publique car leur toxicité et bioaccumulation au travers de la chaine trophique sont incontestables. Les hydrocarbures aromatiques polycycliques (HAP) et le nonylphénol (NP) présents en faible concentration dans l’eau usée sont peu éliminés par le traitement. Ces composés hydrophobes se retrouvent fortement sorbés à la matière organique des boues de station d’épuration. Les procédés de traitement de ces boues, comme la digestion anaérobie (DA) jouent un rôle central car ils constituent une des dernières barrières avant rejet vers l’environnement par épandage. La DA élimine les HAP et le NP mais les performances restent insatisfaisantes. L’objectif de cette thèse est d’améliorer les performances d’élimination des HAP et NP par la DA en utilisant l’électrolyse microbienne et l’ajout des matériaux conducteurs. Les résultats montrent que le graphite poreux permet de lever deux limites à la bioremédiation des HAP: le manque d'accepteurs d'électrons terminaux et la biodisponibilité limitée des HAP. En effet, le graphite poreux semble faciliter l'échange direct d'électrons avec la communauté syntrophique anaérobie ce qui améliore les performances d’hydrolyse de la matière et des contaminants associés, particulièrement, l’élimination de 12 HAP est accrue de 21 à 33 %. Pour le NP, les processus impliqués semblent être différents car aucune amélioration n’est observée quelles que soient les conditions.. L’addition du graphite non-poreux (avec une surface spécifique moindre) et du platine (avec une conductivité plus élevée) n’éliminait que deux HAP de faible poids moléculaire suggérant que la conductivité ne constitue pas un facteur majeur dans la dissipation des HAP. L’ajout du graphite poreux en plus grande quantité, par contre, n’a pas confirmé l’hypothèse qu’une augmentation de surface spécifique du matériau conducteur accroit également l’élimination des HAP. Lors de la DA assistée par différents matériaux, un enrichissement de méthanogènes hydrogénotrophs a été constaté qui pourra être à la racine des performances observées. Dans ce contexte, la composition microbienne de l’inoculum joue un rôle majeur dans l’ampleur d’une biodégradation des HAP. L'utilisation de matériaux conducteurs abordables tels que le graphite poreux et non-poreux pourrait présenter une stratégie de biodégradation alternative pour éliminer les HAP des boues, du sol ou des sédiments. / The elimination of organic micropollutants from the environment has become a public health goal today because of their toxicity and bioaccumulation through the trophic chain. Polycyclic aromatic hydrocarbons (PAHs) and nonylphenol (NP) are found at low concentrations in wastewaters. They are removed from wastewaters by sorption onto sewage sludge due to their hydrophobicity. Anaerobic digesiton (AD) that is used for sewage sludge treatmentThe treatments of these sludge, like anaerobic digestion (AD), therefore, plays a central role in reducing the micropollutant load before dissemination to the environment via sludge spreading. Removal performances of PAHs and NP are removed byunder AD are, yet, but limitedwith low performances. The aim of this PhD work is to enhance removalthese performances thanks to the use of two emerging techniques, microbial electrolysis and the addition of conductive materials. The results demonstrate that independent of the application of a potential porous graphite circumvents two limits of PAH bioremediation: the lack of terminal electron acceptors and PAHs’ limited bioavailability. Mediatorless electron exchange between the anaerobic syntrophic community and the conductive material presumably facilitates sludge hydrolysis which, in turn, leads to the enhanced bioavailability of PAHs and their subsequent biodegradation. The reductions of 12 PAHs were improved by 21 to 33% while NP was eliminated to the same extent in the digesters with and without conductive material. The addition of non-porous graphite (with less specific surface) and platinum (exhibiting higher conductivity) eliminated only two low molecular weight PAHs suggesting that conductivity is not a major factor in the dissipation of PAHs. The addition of porous graphite in larger quantities, however, did not support the hypothesis that an increase in specific surface area of the conductive material also enhances the removal of PAHs. During conductive material supplemented AD, an enrichment of hydrogenotrophic methanogens was ascertained which could be at the root of the removal performance. In this context, the microbial composition of the inoculum plays a major role in the extent of PAH biodegradation. The use of affordable conductive materials such as porous and non-porous graphite may present an alternative biodegradation strategy for removing PAHs from sludge, soil or sediments.
433

Compréhension et optimisation du traitement biologique anaérobie des coproduits de l’industrie sucrière / Study and optimisation of the anaerobic digestion of coproducts from the sugar industry

