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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
191

The effect of inorganic fertilizer application on compost and crop litter decomposition dynamics in sandy soil

Van der Ham, Ilana 03 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Inorganic fertilizer applications are common practice in commercial agriculture, yet not much is known regarding their interaction with organic matter and soil biota. Much research has been done on the effect of inorganic N on forest litter decomposition, yet very little research has focused on the effect of inorganic fertilizers on crop litters and, to our knowledge, none on composted organic matter. Furthermore none of the research has been done in South Africa. The main aim of this research project was to determine the effect of inorganic fertilizer applications on the decomposition of selected organic matter sources commonly used in South African agriculture and forestry. Two decomposition studies were conducted over a 3-month period, one on composts and the other on plant litters, using a local, sandy soil. In the first experiment a lower quality compost, compost A (C:N ratio, 17.67), and higher quality compost, compost B (C:N ratio, 4.92) was treated with three commercially used fertilizer treatments. Two were typical blends used for vegetable (tomato and cabbage) production: tomato fertilizer (10:2:15) (100 kg N, 20 kg P, 150 kg K per ha) and cabbage fertilizer (5:2:4) (250 kg N, 100 kg P, 200 kg K per ha). The third fertilizer blend, an equivalent mass application of N and P applied at 150 kg of each element per ha, is more commonly used in pastures. In the second experiment, five commonly encountered crop and forestry litters, namely kikuyu grass, lucerne residues, pine needles, sugar cane trash and wheat straw, were selected to represent the labile organic matter sources. The litters were treated with the tomato and cabbage fertilizer applications rates. Both decomposition experiments were conducted under ambient laboratory conditions at field water capacity. Decomposition rates were monitored by determining CO2 emissions, DOC production, β-glucosidase and polyphenol oxidase activity (PPO). At the start and end of decomposition study, loss on ignition was performed to assess the total loss of OM. Based on the results obtained from these two experiments, it was concluded that the addition of high N containing inorganic fertilizers enhanced the decomposition of both composted and labile organic matter. For both compost and plant litters, DOC production was greatly enhanced with the addition of inorganic fertilizers regardless of the organic matter quality. The conclusion can be made that inherent N in organic matter played a role in the response of decomposition to inorganic fertilizer application with organic matter low in inherent N showing greater responses in decomposition changes. For labile organic matter polyphenol and cellulose content also played a role in the responses observed from inorganic fertilizer applications. / AFRIKAANSE OPSOMMING: Anorganiese kunsmis toedieningss is algemene praktyk in die kommersiële landbou sektor,maar nog min is bekend oor hul interaksie met organiese materiaal en grond biota. Baie navorsing is reeds oor die uitwerking van anorganiese N op woud en plantasiereste se ontbinding gedoen. Baie min navorsing het gefokus op die uitwerking van anorganiese kunsmis op die gewasreste en tot ons kennis, is daar geen navorsing gedoen op die invloed van anorganiese kunsmis op gekomposteer organiese material nie. Verder is geeneen van die navorsing studies is in Suid-Afrika gedoen nie. Die hoofdoel van hierdie navorsingsprojek was om die effek van anorganiese kunsmis toedienings op die ontbinding van geselekteerde organiese materiaal bronne, wat algemeen gebruik word in die Suid-Afrikaanse landbou en bosbou, te bepaal. Twee ontbinding studies is gedoen oor 'n 3-maande-tydperk, een op kompos en die ander op die plantreste, met die gebruik van 'n plaaslike, sanderige grond. In die eerste eksperiment is ‘n laer gehalte kompos, kompos A (C: N verhouding, 17.67), en 'n hoër gehalte kompos, kompos B (C: N verhouding, 4.92) met drie kommersieel anorganiese bemesting behandelings behandel. Twee was tipiese versnitte gebruik vir die groente (tamatie en kool) produksie: tamatie kunsmis (10: 2:15) (100 kg N, 20 kg P, 150 kg K per ha) en kool kunsmis (5: 2: 4) (250 kg N, 100 kg P, 200 kg K per ha). Die derde kunsmis versnit was 'n ekwivalente massa toepassing van N en P van 150 kg van elke element per ha, wat meer algemeen gebruik word in weiding. In die tweede eksperiment was vyf algemeen gewas en bosbou reste, naamlik kikoejoegras, lusern reste, dennenaalde, suikerriet reste en koring strooi, gekies om die labiele organiese materiaal bronne te verteenwoordig. Die reste is met die tamatie en kool kunsmis toedienings behandel. Beide ontbinding eksperimente is uitgevoer onder normale laboratorium toestande by veldwaterkapasiteit. Ontbinding tempo is deur die bepaling van die CO2-vrystellings, opgelosde organiese koolstof (OOK) produksie, β-glukosidase en polifenol oksidase aktiwiteit (PPO) gemonitor. Aan die begin en einde van ontbinding studie, is verlies op ontbranding uitgevoer om die totale verlies van OM te evalueer. Gebaseer op die resultate van hierdie twee eksperimente, was die gevolgtrekking dat die toevoeging van hoë N bevattende anorganiese bemestingstowwe die ontbinding van beide komposte en plant reste verhoog. Vir beide kompos en plantreste word OOK produksie verhoog met die toevoeging van anorganiese bemesting, ongeag van die organiese materiaal gehalte. Die gevolgtrekking kan gemaak word dat die inherente N in organiese materiaal 'n rol gespeel het in die reaksie van ontbinding op anorganiese bemesting toedienings met die grootste reaksie in organiese material laag in inherente N. Vir labiele organiese material het polifenol en sellulose inhoud ook 'n rol gespeel in die reaksie waargeneeming op anorganiese bemesting.
192

