Made available in DSpace on 2017-05-12T14:46:50Z (GMT). No. of bitstreams: 1 Taiana.pdf: 1049826 bytes, checksum: 6b4cf77a1f5c7d5f54a87597ae4844ae (MD5) Previous issue date: 2013-04-04 / Sheep litter has in its composition manures incorporated to rice husk, which is a lignocellulosic material. Materials with this characteristic are stabilized for longer period of time and have restrictions on decomposing since they present strong fractions that can, sometimes, be inaccessible to micro-organisms. Some alternatives have been used in order to easy these nutrients recycling, for example its ordinary mixing with another residue. Thus, this essay aimed at evaluating vermicomposting, composting and anaerobic co-digestion applied to sheep litter mixed with cattle manure in order to provide available conditions to change such residues. Three assays were carried out from five ratios of sheep litter and cattle manure: 0:100, 25:75, 50:50, 75:25 and 100:0, which represented treatments T100, T75, T50, T25 and T0, respectively. The process of vermicomposting was carried out from November 2011 to march 2012. The material has undergone a preparation in order to eliminate toxic composts. Then, 0.88 kg of dry mass and 15 adult worms (Eisenia foetida) were allocated in the vermireactor. The ≥ 45% ash content was the stability parameter adopted in this assay. The composting piles were carried out from April to July 2012 in a covered area of concrete floor. Each pile had 200 kg of dry mass and received manual turnings two times a week during the first month and weekly from then on. Composting was supervised until the piles reached values close to room temperature, when the material was stabilized. The experimental period for anaerobic co-digestion occurred from May to October 2012. An entry mixture diluted with water was made in order to obtain a 5% content of total solids. And for residues fermentation, PVC bench scale bio-digesters were used to storage 6 L volume of such material. An anaerobic co-digestion was carried out in a batch system and observed until the curve of biogas production had decreased. In all assays, the adopted experimental design was completely randomized with univariate and multivariate statistics for data evaluation. The results showed that 50% of cattle manure was necessary in the mixture so that sheep litter could be efficiently absorbed in composting and in anaerobic co-digestion. This ratio generated a compost and biofertilizer with greater stability and content of nutrients as well as provided a larger scale of biogas production. In vermicomposting, the sheep litter showed potential to be used in a ratio up to 75% in mixture with cattle manure for Eisenia foetida specie development. However, greater ratios than 25% have decreased the vermicompost quality and in all assays, the rice husk was not transformed. / A cama de ovinos é composta por dejeções incorporadas a um material lignocelulósico, a casca de arroz. Materiais com essa característica apresentam maior tempo de estabilização ou limitações na decomposição, pois são constituídos de frações resistentes, por vezes inacessíveis aos microrganismos. Algumas alternativas são utilizadas para facilitar a reciclagem desses nutrientes, como a simples combinação com outro resíduo. Com este propósito, objetivou-se avaliar a vermicompostagem, a compostagem e a co-digestão anaeróbia de cama de ovinos em mistura com dejetos bovinos a fim de que fossem fornecidas condições adequadas para a transformação dos resíduos. Os três ensaios foram realizados a partir de cinco proporções de cama de ovinos e dejetos bovinos: 0: 100, 25: 75, 50: 50, 75: 25 e 100: 0, os quais representavam os tratamentos T100, T75, T50, T25 e T0, respectivamente. A vermicompostagem foi conduzida de novembro de 2011 a março de 2012. O preparo do material foi realizado a fim de que fossem eliminados os compostos tóxicos. Posteriormente, foram depositados 0,88 kg de massa seca e 15 minhocas adultas da espécie Eisenia foetida nos vermireatores. O conteúdo de cinzas de ≥ 45% serviu de parâmetro de estabilidade adotado neste ensaio. As leiras de compostagem foram conduzidas de abril a julho de 2012, em pátio coberto e com piso em concreto. Cada leira contou com 200 kg de massa seca e foram realizados revolvimentos manuais duas vezes por semana no primeiro mês e semanalmente a partir desse momento. A compostagem foi acompanhada até as leiras apresentarem valores de temperatura próximos a ambiente, quando considerou-se o material estabilizado. Na co-digestão anaeróbia, o período experimental foi de maio a outubro de 2012. A mistura de entrada, diluída com água, foi feita a fim de obter-se o teor de sólidos totais de 5%. Para fermentação dos resíduos, utilizaram-se biodigestores de PVC de bancada com volume útil de 6 L. A co-digestão anaeróbia foi conduzida em sistema batelada e acompanhada até o decréscimo da curva de produção de biogás. O delineamento experimental adotado em todos os ensaios foi inteiramente casualizado, com emprego de análises estatísticas univariadas e multivariadas para avaliação dos dados. Os resultados demonstraram a necessidade de 50% de dejetos de bovinos na mistura, para que a cama de ovinos pudesse ser absorvida eficientemente na compostagem e na co-digestão anaeróbia. Essa proporção deu origem a um composto e biofertilizante com maior estabilidade e conteúdo de nutrientes, além de proporcionar maiores produções de biogás. Em vermicompostagem, a cama de ovinos apresentou potencial de ser utilizada em proporção de até 75% na mistura com dejetos bovinos, para desenvolvimento da espécie Eisenia foetida. Porém, proporções superiores a 25% diminuíram a qualidade do vermicomposto. A casca de arroz não foi transformada em todos os ensaios.

