The study was aimed to investigate the effect of corn stalk pre-treatment duration on biogas production when cow dung and corn stalk was co-digested in an anaerobic digestion. Corn stalks were pre-treated in different durations: 2-days, 5-days, and 8-days before being added to cow dung into anaerobic co-digesters. The experiments were set up randomly by using triplicate batch anaerobic apparatus in 21 L containers that run in 60-days. The mixing ratio between a corn stalk and cow dung was 50%: 50% (based on the volatile solid value of each material), but corn stalk was cut into small pieces with around 10 cm length, while the cow dung was air dried. The results of the study indicated that all operation parameters such as temperature, pH, and alkalinity in the anaerobic batch were suitable for biogas production. The results showed that there was a significant improvement in total gas produced in the pre-treated 5-days treatment (206.4±8.4 L) compared to 2-days (153.4±9.6 L), and 8-days ones (174±11.1 L). The biogas yield of the pretreated 2-days, 5-days, and 8-days treatments were 392.7±9.8 L/kg VSfermented, 469.8±10.1 L/kg VSfermented and 497.1±13.3 L/kg VSfermented, respectively, that was not significantly different (5%). In all treatments, low concentration of methane in the beginning phase had been observed but increased and reached the optimum value for energy use after 10 days. The result of the study showed that it is preferable to have 5-days pre-treatment of corn stalk before the corn stalk is loaded to an anaerobic digester in combination with cow dung. / Nghiên cứu này nhằm đánh giá ảnh hưởng của thời gian xử lý thân cây bắp lên năng suất sinh khí khi ủ phối trộn phân bò và thân cây bắp trong điều kiện yếm khí. Ba mức thời gian xử lý thân cây bắp được chọn là 2 ngày, 5 ngày, và 8 ngày. Các thí nghiệm được bố trí ngẫu nhiên trong các bình ủ yếm khí theo mẻ 21 L, vận hành trong 60 ngày liên tiếp và có 3 lần lặp lại. Nguyên liệu ủ được phối trộn theo tỷ lệ 50% phân bò và 50% thân bắp, trong đó thân bắp được cắt nhỏ cỡ 10 cm. Kết quả thí nghiệm cho thấy tất cả các thông số pH, nhiệt độ, độ kiềm của mẻ ủ đều phù hợp để vận hành. Lượng khí sinh ra của các nghiệm thức xử lý ở 2 ngày, 5 ngày, 8 ngày được ghi nhận là 153,4±9,6 L, 206,4±8,4 L và 174±11,1 L; năng suất sinh khí của các nghiệm thức không khác biệt và đạt giá trị 392,7±9,8 L/kg VSphânhủy, 469,8±10,1 L/kg VSphânhủy và 497,1±13,3 L/kg VSphânhủy. Tất cả các nghiệm thức đều sản sinh lượng CH4 thấp ở giai đoạn đầu nhưng tăng dần theo thời gian ủ và đạt hiệu quả sử dụng sau 10 ngày ủ. Kết quả cho thấy có thể chọn mốc thời gian 5 ngày để xử lý thân cây bắp trước khi đưa vào hầm ủ biogas.