Redesign and Development of HotRot1811 Composting Unit and Ancillary Item

Harris, Daniel January 2012 (has links)
This project investigated alternative materials, methods and processes to reduce manufacturing costs while improving the marketability and performance of the HotRot1811 compost machine. Some of the redesign aspects include investigating alternative insulation materials, corrosion within the vessel, stress and strain gauge testing of the shaft and tines, and alternative design considerations. Another aspect of the project is to test and develop a compost classifier. The compost classifier is used for separating contaminants from compost which could be an alternative technology HotRot Organic Solutions Ltd may produce. This report describes the findings, recommendations and conclusions of these investigations.
193

Phosphorus cycling in organic systems

2014 January 1900 (has links)
Soil phosphorus (P) is often unavailable in SK soils due to immobilization by microbial biomass and complexation with cations. The prohibition of synthetic fertilizer use in organic systems means farmers rely on crop rotation or approved inputs to supply P for crops. Legumes in crop rotation add P to soil through decomposition and deposition, and approved fertilizers such as bone meal (BM), rock phosphate (RP), and composted manure add P to soil through dissolution. Arbuscular mycorrhizal fungi (AMF) improve crop access to soil P. The fungi colonize roots of host crops, allowing roots to reach immobile pockets of soil P. Colonization by AMF is usually decreased or delayed following partial fallow periods, non-host plants, and the addition of soluble P fertilizers. This thesis consists of two studies. For the first, the effects of crop rotation were tested on AMF colonization and soil P dynamics. Colonization by AMF of mycorrhizal crops was examined following a non-mycorrhizal crop, a partial fallow period, and mycorrhizal crops. All crops were colonized evenly (63-70%) at flowering despite non-mycorrhizal and partial fallow periods, and the sequence most depleted in soil N (wheat-barley) had the lowest colonization in August (36%). The second study evaluated soil P and plant N and P after applications of BM, hydroxyapatite (HAP), and sheep manure compost. Compost application increased plant P uptake compared to the control (1.26 vs. 0.71 mg pot-1), while applications of BM and HAP alone did not. Compost application did not affect AMF colonization of wheat (Triticum aestivum L.). Overall this research highlights the importance of legumes and composted manure use in organic systems. Legume use in crop rotation simultaneously increased soil P deposition and may have preserved AMF communities despite fallow periods and non-host crops in rotation. Conditions normally affecting AMF colonization in conventional systems did not apply. The use of composted manure in the greenhouse study resulted in the greatest P uptake and concentrations in wheat. Thus the use of legumes and composted manure may increase P availability to crops directly and indirectly: directly through soil P deposition and perhaps indirectly through the preservation of AMF communities.
194