A indústria de laticínios no Brasil gerou no 2014 em torno de 88,5 bilhões de litros de efluente, o resíduo gorduroso (RG) separado no tratamento deste efluente, atualmente carece de tratamento. A digestão anaeróbia (DA) é uma opção de tratamento a partir da qual é possível, entre outras coisas, obter biogás, fonte renovável de energia, que representa uma importante alternativa para compor a matriz energética do país. No entanto, resíduos lipídicos, além de gerar lodos de difícil manejo, descompõem-se em ácidos graxos de cadeia longa (AGCL) que inibem os microrganismos metanogênicos. Como estratégia para tratar efetivamente este resíduo, avaliou se um sistema de co-digestão anaeróbia empregando RG advindo da caixa de gordura de um laticínio, e, bagaço de cana de açúcar (BCA) pré-tratado em condições sub e supercríticas de CO2: (i) 40°C / 70 bar (ii) 60°C / 200 bar e (iii) 80°C / 200 bar, com e sem adição de NaOH, respectivamente. Dos pré-tratamentos avaliados, destaca-se o pré-tratamento com CO2 a 60°C e 200bar pelo qual foi possível remover 8,07% de lignina. A produção metanogênica advinda da digestão anaeróbia de bagaço de cana de açúcar foi aumentada em todos os casos nos quais o material foi pré-tratado com CO2 sub e supercrítico, com exceção do caso no qual se utilizou elevada temperatura e NaOH como modificador de polaridade. Os resíduos advindos da caixa de gordura apresentaram elevado potencial metanogênico na faixa de concentração de substrato estudada, sem que nenhuma inibição fosse verificada. A co-digestão de resíduos gordurosos e bagaço de cana, pré-tratados ou não, não apresentou vantagem com relação à mono-digestão dos materiais. / The dairy industry in Brazil generated in 2014 around 88.5 billion litters of effluent, the fatty residue, separated in the treatment of this effluent, currently lacks treatment. Anaerobic digestion is a treatment option from which it is possible, among other things, to obtain biogas, a renewable source of energy, which represents an important alternative to fix the country\'s energy matrix. However, lipid residues form sludges that are difficult to manage and decompose into long chain fatty acids (LCFAs) that are inhibitory to methanogenic microorganisms. As a strategy to effectively treat this residue, we evaluated an anaerobic co-digestion system employing fatty residues from a fat box of a dairy plant, and sugarcane bagasse pre-treated under sub and supercritical CO2 conditions: (i) 40°C / 70 bar (ii) 60°C / 200 bar and (iii) 80°C / 200 bar, with and without addition of NaOH respectively. Of this pre-treatments, stood out the one with CO2 at 60°C and 200 bar by which was achieved the removal of 8.07% of lignin. The methanogenic production from the anaerobic digestion of sugarcane bagasse was increased in all cases in which the material was pre-treated with sub and supercritical CO2, with the exception to the cases in which high temperatures and NaOH were combined. The residues from the dairy fat box showed high methanogenic potential in the concentration range evaluated and no inhibition was verified. The co-digestion of the greasy residues and the sugarcane bagasse with and without pre-treatment, did not present advantage in compare to the mono-digestion of the materials.