Sogar eine vegetarische Ernährung führt durch den Konsum von Milchprodukten zum Schlachten der nicht mehr produktiven oder ausselektierten Milchkühe sowie der männlichen Nachkommen. Eine Rinderhaltung ohne Schlachtung (ROS) wäre (für Lakto-Vegetarier) hier ein Ausweg. Es wurden narrative und semi-strukturierte Interviews mit Tierhaltern der 5 hier dargestellten Fallbeispiele mit qualitativen Methoden der interpretativen Sozialforschung (Grounded Theory, Biographieforschung und sequentielle Feinanalyse) erhoben und untersucht. Die 5 Fallbeispiele wurden anhand biographischer Entwicklungen, ihrer Ethik und ihrem Tierhaltungssystem sowie anhand ihrer Konventionen verglichen. Der Fallvergleich ergab 5 Grundsätze des Care-Systems einer ROS: 1. Universal, 2. Bedingungslos, 3. Das ganze Leben betreffend - „a lifetime of Care“, 4. Familisierend, 5. Präventiv. Das Agrar-System der Fallbeispiele wurde in drei Betriebsstile differenziert: Reine Sanctuaries (Lebens-/Gnadenhof), Landwirtschaftliche Sanctuaries und Vegetarische Rinderhaltung/Milcherzeugung. Das Care- und das Agrar-System ergeben zusammen ein Agrar-Care-System. Kernelemente des Agrar-Systems der 4 hier untersuchten europäischen Betriebe sind u.a. ein hohes durchschnittliches Abgangsalter der Kühe von 12,5 Jahren und der Ochsen von 10 Jahren, stabile Herden, insg. vielfältige Dungnutzung, eine weitgehend muttergebundene Kälberaufzucht und partielle Ochsenanspannung. Bei dem dritten Fallbeispiel beträgt die Dauer der Laktationen durchschnittlich 2,8 Jahre und es werden dabei 9.055 kg pro Laktation ermolken. Bei Kühen mit sehr langen Laktationen sinken vom ca. 4.-6. Jahr die Leistungen nicht mehr und sind persistent. Die Milchkühe sind für 3,4 Jahre (als Mittel der beiden melkenden Betriebe) „in Rente". Der kostendeckende Milcherlös liegt bei ca. 2,95 bis 3,05 EUR pro kg Milch. Eine gemolkene Kuh trägt dabei die Kosten von 0,63 Kühen „in Rente" sowie von 1,48 Ochsen. Milch und Dung wären hier Beiprodukte des Tierlebens. / Even a vegetarian nutrition, through consumption of milk products, leads to the slaughtering of dairy cows that are no longer productive or have been sorted out, and of their male offspring. A cattle husbandry without slaughtering (here ‘CWS’) could be a solution (for lacto-vegetarians). Narrative and semi-structured interviews with the heads of animal husbandry in a total of five cases have been carried out and reviewed using qualitative methods of interpretive social research (Grounded Theory, biography research and detailed sequential analysis). In a case comparison, the five cases have been compared to each other in terms of their biographical developments, their ethics and their animal husbandry systems and also in terms of their conventions. The following five principles for a care system in CWS were derived: Universality, Unconditionality, A lifetime of care, Familialisation and Prevention. The agri-system of the case studies has been differentiated into three styles of farming: Pure sanctuary, agricultural sanctuary and vegetarian cattle husbandry. The combination of the agri- and care-system becomes the agri-care-system. Core elements of the agricultural system of CWS and of the 4 European farms are: a high average dying age which is 12.5 years for cows and 10 years for oxen, novel dung products, mostly rearing calves with the dam and on some farms the use of oxen for traction. In regard to the third case study, the average duration of lactation is 2.8 years, generating about 9,055 kg milk per lactation cycle. The dairy cows "retire" for a period of 3.4 years as a mean of the two milking case studies. In cows with very long lactation cycles, the milk yield, instead of decreasing from the 4th to the 6th year, rather seems to be constant during this period. The cost-covering milk revenue would be about 2,95 up to 3,05 EUR per kg. Each milked cow carries the cost of ca. 0,63 "retired" cows and 1,48 oxen. Milk and dung are the by-product of the animal life.

Balancing increasing elephant numbers with biodiversity conservation in small reserves has become a concern for many protected area managers. Elephants are considered important agents of disturbance creating heterogeneity and thus contributing to the maintenance of biodiversity. However elephants also damage vegetation through their destructive feeding habits, and this has led to pressure to reduce elephant populations in many reserves. Quantitative data on the impact of elephants on invertebrates, the main component of biodiversity at the species level, are lacking. The aim of this project was to assess the effect that habitat alteration by elephants has on the diversity of selected ground-dwelling invertebrates (ants, centipedes, millipedes, spiders, scorpions and termites) through the provision of logs and dung as a potential refuge niche for these invertebrate communities, and to determine the effect of spatial (vegetation types) and temporal (season and age of dung) variation on the invertebrates using these refugia. Variation in impacts was considered important because savanna is not homogenous and the impact of the refugia is likely to be dynamic in terms of seasonal trends in invertebrate populations, and in terms of changes in the environmental conditions offered by the refugia. Elephant impact on vegetation, quantity of refugia (logs and dung) produced and invertebrate diversity associated