• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 5
  • 2
  • 1
  • Tagged with
  • 8
  • 8
  • 5
  • 4
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 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.
1

Analysis Treatment Efficiencies and Emergy Analysis of Constructed Wetlands¡ÐA Case Study of Kaoping River Old Railroad Bridge Constructed Wetland

Lu, Shih-min 02 February 2007 (has links)
Constructed wetlands have been widely accepted as a natural ecotechnology for wastewater treatment. Constructed wetland system is a treatment system, while it utilizes intertine relationship among water, plants, soils, microorganism and atmosphere in natural environment, and applies natural physics, chemistry and biochemical actions to remove pollutions natural. In addition, the constructed wetland can also to increase the areas to attract more wild animals as their habits. In this study, we analyzed quality of Koping River Old Railroad Bridge constructed wetlands to understand the remove efficiencies for different pollutions. The analytical results showed that A system of the constructed wetlands because some other sewage of A system flowed into the system. However, the treatment system were still better than those in B system. The average removal efficiencies of BOD5 ,COD ,NH3-N ,TP in A system equal to 81.93¢H,50.98¢H,74.89¢H,46,70¢H,respectively. However the average removal efficiencies of SS and Chlorophyll-a were increased for both A and B systems, which might because algae can grow vigorously in summer. Resulting in an increase for both Chlorophyll-a and SS. Besides, in autumn the litter effect of wetland plants might cause the concentrations of nutrients increased. In addition, in this study we also utilized emergy analysis to evaluate the economical values while comparing with a sewage treatment plant. The analytical results showed that the constructed wetlands could remove more pollutants than of the sewage treatment plant. However, the constructed wetland system could still increase the biodiversity. If they could reach steady treatment efficiencies under proper operation and maintenance. It is concluded that the constructed wetland system can provide advantages in both ecology and economics systems.
2

Avaliação emergetica de propriedades agrosilvipastoris do Brasil e da Colombia / Emergy evaluation of agrisilvopastoral systems in Brasil and Colombia

Albuquerque, Teldes Correa 19 April 2006 (has links)
Orientadores: Enrique Ortega Rodriguez, Enrique Murgueitio Restrepo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-08T05:12:03Z (GMT). No. of bitstreams: 1 Albuquerque_TeldesCorrea_M.pdf: 5901634 bytes, checksum: b0f16bda0dcf7960e3a51a4d600be29b (MD5) Previous issue date: 2006 / Mestrado / Mestre em Engenharia de Alimentos
3

Sustainability Analysis and Microbial Community Dynamics in Ambient Temperature Anaerobic Digesters

Ciotola, Richard J. 17 December 2012 (has links)
No description available.
4

Estudo da utilização de microalgas e cianobactérias para a captura de dióxido de carbono e produção de matérias-primas de interesse industrial. / Study on the use of microalgae and cyanobacteria for the fixation of carbon dioxide and production of raw materials for industrial applications.