Transforming Organic Waste Into A Marketable Product: A Conjoint Analysis Of Bulk Compost Preferences And Strategies For Expanding The Compost Market In Vermont

Keeney, Daniel Colin 01 January 2014 (has links)
Organic waste management presents challenges and opportunities alike for community-based economic development. Waste-to-compost transformation can be socially and economically successful by employing ecological design principles, multi-stakeholder collaboration, and values-based supply chains (VCs). An analysis of commercial buyers' preferences for compost will inform approaches to forming effective partnerships of public, private and nonprofit stakeholders to develop a market for local waste resource products. The thesis summarizes the results of a consumer preferences survey of current and prospective bulk compost purchasers and discusses strategies for implementing new organic waste management policies that will strengthen a local market for compost, build social capital and share economic value. A conjoint analysis of bulk compost preferences in Vermont was conducted to identify the market's preference for quality-based attributes of bulk compost. The data was taken from a survey administered by mail to Vermont business professionals in various fields that use--or could potentially use--compost products in providing goods or services. In addition to price (81 percent of the relative importance buyers place on an attribute), local provenance (8 percent) and suitability for organic production (7.6 percent) were demonstrated as statistically significant determinants of the value buyers placed on compost. Willingness to pay for local provenance and suitability for organic production were measured at 15% and 14% above the baseline product price, respectively. Current and prospective compost producers can effectively market their products and retain a competitive edge in the marketplace by collaborating with other businesses. A viable market for Vermont compost could be achieved through cultivation of niche specialties, stable institutional buyers, more stringent regulation of food waste and nutrient management behavior, and a collaborative effort to construct a product narrative that emphasizes compost's role in a larger social-ecological system of nutrient management and sustainable agriculture.
195

Biological Indicators Of Compost-Mediated Disease Suppression Against The Soilborne Plant Pathogen Rhizoctonia Solani

Fang, Lynn 01 January 2015 (has links)
Compost can suppress soilborne plant pathogens that cause significant damage on globally important food crops. However, reports of plant pathogen suppression are inconsistent likely because there are no established standards for feedstock material, application rate, and maturity age upon application. Excellent results can be achieved in greenhouse trials, but field applications are much less reliable. Disease suppression occurs through the activity of biocontrol organisms (direct antagonism), and general microbial competition. Biocontrol species are hypothesized to colonize the pile during the curing phase, but single species may not be as important as microbial consortia. Substrate composition during maturation may give rise to a suppressive microbial community. More research is needed to understand the relationships between feedstock, maturity, and production process on compost microbial ecology. The thesis had two main objectives: 1) identify biological indicators in compost that could (a) characterize maturity, process, and feedstock, and (b) predict disease suppression against R. solani, and 2) identify bacterial and fungal community composition and/or structure that is associated with suppression of soilborne disease. Rhizoctonia solani is a facultative saprophytic fungus and soilborne plant pathogen that attacks many globally important food crops and turfgrass. Prior research suggests that managing carbon quality and compost maturity will alter relative competition between biological control microbes and the R. solani pathogen. The pathogen is responsible for economic losses to organic vegetable production in Vermont and there are no available methods to manage the disease that meet organic certification. R. solani on radish was chosen as a model system given its global importance, competitiveness affected by carbon quality, and lack of disease management options for organic production. Compost samples were most abundant in the bacterial phyla Proteobacteria and Bacteroidetes, and known biocontrol species were not detected in abundance. Compost samples did not differ significantly in fungal community composition, suggesting a dominance effect from the native soil fungal community. Overall, anaerobic digestate and vermicompost were most suppressive against R. solani. Thermophilic composts were not very suppressive overall, though a specially made hardwood bark compost was comparable to the suppressiveness of vermicompost application. Ecoenzyme analysis was able to integrate information on environmental substrate composition, microbial nutrient acquisition, and microbial community metabolism, offering the best view of current ecological conditions in compost. Ecoenzyme analysis showed that the most suppressive composts, anaerobic digestate and vermicompost, were most nutrient limited. All compost samples were severely nitrogen (N) limited, and anaerobic digestate and vermicompost were severely limited in both N and phosphorus (P). The additional P limitation may support non-pathogenic species to outcompete R. solani. The key to disease suppression may lie in matching up the ecology of the plant pathogen with the ecology of biocontrol, which may be engineered in compost.
196