with refugia were determined for 115 transects within Madikwe Game Reserve in the North Western Province, South Africa. Invertebrate abundance, species richness and diversity were always higher under refugia than in areas without refugia. Vegetation utilisation, frequency of refugia production and invertebrate diversity showed strong temporal variation (seasonal); elephant impact and production of logs were higher in winter than in summer because elephants are more likely to feed on woody vegetation in winter when grass nutrient levels are low. Invertebrate diversity under the logs was higher in summer than in winter, and this probably reflected the higher abundance and diversity of invertebrates that are usually associated with the warmer, wetter summer months. The effect of adding refugia to three vegetation types on invertebrate diversity was tested experimentally at Makalali Private Game Reserve in the Limpopo Province, South Africa. Logs and elephant dung were set out in five plots each measuring 20m x 20m within Govender - iii mixed bushveld, riverine and mopane woodland. Significant differences were observed in invertebrate abundance, species richness and diversity between the refugia and control plots that lacked refugia and between the three vegetation types sampled. Similarity between invertebrate communities utilising the different refugia types and between the three different vegetation types were tested using the Jaccard similarity coefficient. The three vegetation types shared fewer than 50% of their species, as did the logs, dung and control sites. However the results obtained do illustrate a higher degree of similarity between the refugia substrates (logs and dung) than the control sites and between the more heterogeneous vegetation types (mixed bushveld and riverine) than the mopane veld. This indicated that invertebrate communities associated with refugia were not uniform, but were influenced by vegetation type. An experimental test of temporal changes in invertebrate community composition illustrated the importance of elephant dung as a microhabitat for different invertebrate groups over different ages of dung (three days, two, four, 12 and 32 weeks old). Colonisation of the dung, by dung beetles was immediate but as the microclimate of the dung changed with time, the new conditions were ideal for other invertebrate taxa. Over a period of eight months, the change of invertebrate communities utilising the dung included dung beetles, followed by millipedes and [mally ant and termite communities. The results of this study illustrated the importance of refugia (logs and dung) produced by elephants for ground-dwelling invertebrate species in the savanna environment. The extent of the influence of the refugia varied both spatially and temporally and this should be considered in future monitoring or in measuring impacts. While further research on a broader range of organisms and at larger scales is necessary, elephants do have a positive impact on at least some components of biodiversity, through the process of facilitation of refugia. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.

O Parque Nacional da Serra do Cipó tem passado por um importante desafio de manejo que é a definição sobre o uso de animais de montaria por parte dos visitantes. Recentemente, o Governo Brasileiro lançou um documento intitulado Diretrizes para visitação em unidades de conservação o qual dita algumas normas para essa atividade de uso público. No entanto, há questões relevantes de incoerências deste com o Sistema Nacional de Unidades de Conservação. A presença dos animais numa unidade de conservação pode causar diversos impactos ambientais, entre eles, a entrada e dispersão de espécies exóticas causando contaminação biológica em área protegida. Os cavalos e muares utilizados pelos visitantes podem ser veículo de entrada dessas espécies exóticas, seja por meio dos pelos, das patas e também das fezes. Esta investigação teve por objetivo investigar se há relação entre o uso de animais de montaria e a contaminação biológica de gramíneas exóticas pelas fezes dos animais no Parque Nacional da Serra do Cipó. Para tanto foram selecionadas duas trilhas do Parque, a do Capão dos Palmitos e a trilha da Farofa, sendo que as mesmas apresentam diferenças relevantes em termos de relevo e de histórico de uso. Com base no trabalho de Campbell e Gibson (2001) definiu-se o método. Em cada uma das trilhas procedeu-se a coleta de fezes eqüinas e de amostras de solo em dois períodos do ano (outono e verão). As amostras foram distribuídas em dois experimentos de germinação, um instalado in situ e outro no Laboratório de Biologia Reprodutiva e Genética de Espécies Arbóreas da ESALQ / USP. Outro experimento, também realizado in situ, verificou a presença de espécies de gramíneas exóticas e de plantas nativas nas áreas de abrangência das duas trilhas. Foram definidos quatro pontos para as amostragens tendo como referência o centro das trilhas, são eles: centro, borda, transição e interior. As análises estatísticas foram realizadas com uso do programa SAS versão 9.3.1. Os resultados mostraram que há maior presença de gramíneas exóticas na trilha da Farofa em relação à trilha do Capão. Na trilha da Farofa houve diferença significativa entre o ponto do centro com os demais. Na trilha do Capão não houve diferença entre os pontos avaliados. As espécies