Made available in DSpace on 2017-07-10T19:23:38Z (GMT). No. of bitstreams: 1 Taiana.pdf: 1049826 bytes, checksum: 6b4cf77a1f5c7d5f54a87597ae4844ae (MD5) Previous issue date: 2013-04-04 / Sheep litter has in its composition manures incorporated to rice husk, which is a lignocellulosic material. Materials with this characteristic are stabilized for longer period of time and have restrictions on decomposing since they present strong fractions that can, sometimes, be inaccessible to micro-organisms. Some alternatives have been used in order to easy these nutrients recycling, for example its ordinary mixing with another residue. Thus, this essay aimed at evaluating vermicomposting, composting and anaerobic co-digestion applied to sheep litter mixed with cattle manure in order to provide available conditions to change such residues. Three assays were carried out from five ratios of sheep litter and cattle manure: 0:100, 25:75, 50:50, 75:25 and 100:0, which represented treatments T100, T75, T50, T25 and T0, respectively. The process of vermicomposting was carried out from November 2011 to march 2012. The material has undergone a preparation in order to eliminate toxic composts. Then, 0.88 kg of dry mass and 15 adult worms (Eisenia foetida) were allocated in the vermireactor. The ≥ 45% ash content was the stability parameter adopted in this assay. The composting piles were carried out from April to July 2012 in a covered area of concrete floor. Each pile had 200 kg of dry mass and received manual turnings two times a week during the first month and weekly from then on. Composting was supervised until the piles reached values close to room temperature, when the material was stabilized. The experimental period for anaerobic co-digestion occurred from May to October 2012. An entry mixture diluted with water was made in order to obtain a 5% content of total solids. And for residues fermentation, PVC bench scale bio-digesters were used to storage 6 L volume of such material. An anaerobic co-digestion was carried out in a batch system and observed until the curve of biogas production had decreased. In all assays, the adopted experimental design was completely randomized with univariate and multivariate statistics for data evaluation. The results showed that 50% of cattle manure was necessary in the mixture so that sheep litter could be efficiently absorbed in composting and in anaerobic co-digestion. This ratio generated a compost and biofertilizer with greater stability and content of nutrients as well as provided a larger scale of biogas production. In vermicomposting, the sheep litter showed potential to be used in a ratio up to 75% in mixture with cattle manure for Eisenia foetida specie development. However, greater ratios than 25% have decreased the vermicompost quality and in all assays, the rice husk was not transformed. / A cama de ovinos é composta por dejeções incorporadas a um material lignocelulósico, a casca de arroz. Materiais com essa característica apresentam maior tempo de estabilização ou limitações na decomposição, pois são constituídos de frações resistentes, por vezes inacessíveis aos microrganismos. Algumas alternativas são utilizadas para facilitar a reciclagem desses nutrientes, como a simples combinação com outro resíduo. Com este propósito, objetivou-se avaliar a vermicompostagem, a compostagem e a co-digestão anaeróbia de cama de ovinos em mistura com dejetos bovinos a fim de que fossem fornecidas condições adequadas para a transformação dos resíduos. Os três ensaios foram realizados a partir de cinco proporções de cama de ovinos e dejetos bovinos: 0: 100, 25: 75, 50: 50, 75: 25 e 100: 0, os quais representavam os tratamentos T100, T75, T50, T25 e T0, respectivamente. A vermicompostagem foi conduzida de novembro de 2011 a março de 2012. O preparo do material foi realizado a fim de que fossem eliminados os compostos tóxicos. Posteriormente, foram depositados 0,88 kg de massa seca e 15 minhocas adultas da espécie Eisenia foetida nos vermireatores. O conteúdo de cinzas de ≥ 45% serviu de parâmetro de estabilidade adotado neste ensaio. As leiras de compostagem foram conduzidas de abril a julho de 2012, em pátio coberto e com piso em concreto. Cada leira contou com 200 kg de massa seca e foram realizados revolvimentos manuais duas vezes por semana no primeiro mês e semanalmente a partir desse momento. A compostagem foi acompanhada até as leiras apresentarem valores de temperatura próximos a ambiente, quando considerou-se o material estabilizado. Na co-digestão anaeróbia, o período experimental foi de maio a outubro de 2012. A mistura de entrada, diluída com água, foi feita a fim de obter-se o teor de sólidos totais de 5%. Para fermentação dos resíduos, utilizaram-se biodigestores de PVC de bancada com volume útil de 6 L. A co-digestão anaeróbia foi conduzida em sistema batelada e acompanhada até o decréscimo da curva de produção de biogás. O delineamento experimental adotado em todos os ensaios foi inteiramente casualizado, com emprego de análises estatísticas univariadas e multivariadas para avaliação dos dados. Os resultados demonstraram a necessidade de 50% de dejetos de bovinos na mistura, para que a cama de ovinos pudesse ser absorvida eficientemente na compostagem e na co-digestão anaeróbia. Essa proporção deu origem a um composto e biofertilizante com maior estabilidade e conteúdo de nutrientes, além de proporcionar maiores produções de biogás. Em vermicompostagem, a cama de ovinos apresentou potencial de ser utilizada em proporção de até 75% na mistura com dejetos bovinos, para desenvolvimento da espécie Eisenia foetida. Porém, proporções superiores a 25% diminuíram a qualidade do vermicomposto. A casca de arroz não foi transformada em todos os ensaios.