Ecological Dynamics in Compost-Amended Soils and the Resulting Effects on Escherichia coli Survival

Cutler, Anya 01 January 2016 (has links)
Escherichia coli (E. coli) are common and typically innocuous copiotrophic bacteria found in the mammalian gut microbiome. However, over the past 30 years, pathogenic E. coli have been responsible for several outbreaks of foodborne illness linked to contaminated produce. The introduction of Escherichia coli to an agricultural soil, via contaminated water, compost, or raw manure, exposes the bacterium to a medley of ecological forces not found in a mammalian gut environment. This study assesses a variety of abiotic and biotic soil factors that influence the ability of an "invasive" copiotrophic coliform bacterium to survive in compost-amended agricultural soil. The study included both field and laboratory components. In the lab experiment, a cocktail of rifampicin-resistant generic E.coli strains was added to sterile and non-sterile extracts of eight different composts and one soil sample from the field sites. E. coli abundance was monitored over a one-week period and composts were analyzed for their nutrient profile. In the field experiment, the same E. coli cocktail was sprayed on plots with the following treatments: 1) dairy windrow compost, 2) dairy vermicompost, 3) poultry windrow compost, or 4) no compost. E. coli abundance, soil water potential, soil temperature, extracellular enzyme activity, microbial respiration, phospholipid fatty acid biomarker abundance, and genetic sequencing of the microbial community were measured over a six-month field season. The lab experiment showed that E. coli were able to grow well in sterile compost extracts, without microbial competition for nutrients. Conversely, E. coli populations were only able to survive in non-sterile soil extracts. These results suggest that copiotrophic organisms adapted for high-nutrient environments may depend on the extracellular enzyme activity of native oligotrophic organisms to acquire sufficient nutrients to survive in soils. Results of the field experiment showed clear and interdependent effects of soil moisture and nutrient availability on microbial community dynamics and E. coli survival. Data suggest that saturated soils cause a decrease in microbial extracellular enzyme activity, and drying-rewetting cycles can cause respiration bursts, nutrient mineralization, and shifts in community composition. The saturation of soils, which mobilizes nutrients and may result in a decrease in competition from aerobic organisms, correlated directly with increased survival of E. coli. Additionally, amendment with ammonium-rich poultry compost resulted in the maintenance of high levels of E. coli throughout the field season. Despite an increase in microbial biomass from dairy vermicompost amendment, poultry compost was the only compost that had a significant effect on E. coli survival. The results suggest that nitrogen availability and water potential are strong drivers of E. coli's survival in soils. Correlations among abiotic factors, community composition, and E. coli survival reveal insights into the complex relationships that occur in disturbed agricultural soil environments. Further research on E. coli's response to targeted organisms, abiotic soil properties, and nutrient inputs could have implications for agricultural considerations in food safety and microbial ecology.
197

Ecological Enhancement of Timber Growth: Applying Compost to Loblolly Pine Plantations

Stuckey, Harold Troy 12 1900 (has links)
This study explored the application of compost onto a small loblolly pine tree forest in northeast Texas. Its purpose was to determine if the application of various amounts of compost would provide for accelerated rates of growth for the trees. Soil parameters were also monitored. A total of 270 trees were planted and studied in a northeast Texas forest ecosystem. Compost rates of 5, 25, and 50 tons per acre with either soil or compost backfill were utilized and compared to a control without compost. Nonparametric and parametric ANOVA and Chi-Square tests were utilized. The results indicated that greater application rates retained greater moisture and higher pH levels in the soil. Compost applications also yielded a greater survival rate as well as larger tree height and diameter when compared to the control. The 25 ton/acre application backfilled in native soil achieved the greatest average in height and diameter when compared to the averages for the control plot. Greater growth differences for the 25S application can be attributed to additional nutrients coupled with a stable pH consistent with native soil acidity.
198