Tozy, Rita 07 October 2016 (has links)
Intégrée dans une unité de production de sucre et d'éthanol, la digestion anaérobie peut fournir une solution écologique pour traiter la matière organique tout en fournissant l'énergie qui peut, en partie, couvrir les besoins énergétiques de l'usine. L’objet de cette thèse de doctorat est la compréhension et l’optimisation de la méthanisation des coproduits de sucrerie et de distillerie de betterave dans l’optique d’une intégration industrielle du procédé. D’une part, la faisabilité de la digestion des pulpes en mono-substrat et sans dilution en réacteur parfaitement agité a été démontrée. La digestion thermophile s’est révélée efficace et stable jusqu’à une charge organique comprise entre 5 et 5,9 kg MO/m3.j. La biodégradabilité des pulpes est élevée, le taux d’abattement de matière organique de 88,1% et la production spécifique de méthane de 0,353 Nm3 CH4/kg MO. Des contraintes technologiques spécifiques aux pulpes, comme par exemple les phénomènes de moussage ou d’abrasion des pompes, ont été mises en évidence.D’autre part, la méthanisation des vinasses en conditions mésophiles a révélé les limites du procédé parfaitement agité. La charge maximale, autour de 3 kg DCO/m3.j, a permis d’obtenir une production spécifique de méthane de 0,353 Nm3 CH4/kg MO mais l’accumulation de sels d’acides gras volatils, y compris à faible charge organique, indique un déséquilibre entre les flores acidogène et méthanogène. D’un point de vue biologique, il semble que c’est la concentration élevée en sels des vinasses (C=31,7 mS/cm et [K]=14 g/L), qui représenterait le frein principal au développement et à l’activité des microorganismes. L’utilisation du modèle AM2, qui distingue deux phases, acidogénèse et méthanogénèse, a mis en évidence un faible taux de croissance spécifique des archées méthanogènes. L’extraction partielle des sels par électrodialyse a permis de lever une partie de cette inhibition, tandis que leur dilution a permis, à charge organique équivalente, de diminuer le temps de séjour d’un facteur 4 sans altérer les performances de la méthanisation, ceci en diminuant les concentrations en acétate et propionate dans le digesteur. Pour permettre l’intensification du procédé, le recyclage des microorganismes dans le digesteur a été étudié et a permis d’atteindre une charge organique de 6 à 7 kg DCO/m3.j. Enfin, la caractérisation des digestats de méthanisation a permis d’envisager leurs différentes voies de traitement (évapoconcentration, séparation solide/liquide,…) et de vérifier leurs caractéristiques agronomiques.En perspective, Cristal Union envisage la construction d’un démonstrateur permettant de tester différentes configurations à l’échelle industrielle. Le traitement successif des coproduits selon leur disponibilité, les pulpes en campagne sucrière, puis les vinasses en intercampagne, est envisagé. Les phases de transition entre ces deux périodes ont été étudiées et la faisabilité d’une alimentation mixte, sans réduction de la charge, démontrée. Dans cette optique, notre choix se porterait sur des conditions de température mésophiles, plus favorables au traitement d’un produit tel que les vinasses. Un système de recyclage de la biomasse est alors indispensable. / The growing international demand for energy and water constitutes a significant challenge for modern industry. Integrated in a sugar and ethanol factory, anaerobic digestion can provide an environmentally friendly solution by using organic matter co-products to provide energy that can partially cover the factory’s needs. The purpose of this doctoral thesis is the study of the anaerobic digestion of sugar beet pulps and distillery vinasses. We used a multiscale approach to achieve the two main objectives: understanding the biological phenomena involved and analyzing the technological problems that can occur in the digesters. We first demonstrated the feasibility of the anaerobic digestion of beet pulps in a continuously stirred tank reactor (CSTR) without water addition. Thermophilic digestion was effective and we achieved a high degradation of pulps with satisfactory biogas yields. The thermophilic process could operate stably up to an organic loading rate of 5 to 5,9 kg VS.m-3.d-1. The biodegradability of pulps was very high and allowed to obtain a VS destruction of 88,1% with a specific methane production of 0,353 Nm3 CH4.kg-1 VS. Next, the mesophilic anaerobic digestion of vinasses revealed the limits of the CSTR process for the treatment of this high strength distillery wastewater. The maximum loading rate reached was between 2 and 3 kg COD.m-3.d-1, with a specific methane production of 0,344 Nm3 CH4.kg-1 VS. However, the accumulation of volatile fatty acid salts, even at low organic loading rates, indicated an imbalance between acidogenic and methanogenic microflora. From a biological perspective, we assumed that the high salt concentration of vinasses (up to 41,3 mS/cm) is the main obstacle to the development and activity of microorganisms, as a two-reaction model (AM2) showed low specific growth rate of methanogens. The partial extraction of salts by electrodialysis allowed to remove a part of this inhibition, while their dilution led, at equivalent organic loading rate, to the reduction of the residence time by a factor 4. This was achieved without decreasing methane yield, while also reducing concentrations of acetate and propionate in the digester. To enable process intensification, biomass recycling in the digester, after the centrifugation, was tested to compensate for their low specific growth rates; loading rates reached 7 kg COD.m-3.d-1. We subsequently put in place a strategy for digesters control, to ensure effective monitoring. Finally, we had to characterize the digestates and to consider their different treatment paths. (evapoconcentration, solid / liquid separation, ...) before final valorization. For the industrial scale up, we envisage the successive treatment of the coproducts according to their availability: pulps during the sugar campaign and then vinasses in the intercampaign. As such, we also studied the transition periods and demonstrated the feasibility of a mixed feed, without reducing the loading rate. For such a project, we would choose mesophilic temperature conditions, more favorable for the treatment of a product like vinasses. A system for biomass recycling, whose efficiency was demonstrated, must be installed when the vinasses are treated. The system needs to be compatible with the treatment of the two substrates proposed, for example centrifugation or filtration.
434