This study aimed at seeking for the solution to recover the energy from agriculture waste in the Mekong Delta, Vietnam. The spent mushroom compost - a residue from the mushroom growing - was chosen for co-digestion with pig manure in anaerobic batch and semi-continuous experiments. The results showed that in case of spent mushroom compost made up 75% of the mixed substrate, the gained biogas volume was not significantly different compared to the treatment fed solely with 100% pig manure. The average produced biogas was 4.1 L×day-1 in the experimental conditions. The semi-continuous experiments remained in good operation up to the 90th day of the fermentation without any special agitating method application. The methane contents in both experiments were around 60%, which was significantly suitable for energy purposes. These results confirm that spent mushroom compost is possibly an acceptable material for energy recovery in the anaerobic fermentation process. / Nghiên cứu này nhằm tìm kiếm giải pháp thu hồi năng lượng từ chất thải nông nghiệp tại ĐBSCL, Việt Nam. Rơm sau ủ nấm - phế phẩm sau khi trồng nấm rơm - được chọn để ủ kết hợp với phân heo trong các bộ ủ yếm khí theo mẻ và bán liên tục. Kết quả cho thấy nếu phối trộn đến 75% rơm sau ủ nấm trong nguyên liệu ủ, tổng lượng khí thu được không khác biệt đáng kể so với thí nghiệm ủ 100% phân heo. Trong điều kiện thí nghiệm, lượng khí thu được trung bình là 4.1 L.ngày-1. Thí nghiệm ủ bán liên tục vẫn vận hành tốt ở ngày thứ 90 mặc dù mẻ ủ không được khuấy đảo. Hàm lượng khí mê-tan đo được chiếm khoảng 60% hoàn toàn có thể sử dụng cho các nhu cầu về năng lượng. Những kết quả thí nghiệm khẳng định có thể sử dụng rơm sau ủ nấm để thu hồi năng lượng thông qua quá trình ủ yếm khí kết hợp.

La limitation des ressources énergétiques fossiles et les lourds impacts environnementaux pouvant résulter de leur exploitation, entraînent un regain d’intérêt pour la digestion anaérobie. Face aux enjeux énergétiques et sanitaires, la conduite d’un méthaniseur implique l’optimisation de la production de méthane, mais aussi d’assurer la qualité sanitaire du digestat du point de vue des micropolluants. C’est dans ce cadre que s’inscrit ce projet de thèse réalisé en partenariat avec la ferme expérimentale de la Bouzule. L’optimisation de la co-digestion de substrats a montré que l’ajout d’herbe ensilée durant 36 semaines, améliorait le rendement du procédé de 20%. Le suivi des micropolluants (métaux lourds et HAPs) contenus dans les herbes provenant des bordures de route a montré que la qualité du digestat ne serait pas affectée si elles sont incorporées au digesteur. L’étude en réacteur batch de l’impact des antibiotiques sur la production de méthane a montré que : à 8 mg/L et 16 mg/L de tétracycline on observe une baisse de 23% et 28% respectivement, à 14 mg/L de spiramycine on observe une baisse de 40%, et à 20 mg/L de tylosine on observe une baisse de 30%. En réacteur continu, les faibles concentrations de tétracycline (0,2 mg/L et 2 mg/L) amélioraient d’environ 5% de la production de méthane au bout de 7 jours. A 200 mg/L et 2000 mg/L de tétracycline, on atteint des baisses de 30% et 40%, et le système ne récupère pas au bout de 7 jours. Quant à la spiramycine, à 1,4 mg/L, 14 mg/L et 140 mg/L, les baisses ont été de 14%, 24% et 39% respectivement, et au bout de 7 jours, une baisse résiduelle est toujours observable. Par ailleurs, les digestats issus des tests avec les antibiotiques sont en accord avec la réglementation / The limitation of fossil energy resources and heavy environmental impacts arising from their operation, there is a renewed interest for anaerobic digestion. According to the energy, and health issues, the monitoring of an anaerobic digester involves the maximization of the methane production, but also to ensure a good quality of digestate from the perspective of micropollutants. It is within this framework that this project of thesis is realized in partnership with the experimental farm of “La Bouzule”. The optimization of the co-digestion of substrates, showed that the