Efeito da aplicação de inoculantes na compostagem de resíduos urbanos / Effect of inoculant application on urban waste composting

Pereira, Rafael Fabri 06 April 2017 (has links)
O processo de compostagem é considerado um dos principais métodos sustentáveis de tratamento de rejeitos orgânicos provenientes dos centros urbanos. Sua importância reside em sua capacidade de sanitizar o material, estabilizar sua fração orgânica e ainda disponibilizar um produto final com características físico-químicas e biológicas que promoverão uma melhoria no sistema produtivo quando aplicado ao solo. Todavia, são vários os fatores que influenciam o desenvolvimento desse processo e exigem um equilíbrio tal que nos casos em que esse tratamento de resíduo é aplicado, muitas vezes o processo é incompleto e o produto final não apresenta as características adequadas de sanitização ou de promoção da qualidade do solo. Portanto, o presente estudo objetivou avaliar o efeito da apliação de inoculantes no desenvolvimento do processo de compostagem e a influência dessa aplicação nas características do produto final, sob a hipótese de que a adição de compostos biológicos energéticos aos resíduos promove a ação decompositora e potencializa o processo da compostagem. Para isso foram montadas leiras de compostagem com material orgânico produzido nos centros urbanos. Foram avaliados os seguintes tratamentos: inoculante usado em compostagem industrial, inoculante desenvolvido pelos pesquisadores e controle (pilhas de controle sem aplicação de inoculantes). Todas as leiras de compostagem foram avaliadas quando à sua temperatura, umidade e densidade, seu pH e conteúdo de macronutrientes, sua atividade microbiana, sua qualidade da matéria orgânica e emissão de gases do efeito estufa. Os dados obtidos demonstraram que o perfil da temperatura das leiras ao longo do processo acompanha o comportamento da atividade microbiológica. Os inoculantes aplicados não alteraram as condições físico-químicas do processo quando comparados ao controle. Foi observado um acúmulo de carbono na menor fração da matéria orgânica, indicando formação de substâncias recalcitrantes pela decomposição. A análise da emissão de gases do efeito estufa demonstrou que esse fator pode ser influenciado pelos manejos realizados sobre a leira de compostagem. Constatou-se que o uso de inoculantes não alterou significativamente nenhum dos parâmetros avaliados quando comparado ao controle, sendo que seu uso não promoveu melhorias na qualidade do produto final, nem tampouco se mostrou essencial ao bom desenvolvimento do processo de compostagem quando se trata resíduos orgânicos, que apresentam facilidade de decomposição. / The composting process is considered one of the main sustainable methods for treatment of the organic waste from urban centers. Its importance lies in its ability to sanitize the material, stabilize its organic fraction and also provide a final product with biological and physicochemical characteristics that will promote an improvement in the productive system when apllied to the soil. However, the factors that influence the development of this process are so many and require such an equilibrium that in cases where this residue treatment methodology is applied, the process is often incomplete and the final product does not have the appropriate sanitation or characteristics that promote soil quality. Therefore, the present study aimed to evaluate the effect of inoculant application on the development of the composting process and the influence of this application on the final product\'s characteristics. For this, composting piles were assembled with organic material produced in urban centers and applied an inoculant used in industrial composting, another one developed by the researchers and control cells were mantained without applications. All compost beds were evaluated for thier temperature, humidity and density, their pH and macronutrient content were measured, along with its microbial activity, quality of organic matter and the greenhouse gas emissions. The data obtained showed that the profile of the temperature of the piles during the process followed the behavior of the microbiological activity. The inoculants applied did not alter the physicochemical conditions of the process when compared to the control. It was observed a carbon accumulation in the smallest fraction of the organic matter, indicating the formation of recalcitrant substances by the decomposition. The analysis of greenhouse gas emissions showed that the management of the composting pile could influence this factor. It was found that the use of inoculants did not significantly alter any of the evaluated parameters when compared to control, and its use did not promote improvements in the final product\'s quality, nor was it essential for the proper development of ther composting process when dealing with organic urban waste, which is easly decomposed.
199