Cruz, Rui Vogt Alves da 08 November 2011 (has links)
O uso de microalgas e cianobactérias para a produção de biocombustíveis e outros produtos e matérias-primas de interesse comercial tem sido amplamente divulgado como uma tecnologia sustentável bastante promissora, em função das elevadas produtividades areais, potencial para fixação de CO2, uso de terras não adequadas para cultivo e possibilidade de utilizar fontes alternativas de nutrientes, tais como água salobra ou efluentes agroindustriais. A produção comercial de cianobactérias em tanques abertos em formato de pista foi estudada combinando-se a modelagem matemática do crescimento nos tanques com a avaliação técnica, econômica e de sustentabilidade do processo. Construiu-se um macromodelo para a simulação dos tanques, que permitiu determinar o impacto de variáveis ambientais como, por exemplo, temperatura e luminosidade, e otimizar condições de operação e coleta. A análise econômica detalhada demonstrou o impacto dos custos de capital, operação e consumo de energia pelo processo, também destacando a importância da receita de produtos de alto valor agregado para a viabilidade do sistema, com base na tecnologia atual. Os valores de transformidade e índices de sustentabilidade e carga ambiental, obtidos através da análise emergética, são comparáveis com outros processos para obtenção de biocombustíveis de segunda geração, mas os elevados custos de construção e operação e grande consumo de energia nas etapas de coleta e extração representam ainda grandes desafios à sua sustentabilidade. A análise de sensibilidade para as principais variáveis de processo e estudos de caso para melhorias e modelos de negócio alternativos permitiram priorizar áreas para pesquisa futura com base no impacto econômico e ambiental. / The use of microalgae and cyanobacteria for the production of biofuels and other substances of commercial interest has been widely advertised as an extremely promising sustainable technology, due to the high areal productivity, potential for fixation of CO2, possibility of using non-arable land and alternative sources of nutrients such as brackish water and agricultural and industrial effluents. The commercial production of cyanobacteria in open raceway ponds was studied through the combination of a mathematical model for the algal growth with technical, economical and sustainability evaluations. A macromodel was developed to simulate the ponds, and it was used to assess the impact of environmental variables, such as light and temperature, and to optimize the process conditions for operation and harvesting. A detailed economic analysis demonstrated the impact of capital, operation costs and energy consumption, also highlighting the importance of revenue from high value products to process viability, considering the current technology. The transformity, emergy sustainability and environmental loading indices obtained by emergy analysis are comparable to other second generation biofuels, but the high construction and operation costs and energy consumption by the harvesting and extraction steps still represent major challenges to sustainability. The sensitivity analysis and evaluation of both technology improvements and alternative business models enabled the prioritization of future research areas, based on economic and environmental impact.
5

Estudo da utilização de microalgas e cianobactérias para a captura de dióxido de carbono e produção de matérias-primas de interesse industrial. / Study on the use of microalgae and cyanobacteria for the fixation of carbon dioxide and production of raw materials for industrial applications.

Rui Vogt Alves da Cruz 08 November 2011 (has links)
O uso de microalgas e cianobactérias para a produção de biocombustíveis e outros produtos e matérias-primas de interesse comercial tem sido amplamente divulgado como uma tecnologia sustentável bastante promissora, em função das elevadas produtividades areais, potencial para fixação de CO2, uso de terras não adequadas para cultivo e possibilidade de utilizar fontes alternativas de nutrientes, tais como água salobra ou efluentes agroindustriais. A produção comercial de cianobactérias em tanques abertos em formato de pista foi estudada combinando-se a modelagem matemática do crescimento nos tanques com a avaliação técnica, econômica e de sustentabilidade do processo. Construiu-se um macromodelo para a simulação dos tanques, que permitiu determinar o impacto de variáveis ambientais como, por exemplo, temperatura e luminosidade, e otimizar condições de operação e coleta. A análise econômica detalhada demonstrou o impacto dos custos de capital, operação e consumo de energia pelo processo, também destacando a importância da receita de produtos de alto valor agregado para a viabilidade do sistema, com base na tecnologia atual. Os valores de transformidade e índices de sustentabilidade e carga ambiental, obtidos através da análise emergética, são comparáveis com outros processos para obtenção de biocombustíveis de segunda geração, mas os elevados custos de construção e operação e grande consumo de energia nas etapas de coleta e extração representam ainda grandes desafios à sua sustentabilidade. A análise de sensibilidade para as principais variáveis de processo e estudos de caso para melhorias e modelos de negócio alternativos permitiram priorizar áreas para pesquisa futura com base no impacto econômico e ambiental. / The use of microalgae and cyanobacteria for the production of biofuels and other substances of commercial interest has been widely advertised as an extremely promising sustainable technology, due to the high areal productivity, potential for fixation of CO2, possibility of using non-arable land and alternative sources of nutrients such as brackish water and agricultural and industrial effluents. The commercial production of cyanobacteria in open raceway ponds was studied through the combination of a mathematical model for the algal growth with technical, economical and sustainability evaluations. A macromodel was developed to simulate the ponds, and it was used to assess the impact of environmental variables, such as light and temperature, and to optimize the process conditions for operation and harvesting. A detailed economic analysis demonstrated the impact of capital, operation costs and energy consumption, also highlighting the importance of revenue from high value products to process viability, considering the current technology. The transformity, emergy sustainability and environmental loading indices obtained by emergy analysis are comparable to other second generation biofuels, but the high construction and operation costs and energy consumption by the harvesting and extraction steps still represent major challenges to sustainability. The sensitivity analysis and evaluation of both technology improvements and alternative business models enabled the prioritization of future research areas, based on economic and environmental impact.
6