nativas foram encontradas com maior frequência na trilha do Capão. Houve diferença do ponto centro para os demais nas duas trilhas avaliadas. Os resultados obtidos pelas amostras de solos que estavam no experimento controlado em laboratório revelaram que não há diferença na germinação de sementes entre as trilhas. As amostras de fezes, no entanto, mostraram diferença entre as trilhas, sendo que há maior germinação de sementes na trilha da Farofa. Tanto para as amostras de fezes como para as de solo, houve grande diferença para a germinação entre os períodos de outono e de verão. Não houve nenhuma germinação no experimento instalado in situ. / Serra do Cipó National Park has undergone a major management challenge that is the definition of the use of horse riding by the visitors. Recently, the Brazilian Government launched a document entitled Diretrizes para visitação em unidades de conservação (Guidelines for visitation in protected areas) which dictates certain rules for recreation ecology activities. However, there are relevant issues that are incoherent with the Brazilian law for protected areas called the Sistema Nacional de Unidades de Conservação (National System of Conservation Areas). The presence of domestic animals in protected areas can cause several environmental impacts, including the entry of alien species causing biological contamination. The horses used by visitors can be a vehicle of entry of alien species, either through the hair, the legs and also the dung. This research aimed to investigate whether there is a relation between the use of horses and biological contamination of exotic grasses by horses\' dung in the Serra do Cipó National Park. Therefore, we selected two trails of the park which present significant differences in terms of topography and land use history: the Capão dos Palmitos trail and the Farofa trail. The method was defined based on the work of Campbell and Gibson (2001). From each of the tracks were collected equine dung and soil samples in two seasons (autumn and summer). The samples were divided into two experiments, one installed in situ and another at the Laboratory of Reproductive Biology and Genetics of Tree Species of ESALQ / USP. Another experiment, also conducted in situ, verified the presence of exotic grasses and native plants in areas served by the two trails. Four points, which had as reference the center of the trails, were defined for sampling: center, edge, transition and interior. Statistical analysis was performed using SAS software, version 9.3.1. The results showed that there has been an increase in the amount of exotic grasses in the trail of Farofa when compared with the path of Capão. On the trail of Farofa significant difference was found among the center point and the others. On the trail of Capão no difference among the points was assessed. The native species were found more frequently on the trail of the Capão. There was a statistical difference between the center points on both trails. The results obtained from soil samples that were in the controlled experiment in the laboratory revealed that there is no difference in germination between the trails. Dung samples, however, showed differences between the tracks, and there is a greater germination in the trail of Farofa. A significant difference in germination between the periods of autumn and summer was found both in the dung samples and in the soil samples. There was no germination in the experiment installed

O Parque Nacional da Serra do Cipó tem passado por um importante desafio de manejo que é a definição sobre o uso de animais de montaria por parte dos visitantes. Recentemente, o Governo Brasileiro lançou um documento intitulado Diretrizes para visitação em unidades de conservação o qual dita algumas normas para essa atividade de uso público. No entanto, há questões relevantes de incoerências deste com o Sistema Nacional de Unidades de Conservação. A presença dos animais numa unidade de conservação pode causar diversos impactos ambientais, entre eles, a entrada e dispersão de espécies exóticas causando contaminação biológica em área protegida. Os cavalos e muares utilizados pelos visitantes podem ser veículo de entrada dessas espécies exóticas, seja por meio dos pelos, das patas e também das fezes. Esta investigação teve por objetivo investigar se há relação entre o uso de animais de montaria e a contaminação biológica de gramíneas exóticas pelas fezes dos animais no Parque Nacional da Serra do Cipó. Para tanto foram selecionadas duas trilhas do Parque, a do Capão dos Palmitos e a trilha da Farofa, sendo que as mesmas apresentam diferenças relevantes em termos de relevo e de histórico de uso. Com base no trabalho de Campbell e Gibson (2001) definiu-se o método. Em cada uma das trilhas procedeu-se a coleta de fezes eqüinas e de amostras de solo em dois períodos do ano (outono e verão). As amostras foram distribuídas em dois experimentos de germinação, um instalado in situ e outro no Laboratório de Biologia Reprodutiva e Genética de Espécies Arbóreas da ESALQ / USP. Outro experimento, também realizado in situ, verificou a presença de espécies de gramíneas exóticas e de plantas nativas nas áreas de abrangência das duas trilhas. Foram definidos quatro pontos para as amostragens tendo como referência o centro das trilhas, são eles: centro, borda, transição e interior. As análises estatísticas foram realizadas