Influência de diferentes composições de resíduos alimentares no processo de biometanização /

Blasius, Jandir Pereira January 2019 (has links)
Orientador: Marcus César Avezum Alves de Castro / Resumo: No Brasil são geradas quantidades significativas de resíduos orgânicos provenientes das perdas no segmento de produção e processamento da cadeia de fornecimento de alimentos, ou desperdiçadas no varejo e no consumo final. Ainda, no país há carência de aplicações do processo de digestão anaeróbia no tratamento dos resíduos orgânicos alimentares, tornando pertinente seu estudo. Este trabalho analisou a influência de diferentes proporções de resíduos alimentares no processo de biometanização. Os substratos consistiram de resíduos orgânicos coletados em restaurante universitário, sendo divididos em dois grupos: Resíduos de Pré-Preparo dos alimentos (RPP) e Resíduos de Sobras das refeições (RS). Testes em batelada foram realizados para avaliar o Potencial Bioquímico de Metano (BMP) das diferentes proporções de resíduos, sob condições mesofílica e termofílica, tendo como fontes de inóculos dois lodos anaeróbios granulares provenientes de reatores UASB (Upflow Anaerobic Sludge Blanket). Para verificar a atividade dos lodos foram realizados testes de Atividade Metanogênica Específica (AME), tendo o acetato como fonte de carbono, com aplicação de diferentes relações Substrato/Inóculo (So/Xo) (0,5, 1,0 e 1,5). Os resultados dos testes de AME sob condições mesofílica e termofílica demonstraram bom desempenho dos inóculos com índices 0,1965 e 0,1559 g DQOCH4.g STV-1.d-1, respectivamente, sendo que a relação So/Xo=1,0 foi a mais indicada para aplicação na biodigestão anaeróbia dos resíduo... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In Brazil, significant amounts of organic waste are generated from losses in the production and processing segment of the food supply chain, or wasted on retail and final consumption. Still, in the country there is a lack of applications of the anaerobic digestion process in the treatment of organic food residues, making its study pertinent. This work analyzed the influence of different proportions of food residues on the biomethanization process. The substrates consisted of organic residues collected in a university restaurant, being divided into two groups: Food Pre-Preparation Residues (RPP) and Residues of Leftovers from meals (RS). Batch tests were carried out to evaluate the Biochemical Potential of Methane (BMP) of the different proportions of residues, under mesophilic and thermophilic conditions, having as inoculum sources two granular anaerobic sludge from UASB (Upflow Anaerobic Sludge Blanket) reactors. In order to verify the activity of the sludges, tests of Specific Methanogenic Activity (AME) were carried out, with acetate as carbon source, applying different Substrate/Inoculum (So/Xo) ratios (0.5, 1.0 and 1.5). The results of the AME tests under mesophilic and thermophilic temperatures showed good performance of the inoculum with indexes 0.1965 and 0.1559 g DQOCH4.g STV-1.d-1, respectively, with the ratio So/Xo=1.0 was the most indicated for application in anaerobic biodigestion of food waste. BMP tests under different proportions of food residues demonstrated ... (Complete abstract click electronic access below) / Mestre
435

Devenir des antibiotiques lors du traitement aérobie et anaérobie des boues de STEPs pour une valorisation agronomique / The fate of antibiotics during aerobic and anaerobic treatment of sludges from WWTPs for an agronomic valorisation