Estudo da utilização de composto orgânico para a remediação de solo contaminado por hidrocarbonetos de petróleo / Study of the use of compost for the remediation of a petroleum hydrocarbons contaminated soil

Guimarães, Camila Camolesi 14 September 2018 (has links)
O Estado de São Paulo apresenta, atualmente, mais de 5.900 áreas contaminadas cadastradas, as quais foram ou devem ser submetidas a um processo de remediação. Os principais contaminantes identificados são os combustíveis automotivos, com destaque para os hidrocarbonetos derivados de petróleo. Dentre as técnicas de remediação existentes, e considerando-se a necessidade de inclusão dos princípios da sustentabilidade aos processos de remediação, destaca-se a estratégia de adição de composto orgânico ao solo contaminado. O composto apresenta grande potencial de biorremediação, pois é capaz de sustentar e promover o crescimento de diversas populações de microrganismos com habilidade de degradar uma série de contaminantes. Nota-se, no Brasil, grande potencial de utilização de composto para a remediação, tanto pelas características climáticas e físico-químicas dos solos quanto pela quantidade de resíduos orgânicos gerados no país. Dessa forma, a presente dissertação tem por objetivo estudar a aplicação de composto orgânico na remediação de solo contaminado por hidrocarbonetos derivados de petróleo, em escala laboratorial. Foi realizada a contaminação artificial de um solo argiloso com óleo diesel e uma mistura de óleo BPF, diesel e querosene, em duas concentrações (10 g/kg e 100 g/kg) e adicionado composto orgânico em duas proporções (1:0,1 e 1:0,5). Os resultados indicaram maiores reduções das concentrações de hidrocarbonetos totais de petróleo ao final do experimento para os tratamentos realizados com óleo diesel, da ordem de 60 % a quase 90 % no período de 91 dias. A presença do composto contribuiu para o aumento dos teores de matéria orgânica, sólidos voláteis, pH e condutividade elétrica dos tratamentos, além da melhoria da estrutura do solo e maior desenvolvimento de populações de microrganismos. Dessa forma, o composto atuou como fonte de energia para os microrganismos autóctones de solo e como fonte de novos microrganismos metabolicamente ativos, contribuindo para o aumento das taxas de biodegradação. Os resultados do presente trabalho indicam que a adição de composto se mostra eficaz na remediação de solos contaminados por hidrocarbonetos de petróleo, promovendo a melhoria das condições físicas, químicas e biológicos do solo e apresentando-se como uma técnica sustentável, com impactos positivos dos pontos de vista ambiental, social e econômico. / The State of São Paulo currently has more than 5,900 registered contaminated sites, which were or have to be submitted to a remediation process. The main contaminants identified are automotive fuels, with emphasis on petroleum-derived hydrocarbons. Among the existent remediation techniques, and considering the need to include sustainability principles to remediation processes, the strategy of adding organic compost to the contaminated soil stands out. The compost presents a great bioremediation potential as it is capable of sustaining and promoting the growth of diverse microorganisms populations, with potential to degrade a series of contaminants. In Brazil, there are great opportunities for the use of compost for the remediation of contaminated soils, both due to the climatic and physical-chemical characteristics of the soils and the amount of organic waste generated in the country. Thus, the present research aims to study the application of compost in the remediation of a hydrocarbon contaminated soil, in laboratory scale. It was performed the artificial contamination of a clay soil with diesel oil and a mixture of bunker oil, diesel and kerosene in two concentrations (10 g/kg and 100 g/kg) and the compost was added in two proportions (1:0.1 and 1:0.5). The results showed greater reductions in the concentrations of total petroleum hydrocarbons at the end of the experiment for treatments with diesel oil, ranging from 60% to almost 90% in a period of 91 days. The presence of compost contributed to an increase in the contents of organic matter and volatile solids, as well as in the values of pH and electrical conductivity. It was also observed an improvement of the soil structure and a greater development of microbial populations. Thus, the compost acted as an energy source for autochthonous soil microorganisms and as a source of new metabolically active organisms, contributing to the increase of biodegradation rates. The results of the present work indicate that the addition of compost is effective in the remediation of petroleum hydrocarbons contamination, promoting the improvement of the soil physical, chemical and biological conditions and being a sustainable technique with positive impacts from the environmental, social and economic points of view.
200