com uso do programa SAS versão 9.3.1. Os resultados mostraram que há maior presença de gramíneas exóticas na trilha da Farofa em relação à trilha do Capão. Na trilha da Farofa houve diferença significativa entre o ponto do centro com os demais. Na trilha do Capão não houve diferença entre os pontos avaliados. As espécies nativas foram encontradas com maior frequência na trilha do Capão. Houve diferença do ponto centro para os demais nas duas trilhas avaliadas. Os resultados obtidos pelas amostras de solos que estavam no experimento controlado em laboratório revelaram que não há diferença na germinação de sementes entre as trilhas. As amostras de fezes, no entanto, mostraram diferença entre as trilhas, sendo que há maior germinação de sementes na trilha da Farofa. Tanto para as amostras de fezes como para as de solo, houve grande diferença para a germinação entre os períodos de outono e de verão. Não houve nenhuma germinação no experimento instalado in situ. / Serra do Cipó National Park has undergone a major management challenge that is the definition of the use of horse riding by the visitors. Recently, the Brazilian Government launched a document entitled Diretrizes para visitação em unidades de conservação (Guidelines for visitation in protected areas) which dictates certain rules for recreation ecology activities. However, there are relevant issues that are incoherent with the Brazilian law for protected areas called the Sistema Nacional de Unidades de Conservação (National System of Conservation Areas). The presence of domestic animals in protected areas can cause several environmental impacts, including the entry of alien species causing biological contamination. The horses used by visitors can be a vehicle of entry of alien species, either through the hair, the legs and also the dung. This research aimed to investigate whether there is a relation between the use of horses and biological contamination of exotic grasses by horses\' dung in the Serra do Cipó National Park. Therefore, we selected two trails of the park which present significant differences in terms of topography and land use history: the Capão dos Palmitos trail and the Farofa trail. The method was defined based on the work of Campbell and Gibson (2001). From each of the tracks were collected equine dung and soil samples in two seasons (autumn and summer). The samples were divided into two experiments, one installed in situ and another at the Laboratory of Reproductive Biology and Genetics of Tree Species of ESALQ / USP. Another experiment, also conducted in situ, verified the presence of exotic grasses and native plants in areas served by the two trails. Four points, which had as reference the center of the trails, were defined for sampling: center, edge, transition and interior. Statistical analysis was performed using SAS software, version 9.3.1. The results showed that there has been an increase in the amount of exotic grasses in the trail of Farofa when compared with the path of Capão. On the trail of Farofa significant difference was found among the center point and the others. On the trail of Capão no difference among the points was assessed. The native species were found more frequently on the trail of the Capão. There was a statistical difference between the center points on both trails. The results obtained from soil samples that were in the controlled experiment in the laboratory revealed that there is no difference in germination between the trails. Dung samples, however, showed differences between the tracks, and there is a greater germination in the trail of Farofa. A significant difference in germination between the periods of autumn and summer was found both in the dung samples and in the soil samples. There was no germination in the experiment installed

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

Les deux principaux objectifs de cette thèse sont de développer les aspects théoriques et expérimentaux sur la co-méthanisation des déchets fermiers et alimentaires. Les objectifs de nos études portent sur l'élimination du maximum de déchets mis en ISDND, la réduction des pollutions des milieux naturels (eau, sol, air) par les effluents d'élevage, les boues de STEP et sur la mise en disposition d'une source énergétique renouvelable via le biogaz obtenu. Premièrement, nous avons effectué des expérimentations sur la co-méthanisation des effluents liquides, lisier de porc, boues de STEP, et de la vinasse et le mélange de ces effluents d'élevage avec les déjections solides des animaux (fumier, fientes) et des biodéchets (restes de repas). Ces expérimentations avaient pour but de suivre l'évolution du milieu réactionnel en fonction du composant du mélange ainsi co-digéré. Deuxièmement des tests des potentiels méthane et biogaz issus de mélange associant plusieurs types de déchets organiques sous différents états physiques (liquide, semi liquide, pâteux, solide) ont été effectués. La problématique qui se posait étant de savoir parmi les déchets à mélanger, quelle proportion de chaque mono-substrat donnera le meilleur potentiel méthanogène et s'il était possible de mettre en avant des effets synergétiques entre déchets. Nous avons fait appel à un outil statistique, le plan de mélange pour définir les mélanges à tester. Pour un mélange à 3 composants (fumier de vache, lisier de porc, restes de repas), le nombre d'expériences optimum à réaliser