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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.
11

Water quality improvement and plant root function in an ecological system treating dairy wastewater

Morgan, Jennifer Anne, January 2007 (has links)
Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 115-119).
12

Avaliação do desenvolvimento e a eficiência do capim vetiver (chrysopogon zizanioides) em sistemas híbridos de alagados construídos

Miranda-Santos, Larissa [UNESP] 20 December 2012 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:29:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-12-20Bitstream added on 2014-06-13T20:59:40Z : No. of bitstreams: 1 mirandasantos_l_me_bauru.pdf: 970517 bytes, checksum: 3f3ada1e5d63953f86063046acf229ea (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Reproduzir processos naturais é um desafio necessário quando se deseja que os resultados de um experimento sejam o mais próximo do real. Tratando-se do tratamento de águas residuárias, a utilização de sistemas de alagados construídos apresenta-se como melhor maneira encontrada para a introdução de tecnologias de otimização de processos. Construídos em forma de tanques, esses sistemas são formados por leitos impermeabilizados com mantas geotextil. Para fins experimentais foram criados 6 tanques para análises conduzidas durante 12 meses. Tais sistemas demonostrarm sua eficiência, uma vez que foram projetados para utilizar plantas que, sob condições ideais, atuam de forma a contribuir com o processo de depuração do esgoto. O tipo de vegetação utilizada nessa pesquisa foi o capim (chrysopogon zizanioides) que, implantado nos leitos de cultivo, atuou como extrator de nutrientes necessários para o seu crescimento e, consequentemente transferindo oxigênio para o substrato, favorecendo o desenvolvimento de biofilmes ativos responsáveis pela degradação dos compostos orgânicos que poluem os recursos hídricos. O capim Vetiver utilizado nessa pesquisa é, portanto, o determinante direto da depuração do meio e pode ser considerado como ideal quando se verifica que trata-se de uma gramínea perene e tolerante a condições ambientais adversas. O capim vetiver exige cortes periódicos, mas por sua notoriedade e resistência, tornou-se objeto dessa pesquisa que, objetivou avaliar a eficiência da gramínea em sistemas de tratamento do tipo alagados construídos. Para tanto foram realizadas análises físico-químicas do efluente bem como análises nutricionais e morfológicas do vegetal. Verificou-se, assim, que as amostras retiradas durante o experimento apresentaram significativas taxas de eficiência... / Reproduced the natural processes is a necessary challenge when want the results of an experiment is the closest to the real. In the case of wastewater treatment, the use of systems 'constructed wetlands appears as the best way found to technology introduction of process optimization. Built in the form of tanks, this system is formed by impermeable beds. For scientific purposes were created 6 tanks for analysis during months. These systems have demonstrated their efficiency as they were designed to use plants that, under ideal conditions, act in ways that contribute to the process of purification of sewage The type vegetation used in this research is the vetiver grass (chrysopogon zizaniodes) that implanted in the beds of culture, acts as an extractor of nutrients required for their growth and consequently transfer oxygen to the substrate favoring the development of active biolfilms responsible for the degradation of organic compounds that pollute water resources. The vetiver grass used in this study is therefore the determinant of the purification and can be considered as ideal when it finds that it is a perennial grass and tolerant of harsh environmental conditions. The vertiver grass exiges periodic shutdowns but for his notoriety and endurance, became the object of this research that has to evaluate the efficiency of the Vertiver grass when used at constructed wetlands. Were made physic-chemical analyzes of the effluent as well as nutritional and morphological analyzes of the plant. It was found thus that the samples taken during the experiment showed significant rate removal efficiency of polluants. Given these results, aspects such as high rates of production of green mass, dry mass by square meter were found in beds filled with expanded polystyrene. It was concluded therefore that... (Complete abstract click electronic access below)
13

Avaliação do desenvolvimento e a eficiência do capim vetiver (chrysopogon zizanioides) em sistemas híbridos de alagados construídos /

