Orientador: Yoon Kil Chang / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-18T15:58:47Z (GMT). No. of bitstreams: 1 Biasutti_ElizaAugustaRolim_D.pdf: 5427328 bytes, checksum: bb45f1359e2ca61015efd7dd7e6eddc1 (MD5) Previous issue date: 2011 / Resumo: Os plásticos de amido apresentam aplicações limitadas devido às pobres propriedades mecânicas e processabilidade, além de serem hidrofílicos. Para superar estas deficiências, a associação do amido com outros polímeros biodegradáveis ou a adição de nanoargilas são formas de se obter materiais de baixo custo, com melhores propriedades e compostáveis. O objetivo geral deste trabalho foi o desenvolvimento e avaliação de blendas poliméricas e nanocompósitos, obtidos por extrusão, extrusão de filme tubular e injeção, cujo principal componente da matriz polimérica foi o amido. No artigo I, para estudar o efeito da nanoargila sobre as propriedades mecânicas e estruturais de blendas poliméricas extrusadas de amido e gelatina, quatro misturas foram obtidas, sendo que as proporções de amido, gelatina, glicerol e água (100:20:40:40) foram mantidas constantes, enquanto o teor de nanoargila das blendas variou de 0 a 2,5%. Os resultados de difração de raios-X dos nanocompósitos revelaram a expansão dos espaços interlamelares consistentes com um processo de intercalação e, consequentemente, foi observado o aumento da resistência à tração (RT). No artigo II, para obtenção dos filmes de blendas poliméricas de amido de milho nativo (AN) e amido reticulado (AM) e poli (adipato de butileno-co-tereftalato) (PBAT) o processo de extrusão de filme tubular foi empregado. Para definição das misturas para produção dos filmes foi usada a metodologia de planejamento de misturas. As propriedades de tração dos filmes foram determinadas nas direções de fabricação (DF) e transversal (DT). Verificou-se que tanto para RT na DF quanto para o alongamento na ruptura (AR) na DF, os maiores valores de resposta, 5,48 MPa e 41,79%, respectivamente, foram encontrados para as composições localizadas próximo ao vértice do triângulo, correspondente às menores concentrações de AM e maiores concentrações de AN. Através da análise do perfil de desejabilidade, obteve-se a mistura ótima, correspondente à formulação com 60% de AN, 10% de AM e 30% de PBAT, que foi avaliada quanto às propriedades de barreira e estruturais (Artigo III). O filme de AN/AM/PBAT 60:10:30 apresentou coeficientes de permeabilidade ao vapor de água e ao oxigênio de 7,56 x 10-6 g. m-1.Pa-1.dia-1 e de 4997 cm3.µm.m-2.dia-1.atm-1, respectivamente. A análise das micrografias de microscopia eletrônica de varredura dos filmes mostrou uma estrutura heterogênea e a presença de grânulos de amido intactos, também visualizados nas micrografias de luz polarizada. Os espectrogramas de espectroscopia no infravermelho com transformada de Fourier e módulo de refletância total atenuada, revelaram que não houve uma boa compatibilização entre os amidos e o PBAT. O ensaio de degradação em solo simulado revelou que após 27 dias, o filme de AN/AM/PBAT 60:10:30 não apresentava fragmentos visíveis, enquanto o filme de PBAT puro havia perdido somente 1,5 % de sua massa inicial. No artigo IV, blendas de AN e PBAT foram obtidas por injeção para avaliar a variação das propriedades mecânicas, em função do tempo de permanência no solo. Verificou-se que, de uma forma geral, a blenda de AN/PBAT 50:50 apresentou uma redução na RT em função do tempo de enterramento no solo (cerca de 50% após 30 dias em solo), enquanto que a blenda de AN/PBAT 60:40 apresentou um comportamento completamente distinto, exibindo um aumento da RT em função do tempo de permanência no solo. Concluiu-se, portanto, que a obtenção de blendas poliméricas e nanocompósitos, à base de amido, empregando-se os processos de extrusão, extrusão de filme tubular e injeção, é uma alternativa tecnologicamente viável para o estudo e desenvolvimento de produtos plásticos biodegradáveis/compostáveis / Abstract: Starch plastics have limited applications due to poor mechanical properties and processability, in addition to being hydrophilic. To overcome these shortcomings, the combination of starch with other biodegradable polymers or the addition of nanoclays are ways to obtain low-cost compostable materials with improved properties. The aim of this work was the development and evaluation of polymeric blends and nanocomposites, obtained by extrusion, blown film extrusion and injection, whose main component of the polymeric matrix was starch. In article I, to study the effect of nanoclays on the mechanical and structural properties of extruded starch-gelatin blends, four mixtures were obtained with proportions of starch, gelatin, glycerol and water (100:20:40:40) that were kept constant while the nanoclay content ranged from 0 to 2.5%. The X-ray diffraction results revealed an expansion of the interlayer spaces consistent with an intercalation process, and, consequently, tensile strength (RT) increases were observed. In article II, to obtain films of polymeric blends of native cornstarch (AN), cross-linked starch (AM) and polybutylene adipate co-terephthalate (PBAT), the process of blown film extrusion was employed. To set the raw material mixtures for film production the methodology of mixture design was used. The tensile properties of the films were determined in the manufacture (DF) and transverse (DT) directions. It was found that both RT and elongation at break, both in the DF, the highest responses, 5.48 MPa and 41.79% respectively, were found for the compositions located near the apex of the triangle, corresponding to lower concentrations of AM and higher concentrations of AN. By analyzing the profile of desirability, the optimum mix ratio was obtained, corresponding to the formulation with 60% native cornstarch, 10% crosslinked starch and 30% PBAT, which was evaluated for barrier and structural properties (article III). The film of AN/ AM/ PBAT 60:10:30 showed coefficients of permeability to water vapor and oxygen of 7.56 x 10-6 g. m-1.Pa-1.day-1 and 4997 cm3.