a été de 13. La réalisation du plan de mélange, c'est à dire la campagne expérimentale sur les co-méthanisations des 13 mélanges proposés nous a permis d'observer que le potentiel méthane d'un mélange dépend tout premièrement de sa texture (état physique) à l'entrée du processus. Un mélange contenant un maximum en proportion en co-produits liquides (lisier de porc) associé avec le maximum de déchets riches en substrats solubles (restes de repas) nous a donné les meilleurs potentiels méthane et biogaz. Cette observation a été confirmée par le taux de conversion de la matière sèche (MS) en matière volatile (MV) du mélange. Compte tenu du taux de MS, MV et le ratio MV/MS d'un mélange, ainsi que les interactions entre les composants du mélange, une loi permettant de prédire le potentiel biogaz d'un mélange doit considérer ces facteurs. Cette loi doit tenir compte de l'effet positif (synergisme) et l'effet négatif (antagonisme) entre les composants du mélange. Cette loi a été définie dans le but de prédire le potentiel méthane des mélanges constitués de fumier de vache, lisier de porc et restes de repas et se situant à l'intérieur du domaine expérimental défini par les limites sur les proportions minimale et maximale de chaque composant du mélange. Toutefois, cette loi définie n'est applicable qu'aux mélanges d'association de fumier de vache, de lisier de porc et des restes de repas. Cette loi a été définie pour estimer le BMP des mélanges, et ne permet pas de suivre le procédé de la méthanisation. Aussi, pour prédire le volume de biogaz (méthane) journalier ou cumulé de la cométhanisation. / The two main objectives of this thesis are to develop theoretical and experimental aspects of the anaerobic co-digestion of farm wastes associated with food. Our general studies have for objectives the elimination as much as possible the maximum of organic waste into non-hazardous landfills, reduce pollution of natural environments (water, soil, air) by the effluent livestock, sewage sludge, and dispose of energy via the produced biogas.Firstly, we carried out experiments on the anaerobic co-digestion of the liquid effluents association (pig slurry, sewage sludge, vinasse effluents) and the mixture of animal slurries, manures, and food waste. The aim of these experiments was to follow the evolution of the reactor behavior according to the component of the co-digested mixture.Secondly, BMP tests of mixture of association several types of organic waste under different physical condition (liquid, semi liquid, pasty, solid) were carried out. We have been tried to know, which proportion of each mono-substrate will give the best BMP among waste to mix? We used a statistical tool, the mixture design to define the mixtures to be tested. For a mixture with 3 components (cow dung, pig slurry, food waste), the optimum number of experiments to realize was 13.The realization of the mixture design, i.e. the experiment series on the anaerobic co-digestion of the 13 proposed mixtures enabled us to observe that the BMP of a mixture firstly depends on its texture (physical state) at the entry of the process. A mixture containing a maximum in proportion in liquid substrate (pig slurry) associated with food waste gave us the best biogas and methane potential. This observation was confirmed by the conversion rate of dry matter to volatile solid (VS) of the mixture. These results were proven by the activity (synergism, antagonism) of mixtures components influencing to BMP tests.The empiric law defined to predict the BMP of a mixture must to account the rate of VS/DM of a mixture, and the interactions between components of the mixture. This law must also include the positive effect (synergism) and negative (antagonism) between components of the mixture. This law has been defined in order to predict the potential methane mixtures of cow dung, pig slurry and food wastes and being within the experimental domain defined by the limits on minimum and maximum proportions of each component of the mixture. However, this definite law is applicable only to the mixtures of cow dung, pig slurry and food waste. The definite law is limited for prediction of mixtures BMP. However, this empiric law can not be used to follow reactor process. Model with three stages (hydrolysis of soluble substrate, acidogenic production stage and methanogenic stage) was used to predict daily and cumulative of biogas and methane production of anaerobic digestion of farm waste associated with vegetable waste. This model must be adapted with substrate type used and experimentations conditions (batch and mesophilic conditions). An adjustment of the model equations describing hydrolysis polymers stage was necessary in order to take into account of the concentration of polymers in particulate forms contained in complex substrates such as manure, slurry, and vegetable food waste. This adapted model was called model of Coupling. Indeed, a calibration of the most influential parameters of the model of Coupling, on the output must be carried out in order to validate the model.Daily and cumulative predictions of biogas and methane production of anaerobic digestion of farm waste associated with food waste were obtained by using adapted dynamical model. Model parameters values depend on the substrate type using in experimentation processes. Moreover, parameters values must be verified, needing further work.