Miranda-Santos, Larissa. January 2012 (has links)
Orientador: Eduardo Luiz de Oliveira / Banca: Jandira Lira B. Talamoni / Banca: Ilza Machado Kaiser / Resumo: Reproduzir processos naturais é um desafio necessário quando se deseja que os resultados de um experimento sejam o mais próximo do real. Tratando-se do tratamento de águas residuárias, a utilização de sistemas de "alagados construídos" apresenta-se como melhor maneira encontrada para a introdução de tecnologias de otimização de processos. Construídos em forma de tanques, esses sistemas são formados por leitos impermeabilizados com mantas geotextil. Para fins experimentais foram criados 6 tanques para análises conduzidas durante 12 meses. Tais sistemas demonostrarm sua eficiência, uma vez que foram projetados para utilizar plantas que, sob condições ideais, atuam de forma a contribuir com o processo de depuração do esgoto. O tipo de vegetação utilizada nessa pesquisa foi o capim (chrysopogon zizanioides) que, implantado nos leitos de cultivo, atuou como extrator de nutrientes necessários para o seu crescimento e, consequentemente transferindo oxigênio para o substrato, favorecendo o desenvolvimento de biofilmes ativos responsáveis pela degradação dos compostos orgânicos que poluem os recursos hídricos. O capim Vetiver utilizado nessa pesquisa é, portanto, o determinante direto da depuração do meio e pode ser considerado como ideal quando se verifica que trata-se de uma gramínea perene e tolerante a condições ambientais adversas. O capim vetiver exige cortes periódicos, mas por sua notoriedade e resistência, tornou-se objeto dessa pesquisa que, objetivou avaliar a eficiência da gramínea em sistemas de tratamento do tipo "alagados construídos". Para tanto foram realizadas análises físico-químicas do efluente bem como análises nutricionais e morfológicas do vegetal. Verificou-se, assim, que as amostras retiradas durante o experimento apresentaram significativas taxas de eficiência... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Reproduced the natural processes is a necessary challenge when want the results of an experiment is the closest to the real. In the case of wastewater treatment, the use of systems 'constructed wetlands" appears as the best way found to technology introduction of process optimization. Built in the form of tanks, this system is formed by impermeable beds. For scientific purposes were created 6 tanks for analysis during months. These systems have demonstrated their efficiency as they were designed to use plants that, under ideal conditions, act in ways that contribute to the process of purification of sewage The type vegetation used in this research is the vetiver grass (chrysopogon zizaniodes) that implanted in the beds of culture, acts as an extractor of nutrients required for their growth and consequently transfer oxygen to the substrate favoring the development of active biolfilms responsible for the degradation of organic compounds that pollute water resources. The vetiver grass used in this study is therefore the determinant of the purification and can be considered as ideal when it finds that it is a perennial grass and tolerant of harsh environmental conditions. The vertiver grass exiges periodic shutdowns but for his notoriety and endurance, became the object of this research that has to evaluate the efficiency of the Vertiver grass when used at "constructed wetlands". Were made physic-chemical analyzes of the effluent as well as nutritional and morphological analyzes of the plant. It was found thus that the samples taken during the experiment showed significant rate removal efficiency of polluants. Given these results, aspects such as high rates of production of green mass, dry mass by square meter were found in beds filled with expanded polystyrene. It was concluded therefore that... (Complete abstract click electronic access below) / Mestre
14

Capillary membrane-immobilised polyphenol oxidase and the bioremediation of industrial phenolic effluent

