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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.
251

Internal mixing in a mine lake

Huber, Anita January 2007 (has links)
[Truncated abstract] Mine lakes are a water body created after an open-cut mine ceases operating. The lakes develop in the former mine-pit due to the combination of groundwater inflow, surface run-off and, in some cases, due to rapid filling from river diversion. While potentially valuable water resources, these lakes often have poor water quality and managing the water body is an important part of the overall process of mine site rehabilitation. As mine lakes form in man-made pits, they have a bathymetry that is typically quite distinct from natural lakes and this can, in turn, strongly influence the hydrodynamics and hence the water quality of the water body. Despite the potential importance of these water bodies, there have been very few studies on the hydrodynamics of mine lakes. This study describes a field investigation of the hydrodynamics of a former coal mine lake, Lake Kepwari, in south-western Western Australia. In particular, this study examines the hydrodynamic processes in both the surface mixing layers and the internal mixing in the density stratified lake. Wind sheltering in the surface mixing layer occurs due to the presence of the steep walls and lake embankments. A week long field experiment was conducted in December 2003 using a combination of moored thermistor chains with meteorological stations and the deployment of rapid vertical profiling turbulent microstructure instruments and CTD drops from two boats operating on the lake. ... Simulations indicated that inclusion of a site specific sheltering effect, based on the results of the field campaign, significantly improved the models‘ performance in capturing the surface mixed layer deepening associated with episodic strong wind events that occur on the lake. Considerable internal mixing was indicated by the high dissipation rates observed, particularly near the boundaries. Large basin-wide diffusivities were also calculated from the heat budget method over long periods, showed a consistency with time, and were slightly higher in summer than during the Autumn Winter period. Although light, there are persistent winds over the lake and yet little basin-scale internal wave activity or seiching. It is hypothesized that any seiching motion was rapidly damped by strong mixing over the hydraulically rough bathymetry bathymetry created by the remnant benches from the open cut mining operation itself. This boundary mixing, in turn, drives secondary relaxation currents that transport mixed fluid from the boundaries to the interior, resulting in high effective basin-wide diffusivities. A simple boundary mixing model is proposed to describe this process.
252

Chov ryb v rybnících zatížených komunálními vodami / Fish farming in ponds exposed to municipal water management

CHMELICKÝ, Petr January 2017 (has links)
In August 2014 a total die-off of fish stock occurred in Záhumenní velký, a pond with a surface area of 5.85 ha. The investigation of the fish kill revealed that the Jabkenice WWTP located above the pond area had discharged water of inappropriate quality (N-NH4+ -99.3 mg/l-1) into the pond. This event resulted in the monitoring of physical and chemical parameters of water quality, zooplankton sampling and measuring of growth dynamics of fish stock by using control reduction fishing. The survey conducted in 2015 studied three different ponds (Ohrada 0.85 ha, Záhumenní velký 5.85 ha and Vlkava 22.1 ha), located in the fertile lowland areas around Mladá Boleslav where pre-cleaned sewage water from the sewage treatment plants flows. The water samples taken both at the outflow of the waste water treatment plant and in the pond were analysed in an accredited laboratory. The following parameters were examined: BOD5, TN, CODCr, ammoniacal nitrogen, TP, nitrites, nitrates and others.
253

Produção de biomassa de algas em lagoas de alta taxa alimentadas com esgoto sanitário com posteior separação por flotação por ar dissolvido