µm.m-2.day-1.atm-1, respectively. The film MEV analysis showed a heterogeneous structure and the presence of intact starch granules, also visualized through polarized light microscopy. FTIR-ATR analysis revealed that there not was a good match between the starches and PBAT. The degradation test in simulated soil showed that the film, after 27 days, did not present visible fragments in soil, while the PBAT lost just 1.5% of its initial mass. In article IV, AN and PBAT blends were obtained by injection to evaluate the changes on mechanical properties as a function of length of stay in simulated soil. It was found that, in general, the blend of AN/ PBAT 50:50 showed a reduction in the RT as a function of time in the soil (about 50% after 30 days), while the blend of AN/ PBAT 60:40 presented a completely different behavior, showing an increase of RT as a function of time in soil. Therefore, obtaining starch-based polymeric blends and nanocomposites, using the processes of extrusion, blown film extrusion and injection, is a technologically feasible alternative for the study and development of biodegradable/ compostable plastic products / Doutorado / Tecnologia de Alimentos / Doutor em Tecnologia de Alimentos

No Brasil, a parcela orgânica dos resíduos sólidos urbanos (RSU) representa mais de 50% de sua composição, na grande maioria dos municípios. No entanto, a compostagem, como método de tratamento dos resíduos orgânicos, não é empregada como poderia, somente 1,5% dos RSU no país é compostados; mesmo a compostagem caseira sendo prática de baixo custo e apropriada a áreas residenciais não é usual. O presente trabalho enfatiza a educação ambiental (EA) como instrumento para a organização e participação social, visando à minimização de resíduos sólidos urbanos, através da implantação de composteiras caseiras. O enfoque é dado no envio dos resíduos orgânicos domiciliares para compostagem caseira e na incorporação de novos hábitos, após execução de programa de educação ambiental em uma comunidade, do município de Campos do Jordão, São Paulo, Brasil. No presente estudo, partiu-se das seguintes hipóteses; comunidades de baixos ingressos e pouca instrução, localizadas em bairros periféricos de centros urbanos, são capazes de se organizar e alterar seu comportamento com relação à questão da geração e descarte de RSU, quando convidados a integrar grupos submetidos a programa de Educação Ambiental, com metodologia participativa; aliando-se atividades teóricas e práticas elaborado de acordo com as necessidades específicas da comunidade e implantados considerando-se a realidade local. Os resultados alcançados foram a organização social da comunidade, com o desvio de 83,5% dos resíduos orgânicos do aterro para a compostagem, isso quando não foram minimizados antes, no aproveitamento completo dos alimentos. A prática da compostagem possibilitou testar vários tipos de composteira caseira e garantiu melhorias nas condições de disposição dos RSU, reduzindo os impactos ambientais. / In Brazil, the organic portion of the solid wastes represents more than 50% of its composition in most of the cities. However, the composting , as a method of organic wastes treatment, is not applied as it could be, only 1.5% of the Urban Solid Waste (USW or in Portuguese, RSU) is recycled; even the home composting, which has a low cost and is appropriated in residential areas, is not common. This current paper emphasizes the environmental education as an instrument for the social organization and participation as well as minimization of solid wastes, which are essential elements for a sustainable development. The approach is based on the reduction of solid wastes by sending the home organic waste to home composting and the incorporation of new habits after the execution of an environmental education program in a community from the city of Campos do Jordão (São Paulo - Brazil). The research was originated on the hypothesis that communities with lack of basic facilities and lower education rates located in surrounding areas of urban centers are capable of organizing and changing its habits in relation to production and discarding of USW. This is possible especially when people are invited to integrate groups committed to an environmental education program according to the specific needs of the community and considering the local reality. The obtained results were the social organization of the community, with the allocation of 83,5% of the organic wastes from landfills to composting, that is when it was not minimized before, with the complete use of food. The composting made it to possible to test various types of home composting and assured improvements in the disposal conditions of the USW, reducing environmental impact.

