Production of biogas is one of several alternatives to meet sustainable energy solutions and waste management. However, managing the by-product (digestate) can be problematic with its high handling costs. Digestate from wet co-digestion biogas plants contains large volumes of water, causing high transportation costs and low concentration of the valuable nutrients. An alternative to try and reduce the associated costs is by processing the digestate. Processing the digestate for volume reduction allow for more economic and resource efficient ways of handling the product. This master thesis was performed on an initiative from Tekniska verken AB and address digestate handling from Linköping biogas plant, a large co-digestion biogas plant in Sweden. The project aimed to find a feasible, more resource efficient management of their digestate by looking at digestate processing alternatives.The approach systematically evaluated a large number of processing techniques by both literature and communication with TvAB or experts. A selection of techniques were further evaluated were studies in laboratory and a market analysis on digestate provided complementary information, aiding the economical evaluation. Results suggest that processing by centrifuge is a viable, economic option when digestate management is costly and a liquid fraction can be recirculated in the process. It has the potential to significantly reducing digestate management costs. Other processing alternatives may be beneficial if transportation distance can be greatly reduced and/or synergies can be found, but the findings in this project suggest that only treatment with centrifuge is of interest. The results are subject to a number of conditions (such as size of the plant) and assumptions (such as recirculation of a liquid fraction) and therefore need individual adaption to be applicable at any specific plant. Conclusive remarks are that although site specific conditions affect the choice of processing, a project such as this may help reducing the necessary time spent on evaluation. Both research process and results may provide valuable findings for similar evaluations in any industry.

In order to investigate the effect of foliar application of organic fertilizer and micronutrients on quantitative and qualitative characteristics of Niger plant, a field experiment was conducted in a complete randomized block design with three replications at Shahrekord University Research Farm during the years 2013-2014. Treatments included three levels of humic acid (1, 3, and 6 liters of humic acid per hectare), iron (4 parts per million, ppm), zinc (4 parts per million, ppm) and control (without humic acid iron, and zinc). In this experiment, traits of the number of heads per plant, seeds number per head, 1000 seeds' weight, grain yield, and also oil and protein content were evaluated. The findings showed that foliar application of humic acid, zinc and iron resulted in a significant increase in all analyzed traits. The most significant plant response was obtained with the use of 6 liters humic acid per hectare, and the second most significant plant response was seen with the sprayed zinc treatment which was probably due to limited absorption and deficiency of these elements in the tested soil.

Submitted by Silvana Teresinha Dornelles Studzinski (sstudzinski) on 2016-10-18T12:56:20Z No. of bitstreams: 1 Douglas Ferreira Velho_.pdf: 2524832 bytes, checksum: dd171e639a007511b6cceb2258575af8 (MD5) / Made available in DSpace on 2016-10-18T12:56:21Z (GMT). No. of bitstreams: 1 Douglas Ferreira Velho_.pdf: 2524832 bytes, checksum: dd171e639a007511b6cceb2258575af8 (MD5) Previous issue date: 2016-07-29 / Comitesinos - Comitê de Gerenciamento da Bacia Hidrográfica do Rio dos Sinos / FUNDEPE - Fundação Universitária para Desenvolvimento do Ensino e da Pesquisa / Petrobras - Petróleo Brasileiro S. A. / UNISINOS - Universidade do Vale do Rio dos Sinos / O crescente aumento na geração de resíduos sólidos urbanos, somado às formas inadequadas de tratamento e disposição contribuem de forma direta e significativa com a problemática ambiental. Diante deste cenário, se faz necessário o desenvolvimento de alternativas que permitam outros benefícios além da disposição final apropriada. A digestão anaeróbia é uma alternativa viável e economicamente interessante para tratamento da fração orgânica dos resíduos sólidos urbanos. Considerando que em nosso país a fração orgânica é predominante nos resíduos sólidos urbanos, correspondendo em média a mais de 40% na composição, ao mesmo tempo que reduz o volume de resíduos enviados para os aterros sanitários, o processo gera produtos como o biogás e biofertilizante para uso agrícola. Esta pesquisa teve como objetivo avaliar a tratabilidade da fração orgânica dos resíduos sólidos domésticos provenientes do preparo e pós consumo das refeições de um restaurante universitário em um reator operado por batelada e qualificar as características do biofertilizante gerado. Para atingir este objetivo, a pesquisa foi realizada em três etapas, sendo que na etapa inicial foram realizadas quatro bateladas nas quais foram analisadas a proporção adequada de resíduos e inóculo para partida do reator