Ezzariai, Amine 15 September 2018 (has links)
L’utilisation massive des antibiotiques contribue à leur accumulation dans les boues des stations d’épurations. L’application directe des boues est parmi les sources de dissémination des antibiotiques et des gènes de résistance aux antibiotiques. Le compostage et la méthanisation sont parmi les bioprocédés de traitement des boues qui permettent d’éliminer ou réduire les teneurs de certains antibiotiques. Dans ce travail, une boue primaire de la STEP de Marrakech a été contaminée par trois familles d’antibiotiques (macrolides, tétracyclines, fluoroquinolones) pour conduire 4 essais de compostage à différentes doses (dont un essai témoin) et un essai deméthanisation en mode semi-continu. Les résultats du compostage ont montré que l’augmentation des concentrations d’antibiotiques retarde la dégradation de la matière organique et affecte le ratioC/N. De même, la phase thermophile est perturbée, retardée et réduite dans le temps. Pour la méthanisation, une concentration unique et réaliste a été testée. Dans ces conditions, aucun effet sur la production du biogaz ou sur la dégradation de la matière organique n’a été observé. Afin de suivre la dissipation des trois familles d’antibiotiques utilisées au cours du compostage et de la méthanisation, une approche analytique basée sur l’extraction accélérée par solvant (ASE) suivie par l’application d’une méthode des ajouts dosés avant quantification par chromatographie liquide couplée à de la spectrométrie de masse en tandem (UPLC-MS/MS) a du être mise en point. Le compostage et la méthanisation permettent de réduire significativement les concentrations des molécules parents appartenant à la famille des macrolides et des tétracyclines. Par contre,l’élimination des fluoroquinolones est non-significative et ne dépasse pas 30%. Au cours du compostage, la dissipation des macrolides se fait en phase de stabilisation tandis que la phase de maturation est impliquée dans la dissipation des tétracyclines. Les concentrations encirprofloxacine (fluoroquinolone) semblent légèrement évoluer au cours du procédé probablement en raison d’une adsorption/désorption sur le co-substrat lignocellulosique utilisé. Concernant la méthanisation, l’élimination des macrolides et des tétracyclines est significative durant la stabilisation du procédé mais n’atteinds pas les rendements observés lors du compostage. Ladiminution des concentrations des molécules parents est probablement accompagnée par une biotransformation des antibiotiques sous forme de métabolites qui à ce stade ne sont pas connus.La question de la rémanence de certaines molécules comme les fluoroquinolones, interpelle quand au risque d’antibiorésistance. Ainsi, la valorisation des composts/digestats comme amendements organiques des sols dois à terme conduire à une réflexion concernant la réglementation qui inclus la présence de molécule de la classe des antibiotiques. / The intensive use of antibiotics for human purposes leads to their presence and accumulation inthe sludge produced from wastewater treatment plants. The direct application of sludge is amongthe sources of dissemination of antibiotics and antibiotics resistance genes. Composting andanaerobic digestion are some of the most used bioprocess for sludge treatment, and which allowthe removal/decrease of some antibiotics families. In this work, a primary sludge from thewastewater treatment plant of Marrakesh was spiked using 3 families of antibiotics (macrolides,tetracyclines, fluoroquinolones) to conduct (1) 4 composting experiments with variousconcentrations levels, and (2) an anaerobic digestion experiment in a semi-continuous mode.Composting results showed that the organic matter degradation was delayed and the C/N ratiowas affected by an increase of antibiotics concentrations. Likewise, the thermophilic stage wasdisturbed, the heat release was affected and the coming of the temperature maxima was delayed.In the other hand, one realistic concentration was used during the anaerobic digestion. In thiscondition, no effect was observed especially on the biogas production as well as the organicmatter degradation. To assess the fate of antibiotics during composting and anaerobic digestion,an analytical approach based on the accelerated solvent extraction followed by the standardaddition method and the UPLC-MS/MS was developed. Composting and anaerobic digestion leadto a significant removal of parent compounds belonging to the family of macrolides andtetracyclines. In contrast, the fluoroquinolones removal is not-significant and has not exceeded30%. During composting, the thermophilic stage was responsible on macrolides elimination. Incontrast, the maturation stage was more implicated on the removal of tetracyclines. Ciprofloxacin(fluoroquinolone) showed some fluctuations in concentrations. The sorption/desorption on palmrachis could probably explain the observed behavior of this molecule during composting. Duringthe anaerobic digestion, the removal of macrolides and tetracyclines was significant, within thestabilization, but still lower than the observed ones during composting. The decrease of parentcompounds of antibiotics is probably accompanied by a biotransformation of these compounds inunknown metabolites. The presence of recalcitrant compounds after the bioprocess could promotethe development of resistant bacteria including pathogens. In the future regulations, thevalorization of compost/digestate as an amendment of agricultural soil requires taking into accountthe presence of antibiotics.
436

Analyse du traitement et de la gestion durable des boues d’épuration en Corse. Proposition de solutions énergétiques alternatives, axées sur la méthanisation des boues avec production d’énergies, aux méthodes appliquées en Corse. Utilisation de l’outil d’aide multicritère à la décision dans le cadre du surclassement de ces nouveaux procédés / Analysis of treatment and management of sewage sludge in Corsica. Proposal for alternative energy solutions, focusing on methanisation of sludge with production of Energies, to methods applied in Corsica.Use of the multicriteria decision support tool in the context of the upgrade of these new processes.