Edwards, Wade January 1999 (has links)
Waste-generating industrialisation is intrinsically associated with population and economic proliferation. This places considerable emphasis on South Africa's water shortage due to the integral relationship between population growth rate and infrastructure development. Of the various types of industry-generated effluents, those containing organic pollutants such as phenols are generally difficult to remediate. Much work has been reported in the literature on the use of enzymes for the removal of phenols from these waste-streams but little application of this bioremediation approach has reached practical fruition. This study focuses on integrating and synergistically combining the advantages of enzyme-mediated dephenolisation of synthetic and industrial effluent with that of membrane teclmology. The ability of the enzyme polyphenol oxidase to convert phenol and a number of its derivatives to chemically reactive o-quinones has been reported extensively in the literature. These o-quinones can then physically be removed from solution using various precipitation or adsorption techniques. The enzyme is, however, plagued by a product-induced phenomenon known as suicide inactivation, which renders it inactive and thus limits its application as a bioremediation tool. Integrating membrane technology with the enzyme's catalytic ability by immobilising polyphenol oxidase onto polysulphone and poly(ether sulphone) capillary membranes enabled the physical removal of these inhibitory products from the micro-environment of the immobilised enzyme which therefore increased the phenol conversion capability of the immobilised biocatalyst. Under non-immobilised conditions it was found that when exposed to a mixture of various phenols the substrate preference of the enzyme is a function of the R-group. Under immobilised conditions, however, the substrate preference of the enzyme becomes a function of certain transport constraints imposed by the capillary membrane itself. Furthermore, by integrating a quinone-removal process in the enzyme-immobilised bioreactor configuration, a 21-fold increase in the amount of substrate converted per Unit enzyme was observed when compared to the conversion capacity of the inunobilised enzyme without the product removal step. Comparisons were also made using different membrane bioreactor configurations (orientating the capillaries transverse as opposed to parallel to the module axis) and different immobilisation matrices (poly(ether sulphone) and polysulphone capillary membranes). Conversion efficiencies as high as 77% were maintained for several hours using the combination of transverse-flow modules and novel polysulphone capillary membranes. It was therefore concluded that immobilisation of polyphenol oxidase on capillary membranes does indeed show considerable potential for future development.
15

Evaluation of Percolation Ponds for Design and Operation

Baar, David A. 01 January 1985 (has links) (PDF)
Land application of domestic wastewater effluent by rapid rate infiltration (i.e., percolation ponds) is a very successful and cost-effective method for wastewater management. Municipal percolation pond systems have been successfully operated in the United States for about 100 years. The disposal concept depends on a relatively high rate of secondary wastewater effluent infiltration into the soil by rapid percolation, either vertically or horizontally, away from the application surface area. This study was accomplished to determine infiltration rates at two working percolation pond systems and the variability of these rates, to compare the operating results with the initial design, and to create a stochastic computer based simulation program for design and operation. The initial study site was located west of Orlando, Florida, and consisted of a system of two percolation ponds. Daily readings were obtained on evaporation, rainfall, flow to the ponds, pond depth and groundwater table elevations. A mass balance inventory equation was formulated and the infiltration parameter was determined. A frequency distribution was created for the rainfall, evaporation and calculated infiltration from the initial site, and then a stochastic computer based simulation program was written with this data. The program calculated results which compared favorably with the design for this initial percolation pond site. A second site was chosen, also located in the Orlando area, to confirm the usefulness of the program and its operational capabilities.
16

Effluent analysis of model pyrrone compounds by gas chromatography

Young, Philip Ross January 1971 (has links)
A gas chromatographic study was made to quantitatively analyze the effluents produced during the thermal cyclization of several polyimidazopyrrolone (pyrrone) model compounds. The study yielded information on analogous polymeric reactions. The model compounds were programed at 5° C/min from 25° to 400° C and volatile species were purged into a gas chromatograph at 25° intervals. An analysis of the effluents revealed that the cyclization reactions are concerted and generally occur below 250°C. The percent of conversion of the model compounds is readily determined by quantitating those reaction products amenable to gas chromatographic analysis. Only the amide-acid-amine and meta-benzimidazole-acid model compounds exhibited complete conversion to the pyrrone structure. Evidence that decarbo:xylation has occurred in the other compounds is presented. / Master of Science
17

Characterisation of SAPPI SAICCOR pulp mill's effluent.