This diploma thesis deals with the bioreactor system and its use for the production of heat and biogas. The bioreactor uses the composting and metanogation process of fermentation that humanity has known for hundreds of years, but the combination of these processes is a relatively unexplored area. The theoretical part of the thesis analyzes the existing possibilities of utilization of the heat generated in the compost, and also describes the used technology of small biogas stations and other small systems for biogas production. It follows the practical part of the work, when it was the task to design a bioreactor working at low temperatures during the winter. Part of the solution is the initial design and testing of the basic test structure of the bioreactor, followed by the implementation of a more advanced and more complex system, including a control and measuring center realized by a microcontroller.

The master thesis deals with the information system. It contains an analysis of the current state of the system and there are used methods of risk analysis. Based on these analyzes and methods it is developed design of information system for company, which deals with the processing of biological waste. The thesis includes some practical solutions to problems related to the management of business processes.

Orientador: Rosane Aparecida Gomes Battistelle / Resumo: A compostagem é um conjunto de técnicas muito importante para o tratamento da fração orgânica dos resíduos sólidos, por meio do uso de tecnologias sustentáveis que processam os resíduos orgânicos originados da agricultura, agroindústria, silvicultura, resíduos orgânicos domiciliares e, ainda, o lodo de esgoto. A busca da sociedade por melhores condições ambientais, aponta para uma tendência de ocorrer um incremento substancial na quantidade de lodo a ser disposto nos próximos anos, surgindo, portanto, a necessidade de que sejam apresen¬tadas técnicas que possibilitem um tra¬tamento eficiente e adequado dos mesmos. O emprego do processo de compostagem no Brasil, é ainda bastante incipiente e possui alto grau de empirismo no controle e avaliação do processo, devido a falta de conhecimento técnico mais aprofundado, sendo necessário o implemento de novas formas de análise e controle eficazes. No processo avaliativo chamado método "respirométrico", utiliza-se uma nova metodologia na qual os parâmetros de degradação biológica dos resíduos não são medidos na fase sólida, mas em sua fase gasosa. A análise do lodo de esgoto pelo método respirométrico, demonstrou ser uma ferramenta, pode a vir a ser muito útil, desde que sejam levados em considerações todos parâmetros apontados na literatura, buscando o equilíbrio destes parâmetros na escolha e quantificação dos resíduos. O reator rotativo hermético apresentou como vantagens a homogeneização dos resíduos, favorecendo o contato de toda ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Composting is a very important set of techniques for the treatment of the organic fraction of solid waste, through the use of sustainable technologies that process organic waste originating from agriculture, agribusiness, forestry, household organic waste and, also, sewage sludge. Society's search for better environmental conditions points to a tendency for there to be a substantial increase in the amount of sludge to be disposed of in the coming years, therefore, the need arises for techniques to be presented that enable efficient and efficient treatment. of them. The use of the composting process in Brazil, is still quite incipient and has a high degree of empiricism in the control and evaluation of the process, due to the lack of more in-depth technical knowledge, requiring the implementation of new forms of effective analysis and control. In the evaluation process called the "respirometric" method, a new methodology is used in which the biological degradation parameters of the residues are not measured in the solid phase, but in the gas phase. The analysis of sewage sludge using the respirometric method, proved to be a tool, it may prove to be very useful, provided that all parameters pointed out in the literature are taken into consideration, seeking to balance these parameters in the choice and quantification of waste. The hermetic rotary reactor had as advantages the homogenization of residues, favoring the contact of all organic matter with the decomposing bacteria, s... (Complete abstract click electronic access below) / Doutor