Tramoni, Félicien 15 December 2015 (has links)
La qualité des boues est directement liée à la qualité des étapes de traitement présentes au sein d’une station d’épuration. En termes de traitement et d’élimination des boues, nous observons de la part des acteurs locaux, une volonté d’abandon définitif et durable de la filière « dépôt en centre de stockage », étant donnée une règlementation et des plans régionaux (notamment le PREDIS de Corse), toujours plus exigeant en termes de valorisations des déchets industriels et spéciaux. Nous observons également un abandon progressif et programmé des pratiques relatives à l’épandage. En effet, l’épandage des boues d’épuration fait l’objet d’une vaste controverse qui met en avant les risques sanitaires et environnementaux qu’elle engendrerait sur les sols agricoles. Au sein de notre région, cette pratique est réalisée de manière non règlementaire. En Corse, les acteurs locaux semblent avoir optés pour la solution du compostage en vue de valoriser la production de boues d’épuration. En effet, près des 2/3 du tonnage annuel en MS de boues sont actuellement valorisés via cette filière. Le processus de compostage équivaut à une fermentation aérobie, faisant intervenir une multitude de micro-organismes. Cette filière de compostage, au même titre que l’épandage, a connu une forte expansion de son activité mais semble avoir des failles et des limites : problèmes de mauvaises odeurs ; règlementation de plus en plus exigeante ; et enfin surproduction de compost invendable aux vues de la demande. Une autre solution pourrait présenter des atouts supérieurs : la méthanisation avec production d’électricité et de chaleur par cogénération. Cette production d’énergies passe obligatoirement par la valorisation du biogaz produit par ce système. En effet, le biogaz est un mélange contenant principalement du méthane (50 à 70%) et du dioxyde de carbone Du fait d’une forte concentration en méthane, le biogaz est un bon fournisseur d’énergie (1m3 de biogaz a un pouvoir calorifique de 6 kWh soit l’équivalent de 0,6 l de fuel). Pour produire de l’électricité, le processus de méthanisation doit être couplé à un moteur à cogénération ou à plusieurs microturbines. EDF a alors l’obligation de racheter l’électricité produite à un prix se situant entre 11 et 14 centimes d’euros/kwh., Après 15 ans, le rachat du kwh produit se fait aux taux proposés par EDF. En Corse, seulement une station d’épuration est équipée d’un digesteur couplé en série à cinq microturbines, produisant de la chaleur et de l’électricité par cogénération : La station de traitement des eaux usées de Campo Dell’Oro à Ajaccio. Ce procédé de valorisation énergétique pourrait être amélioré via le remplacement à terme, des microtubines par un moteur à cogénération. Une AMCDP a notamment permis de surclasser cette technologie vis-à-vis des microturbines, beaucoup moins efficaces en termes de rendement mais aussi de fonctionnement. L’équipement des stations d’épuration de plus fortes capacités en Corse, de digesteurs associés à un moteur à cogénération pourrait être une solution durable à la problématique de la valorisation énergétique des boues. / Sludge quality is directly related to the quality of of these processing steps present in a water treatment plant. In terms of treatment and disposal of sludge, we observe on the part of local actors, a willingness to permanent and lasting abandonment of the sector 'deposit in storage centre'', given a regional plans and regulations (including the PREDIS Corsica), increasingly demanding in terms of valuations of industrial and special waste. We also observe a gradual and planned abandonment of practices for spreading. Indeed, the spreading of sewage sludge is the subject of widespread controversy which highlights the health and environmental risks it would lead to agricultural soils. In our region, this practice is not carried out regulatory manner. In Corsica, the local actors seem to have opted for the solution of compost to enhance the production of sewage sludge. Nearly 2/3 of the annual tonnage MS sludge is currently valued via this pathway. The composting process is equivalent to an aerobic fermentation involving a multitude of microorganisms. This composting stream, as well as spreading, experienced strong expansion of its business but seems to have flaws and limitations: problems with odors; regulatory increasingly demanding; and finally overproduction unsaleable compost to the views of the application.Another solution could present higher advantages: anaerobic digestion with production of electricity and heat from cogeneration. . This energy production go through the biogas produced by this system. Indeed, the biogas is a mixture containing mostly methane (50 – 70 %) and carbon dioxide. Due to a high concentration of methane, biogas is a good energy supplier (1m3 biogas has a calorific value 6 kWh equivalent to 0.6 liters of fuel). To generate electricity, the anaerobic digestion process must be coupled to an engine cogeneration or several microturbines. EDF has the obligation to purchase electricity at a price ranging between 11 and 14 euro cents/kwh. After 15 years, the redemption of the kwh produced is done at the rate offered by EDF.In Corsica, only a treatment plant is equipped with a digester coupled in series to five microturbines, producing heat and electricity cogeneration: The wastewater treatment plant at Campo Dell'Oro /Ajaccio. This energy recovery process could be improved with an eventual replacement of the microtubines by a cogeneration engine. An AMCDP allowed to outperform this technology towards microturbines, much less efficient in terms of performance.The equipment of the highest capacity treatment plants in Corsica, digesters associated with a cogeneration engine could be a lasting solution to the problem of energy recovery of sewage sludge.
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Rôle des gaz dissous dans la digestion anaérobie par voie sèche de déchets ligno-cellulosiques / Impact of dissolved gas on dry anaerobic digestion of lignocellulosic residues