use of 36 weeks grass silage improved the process yield by 20%. The monitoring of heavy metals and PAHs content in the grasses from roadsides showed that these grasses – if used as co-substrate in the digester – will not affect the digestate quality. The study of the impact of antibiotics on methane production in batch reactor showed that: 8 mg/L and 16 mg/L of tetracycline led to 23% and 48% decrease respectively, 14 mg/L of spiramycin led to 40% decrease, and 20 mg/L tylosin to 30% decrease. The monitoring of the continuous reactor showed that low levels of tetracycline (0.2 mg/L and 2 mg/L) led to an improvement of about 5% of the methane production. At 200 mg/L and 2000 mg/L of tetracycline, reductions of 30% and 40% are achieved, and the system did not recover after 7 days. The addition of spiramycin to the continuous reactor at 1.4 mg/L, 14 mg/L and 140 mg/L resulted in decreases of 14%, 24% and 39% respectively. For the latter, after one week, a residual drop is still observable. Furthermore, the digestate resulting from the monitoring of the continuous reactor during the tests with antibiotics is in accordance with current regulations

CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / The production of renewable energy and fertilizer, through anaerobic biodegradation (AnBio) of waste from pig farming, presents itself as a strategic solution to minimize the negative effects associated with the large volume of manure generated in a small production space. However, further studies should be conducted to improve the understanding on the process and propose improvements. In this sense, this work was divided into three stages. In the first stage, a study was conducted to evaluate the changes that occur in organic matter and in organic and inorganic forms of nitrogen (N) and phosphorus (P) of the solid fraction of pig manure (PM) using anaerobic bench-top reactors as a function of seven hydraulic retention times (7, 14, 21, 28, 35, 42 and 49 days of biodegradation) and compared with the raw manure. In the second stage, we developed a study of anaerobic co-digestion, in a semi-continuous reactor, using the PM and the industrial waste of tomato processing (WTP) at different mixing ratios, to improve the performance of digestion and establish the best ratio of the two substrates for the production of biogas and methane. The following proportions were used (% PM + % WTP): 10% + 90%, 20% + 80%, 30% + 70%, 50% + 50% and 40% + 60%. In the third stage, there was an innovative study to recover the N present in the digestate generated after AnBio, using semipermeable membranes made of expanded polytetrafluoroethylene (PTFE) submerged in the material. This system consists of forcing the volatilization of N present in the digestate in the form of NH3 and then recover it in an acid solution of 1N H2SO4 flowing through the inside of the PTFE membrane. The N is recovered as the ammonium ion (NH4+), with potential for being used as fertilizer. Besides the digestate, raw pig manure (RPM) was used to compare the N recovery potential of both materials. The accumulation of the NH4+ formed was determined at nine sampling times (0, 7, 20, 30, 44, 54, 70, 79 and 93 hours). Based on the results obtained in the first stage, it was concluded that, during the digestion process, the organic matter of higher lability, represented by the carbon of the fulvic acid fraction and carbon oxidizable with 2.5 mL of H2SO4, was partially consumed, promoting the accumulation of recalcitrant organic matter at the end of the process. The contents of organic N and NH4+ reduced respectively by 45.2% and 54.2%, compared with their initial contents in the RPM, probably due to loss by volatilization. The P content reduced by 41.25% in relation to the initial content, due to the chemical precipitation of the inorganic fraction extractable in water with metallic cations within the reactor. In the case of co-digestion, increasing PM proportion to up to 30% of the feed mixture led to the maximum daily production of biogas (175 L) and the largest proportion of