Análise do impacto ambiental de unidades agropecuária = estudo de caso : microbacia do rio Pinhal, Santa Catarina / Analysis of the environmental impact of agribusiness units : case study : pinhal river watershed, Santa Catarin

Teixeira, Mariana Barros 19 August 2018 (has links)
Orientadores: Enrique Ortega Rodriguez, Sandra Furlan Nogueira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-19T16:52:26Z (GMT). No. of bitstreams: 1 Teixeira_MarianaBarros_M.pdf: 3071623 bytes, checksum: cd6cd7c977e91a71e35f2508302c65c0 (MD5) Previous issue date: 2012 / Resumo: O objetivo deste trabalho de pesquisa foi avaliar a sustentabilidade ambiental da microbacia hidrografica do rio Pinhal atraves do uso combinado do Sistema de Informacoes Geograficas (SIG), Balanco de nutrientes e Avaliacao Emergetica auxiliando na compreensao do sistema de producao pecuario atual e fornecendo subsidios potenciais a gestao da microbacia. Para tanto, primeiramente foram analisados todas as propriedades com atividade pecuaria da microbacia para quantificar os excedentes de nutrientes no solo (nitrogenio e fosforo) existentes e avaliar o seu risco ambiental. Em seguida, foram comparadas propriedades com atividades pecuarias distintas (bovinocultura, suinocultura, avicultura e suinocultura com utilizacao de biodigestores no tratamento de dejetos animais) para avaliar qual dentre estas tem maior influencia nesses valores e qual causa maior impacto ao meio ambiente. E por ultimo foram realizados calculos de areas necessarias de florestas, por meio da metodologia SANPP, e areas necessarias de terras umidas, considerando o excedente de nutrientes, para quantificar o impacto ocasionado pelas atividades pecuarias. Os resultados mostram que há um excesso de nitrogenio e fosforo na microbacia, cerca de 15 e 26 Mg.ano-1, respectivamente, ocasionado principalmente pelo excesso de fertilizantes e adubos organicos aplicados no solo. Estes excedentes podem contaminar rios e lencois freaticos devido ao processo de escoamento superficial e lixiviacao. Alem disso, a analise dos indicadores emergeticos indicou a suinocultura como a atividade pecuaria com mais influencia na contaminacao ambiental da regiao, sendo a atividade menos sustentavel dentre as quatro analisadas. Esta atividade utiliza menos recursos renovaveis (Renovabilidade = 5,24%), requer mais energia (Transformidade = 588,477 seJ.J-1), apresenta menor potencial para exportacao dos recursos locais com maior emergia investida (EYR = 1,0), possui maior dependencia dos recursos da economia (EIR = 101,98) e apresenta alta carga ambiental (ELR = 18,08). Em contrapartida, a bovinocultura apresentou como a atividade mais sustentavel, com maior Renovabilidade (17,45%) e EYR (1,22), menor Transformidade (184,942 seJ.J-1), EIR (3,13) e ELR (4,73). Em relacao a utilizacao de biodigestores no tratamento de dejetos animais, os indicadores mostram que a incorporacao deste levou a uma melhora do sistema do ponto de vista ambiental. A Transformidade do sistema foi diminuida, houve uma producao maior de emergia pelo sistema diluindo a emergia requerida, uma diminuicao do valor do EIR e ELR, aumento da Renovabilidade e o pequeno aumento do EYR. O balanco economico dos quatro sistemas mostrou que todas as atividades sao lucrativas aos produtores apresentando valores de EER menores que 1, sendo que a incorporacao do biodigestor diminuiu o valor do EER, diminuindo a lucratividade do sistema. Assim, a area