Cazier, Elisabeth, A. 26 November 2015 (has links)
La digestion anaérobie par voie sèche est un procédé de valorisation des déchets organiques qui est défini par une teneur en matière sèche supérieure à 15%. Ce procédé est particulièrement adapté aux déchets ligno-cellulosiques puisqu’il ne nécessite qu’un ajout limité en eau. Cependant, la digestion anaérobie est inhibée pour des teneurs en matière sèche élevées, due à une diminution des transferts gaz-liquide au sein du milieu qui provoquerait des accumulations locales de produits inhibiteurs comme les gaz dissous. L’objectif de cette thèse est donc de comprendre le rôle des gaz dissous dans la digestion anaérobie par voie sèche à l’échelle microscopique et mésoscopique. Les principaux résultats montrent que l’hydrogène inhibe spécifiquement l’hydrolyse de la matière ligno-cellulosique à l’échelle microscopique. Cette inhibition est réversible en ajoutant du dioxyde de carbone, par consommation de l’hydrogène, avec cependant des effets rémanents inhibiteurs visibles sur la méthanogenèse et la dégradation de l’acétate. A l’échelle mésoscopique, la diminution des transferts de matière inhiberait l’hydrolyse, par l’accumulation locale d’hydrogène. De plus, un gradient de concentration d’hydrogène se met en place et serait responsable du gradient de concentration des acides gras volatils au sein du milieu. De plus, l’ajout de dioxyde de carbone à l’échelle mésoscopique avec un transfert gaz-liquide limitant augmente la concentration en acides gras volatils et baisse le pH du milieu, ce qui indique le rôle important du dioxyde de carbone dans la diminution des performances de la digestion anaérobie pour de fortes teneurs en matières sèches. / Dry anaerobic digestion is a method of organic waste treatment and conversion to bioenergy, defined by a total solid content over 15%. This process is particularly suitable for lignocellulosic residues since the quantity of water to be added for the process is rather limited. However, dry anaerobic digestion processes is inhibited for a high total solid content, due to a decrease of the gas-liquid transfer within the medium, which may cause local accumulations of inhibitory byproducts, such as dissolved gases. This thesis aims to better understand the role of dissolved gas in dry anaerobic digestion at microscopic and mesoscopic scale. It was shown that hydrogen can inhibit specifically the hydrolysis step of lignocellulosic residues at microscopic level. This inhibition was reversible after addition of carbon dioxide, with remaining inhibitory effect on the acetate degradation and methanogenesis. At mesoscopic scale, the decrease of the mass transfer inhibits the hydrolysis, by dissolved hydrogen accumulation. Moreover, a local hydrogen concentration gradient was present and seems responsible for a concentration gradient of volatile fatty acids in the medium. Moreover, adding carbon dioxide at mesoscopic scale, with a limited gas-liquid transfer, increased the volatile fatty acids concentration and decreased the pH, which showed the important role of carbon dioxide in the inhibition of anaerobic digestion under high dry matter content.
438