Barroso Júnior, José Carlos Alves January 2015 (has links)
A energia é algo essencial para a vida, auxiliando no desenvolvimento e conforto da humanidade, porém são necessários constantes avanços para produção de energias mais limpas e utilização com maior eficiência. Dentro deste enfoque destacam-se as fontes renováveis de energia, as quais atendem requisitos básicos de sustentabilidade e reduzida agressão ao ambiente. Nesta pesquisa o objetivo principal consistiu na avaliação da produtividade de microalgas em Lagoas de Alta Taxa (LAT) alimentadas com esgoto sanitário (bruto e pré-tratado em reator UASB) e operadas em condições de clima subtropical. A separação da biomassa algal foi realizada pelo processo de Flotação por Ar Dissolvido (FAD), utilizando dois coagulantes inorgânicos (cloreto férrico e sulfato de alumínio) e dois floculantes orgânicos (Sulfloc 5000 e Tanac sg). Foi também avaliada a remoção de matéria orgânica e nutrientes pelas lagoas e processo de flotação. A atividade experimental compreendeu duas Etapas, em função do TDH das lagoas, sendo que na Etapa I (TDH= 3 dias) a LAT-A foi alimentada por esgoto bruto e a LAT-B com efluente de reator UASB. Nesta Etapa foi empregado sistema de coagulação/floculação helicoidal para formação dos flocos de biomassa a serem separados na unidade de flotação. Na Etapa II as duas lagoas foram operadas com TDH= 6,1 dias e alimentadas com efluente do reator UASB. Nesta Etapa foi empregado sistema de coagulação/floculação mecanizado, devido à baixa eficiência obtida pelo floculador helicoidal. Durante a Etapa I, o emprego do coagulante cloreto férrico com dosagens de 20 mg/L resultou em maior eficiência de remoção de matéria orgânica (DQO5, DBO), sólidos e nutrientes (Pt, NTK), seguido pelo floculante orgânico sulfloc 5000 com dosagem de 50 mg/L. Na Etapa II o floculante orgânico Tanac sg resultou em maior eficiência, exceto na remoção de Pt, onde cloreto férrico com dosagem de 40 mg/L apresentou melhor resultado. A presença de microalgas na LAT- B, estimada pelo parâmetro Sólidos Suspensos Voláteis (SSV) durante a Etapa I e Etapa II foi de 90,7 ± 44,1 mg/L e 125,6 ± 68,3 mg/L respectivamente, obtendo produtividade de algas de 9,1 ± 4,4 g/(m²∙d) e 6,2± 3,4g/(m²∙d). Cabe também destacar que na primavera (setembro - dezembro) foram verificados os valores médios mais elevados de SSV, de 112,1 ± 55,1 mg/L para Etapa I e 159,8 ± 71,0 para Etapa II. Nesta pesquisa, a produtividade de algas na Etapa I, expressa em g/(m²∙d), atingiu valores 38 % mais elevados que na Etapa II devido a maior vazão aplicada. Porém na Etapa II foi obtido efluente final com melhor qualidade, o qual é um aspecto de importância para definição dos parâmetros recomendados para projeto de lagoas de alta taxa de produção de algas. / Energy is something essential for life, assisting in the development and comfort of humanity, however constant advances for the production of cleaner energy and more efficiently use is necessary. Within this approach the renewable source of the energy deserve attention, which meet basic requirements of sustainability and reduced environmental nuisance. In this research the main objective consisted of evaluating the productivity of microalgae cultivate on High Rate Ponds (HRP) fed with domestic wastewater (raw and pretreated in UASB) and operated in subtropical conditions. The biomass separation was performed by Dissolved Air Flotation (DAF), testing two inorganic coagulants (ferric chloride and aluminum sulfate) and two organics flocculants (Sulfloc 5000 and Tanac sg). It was also evaluated the removal of organic matter and nutrients obtained by the flotation process and raceways. The experiment involved two stages, according to the hydraulic retention time (HRT) of the pounds, where in Stage I (HRT = 3 days) the LAT- A was feed by raw wastewater and the LAT- B with UASB reactor effluent. In this Stage a coagulation/flocculation helical system was used to form flocs of biomass to be separated in the flotation unit. During Stage II the ponds were operated with a HRT= 6.1 days and fed with effluent from UASB. In this Stage was used a mechanical coagulation/flocculation system, owing to the low efficiency obtained by helical flocculator. During Stage I, the use of ferric chloride coagulant with dosages of 20 mg/L resulted in higher removal efficiency of organic matter (COD, BOD5), solids and nutrient (Pt, TKN), followed by the organic flocculant sulfloc 5000 with dosing 50 mg/L. In Stage II the organic flocculant Tanac sg resulted in greater efficiency, except for Pt removal, where ferric chloride at dosage of 40 mg/L showed better results. The amount of algae biomass in LAT- B, estimated by the parameter Volatile Suspended Solids (VSS) was 90.7 ± 44.1 mg/L and 125.6 ± 68.3 mg/L, during Stage I and II respectively, providing productivity of algae at 9.1 ± 4.4 g / (m²∙d)at Stage I and 6.2 ± 3.4 g / (m²∙d) ate Stage II. It is also worth noting that in the spring (September to December) were recorded the highest average values of VSS, namely 112.1 ± 55.1 mg/L for Stage I and 159.8 ± 71.0 for Stage II. In this research, algal productivity in Stage I in g / (m² ∙ d), reached values 38% higher than in Stage II due to increased flow applied. But in Stage II it was obtained better quality effluent, which is an aspect of importance for defining the recommended parameters for design and operation of high rate of algae production in raceways.
254

Estudos ecológicos da comunidade planctônica de vinte e cinco ecossistemas aquáticos temporários tropicais