methane (60%). Amounts above 30% of manure in the mixture reduced biogas and methane production due to the increase of free NH3 concentration (272 mg L-1), which is toxic to most methanogens. As regards the recovery of N using PTFE membranes, it was observed that the recovery efficiency of the digestate was 12% higher compared with that observed in the RPM. Quantitatively, 4555 mg NH4+ could be recovered from the digestate in 93 hours of experiment, which can be used later as a source of N to agricultural crops. / A produÃÃo de energia renovÃvel e fertilizante, atravÃs da biodegradaÃÃo anaerÃbia (BioAn) dos dejetos da suinocultura, apresenta-se como uma soluÃÃo estratÃgica para minimizar os efeitos negativos associados ao grande volume de dejeto gerado em um reduzido espaÃo de produÃÃo. Contudo, mais estudos devem ser realizados para melhorar o entendimento do processo e propor melhorias. Nesse sentido, realizou-se este trabalho que foi dividido em trÃs etapas. Na primeira, foi realizado um estudo com o objetivo de avaliar as mudanÃas que ocorrem na matÃria orgÃnica e nas formas orgÃnicas e inorgÃnicas de nitrogÃnio (N) e fÃsforo (P) da fraÃÃo sÃlida do dejeto suÃno (DS), utilizando reatores anaerÃbios de bancada, em funÃÃo de sete tempos de retenÃÃo hidrÃulica (7, 14, 21, 28, 35, 42 e 49 dias de biodegradaÃÃo) e comparados com o dejeto nÃo degradado. Na segunda etapa, desenvolveu-se um estudo de co-digestÃo anaerÃbia, em um reator semicontÃnuo, utilizando o DS e o resÃduo da indÃstria do processamento do tomate (RPT) em diferentes proporÃÃes de mistura, visando melhorar o desempenho da biodegradaÃÃo e estabelecer a melhor proporÃÃo dos dois substratos para a produÃÃo de biogÃs e metano. Utilizaram-se as seguintes proporÃÃes (% de DS + % de RPT): 10% + 90%, 20% + 80%, 30% + 70%, 50% + 50% e 60% + 40%. Na terceira etapa, realizou-se um estudo inovador visando recuperar o N presente no digestato gerado apÃs a biodegradaÃÃo, utilizando membranas semipermeÃveis de politetrafluoroetileno expandido (PTFE) submersas no material. Esse sistema consistiu em forÃar a volatilizaÃÃo do N presente no digestato na forma de NH3 e, posteriormente, recuperÃ-lo em uma soluÃÃo Ãcida de H2SO4 1N que circulava pelo interior da membrana de PTFE. O N foi recuperado na forma do Ãon amÃnio (NH4+), com potencial para ser utilizado como fertilizante. Utilizou-se alÃm do digestato, DS nÃo degradado, para comparaÃÃo do potencial de recuperaÃÃo de N dos dois materiais. A determinaÃÃo do acÃmulo de NH4+ formado foi realizada em nove tempos de amostragem (0, 7, 20, 30, 44, 54, 70, 79 e 93 horas). Com base nos resultados obtidos na etapa 1, concluiu-se que durante a biodegradaÃÃo, a matÃria orgÃnica de maior labilidade, representada pelo carbono da fraÃÃo Ãcido fÃlvico e carbono oxidÃvel com 2,5 mL de H2SO4, foi parcialmente consumida, promovendo o acÃmulo de matÃria orgÃnica recalcitrante no final do processo. Os conteÃdos de N orgÃnico e NH4+ reduziram respectivamente, 45,2% e 54,2% em relaÃÃo aos seus conteÃdos iniciais no dejeto nÃo degradado, devido, provavelmente, a perda por volatilizaÃÃo. O conteÃdo de P reduziu 41,25% em relaÃÃo ao seu conteÃdo inicial, devido à precipitaÃÃo quÃmica da fraÃÃo inorgÃnica extraÃvel em Ãgua com cÃtions metÃlicos no interior do reator. No caso da co-digestÃo, o aumento da proporÃÃo do DS atà o limite de 30% da mistura de alimentaÃÃo, proporcionou a mÃxima produÃÃo diÃria de biogÃs (175 L) e a maior proporÃÃo de metano (60%). Quantidades superiores a 30% de dejeto na mistura, reduziram a produÃÃo de biogÃs e metano devido ao aumento da concentraÃÃo de NH3 Livre (272 mg L-1) tÃxico a maioria dos microrganismos metanogÃnicos. No que se refere à recuperaÃÃo do N utilizando as membranas de PTFE, observou-se que a eficiÃncia de recuperaÃÃo no digestato foi superior em 12% em relaÃÃo ao observado no dejeto nÃo degradado. Em termos quantitativos, conseguiu-se recuperar 4555 mg de NH4+ proveniente do digestato durante 93 horas de experimento que poderÃ, posteriormente, ser utilizado como fonte de N para as culturas agrÃcolas.