TRATAMENTO BIOLÓGICO DE EFLUENTES DE LAVA-JATO

Costa, Maria José Comandante 21 February 2006 (has links)
Made available in DSpace on 2015-09-25T12:23:32Z (GMT). No. of bitstreams: 1 MARIA_JOSE_COMANDANTE_COSTA.pdf: 1369694 bytes, checksum: 2b63fa3023c60448918ab6ae6b29a54f (MD5) Previous issue date: 2006-02-21 / The research was realized in four phases. In the 1st phase, interviews were accomplished with proprietors of car-washes with the objective of knowing your environmental and social impacts. In the 2nd phase synthetic effluents of car-washes were treated during 147 days in batch anaerobic reactors with five different oil and detergent concentrations. In the 3rd phase six reactors were monitored in batch form, during 20 days, with substrate containing high oil concentrations (0,5 to 2,5 g.l-1) and surfactants concentrations (5,0g.L-1). These treatments were realized with purpose to verified the relation between oil concentration and inhibition of the biologic activity. In the 4th phase six batch anaerobic reactors, with different proportions of the surfactant, were monitored during 35 days. The concentrations of organic matter influent and effluent were analyzed in all the treatments and in the sludge were determined solid concentration. Daily the biogas produced was measures and characterized. In the 2nd phase the average removal of soluble COD was about 82%, for a monitoring period of 18 days. For raw COD during 100 days of operation the average removal was approximately 76% and the production of methane was directly proportional the substrate concentrations. It was verified that the anaerobic biological activity occurs in surfactant concentration below 0,5 g.L-1, and starting from that concentration it begins to happen inhibition of the process. / O presente trabalho foi desenvolvido em quatro fases. A primeira fase teve o objetivo de levantar dados sobre os impactos ambientais e sociais causados pelos lava-jatos. Para tanto, foram realizadas entrevistas com seus proprietários. Na segunda fase, foram tratados anaerobiamente, durante 147 dias, em reatores de batelada, efluentes sintéticos de lava-jatos com cinco diferentes concentrações de óleo e detergente. Na terceira fase, foram monitorados seis reatores anaeróbios, em regime de batelada, durante 20 dias, com substratos contendo altas concentrações de óleo (0,5 a 2,5 g.L-1) e surfactantes (5,0 g.L-1). Estes tratamentos tiveram por finalidade verificar se, com o aumento da concentração de óleo, haveria inibição da atividade biológica. Na quarta fase, foram realizados, anaerobiamente, em reatores de batelada, durante 35 dias, seis experimentos com diferentes concentrações de surfactante para verificar que concentração inibiria o processo biológico anaeróbio. Para todos os tratamentos foram analisadas as concentrações de matéria orgânica (DQO) afluente e efluente, bem como as concentrações de sólidos do lodo. Diariamente, foram realizadas leituras do volume e da composição do biogás. Como resultados da segunda fase, verificaram-se remoções de DQO solúvel média de 82% aos 18 dias e para DQO bruta em torno de 76% para os cinco tratamentos, durante 100 dias de operação. A produção de metano foi diretamente proporcional às concentrações dos substratos. Constatou-se que a atividade biológica anaeróbia ocorre numa concentração de surfactante de até aproximadamente 0,5 g.L-1, sendo que a partir daí, começa a ocorrer inibição do processo.
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O tratamento dos resíduos orgânicos como cumprimento da Política Nacional de Resíduos Sólidos: análise dos planos municipais da bacia do Alto Tietê / The treatment of organic waste as a fulfillment of the National Policy on Solid Waste: analysis of municipal plans Alto Tietê\'s Basin

Caio Souza Pires 12 April 2013 (has links)
A pesquisa teve como objetivo estudar as possibilidades de tratamento, aeróbio e anaeróbio, da fração orgânica dos Resíduos Sólidos Urbanos (RSU) de forma a atender ao disposto na Política Nacional de Resíduos Sólidos (PNRS). Além de ser previsto em lei, o tratamento da fração orgânica se faz necessário já que no Brasil são gerados quase 100 mil toneladas por dia de resíduos orgânicos. A maioria desses resíduos é atualmente disposta em aterros sanitários. Porém, a PNRS determina que a partir de agosto de 2014 apenas sejam dispostos em Aterros Sanitários os rejeitos, resíduos os quais já se esgotaram as possibilidades técnicas e econômicas de tratamento. Verificou-se que os resíduos orgânicos podem ser tratados através da compostagem e biodigestão. Outro objetivo da pesquisa foi analisar os objetivos relacionados ao tratamento da fração orgânica dos RSU dos Planos Municipais de Gerenciamento Integrado de Resíduos Sólidos (PMGIRS) dos municípios da bacia hidrográfica do Alto Tietê. Esses planos são outra obrigatoriedade prevista na PNRS. Essa lei determinou um prazo (Agosto de 2012) para que os municípios tivessem apresentado seus planos e, assim, tivessem acesso aos recursos da União destinados a gestão e o gerenciamento de resíduos sólidos. A Bacia em estudo está localizada na região sudeste e possui 34 municípios. Juntos, esses municípios geram mais de 12 mil toneladas por dia de resíduos orgânicos. De todos os municípios da bacia apenas sete, aproximadamente 20%, apresentaram o PMGIRS. As metas relacionadas ao tratamento de resíduos orgânicos dos PMGIRS estudados foram avaliadas e, dos sete municípios que apresentaram o plano municipal, apenas dois apresentaram metas favoráveis, dois apresentaram metas intermediárias e dois apresentaram metas desfavoráveis, segundo critério de classificação apresentado pela prévia do Plano Nacional de Resíduos Sólidos. Apenas um município não apresentou nenhuma meta relacionada ao tratamento de resíduos orgânicos. Após análise dos PMGIRS foi proposto um modelo de gestão da fração orgânica dos RSU para os municípios da bacia do Alto Tietê. / The research studied the treatment possibilities for the organic fraction of municipal solid waste (MSW) in order to meet the provisions of the National Policy on Solid Waste (PNRS). Besides being provided by law, the treatment of the organic fraction is necessary since in Brazil are generated almost 100 tons per day of organic waste. Most of this waste is currently disposed of in landfills. However, PNRS determines that from 2014 only tailings, waste which has already exhausted the technical and economical possibilities of treatment, can be disposed in landfills. It was found that the organic waste can be treated by composting and digestion. Another objective of the research was to analyze the objectives related to the treatment of the organic fraction of MSW presented by the Municipal Plans for Integrated Solid Waste Management (PMGIRS) of the municipalities of Alto Tietê basin. These plans are another requirement provided for in PNRS. This law set a deadline (August 2012) for the municipalities had submitted their plans and thus have access to the resources of the Union for the solid waste management. The study basin is located in the Brazilian southeastern region and has 34 municipalities. Together, these municipalities generate more than 12 tons of organic waste per day. Only seven (20%) of all the municipalities of the basin showed the PMGIRS. The goals related to the treatment of organic waste were evaluated, and of all PMGIRS that were presented only two had positive goals, other two had intermediate goals and two had unfavorable goals, according to classification criteria presented by the National Plan of Solid Waste. Only one municipality did not have any goals related to organic waste treatment. After analyzing the PMGIRS was proposed a management model for the organic fraction of MSW for the municipalities of Alto Tietê basin.
440

