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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.
91

Modelagem do desempenho de "wetlands" construídas.

Lautenschlager, Sandro Rogério 14 May 2001 (has links)
Este trabalho contém uma revisão bibliográfica relativa à eficiência de wetlands construídas para a remoção de nitrogênio total e fósforo total. Também foram revisados diversos modelos matemáticos para a simulação desta remoção e foi efetuada uma análise crítica destes modelos. Foram empregados dados de domínio público da eficiência de remoção de nutrientes por wetlands construídas de fluxo superficial. Estes dados foram analisados procurando-se calibrar um modelo matemático para a simulação da eficiência de remoção. Observou-se, porém, que estes dados apresentam comportamento bastante complexo, sendo que, por vezes, a eficiência de remoção medida apresenta valores negativos. Partiu-se então para uma abordagem estatística destes dados, a qual poderá servir para a avaliação do risco de ocorrência de desempenho insatisfatório envolvido no dimensionamento de wetlands construídas. / This work presents a bibliographic review about the efficiency of constructed wetlands to remove total nitrogen and total phosphorus. Also many mathematics models to simulate this removal were reviewed and a critical analysis of these models was carried out. Public domain data about the removal efficiency of nutrients by constructed wetlands of surface flux were used. These data were analyzed in order to fit a mathematical model to simulate the removal efficiency. However it was found that these data present a complex behavior, including the occurrence of negative values. A statistical approach of these data was then carried out as an attempt to assess the risk of unsatisfactory performance involved in the design of constructed wetlands.
92

Modelagem do desempenho de "wetlands" construídas.

Sandro Rogério Lautenschlager 14 May 2001 (has links)
Este trabalho contém uma revisão bibliográfica relativa à eficiência de wetlands construídas para a remoção de nitrogênio total e fósforo total. Também foram revisados diversos modelos matemáticos para a simulação desta remoção e foi efetuada uma análise crítica destes modelos. Foram empregados dados de domínio público da eficiência de remoção de nutrientes por wetlands construídas de fluxo superficial. Estes dados foram analisados procurando-se calibrar um modelo matemático para a simulação da eficiência de remoção. Observou-se, porém, que estes dados apresentam comportamento bastante complexo, sendo que, por vezes, a eficiência de remoção medida apresenta valores negativos. Partiu-se então para uma abordagem estatística destes dados, a qual poderá servir para a avaliação do risco de ocorrência de desempenho insatisfatório envolvido no dimensionamento de wetlands construídas. / This work presents a bibliographic review about the efficiency of constructed wetlands to remove total nitrogen and total phosphorus. Also many mathematics models to simulate this removal were reviewed and a critical analysis of these models was carried out. Public domain data about the removal efficiency of nutrients by constructed wetlands of surface flux were used. These data were analyzed in order to fit a mathematical model to simulate the removal efficiency. However it was found that these data present a complex behavior, including the occurrence of negative values. A statistical approach of these data was then carried out as an attempt to assess the risk of unsatisfactory performance involved in the design of constructed wetlands.
93

Vibrant green spine and constructed wetland in Tuen Mun River

Chow, Siu-hang. January 2007 (has links)
Thesis (M. L. A.)--University of Hong Kong, 2007. / Title proper from title frame. Includes special report study entitled: Constructed wetland for wildlife, drainage and sewage treatment. Also available in printed format.
94

Building up the bog : the multi-thematic landscape of the Danish bogs and wetlands /

Slocum, Terrance Lee. January 2001 (has links)
Thesis (M.S.)--University of Oregon, 2001. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 163-177). Also available for download via the World Wide Web; free to UO users.
95

The status of freshwater compensatory wetland migration in Washington State

Johnson, Patricia Ann. January 2004 (has links) (PDF)
Thesis (M.E.S.)--The Evergreen State College, 2004. / Title from title screen (viewed 3/11/2010). Includes bibliographical references (p. 139-150).
96

Assessment of the Viability of a Natural Urban Wetland in the Treatment of Stormwater