No description available.

Im Laborversuch konnte der positive Einfluss einer thermobarischen Vorbehandlung auf die Hydrolysier- und Vergärbarkeit von Rinderfestmist und Rindergülle nachgewiesen werden. Die Laborergebnisse wurden innerhalb eines theoretischen Modells in den Praxismaßstab übertragen, um den Einfluss auf Treibhausgasemissionen, Energiebilanz und Ökonomie zu bewerten. Die Vorbehandlungstemperaturen im Labor lagen zwischen 140 und 220°C in Schritten von 20 K und einer Vorbehandlungszeit von jeweils 5 Minuten. Die höchste Methanmehr¬ausbeute von 58 % konnte bei einer Temperatur von 180°C ermittelt werden. Das Auftreten von Inhibitoren und nicht vergärbaren Bestandteilen führte bei einer Aufbereitungstemperatur von 220°C zu Methanausbeuten, die geringer waren als die des unaufbereiteten Einsatzstoffes. In einer erweiterten Analyse konnte ein funktioneller Zusammenhang zwischen der Methanausbeute nach 30 Tagen und der Methanbildungsrate und -ausbeute während der Beschleunigungsphase gezeigt werden. Mittels einer Regressionsanalyse der so ermittelten Werte wurde nachgewiesen, dass die optimale Aufbereitungstemperatur 164°C ist und die minimale größer als 115°C zu sein hat. Treibhausgasemissionen und Energiebilanz wurden im Rahmen einer Ökobilanz nach ISO 14044 (2006) ermittelt, sowie eine Kosten-Nutzen-Analyse durchgeführt. Dazu wurde eine Anlage zur thermobarischen Vorbehandlung entwickelt und innerhalb eines Modells in eine Biogasanlage integriert. Weiterhin wurde in diesem Modell Maissilage durch Rinderfestmist und / oder Rindergülle als Einsatzstoff ersetzt. Rinderfestmist, ein Einsatzstoff mit hohem organischen Trockenmassegehalt, der ohne Vorbehandlung nicht einsetzbar wäre, erreichte eine energetische Amortisationszeit von 9 Monaten, eine Vermeidung in Höhe der während der Herstellung emittierten Treibhausgase innerhalb von 3 Monaten und eine ökonomische Amortisationszeit von 3 Jahren 3 Monaten, wohingegen Rindergülle keine positiven Effekte zeigte. / Hydrolysis and digestibility of cattle waste as feedstock for anaerobic digestion were improved by thermobarical treatment in lab-scale experiments. The effects of this improvement on greenhouse gas emissions, energy balance and economic benefit was assessed in a full-scale model application. Thermobarical treatment temperatures in lab-scale experiments were 140 to 220°C in 20 K steps for a 5-minute duration. Methane yields could be increased by up to 58 % at a treatment temperature of 180°C. At 220°C, the abundance of inhibitors and other non-digestible substances led to lower methane yields than those obtained from untreated material. In an extended analysis, it could be demonstrated that there is a functional correlation between the methane yields after 30 days and the formation rate and methane yield in the acceleration phase. It could be proved in a regression of these correlation values that the optimum treatment temperature is 164°C and that the minimum treatment temperature should be above 115°C. The theoretical application of a full-scale model was used for assessing energy balance and greenhouse gas emissions following an LCA approach according to ISO 14044 (2006) as well as economy. A model device for thermobarical treatment has been suggested for and theoretically integrated in a biogas plant. The assessment considered the replacement of maize silage as feedstock with liquid and / or solid cattle waste. The integration of thermobarical pretreatment is beneficial for raw material with high organic dry matter content that needs pretreatment to be suitable for anaerobic digestion: Solid cattle waste revealed very short payback times, e.g. 9 months for energy, 3 months for greenhouse gases, and 3 years 3 months for economic amortization, whereas, in contrast, liquid cattle waste did not perform positive replacement effects in this analysis.