Moodley, Brenda. January 2001 (has links)
SAPPI SAJCCOR, whose factory is situated south of Durban, South Africa, is one of the few paper and pulp mills that uses the acid sulphite process with calcium and magnesium bases to produce a high-grade cellulose pulp. Four streams of effluent, namely, the calcium - spent liquor stream, the magnesium condensate stream and two streams from the bleaching effluent are produced during this sulphite pulping process and they contain a variety of organic compounds extracted from the wood. Characterisation of the effluent was based on isolation using column chromatography and identification using NMR techniques. A range of constituents, such as lignans and lignin - type precursors, a trilerpenoid and fatty acids were isolated and identified. X-ray diffraction was used to identify an inorganic residue obtained from the calcium - spent liquor stream and gas chromatography/mass spectrometry was used to identify a wax residue. which builds up in the process. In addition to this, the carbohydrate content of the four streams of effluent was detennined using UV/visiblc spectroscopy. / Thesis (M.Sc.)-University of Natal, Durban, 2001.
18

Toxicity and biodegradability assays for hazardous landfill leachate and textile size effluents

Rakgotho, Thabisile January 2005 (has links)
Submitted in fulfillment of the academic requirements for the Degree of Master of Technology: Biotechnology, Durban Institute of Technology, 2005. / The cumulative effects of pollution have led to increased public concern, which is resulting in strict legislation on the discharge of wastes in whatever state they are present, i.e. solid, liquid or gas. Currently, in South Africa, effluents with a high organic load are sent to landfills or marine outfall because the cost of discharge to sewer is prohibitive. In regions where there is a net surplus of rainfall, landfill sites have the potential to pollute the groundwater due to saturated soil conditions. Therefore, many landfill sites should not receive liquid effluents. If liquid wastes are disposed onto landfills, then an alternate sink is required for the treatment of the high volumes of leachate that are generated. These concentrated effluents could then be treated by biological, chemical or physical methods to reduce the pollution load in the natural water resources. In this study, anaerobic digestion has been identified as one of the biological processes that can be applied to treat high-strength or toxic organic liquid effluents, since a survey conducted by Sacks (1997) indicated that many anaerobic digesters in the KwaZulu-Natal region have spare capacity. However before high strength industrial wastes can be treated in existing anaerobic digesters, their impact on the digestion process, i.e. their toxicity and biodegradability under anaerobic conditions, needs to be determined. During this project, several high-strength or toxic industrial effluents were tested to assess their toxicity and biodegradability under anaerobic conditions. These include three synthetic textile size effluents from the textile industry (Textile effluent 1, 2, and 3) and three hazardous landfillieachates (Holfontein, Shongweni and Aloes). In addition, the components of a textile effluent, i.e., starch and wax, were tested to determine which / M
19

Ozonizaçãoe peroxização de efluente sanitário proveniente de alagados construídos e reator compartimentado anaeróbio/aeróbio visando reuso /