adicional de floresta calculada atraves da abordagem SANPP foi de 957 hectares enquanto que a area necessaria de terras umidas de florestas considerando o excedente de nutrientes foi de 6.000 hectares. Portanto, medidas mitigatorias no intuito de diminuir o uso de fertilizantes no solo e melhorar o uso de fontes nao renovaveis nos sistemas pecuarios se fazem necessarias / Abstract: The objective of this research was to evaluate the environmental sustainability of the Pine River watershed through the integrated use of Geographical Information System (GIS), Balance of nutrients and Emergy Analysis, assessment and through this understanding of subsidizing livestock production system and current provide potential benefits to the management of the watershed. Initially, we analyzed all properties with cattle ranching as the watershed to excess nutrients (nitrogen and phosphorus) and assess their environmental risk. Properties were then compared with different livestock activities (cattle, swine, poultry and swine with the use of digesters to treat manure) to evaluate which reported the highest surplus and which cause greater impact to the environment. And last estimates were made necessary areas of forests, using the methodology SANPP and necessary areas of wetlands, considering the surplus of nutrients, to mitigate the impact caused by cattle ranching. The results showed excess nitrogen and phosphorus in the watershed, about 15 and 26 mg year-1, respectively, caused mainly by the use of fertilizers and organic fertilizers applied to the soil. Such surpluses can contaminate rivers and groundwater as preprocesses runoff and leaching. Furthermore, analysis of emergy indicators showed the pig as the cattle industry with the greatest influence on environmental contamination in the region, being less sustainable the activity of the four analyzed. This activity uses less renewable resources (Renewability = 5.24%), requires more energy (Transformity = 588.477 seJ.J-1), has less potential for export of local resources with greater invested emergy (EYR = 1.0), higher depending on the resources of the economy (EIR = 101.98) and has a high environmental load (ELR = 18.08). In contrast, cattle represented the activity more sustainable. This activity has increased Renewability (17.45%) and EYR (1.22), lower value of Transformity (184.942 seJ.J-1), EIR (3.13) and ELR (4.73). Regarding the use of digesters to treat manure, the indicators showed that the incorporation of this technology has improved the system of the environmental point of view. The Transformity of the system was decreased, there was a greater production of the emerging system emerged diluting required, a decrease in the value of the index EIR, Renewability increased, ELR decreased and the small increase in EYR. The economic balance of the four systems showed that all activities are profitable for producers presenting EER values smaller than 1, and the incorporation of the digester decreased profitability due to decrease in value of the EER. Thus, the additional area calculated using the approach SANPP was 957 hectares while the area required for wetland forests considering the surplus of nutrients was 6,000 hectares. Therefore, mitigation measures in order to reduce the use of fertilizers in the soil and improve the use of non-renewable sources in livestock systems are needed / Mestrado / Engenharia de Alimentos / Mestre em Engenharia de Alimentos
7