La co-digestion anaérobie (CoDA) des substrats agro-industriels s’inscrit pleinement dans les objectifs sociétaux d’une gestion optimisée des agroressources, d’une réduction des impacts anthropogéniques, ainsi que d’un développement des énergies renouvelables. Toutefois, en considérant les verrous industriels et scientifiques, il est apparu que la problématique méthodologique, relative à l’étude et à l’optimisation, était primordiale dans l’amélioration des performances méthanogènes en CoDA. En cela, il s’est avéré que le principal actionneur pour l’optimisation de la CoDA soit la formulation du mélange en substrats et co-substrats constituant l’intrant du digesteur. Ainsi, les travaux de thèse étaient inscrits dans un double objectif, industriel et scientifique, dont les résultats ont permis de (i) mettre en œuvre des méthodes simples, peu chronophages et surtout peu coûteuses, pour la caractérisation des intrants et le suivi de la CoDA, (ii) déterminer la relation fondamentale entre la formulation du mélange de substrats et son potentiel biométhanogène, (iii) développer des outils de prédiction du potentiel biométhanogène des mélanges de substrats, ainsi que des biodégradabilités globales et spécifiques de ces derniers, (iv) améliorer la compréhension des interactions entre les substrats codigérés et le consortium microbien de digestion, ainsi que la capacité de ce dernier à s’adapter aux diverses charges organiques qui lui sont appliquées (capacité homéostasique). / The co-digestion of agro-industrial substrates in anaerobic conditions falls within the objectives of an optimized management of agricultural resources along with reduction of anthropogenic impacts and development of renewable energies. Considering scientific and industrial bottlenecks from literature review, it could be identified that a methodological approach was the key to an enhanced understanding of anaerobic co-digestion. Ultimately, formulation of the substrate and co-substrates (digestor’s inputs) appeared to be the main actuator to optimize anaerobic co-digestion. Conciliating both scientific and industrial issues, this thesis led to the following findings : (i) an implementation of simple and cost-saving methods to characterize the inputs of digestor and biogas production, (ii) a determination of fundamental relationship between substrate blend and his biomethane potential, (iii) a development of predictive tools for biomethane potential of substrate blends as well as global and specific biodegradability of substrates, (iv) an enhanced comprehension of first, interactions between codigested substrates and the microbial consortium and second, the adaptation capacity of the microbial consortium to various organic loading (homeostatic capacity).

<p dir="ltr">Improving environmental sustainability in energy production and waste management are of critical importance. Anaerobic digestion (AD) uses microbes to biologically decompose organic waste and produce biogas, which can be used for various forms of sustainable energy. It can be particularly valuable for livestock facilities considering AD of their manure, and potentially other feedstocks as well, a process known as co-digestion. Improved understanding of co-digestion of agro-industrial feedstocks is critical for these facilities. Understanding the macromolecular composition (carbohydrate, protein, and lipid portions) of potential AD feedstocks has the potential to provide important information for predicting important parameters of AD behavior. However, the stability of these macromolecules in AD samples during long-term storage must be confirmed. Furthermore, synergistic and antagonistic impacts of co-digestion on methane production and digestate composition need to be more thoroughly explored.</p><p dir="ltr">This dissertation investigates the impact of storage at refrigeration temperatures (4°C) for up to one-year on the macromolecular composition of various agro-industrial feedstocks (beef manure, starch, slaughterhouse waste, soap stock, and filter press slurry) and anaerobic co-digestion samples. These same feedstocks were co-digested with manure in batch digesters at different proportions, using two or three feedstocks to determine possible synergistic effects.</p><p dir="ltr">The findings show that minimal macromolecular degradation occurred in AD samples during storage at refrigeration temperatures for up to one-year. A major exception was samples containing high concentrations of readily biodegradable starches, which did experience >50% carbohydrate degradation. This indicates a need for methodological rigor during sample storage and reporting experimental design.</p><p dir="ltr">Furthermore, the co-digestion experiments demonstrated frequent improvements or synergy in specific methane yield, methane production rate, and a wide variety of physical and chemical parameters in the digester effluent. Specific methane yield was shown to be at least additive, with improvement ranging from 3-168%. Some improvements in kinetic performance were also observed and quantified. Statistical results suggest that influent characteristics could be useful as predictors for methane production. This research could catalyze additional work needed to optimize co-digestion feeding strategies for full-scale digesters.</p>

The characteristics of anaerobic batch co-digestion of water hyacinth (WH) with pig manure (PM) under seven mixing ratio 100%WH; 80%WH : 20%PM; 60%WH : 40%PM; 50%WH : 50%PM; 40%WH : 60%PM; 20%WH : 80%PM and 100%PM were investigated, each treatment was conducted in five replications with daily loading rate at 1 gVS.L-1.day-1. During the anaerobic digestion process of 60 days, maximum biogas production occurred in two periods, the first stage from 12- 22 days and second stage from 30 - 35 days. The maximum daily biogas productions from each stage were 17.2 L.day-1 and 15.1 L.day-1, respectively. The cumulative biogas production varied between 60 L (100%PM) and 360 L (60%WH : 40%PM). The results showed that the biogas yields of co-digestion 40- 80%WH were higher from 34.6 to 56.1% in comparison with 100%PM and from 109 to 143% in comparison with 100%WH. When mixing with WH, treatments were received more methane and the methane contents were higher than 45% (v/v) that good for energy using purposes. / Nghiên cứu được thực hiện nhằm khảo sát khả năng gia tăng lượng khí sinh học khi tiến hành đồng phân hủy yếm khí lục bình (WH) và phân heo (PM) ở các tỉ lệ phối trộn khác nhau gồm 100%WH; 80%WH : 20%PM; 60%WH : 40%PM; 50%WH : 50%PM; 40%WH : 60%PM; 20%WH : 80%PM và 100%PM. Các nghiệm thức được nạp lượng nguyên liệu là 1 gVS.L-1.ngày-1 và bố trí lặp lại 5 lần. Theo dõi quá trình phân hủy của các nghiệm thức trong 60 ngày ghi nhận có 2 khoảng thời gian lượng khí sản sinh nhiều nhất - giai đoạn 1 từ ngày 12 đến 22, giai đoạn 2 từ ngày 30 đến 35. Lượng khí sản sinh cao nhất tương ứng trong mỗi giai đoạn là 17.2 L.ngày-1 và 15.1 L.ngày-1. Lượng khí tích lũy trong suốt thời gian thí nghiệm ghi nhận thấp nhất ở nghiệm thức 100%PM đạt 60 L, và cao nhất ở nghiệm thức 60%WH : 40%PM đạt 360 L. Năng suất khí sinh ra của các nghiệm thức phối trộn lục bình từ 40 đến 80% cao hơn từ 34,6 đến 56,1% so với nghiệm thức 100%PM và cao hơn từ 109% đến 143% so với nghiệm thức 100%WH. Hàm lượng mê-tan sinh ra từ các nghiệm thức có phối trộn lục bình ổn định trong khoảng > 45% đảm bảo nhiệt lượng cho nhu cầu sử dụng năng lượng.