Modificação da fração lignocelulósica durante o processo de compostagem do bagaço de cana-de-açúcar /

Bernabé, Giseli Aparecida. January 2012 (has links)
Orientador: Ribeiro, Clóvis Augusto / Banca: Salvador Claro Neto / Banca: Eder Tadeu Gomes Cavalheiro / Banca: Luciana Camargo de Oliveira / Banca: Evaneide Nascimento Lima / Resumo: O crescimento na produção brasileira de cana-de-açúcar devido, principalmente, à obtenção de açúcar e álcool é motivado pelo aumento na exportação deste subproduto e produção de veículos bicombustíveis, respectivamente. Desta maneira, há maior geração de bagaço, embora possuindo inúmeras utilidades, muitas vezes existe um excesso remanescente do total gerado. Assim, são necessários estudos que viabilizem o uso deste resíduo. Neste trabalho foi estudada a modificação da fração lignocelulósica durante o processo de compostagem e biodigestão anaeróbia do bagaço de cana-de-açúcar. Amostras foram coletadas em diferentes períodos para ambos os processos (0 (cru), 7; 45; 60; 90; 120; 272 dias; 1 ano e 1 ano e 2 meses) e acompanhadas por meio de parâmetros como: pH, umidade, temperatura, presença de metais e demanda química de oxigênio. A caracterização foi feita com o auxílio de técnicas termoanalíticas (TG/DTG/DTA e DSC) e espectroscopia na região do infravermelho. As amostras provenientes dos processos aeróbios e anaeróbios foram submetidas às extrações de lignina, utilizando-se dioxano/HCl (9:1) e, de celulose e hemicelulose, as quais foram obtidas do resíduo sólido resultante da extração de lignina. O comportamento térmico e espectros de infravermelho dessas substâncias foram avaliados e, comparadas suas degradações e modificações na ausência e presença de oxigênio. Os resultados obtidos mostraram que a digestão anaeróbia é mais lenta que a compostagem na decomposição de seus constituintes, principalmente, lignina e celulose/hemicelulose, fato comprovado por suas respectivas curvas de Calorimetria Exploratória Diferencial (DSC); além da constatação de modificações nas estruturas de lignina e celulose ao longo dos dois processos, bem como, fortes evidências... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The growth in the Brazilian sugarcane production, mainly, due to obtain sugar and alcohol is motivated by the increase in export of this subproduct and production of flex-fuel vehicles, respectively. This way, there is a larger bagasse generation, although having many uses, often there is an excess remaining of the total generated. Thus, studies are needed that allow the use of this waste. The modification lignocellulosic fraction during composting and anaerobic biodigestion process of sugarcane bagasse was studied in this work. Samples were collected in different periods for both process (0 (raw); 7; 45; 60; 90; 120; 272 days and 1 year and 1 year and 2 months) and monitored by parameters, such as: pH, humidity, temperature, presence of metals and chemical oxygen demand. The characterization was made with help of thermoanalytical techniques (TG/DTG/DTA e DSC) and infrared spectroscopy. The samples from aerobic and anaerobic process were submitted to lignin extraction, using dioxane/ HCl (9:1), and hemicelluloses/cellulose extraction which were obtained from solid residue resulting of lignin extraction. The thermal behavior and infrared spectra from these substances were evaluated and then compared their degradation and changes in the oxygen presence and absence. The obtained results have showed that anaerobic digestion is slower than composting in its constituents decomposition, mainly, lignin and cellulose/hemicellulose, as demonstrated by their respective curves of Differential Scanning Calorimetry (DSC); besides verifying changes in the cellulose and lignin structures through the two process, as well as, strong evidences of lignin in the cellulose extract and, rare assignments of cellulose to lignin extracted. Concerning to humification, a greater tendency for composting samples was observed, mainly... (Complete abstract click electronic access below) / Doutor

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