Orientador: Sérgio Valiengo Valeri / Banca: Miguel Luís Menezes Freitas / Banca: Iraê Amaral Guerrini / Banca: Rinaldo César de Paula / Banca: Mara Cristina Pessôa da Cruz / Resumo: Foram conduzidos experimentos em casa de vegetação e em condições de campo, com os seguintes objetivos: a) avaliar o efeito de doses de composto de resíduos de indústria de celulose e papel na fertilidade do solo, no desenvolvimento, na produção de matéria seca e na concentração e acúmulo de nutrientes nas folhas de um clone de Eucalyptus grandis x E. urophylla; b) avaliar os efeitos da aplicação em diferentes épocas de dois resíduos da indústria de celulose e papel (lodo ativado e não decomposto e dregs + grits), no desenvolvimento das árvores, produção de madeira e acúmulo de nutrientes nas folhas de um clone de Eucalyptus grandis x E. urophylla. As principais conclusões foram: a) A aplicação de composto de resíduos de indústria de celulose e papel (CRICP) propiciou ganhos em altura aos 60 dias após o plantio em colunas de PVC, em diâmetro do coleto e em produção de biomassa das plantas de eucalipto aos 120 dias. O CRICP resultou em aumento no valor de pH e nos teores de Ca e Mg do solo. Também elevou os teores de P, K e Na no solo. A concentração nas folhas e o acúmulo de P, K, Ca e S aumentaram com a aplicação do composto; b) Os resíduos da fábrica de celulose e papel são eficientes corretivos da acidez do solo. A aplicação de 8 t ha-1 de dregs + grits no plantio proporcionou maior crescimento em diâmetro e produção de madeira de eucalipto do que a aplicação de 15 t ha-1 de lodo ativado não decomposto. Essa dose e elevou os teores de Ca e Mg e a porcentagem de saturação por bases de Latossolo Vermelho distrófico para valores adequados para uma produtividade de madeira de 40 m3 ha-1 ano-1, aos 6,5 anos, quando aplicados no plantio ou três meses após o mesmo. / Abstract: Experiments in greenhouse and field were carried out with the objectives: a) to evaluate the effect of industrial residues from pulp and paper mill compost rates on soil fertility, on development, on dry matter production and nutrient contents and accumulation in the leaves of Eucalyptus grandis x E. urophylla clone; b) to evaluate the application effects in different times of two industrial residues from pulp and paper mill (cellulose sludge and dregs + grits) on tree development, wood production and nutrient accumulation in the leaves of Eucalyptus grandis x E. urophylla clone. The main conclusions were: a) the industrial residues from pulp and paper mill compost (IRPPMC) application promoted increases on height at 60 days after planting, on stem diameter and on biomass production of eucalypt plants at 120 days. The IRPPMC increase the pH value and Ca and Mg soil content. The P, K, and Na soil content also increased. The P, K, Ca e S contents and accumulation in the leaves were increased with compost application; b) industrial residues from pulp and paper mill are efficient in the liming of soil acidity. The application of 8 Mg ha-1 of dregs + grits promoted major growth on diameter and on wood production of eucalypt that 15 Mg ha-1 of activated sludge in combination with chemical fertilizer application. This dose increased Ca and Mg and the base saturation of Red Latosol (Oxisol) to adequate values to reached 40 m3 ha-1 ano-1 wood productivity, at 6,5 years, when application was in the plantation or three months later. / Doutor

Cette thèse s'intéresse aux dispositifs de compostage de proximité en Île-de-France. Développés par les collectivités depuis le début des années 2000 en marge du service urbain traditionnel de collecte et de traitement des déchets, ils permettent de recycler les biodéchets en proximité, directement au pied des immeubles ou dans les quartiers; ils semblent ainsi permettre de transposer le service traditionnel en l'adaptant aux nouvelles exigences environnementales de réduction et de recyclage des flux de matières. La thèse part du constat que les usagers participants, toujours volontaires, semblent particulièrement investis dans le processus de compostage et que ce dernier paraît plus complexe que le tri sélectif. Elle propose alors de regarder le compostage de proximité non plus comme un dispositif de gestion de déchets mais comme une technique, au sens anthropologique du terme, c'est-à-dire une action socialisée par laquelle les habitants prennent en charge des matières, qu'ils transforment en l'occurrence en compost, mus par des objectifs potentiellement variés que cette recherche se propose justement d'explorer. La thèse montre d'abord que le compostage de proximité est davantage développé comme un outil de communication que comme une technique performante de gestion des déchets par les institutions étatiques et