sem que ocorresse acidificação. A segunda etapa consistiu na realização de seis bateladas, nas quais foram monitorados os principais parâmetros de operação e a terceira etapa onde foram avaliados os parâmetros químicos, físicos e microbiológicos do biofertilizante gerado ao final dos ensaios da segunda etapa. Os resultados da primeira etapa apontaram que a proporção de 6:1 em termos de sólidos totais voláteis, sendo lodo proveniente de um reator UASB e resíduos sólidos putrescíveis respectivamente, apresentaram uma partida adequada do sistema, sem que ocorresse acidificação, com o pH variando entre 6,9 e 7,7. Na segunda fase o monitoramento dos principais parâmetros de operação permitiu que no decorrer dos ensaios a proporção em termos de STV fosse reduzida, chegando a 1:1 de inóculo e substrato respectivamente, na batelada 10, portanto permitindo o tratamento de uma quantidade maior de resíduos em relação aos ensaios iniciais. Os resultados obtidos no monitoramento apontaram que o pH manteve-se dentro da faixa considerada ideal entre 6,0 e 8,0, porém o período de vinte e dois dias adotado como tempo de retenção mostrou-se insuficiente para degradação e consequente remoção da matéria orgânica, sendo que apenas a batelada 10 mostrou-se eficiente na remoção de STV 8,1% e carbono orgânico total 33,5%. A análise física do biofertilizante gerado no final de cada ensaio apontou umidade acima do permitido pela legislação, sendo indicado apenas para uso via aspersão. Quimicamente o biofertilizante apresentou insuficiência de nitrogênio, evidenciada nas elevadas relações C:N iniciais e finais obtidas e carência de macronutrientes como fósforo cujos resultados ficaram abaixo de 1%, mínimo imposto pela legislação e potássio, elemento que não foi detectado na pelo equipamento utilizado. A qualidade sanitária do composto atendeu a legislação quanto a presença de ovos viáveis de helmintos, sendo que todos os ensaios apresentaram resultados inferiores a uma unidade/4g, porém apresentou resultados acima do limite estabelecido para coliformes termotolerantes. O teste de germinação confirmou a ausência da fitotoxidade dos produtos. / The increase in the generation of municipal solid waste, together with the inadequate forms of treatment and disposal contribute directly and significantly to the environmental problems. In this scenario, it is necessary to develop alternatives to other benefits in addition to the appropriate disposal. Anaerobic digestion is a viable alternative and economically interesting for the treatment of the organic fraction of municipal solid waste. Whereas in our country the organic fraction is predominant in urban solid waste, corresponding to an average of over 40% in the composition, at the same time reducing the volume of waste sent to landfills, the process generates products such as biogas and biofertilizers for agricultural use. This research aimed to evaluate the treatability of the organic fraction of household waste from the preparation and after consumption of meals from a university restaurant in a reactor operated by batch and qualify the characteristics of the generated biofertilizers. To achieve this goal, the research was conducted in three phases, with the initial phase were held four batches were analyzed in which the proportions of the waste and inoculum for starting the reactor without acidification occurred. The second stage consisted of six batches, which were monitored in the main operating parameters and the third stage where we evaluated the chemical, physical and microbiological biofertilizer generated at the end of the second stage trials. The first step results indicated that the ratio of 6: 1 in terms of total volatile solids, and sludge from a UASB reactor and solid waste putrescible respectively, showed a suitable starting system without occur acidification to pH between 6.9 and 7.7. In the second stage, the monitoring of key operating parameters allowed during the experiment the proportion in terms STV be reduced, reaching 1: 1 inoculum and substrate respectively in the batch 10, thus allowing treatment of a larger quantity of waste compared to the initial test. The results showed that monitoring the pH was maintained within the range considered optimal between 6.0 and 8.0, but the period twenty-two days adopted as the retention time was insufficient to degradation and subsequent removal of matter organic, and only the batch 10 was effective in removing STV 8.1% and 33.5% total organic carbon. Physical analysis of biofertilizers generated at the end of each test pointed humidity above those permitted by law and is intended only for use via spraying. Chemically biofertilizer showed nitrogen deficiency, evidenced in the high ratios C: Initial N and obtained final and lack of nutrients such as phosphorus whose results were below 1% minimum required by the legislation and potassium, an element that was not detected in the equipment used. The sanitary quality of the compound met the legislation for the presence of viable helminth eggs, and all tests showed lower results to a unit / 4G, but showed results above the limit for fecal coliforms. The germination test confirmed the absence of phytotoxicity of products.