Efeito da variação gradual da taxa de recirculação do lixiviado em reatores anaeróbios híbridos na digestão da fração orgânica dos resíduos sólidos urbanos / Effect of the gradual variation of the leachate recirculation rate in hybrid anaerobic reactors treating the organic fraction of municipal solid wastes

Gabriel D'Arrigo de Brito Souto 09 June 2005 (has links)
O presente estudo teve por finalidade testar a hipótese de que o uso de uma taxa de recirculação variável do lixiviado de um reator tratando a fração orgânica dos resíduos sólidos urbanos domésticos, em um sistema em batelada híbrido, seria capaz de acelerar a degradação deste substrato em comparação com um sistema idêntico, porém que operasse com taxa de recirculação constante. Dois conjuntos de reatores foram operados, um com taxa de recirculação constante (sistema controle) e o outro com taxa de recirculação variável (sistema experimental). Os reatores foram mantidos em sala climatizada, com temperatura mantida em 35 ºC '+ OU -' 1 ºC. Cada conjunto era composto de um reator de sólidos, preenchido com o resíduo a ser digerido misturado a lixiviado de aterro sanitário, e um filtro anaeróbio, destinado a tratar o lixiviado que saía do primeiro. O substrato utilizado foi a fração orgânica dos resíduos sólidos urbanos domésticos padronizada (FORSUDp). Diversas variáveis foram medidas para o acompanhamento do processo: DQO de amostras filtradas e não filtradas, alcalinidade total, alcalinidade a ácidos voláteis, série de sólidos, nitrogênio total Kjeldahl e amoniacal, fósforo total, ácidos voláteis e composição do biogás por cromatografia gasosa. Também se acompanhou o desenvolvimento da microbiota anaeróbia por microscopia óptica de contraste de fase e fluorescência. A microscopia eletrônica de varredura indicou desenvolvimento de biofilme no meio suporte dos filtros anaeróbios. Concluiu-se que a taxa de recirculação variável consegue acelerar o processo, além de alterar de forma significativa o comportamento dos reatores e a forma de interação entre os mesmos / The objective of this study was to test the following hypothesis: varying the leachate recirculation rate in a hybrid batch reactor would make it possible to shorten the time required for the digestion of MSW, in comparison to a similar system operating with constant recirculation rate. Two sets of reactors were operated, one with constant recirculation rate (control system) and the other with varying rate (experimental system). The reactors were kept in a room which internal temperature was controlled. The temperature was kept at 35 ºC '+ OU -' 1ºC. Each set of reactors was composed of a solids reactor, filled with solid wastes and inoculated with landfill leachate, and an anaerobic filter, that should treat the leachate form the first one. The substract used was the standardized organic fraction of the municipal solid wastes (FORSUDp). Several parameters were measured for process monitoring: COD (in filtered and not filtered samples), total alkalinity, volatile acids alkalinity, solids, Kjeldahl nitrogen, ammonium nitrogen, total phosphorus, volatile acids by gas chromatography and biogas composition. The development of the anaerobic microorganisms was observed with phase-contrast and fluorescence microscopy. Scanning electron microscopy of the packed bed media showed biofilm development. It was concluded that the varying leachate recirculation rate proved to be able to enhance the degradation process. Besides, this operational strategy entirely changed the behaviour and interaction of the reactors

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