McGuigan, Janeen 19 July 2013 (has links)
Stormwater runoff generated from urban areas can be a source of contamination and may negatively impact receiving waters. Best management practices, including the use of treatment wetlands, are recommended to minimize impacts and maintain the quality of water bodies receiving stormwater discharge. This study focuses on the viability of a natural wetland in the treatment of urban runoff. Kuhn Marsh is a natural urban wetland located in Dartmouth, NS. The wetland is approximately 2 ha in size and the primary inlet is a stormwater outfall servicing a 28 ha urban drainage area. Kuhn Marsh has been receiving stormwater generated from the urban drainage area for decades. A wetland drainage area of approximately 9 ha contributes to surface runoff downstream of the wetland inlet. Project objectives are defined as: (i) characterization of the hydrology and hydraulics of the wetland system, (ii) characterization of contaminant fluxes within the wetland system, and (iii) analysis of the treatment performance of Kuhn Marsh. Research strategies used to achieve project objectives include physical and hydrologic characterization of the wetland and contributing watersheds as well as surface and ground water quality analysis. Monitoring was conducted in the wetland during both baseflow and stormflow conditions from May 2011 through October 2012, with the exception of November 2011 to January 2012. Surface water samples were analyzed in the laboratory for TSS, TOC, TN, TP, turbidity, E.coli, and a suite of heavy metals including Fe, Pb, Cu, Cd and Zn. In-situ surface water monitoring included DO, temperature, conductivity and pH. Groundwater samples were analyzed for E.coli and microbial source tracking was performed on all well samples in addition to samples from the inlet and outlet of the wetland. Results from the well samples and the wetland outlet were inconclusive, however the wetland inlet showed human source bacteria indicating potential sewer cross connections within the stormwater system. It was determined that the wetland is an area of groundwater discharge, with groundwater accounting for an average of 50% of the volume discharging through the outlet control structure. Largely due to groundwater influence, Kuhn Marsh shows no peak flow dampening or volume reduction between inlet and outlet. Minimal hydraulic retention times, between 2 and 4 hours, were calculated during stormflow conditions, indicating potential short circuiting of flows through the wetland. Wetland treatment performance was analyzed on a concentration and mass reduction basis and on the number samples that exceeded parameter guidelines at the outlet of the wetland. Guideline exceedances were reported for the majority of samples taken and increases in concentration between inlet and outlet resulted in a larger number of samples exceeding guidelines at the outlet. Despite dilution from groundwater discharge, minimal to no concentration reduction was reported between the inlet and outlet of the wetland. Mass reduction did not occur between the inlet and outlet and Kuhn Marsh was found to be a source of all contaminants sampled. Results of this study show that Kuhn Marsh is no longer acting as a reservoir for stormwater contaminants and, based on the fact that the wetland has been receiving stormwater input on the order of decades, study results may be indicative of the long-term treatment capacity of a stormwater treatment wetland. In the future, comprehensive sampling of groundwater is recommended to determine if contaminants are entering the wetland via groundwater discharge, and if possible, surface water sampling should be conducted on a finer scale to better estimate mass fluxes and contaminant loading rates.
97

Riparian marshland composition and productivity mapping using IKONOS imagery /

Dillabaugh, Kristie A. January 1900 (has links)
Thesis (M.Sc.) - Carleton University, 2006. / Includes bibliographical references (p. 122-130). Also available in electronic format on the Internet.
98

Linking the ecological and economic values of wetlands a case study of the wetlands of Moreton Bay /

Clouston, Elizabeth M. January 2002 (has links)
Thesis (Ph. D.)--Griffith University, 2002. / Title from PDF title page (viewed on May 7, 2005). Includes bibliographical references (p. 343-382).
99

Avaliação de diferentes substratos no tratamento de esgoto sanitário por zona de raízes / Evaluation of different substrates in the treatment of sanitary sewage by root zone