territoriales qui le mettent en œuvre, prisonnières d'un sentier technique hérité des services urbains traditionnels en réseau et qui contribue à rendre le compostage de proximité peu efficace. Après avoir décrit ces mécanismes conduisant à sa disqualification du champ des solutions techniques possibles à la gestion des biodéchets, la thèse propose une étude technologique des dispositifs du compostage en pied d'immeuble porté par la Ville de Paris : la construction de chaînes opératoires permet de retracer le processus technique du compostage en tenant compte des matières qu'il met en jeu (les biodéchets), des outils utilisés (les composteurs, des sécateurs, des fourches) et des acteurs mobilisés (les habitants au premier chef). Le processus technique s'avère relativement efficace d'un point de vue matériel, mais relève plus d'un nouveau loisir urbain que d'un dispositif de gestion des déchets : les habitants ne cherchent pas particulièrement l'efficacité technique du processus. Outil de communication pour les institutions, loisir pour les habitants, le compostage de proximité n'est une technique de gestion des déchets pour aucun des acteurs, malgré sa relative efficacité. La thèse défendue est alors que ce type de dispositif renforce, plus qu'il ne le remet en cause, le grand réseau technique traditionnel comme modèle unique de fourniture des services urbains que les institutions cherchent à transformer. / This thesis studies collective composting devices in Île-de-France (Paris region). As the traditional network infrastructure of waste disposal has coped with the reduction of waste flows with difficulty, local governments in charge of waste management have developed alternative collective composting systems since the beginning of the 2000s. Composting bins allowing users to recycle bio-waste locally were seen as a solution to current problems in urban services transformation. As a starting point, this work observes that service users involved in local composting are particularly motivated, and that the technical process they are involved in seems more complex than selective sorting. Thus, the thesis argues that collective composting cannot any longer be considered as a waste management device, but as a technology, in the anthropological meaning of the term. In that way, composting appears as a socialized action in which inhabitants take biological matters in charge, transforming them into compost for a variety of reasons and objectives analyzed in this thesis. First, this work shows how the French State and local governments developed collective composting more like a communication tool than a real technological device, as if institutions involved in waste management were trapped in a traditional urban technical network while still trying to transform it. As a result, alternative waste devices were disqualified from the field of serious technological solutions. The second part of this thesis offers a technological study of collective home composting in order to understand how it precisely works. This thesis uses the anthropological concept of “chaînes opératoires” which allows to examine every stage of the composting process, by studying how biological matters (in this case, bio-waste) are transformed, with which kind of tool (shovel, composting bins, garden).

Wood contaminated by polycyclic aromatic hydrocarbons (PAH) represent a serious environmental risk. Composting seems to be an effective method for decontamination of such waste material. PAHs are degraded mainly under aerobic conditions the efficiency of composting could be strongly affected by the process conditions. This work is aimed at the comparison of PAH removal by a 340-days-long composting in laboratory scale composting pilots and a 240-days-long process in a pilot scale. To set up composting piles a "green substrate" commercially used for button-mushroom production and a grass substrate were used. The use of the grass substrate led to a higher PAHs removal (97% of the initial sum of PAHs) in comparison to the green substrate (81% of the initial sum of PAHs). Further, the effect of the size of wood particles on the PAHs removal efficiency was demonstrated. Analysis of phospholipid fatty acids showed an enhanced growth of gramm-negative bacteria and fungi during the composting processes. During the degradation process the enzyme activity of laccase was detected. The ecotoxicological test using a bioluminescent bacteria Vibrio fischeri and a seed germination test using seeds of Hordeum vulgare L. showed that probably no toxic products were formed during the PAHs degradation in these experiments.