Miranda, Nathalie Dyane. January 2014 (has links)
Orientador: Gustavo Henrique Ribeiro da Silva / Banca: Jorge Hamada / Banca: Luiz Antônio Daniel / Resumo: Esta pesquisa teve por objetivo principal estudar a desinfecção de esgoto sanitário proveniente do tratamento de uma nova configuração de um reator compartilhamentado aneróbio/aeróbio e de alagados construídos, utilizando o ozônio e peroxônio. Avaliaram-se como estes atuam no processo de oxidação e inativação de coliformes totais e Escherichia coli, comparando suas eficiências e a formação do formaldeído, que é principal aldeído formado durante a aplicação de ozônio e peroxônio para desinfecção. A formação de formaldeído foi fortemente da dose de ozônio, porém um tempo de contato maior também favoreceu uma maior formação de formaldeído, mesmo que não significativa segundo os testes estatísticos aplicados. Os ensaios de peroxização com uma dose de 5 mg O3 L-1 promoveram uma média de formação de formaldeído maior que quando apenas aplicando somente a mesma dose de ozônio. Com uma dose de 8 e 10 mg O3 L-1, a formação de formaldeído foi em geral menor que quando aplicada durante somente a mesma dose de ozônio. Ou seja, doses maiores de ozônio durante a peroxização favoreceram uma menor concentração de formaldeído no efluente final. Todos os ensaios de ozonização e peroxização promoveram concentrações de formaldeído que estavam dentro do limite imposto pela OMS (água potável). Tanto para o efluente proveniente dos A.C. quanto do reator compartimentado, doses maiores de ozônio ou um tempo de contato maior não favoreceu uma inativação significativamente maior. A inativação de E. coli, no efluente proveniente do reator compartilhamentado, não foi superior ao se adicionar peróxido de hidrogênio. Já a inativação de coliformes totais foi na maioria dos testes superior aos resultados encontrado quando aplicado somente ozônio, sendo que o consumo de ozônio durante a peroxização foi menor que na ozonização. Pode assim concluir que a adição de peróxido de hidrogênio foi à... / Abstract: This research was aimed to study the disinfection of wastewater from treatment by a new configuration of an anaerobic/aerobic baffled reactor and by constructed wetlands, using ozone and peroxone. Were avaluated how these processes acted in the oxidation and inactivation of total coliforms and Eschechia coli, comparing their efficiency and formation of formaldehyde, which is the main aldehyde formed during the application of ozone and peroxone for disinfection. The formation of frmaldehyde was strongly depend on the dose of ozone, by a longer contact time also favored an increased in the formation of formaldehyde, even not significant according to the statistical tests applied. Peroxidation tests with a dose of 5 mg O3L-1 promoted a higher average formation of formaldehyde than when applying only just the same dose of ozone. For doses of 8 and 10 mg O3L-1, the formation of formaldehyde was generally smaller than when applied just the same dose of ozone. I.e., higher ozone doses during peroxidation favored a lower formaldehyde concentration in the final effluent. All tests ozonation and peroxidation promoted formaldehyde concentrations that were within the limit imposed by WHO (drinking water). For both the effluent from the C.W. as the anaerobic/aerobic baffled reactor, higher ozone doses or a longer contact time did not favor a significantly higher inactivation. Inactivation of Escherichia coli in effluent from the anaerobic/aerobic baffled reactor was no better when added hydrogen peroxide. The inactivation of total coliforms was higher in most of the tests when applied just ozone, and the consumption of ozone during peroxidation was lower than in ozonation tests. This way, is possible to conclude that the addition of hydrogen peroxide was favorable to the inactivation of total coliforms. For the effluent from the anerobic/aerobic baffled reactor only with the application of ozone was required a dose of 8 mg O3 L-1 for the effluent... / Mestre
20

Transport and transformations of nitrogen compounds in effluent from sand filter-septic system draintile fields

Bushman, Jennifer L. 12 February 1996 (has links)
A total of 44 intermittent sand filter-septic systems, in five counties of Western Oregon, were sampled over a three-month period during the summer of 1995. The sand filter systems varied in age from 36 months up to 167 months (3 to 13.9 years). Liquid samples were taken from the septic tank and distribution box. In addition, soil samples were taken adjacent to the disposal trench and away from the disposal field area (control). All samples were analyzed for Total Kjeldahl Nitrogen (TKN) and nitrate and nitrite. Nitrite was not detected in any of the samples. The average removal of total nitrogen (TKN + nitrate) through the filter was found to be 43%. Nitrate was determined to be the dominant form of nitrogen in the sand filter effluent making up 94% of the total nitrogen. The age of the system was found not to be a predictor of the system's performance. Once the effluent entered the disposal field, little if any transformation of nitrogen occurred at an average depth of 30 inches (76.2 cm). / Graduation date: 1996

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