Pitaluga, Douglas Pereira da Silva 28 June 2011 (has links)
Submitted by Erika Demachki (erikademachki@gmail.com) on 2016-01-14T12:59:48Z No. of bitstreams: 2 Dissertação - Douglas Pereira da Silva Pitaluga - 2014.pdf: 5824789 bytes, checksum: 85a87385cf42dae67ee7e83bc0803d6e (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2016-01-14T13:05:22Z (GMT) No. of bitstreams: 2 Dissertação - Douglas Pereira da Silva Pitaluga - 2014.pdf: 5824789 bytes, checksum: 85a87385cf42dae67ee7e83bc0803d6e (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-01-14T13:05:22Z (GMT). No. of bitstreams: 2 Dissertação - Douglas Pereira da Silva Pitaluga - 2014.pdf: 5824789 bytes, checksum: 85a87385cf42dae67ee7e83bc0803d6e (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2011-06-28 / The present study had the goal of assessing the efficiency and behavior of three substrates in the treatment of sanitary sewage in a root zone system. Specifically the objectives were to assess the behavior of the washed sand, gravel # 0 and gravel # 1 substrates and relate their efficacies in a root zone system with sub-superficial horizontal flow preceded by a septic tank and an anaerobic filter in the treatment of a sewage coming from one university unit. The repetitions of raw sewage constituted of five simple samples and five composed samples. The repetitions of the effluent of each stage of the treatment constituted of nineteen simple samples. All the samples were performed fortnightly and submitted to laboratorial analysis. Were assessed parameters the BOD, DO, COD, thermotolerant coliforms, pH, total phosphorus, Kjeldahl total nitrogen, ammoniacal nitrogen, oil and grease, total solids, total fixed solids and suspended solids. The experimental system of sewage treatment was set up at the Civil Engineering College, located at Campus I of the Federal University of Goiás, in the east region of the city of Goiânia – Goiás, Brazil, which constituted of a septic tank and an anaerobic filter, followed by three independent units of root zones. Each unit of the root zones received the flow of 180 L d-1, which corresponds to the area of a treatment station of 3 m2 per inhabitant. The treatment in these units occurred simultaneously. After thirty days from the beginning of the sewage application in the root zones, the collection of the samples to the analysis of the effluent and affluent quality were started. Considering the plant evapotranspiration, the results were analyzed by the tool Statistical Analysis System – SAS, performing F tests and Tukey – Kramer test with a 5% probability. The percentage efficacies of the three substrates used were similar. There hasn’t been any significant difference between the efficacies of the treatments in the removal of the attributes: COD, Kjeldahl total nitrogen, ammoniacal nitrogen, oil and grease. The treatment with washed sand substrate was more efficient in the removal of BOD and total phosphorous. The gravel # 0 was more efficient in the removal of thermotolerant coliforms, total solids and fixed total solids, and gravel # 1 was more efficient in the removal of suspended solids. After 18 months the system started working, the channel filled with washed sand colmatated. / O presente estudo teve como objetivo avaliar a eficiência e o comportamento de três substratos no tratamento de esgoto sanitário, num sistema do tipo zona de raízes. De modo específico, objetivou-se avaliar o comportamento dos substratos areia lavada, brita # 0 e brita # 1 e relacionar suas eficiências num sistema do tipo zona de raízes de fluxo subsuperficial horizontal, precedido de tanque séptico e filtro anaeróbio, no tratamento do esgoto gerado numa unidade universitária. As repetições do esgoto bruto foram constituídas por cinco amostragens compostas e cinco amostragens simples. Já as repetições do efluente de cada etapa do tratamento foram constituídas por dezenove amostragens simples. Todas as amostragens foram realizadas quinzenalmente e submetidas a análises laboratoriais. Foram avaliados os parâmetros de DBO, OD, DQO, coliformes termotolerantes, pH, óleos e graxas, fósforo total, nitrogênio total Kjeldahl, nitrogênio amoniacal, sólidos totais, sólidos totais fixos e sólidos suspensos. O sistema experimental de tratamento de esgotos foi implantado na Escola de Engenharias, localizada no Campus I da Universidade Federal de Goiás (UFG), região Leste da cidade de Goiânia-GO e constituiu-se de um tanque séptico e um filtro anaeróbio, seguidos por três unidades de zona de raízes independentes. Cada unidade de zona de raízes recebeu uma vazão de 180 L d-1, correspondente a uma área de sistema zona de raízes de 3 m2 por habitante. O tratamento nestas unidades ocorreu de forma simultânea. Após trinta dias do início da aplicação de esgoto nas zonas de raízes, iniciaram-se as amostragens para a análise da qualidade do afluente e dos efluentes. Considerando a evapotranspiração das plantas, os resultados foram analisados pela ferramenta Statistical Analysis System – SAS, realizando os Testes F e de Tukey – Kramer, a 5% de probabilidade. As eficiências percentuais dos três substratos utilizados foram semelhantes. Não houve diferença significativa entre as eficiências dos tratamentos na remoção dos atributos: DQO, nitrogênio total Kjeldahl, nitrogênio amoniacal e óleos e graxas. O tratamento com substrato areia lavada foi mais eficiente na remoção de: DBO e fósforo total; o substrato brita # 0 foi mais eficiente na remoção de coliformes termotolerantes, sólidos totais e sólidos totais fixos, e a brita # 1 foi mais eficiente na redução dos sólidos suspensos. Após 18 meses do início de funcionamento do sistema o leito preenchido com areia lavada colmatou.
100

A framework methodology for the cumulative impact assessment of wetlands

Stoop, Aiden 23 June 2008 (has links)
Mrs. D.C. Schoeman

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