The ever-increasing population in the metropolis of Accra, Ghana resulting in con-cerns for finding lasting solutions to manage large volumes of waste produced can be tackled through composting for urban agriculture. With insanitary land filling serving as the major disposal option in the metropolis, plans to build the first ever sanitary landfill facility in the metropolis calls for measures to be taken in order to prolong the lifespan of the facility. This therefore necessitates the need to look into an alternative means of diverting organic waste from landfills. The objective of this research is to re-view the Municipal Solid Waste (MSW) management situations in Accra Metropolitan Assembly upon which an investigation is made into the various process steps involved in aerobic windrow composting and also finding out the possibility for integrating composting with urban agriculture. The study relied mainly on secondary data obtained from books, published articles, governmental documents, internet, and master thesis reports on related topics. By the help of a causal loop diagram, the interdependence of various policy actions and sys-tem elements in the waste management process are linked to illustrate the possibility of a composting programme for urban agriculture. Even though the metropolis for some time back has been operating a centralized composting facility, the facility is confirmed to be closed down due to problems ema-nating from financial inadequacy, power failure and mechanical breakdown. The study delve into the process steps in windrow composting and finally identified potentials for composting in the metropolis but however enumerated constraints ranging from human and environmental health, financial, institutional, policy directives, to public and leadership attitudes as stumbling blocks to the implementation of a centralized composting scheme. It finally concluded that the metropolis has the potentials to embark on composting for urban agriculture however, until measures are taken to overcome these constraints, implementing a centralized composting scheme in the metropolis may not be a sustainable option. It is further recommended that whiles the city authorities continue to tackle the constraints to pave way for the implementation of the program, efforts must be made in promoting small scale composting that rely on manually operated tools to help reduce organic waste loads in the municipal waste stream.

Le compostage est un procédé anthropique basé sur le processus naturel de décomposition de la biomasse qui exploite l'activité enzymatique des microorganismes sous le contrôle de plusieurs facteurs environnementaux. Les résidus lignocellulosiques de par leur composition et leur faible pourcentage d'humidité sont particulièrement adaptés au compostage dans lequel ils jouent le rôle d’élément structurant. Bien que majoritairement d’origine végétale, la matière organique dirigée vers les sites de compostages est très diversifiée, tout comme les types de contaminants qu’elle peut incidemment contenir et dont l’impact sur les processus de biodégradation, et de surcroit leur rémanence dans l’environnement, reste largement à investiguer. L’objectif de cette thèse vise ainsi à faire état de l’effet de la composition de la biomasse lignocellulosique et de la présence d’un contaminant fréquent tel que le glyphosate sur le compostage. Pour ce faire, le suivi de la transformation de la matière organique végétale et de la dégradation du glyphosate, l’évolution des paramètres physicochimiques et la dynamique de recrutement des populations bactériennes ont été effectués tout au long du processus. Deux expériences menées sur le terrain visaient dans un premier temps à mesurer l’effet de l’âge d’une plante ligneuse, dans ce cas-ci le saule arbustif (Salix), et d’une période d’entreposage hivernal sur la transformation de la biomasse, et dans un deuxième temps à étudier les dynamiques de succession bactériennes impliquées dans le cycle du carbone et de l’azote lors du compostage de résidus végétaux. Les résultats obtenus ont révélé une différence dans la composition de la biomasse des tiges âgées de 2 ans et de 3 ans. Alors que les premiers contenaient plus de composés extractibles, les seconds étaient plus riches en sucres structuraux. Ces différences expliquent une hausse des températures plus forte et plus rapide dans le tas de copeaux de tiges plus jeunes. La diminution des composés extractibles, la conservation des sucres structuraux et l’augmentation de la proportion de lignine démontrent l’importance de la source de carbone soluble pour l’initiation de la décomposition du bois et la récalcitrance des éléments lignocellulosiques durant l’entreposage hivernal. La seconde expérience a mis en évidence une très grande diversité de bactéries responsables de la décomposition de la cellulose, des hémicelluloses et de la lignine durant la phase thermophile du compostage. Cette phase qui était le théâtre d’une activité intense comptait moins d’espèces, mais ces dernières étaient très abondantes, une tendance qui s’est inversée avec la maturation de la matière organique. La dynamique observée traduit une redondance fonctionnelle des communautés qui semblent évoluer selon la température, le taux d’oxygène et la nature du substrat disponible. Une troisième expérience