Der Mangel an Nährstoffen im Boden, hauptsächlich an Phosphor (P) und Stickstoff (N), verbunden mit einem hohen Salzgehalt und der generellen Verarmung landwirtschaftlicher Böden , sind ein ernstes Problem für die landwirtschaftliche Produktion weltweit. Daher besteht ein dringender Bedarf an Forschung und Entwicklung geeigneter landwirtschaftlicher Praktiken, um ungünstige Bodenbedingungen zu verringern und wenn möglich die Fruchtbarkeit von Kulturland wiederherzustellen. Die Verwendung von Rhizobakterien, die das Pflanzenwachstum (PGPR) fördern, kann sich bei der Entwicklung von Strategien zur Erleichterung des Pflanzenwachstums unter normalen Wachstumsbedingungen sowie unter abiotischen Stress als nützlich erweisen. Diese Bakterien bieten ihren pflanzlichen Wirten Vorteile, indem sie die Aufnahme von Bodenmineralien fördern und Pflanzen vor schädlichen Umwelteinflüssen schützen. Die vorliegende Arbeit bewertet die Rolle von in Kamerun natürlich vorkommenden PGPR an Mais und untersucht deren Potenzial als Bioimpfstoffe zur Steigerung des Pflanzenwachstums in Kamerun. Wir prüfen die Hypothese, dass einheimische Bakteriengemeinschaften aus Kamerun einen hohen Anteil an Bakterien aufweisen, deren Eigenschaften Kulturpflanzen helfen, mit ungünstigen Bedingungen umzugehen. In der vorliegenden Arbeit wurden dazu Bakteriengemeinschaften der Rhizosphäre von in Kamerun angebautem Mais isoliert und untersucht. Zum ersten Mal erfolgte eine umfassende phylogenetische Zuordnung aller kultivierbaren Bakterien, auf Grundlage ihrer potenziellen Fähigkeiten zur Förderung des Pflanzenwachstums. / Nutrient deficiencies in soil, mainly in phosphorus (P) and nitrogen (N), coupled to salinity and the impoverishment of agricultural soils, are a severe problem for agricultural production worldwide. Therefore, there is an urgent need for research and development of more suitable agricultural practices in order to reduce unfavorable conditions, and if possible, to restore the fertility of cultivated lands. The use of rhizobacteria, which promote plant growth (PGPR), can prove useful in developing strategies to facilitate plant growth under normal as well as under abiotic stress conditions. These bacteria offer benefits to plant hosts by promoting the uptake of soil minerals and protecting plants from environmental stresses. The thesis evaluates the role of native PGPR associated with maize as potential bio-inoculants for plants growth in Cameroon. We hypothesized that native bacterial communities from Cameroon include a high potential of bacteria helping the plant cope with unfavorable conditions. Here, we provide for the first time a comprehensive phylogenetic affiliation of cultivable bacterial communities associated with maize rhizosphere grown in Cameroon in relationship to their potential plant growth-promoting abilities.