Le traitement biologique des eaux usées urbaines et industrielles reste une activité ayant un impact négatif sur l’environnement et sur le changement climatique par l’émission des gaz à effet de serre (GES), notamment le CO2. Les changements innovants au niveau des procédés de traitement des eaux usées par l’intégration des flocs de microalgues-bactéries ont abouti à des procédés multitrophiques sans apport d’O2 et sans dégagement du CO2. Il s'agit d'une étude de faisabilité de ces flocs-MaB pour la photobioremédiation des polluants (organiques et minéraux) et pour la production de biomasse valorisable en bioénergie dans le cadre de l'économie circulaire. En présence de la lumière, les flocs-MaB ont été intégrés dans des photobioréacteurs à biomasse fixe afin d'assurer un traitement durable des eaux usées grâce aux échanges symbiotiques entre les micro-oragnismes en terme de nutriments et de gaz. L'encapsulation des flocs-MaB dans des billes de PVA-alginate a montré l'effet des conditions physico-chimiques et hydrodynamiques sur l'élimination des polluants et l'évolution multicellulaire des flocs au sein des réacteurs à multi-échelles. Par ailleurs, la biomasse multitrophique immobilisée sur des supports biodégradables d'olive (OPP) et sur des disques en PVC a assuré une meilleure performance des bioréacteurs à lit fluidisé et à disques rotatifs, respectivement, pour la bioremédiation des eaux usées. Les propriétés des supports (porosité, rugosité et structure) et les comportements hydrodynamiques ont été contrôlés pour favoriser l'attachement des biofilms multitrophiques. Le développement de biofilm montre l'effet des interactions multitrophiques entre les microalgues et les bactéries sur l'élimination des composés organiques (DCO) et nutriments (ammonium et phosphore). La biomasse des flocs-MaB a été récupérée et réutilisée pour le traitement du digestat liquide à l'issu du digesteur et pour améliorer la production de biométhane par une co-digestion anaérobie. Ce procédé multitrophique et intégré permet d'obtenir Zéro déchet à la sortie du processus / The biological treatment of urban and industrial wastewaters represents a process with a negative impact on the environment and on climate change through the emission of greenhouse gases (GHG), particularly CO2. In the presence of light, microalgae-bacteria flocs (MaB-flocs) have been integrated into photobioreactors with fixed biomass to ensure a sustainable wastewater treatment without O2 supply and CO2 release. The entrapment of flocs in PVA-alginate beads has shown the effect of physicochemical and hydrodynamic conditions on the elimination of pollutants and the multicellularity evolution within multi-scale bioreactors. In addition, the immobilization of biomass on biodegradable olive carriers and on PVC disks provided a better performance of fluidized bed and rotating discs bioreactors, respectively, for the bioremediation of wastewater. The properties of the supports (porosity, roughness, and structure) and the hydrodynamic behaviors have favored the attachment of multitrophic biofilms. Biofilm development shows the effect of multitrophic interactions between microalgae and bacteria on the organic compounds (COD) and nutrients (ammonium and phosphorus) removals. The MaB-flocs biomass was recovered and reused for the treatment of the digestate and to improve the production of biomethane by anaerobic co-digestion. This integrated multitrophic technology makes it possible to obtain zero wastes at the end of the process