menée en milieu contrôlé a ensuite démontré l’impact négligeable du glyphosate sur l’activité microbienne et l’évolution des paramètres physicochimiques lors du compostage. Le glyphosate était presque ou entièrement dégradé à l’issue du compostage et la présence du principal produit de dégradation, l’acide aminométhylphosphonique (AMPA) n’a d’ailleurs même pas pu être quantifiée durant l’expérience. L’impact du glyphosate sur les communautés bactériennes était également négligeable. Seules quelques bactéries étaient différentiellement abondantes entre les deux traitements, la grande majorité étant moins abondante dans le traitement contenant du glyphosate. La richesse en espèces aux différents temps d’échantillonnage était la même entre le traitement témoin et le traitement contenant du glyphosate « pur » et l’analyse de la bêta-diversité n’a relevé aucune différence significative entre les communautés présentes dans le traitement témoin et le traitement glyphosate. Cette thèse a ainsi fait valoir l’importance de la nature initiale de la matière organique sur l’activité microbienne, le recrutement et la dynamique des communautés durant le compostage, tandis que la présence du contaminant glyphosate s’est présenté comme un facteur beaucoup moins déterminant sur les processus de décomposition et l’abondance des espèces bactériennes. Ces informations devraient non seulement permettre d’optimiser le traitement de la matière organique par compostage, mais aussi de mieux évaluer les risques potentiels associés au compostage de biomasse contaminé. / Composting is an anthropic process based on the natural decay of biomass that exploits the enzymatic activity of microorganisms under the control of several environmental factors. Due to their composition and low moisture content, lignocellulosic residues are particularly suitable for composting and serve as a structuring element, which confers them an important role in the process. Although mostly of plant origin, the organic matter (OM) directed towards composting sites is highly diversified, as are the types of contaminants it can contain. The impact of these contaminants, such as glyphosate, on the biodegradation process and their persistence in the environment remain to be investigated. The objective of this thesis is thus to report on the effect of the composition of the lignocellulosic biomass and the presence of glyphosate on the evolution of the physicochemical parameters and the recruitment of bacteria during composting, while ensuring the follow-up of the transformation of the vegetable organic matter and the degradation of glyphosate during the process. Two field studies were conducted to measure the effect of stem age and winter storage on the transformation of wood chips, and to study the dynamics of bacterial succession involved in the carbon and nitrogen cycle during the composting of plant residues. The results obtained revealed a difference in the composition of 2-year-old and 3-year-old stems from shrub willow (Salix sp.), with the younger ones containing more extractable compounds and the more mature ones richer in structural sugars. These differences were reflected in a higher and faster temperature rise in the younger chip pile. A decrease in extractives, retention of structural sugars, and an increase in the proportion of lignin demonstrate the importance of the soluble carbon source for the initiation of wood decomposition and recalcitrance of lignocellulosic elements. The second experiment revealed a very high diversity of bacteria responsible for the decomposition of cellulose, hemicelluloses and lignin during the thermophilic phase of composting. This phase, during which intense activity took place, had fewer species, but they were very abundant, a trend that reversed as the organic matter matured. The observed dynamics reflect a functional redundancy of the communities, which seems to evolve according to the temperature, oxygen level and nature of the available substrate. A third experiment conducted in a controlled environment demonstrated the negligible impact of glyphosate on microbial activity and the evolution of physicochemical parameters during composting. Glyphosate was almost or completely degraded after composting, while the main product of degradation, aminoethylphosphonic acid (AMPA), was not detected. The impact of glyphosate on bacterial communities was also negligible, while species richness at different sampling times was the same when comparing the control treatment and the treatment containing "pure" glyphosate. The beta-diversity analysis found no significant difference between the communities present in the control and glyphosate treatments, while a few bacteria were differentially abundant between the two treatments, the vast majority being less abundant in the glyphosate treatment. This thesis has thus highlighted the importance of the initial nature of the organic matter on microbial activity as well as on the recruitment and dynamics of bacterial communities during composting, while the presence of glyphosate was shown to be a weak determinant of decomposition processes and species abundance. This information should help to optimize the treatment of organic matter by composting and to better assess the potential risks associated with composting contaminated biomass.