Analise do ciclo de vida da soja / Life cycle assesment of soybean

Cavalett, Otavio 10 August 2018 (has links)
Orientador: Enrique Ortega Rodriguez / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-10T19:25:37Z (GMT). No. of bitstreams: 1 Cavalett_Otavio_D.pdf: 1768365 bytes, checksum: 167e95b088960c318d1d668f8a548c6b (MD5) Previous issue date: 2008 / Resumo: O objetivo deste trabalho de pesquisa é avaliar o ciclo de vida da soja para quantificar as contribuições ambientais e econômicas necessárias em cada etapa de produção, transporte e processamento de soja e seus principais produtos. Para tanto, foram utilizadas a análise de energia incorporada, a análise de intensidade de materiais e a análise emergética, além de indicadores econômicos e sociais. Os resultados mostram que produção agrícola da soja é a etapa que utiliza maior quantidade de recursos no ciclo de vida dos produtos considerados: farelo de soja exportado para a Europa, biodiesel e óleo de soja refinado. Por isso, esta é a etapa agrícola é aquela que requer mais atenção dos tomadores de decisões em políticas publicas para um ciclo de vida da soja mais sustentável. Os resultados mostram que a produção de biodiesel de soja convencional não é uma alternativa sustentável (renovabilidade = 31%) para fornecimento de energia para a sociedade e também que os fluxos de farelo de soja exportados para a Europa são responsáveis por grandes impactos ambientais (índice de carga ambiental = 2,83). Entretanto, os resultados obtidos mostram que a soja pode ser produzida em sistemas alternativos mais sustentáveis de forma a reduzir estes impactos negativos / Abstract: The objective of this study is to assess the soybean life cycle to quantify the environmental and economic contributions at each stage of soybean and soybean products production, transport and processing phases. In order of that, it were used the Embodied Energy Analysis, the Material Intensity Analysis and the Emergy Synthesis as well other economic and social indicators. The results showed that agricultural production stage is the phase that uses larger amount of resources in the life cycle of soybean products considered: soy meal exported to Europe, biodiesel and refined soy oil. Therefore, the agricultural phase requires more attention of decision-makers for public policies toward a more sustainable soybean chain. Quantitative indicators showed that biodiesel production from conventional soybean is not a sustainable (renewability = 31%) alternative for energy supply to the society. Also, the soy meal flows exported to Europe are responsible for high environmental damages (environmental loading ratio = 2.83). However, the results showed that soybean can be produced in more sustainable alternative systems in order to reduce these negative impacts / Doutorado / Doutor em Engenharia de Alimentos
8

Making Sense of Environmental Values : Wetlands in Kenya / Att förstå olika miljövärden : Våtmarker i Kenya

Billgren, Charlotte January 2008 (has links)
En av de viktigaste frågorna i världen idag är naturresurshantering. Med en väx-ande befolkning och hoten från klimatförändringar kommer förvaltningen av jordens naturresurser bli än viktigare, såväl för dagens generation som kommande generationer. En viktig aspekt när det gäller naturresurshantering är hur människor uppfattar och värderar naturen. För att komma närmare dessa miljövärden har ett flertal olika vetenskapliga tillvägagångssätt föreslagits. Den här avhandlingen undersöker hur det är möjligt att närma sig miljövärden under olika omständighe-ter och utifrån olika behov. Detta görs genom att undersöka hur olika teorier har använts, och kan användas, avseende olika våtmarker i Kenya. I utvecklingslän-der har naturresurser, teoretiskt sett, ett högre värde eftersom fattiga människor till en högre grad är direkt beroende av naturresurser och ekosystemtjänster. Ut-gångspunkten i denna avhandling är sex våtmarksområden i Kenya under olika förvaltning och med ett flertal, både aktuella och potentiella, användare. I av-handlingen undersöks hur lokalsamhället, myndigheter, industrier och turister uppfattar och värderar våtmarkerna. Genom att applicera ett arenaperspektiv, som betonar vikten av tvärvetenskap, diskuteras i avhandlingen det ekonomiska värdet av miljön för att sedan applicera andra metoder såsom emergy analys, stakeholder analys, kulturteori och riskanalys för att bredda och berika värderingen av miljön. / One of the most important issues in the world, both for present and future genera-tions, concerns natural resource management. With a growing global population and the threat of climate change, issues relating to natural resource management will grow in importance with time. One fundamental aspect of natural resource management is how people perceive and value the environment. The value that is ascribed to natural resources will be one of the determinants in the choices that people face in regards to their management. A wide range of approaches have been suggested to approach environmental values. This thesis focuses on analys-ing the assessment of environmental values under different circumstances and needs. This is done by exploring the ways various theories have and can be used to approach natural resource valuation in different wetland management situations in Kenya. In the developing world the value of natural resources can, theoreti-cally, be seen as even higher than in the developed world, due to poor peoples’ direct dependency on their natural resources and the ecosystem services and goods that they provide. The point of departure in this thesis is six wetland areas with different management strategies and with multiple users. It examines how local communities, governmental authorities, industries and tourists perceive the value of the wetlands. By applying an arena perspective, that emphasises the need of interdisciplinarity, this thesis discusses the economic value of the environment and applies other methods such as, emergy analysis, stakeholder analysis, cultural theory and risk analysis, to enrich the valuation of environment.

Page generated in 0.0581 seconds