Passos, Rodrigo Ferroni 06 June 2017 (has links)
Submitted by Aelson Maciera (aelsoncm@terra.com.br) on 2017-10-06T19:48:50Z No. of bitstreams: 1 TeseRFP.pdf: 32637155 bytes, checksum: d3cc624aead32f85bad14acdb9612054 (MD5) / Approved for entry into archive by Ronildo Prado (producaointelectual.bco@ufscar.br) on 2017-10-10T19:37:58Z (GMT) No. of bitstreams: 1 TeseRFP.pdf: 32637155 bytes, checksum: d3cc624aead32f85bad14acdb9612054 (MD5) / Approved for entry into archive by Ronildo Prado (producaointelectual.bco@ufscar.br) on 2017-10-10T19:38:10Z (GMT) No. of bitstreams: 1 TeseRFP.pdf: 32637155 bytes, checksum: d3cc624aead32f85bad14acdb9612054 (MD5) / Made available in DSpace on 2017-10-10T19:42:50Z (GMT). No. of bitstreams: 1 TeseRFP.pdf: 32637155 bytes, checksum: d3cc624aead32f85bad14acdb9612054 (MD5) Previous issue date: 2017-06-06 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Ecological studies were carried out in twenty-five natural temporary aquatic environments, located in the cities of Urucuia, Lagoa Grande and Pirapora, in the north and northwest of the state of Minas Gerais, Brazil. In each environment, collections were carried out in April 2015, May 2016 and January 2017, during which limnological variables were measured and samples from the phytoplankton (qualitative) and zooplankton (qualitative and quantitative) communities, as well as from sediment, were collected. Experiments were also carried out in the laboratory to evaluate the effects of different temperatures and luminosity on the hatching of diapause eggs of zooplankton species present in these environments. In general, the values obtained for the physical and chemical variables of the studied environments were in a favorable range to the development of the phytoplankton community. However the low concentration of chlorophyll a and the low richness of phytoplankton species may be reflections of the low water transparency, and the turbidity may limit the growth of the phytoplankton. Qualitative and quantitative analyzes of the zooplankton community indicated low species richness in these ponds. Although Rotifera presented a greater richness of taxa, Copepoda Cyclopoida was the most abundant and numerically representative group. The presence or absence of the Anostraca Dendrocephalus brasiliensis does not seem to interfere in the composition and density of the zoplanktonic community. Species richness and local diversity should be related to disturbances and environmental dynamics. The results obtained in the experiment of hatching of zooplankton diapause eggs showed that the different ponds have similar hatching values, and low temperatures (20°C) and absence of light have a negative influence on hatching these eggs. In addition, it was observed that higher temperatures (35°C) accelerated the hatching of the diapause eggs during the first days of incubation. Thus we can infer that, in general, zooplankton community present in all the studied temporary aquatic environments behave in a similar way. / Foram realizados estudos ecológicos em vinte e cinco ambientes aquáticos temporários naturais, localizados nos municípios de Urucuia, Lagoa Grande e Pirapora, a norte e noroeste do estado de Minas Gerais, Brasil. Em cada ambiente, foram realizadas coletas em abril de 2015, maio de 2016 e janeiro de 2017, durante as quais foram medidas variáveis limnológicas e tomadas amostras das comunidades fitoplanctônica (qualitativas) e zooplanctônicas (qualitativas e quantitativas), além de amostras do sedimento. Também foram realizados experimentos em laboratório para avaliar os efeitos de diferentes temperaturas e da luminosidade sobre a eclosão de ovos de diapausa de espécies zooplanctônicas presentes nesses ambientes. De modo geral, os valores obtidos para as variáveis físicas e químicas dos ambientes estudados encontraram-se numa faixa favorável ao desenvolvimento da comunidade fitoplanctônica. No entanto, a baixa concentração de clorofila a e a baixa riqueza de espécies fitoplanctônicas podem ser reflexos da baixa transparência da água, sendo que a turbidez pode limitar o crescimento do fitoplâncton. Análises qualitativa e quantitativa da comunidade zooplanctônica indicaram baixa riqueza de espécies nessas lagoas. Embora o grupo Rotifera tenha apresentado maior riqueza de táxons, o grupo Copepoda Cyclopoida foi o mais abundante e representativo numericamente. A presença ou ausência do Anostraca Dendrocephalus brasiliensis parece não interferir na composição e na densidade da comunidade zooplanctônica, sendo que a riqueza de espécie e a diversidade local devem estar relacionadas a perturbações e dinâmica do ambiente. Os resultados obtidos no experimento de eclosão de ovos de diapausa do zooplâncton evidenciaram que as diferentes lagoas têm valores semelhantes de eclosão, sendo que baixas temperaturas (20°C) e ausência de luz têm influência negativa sobre a eclosão desses ovos. Além disso, foi observado que temperaturas mais elevadas (35°C) aceleraram a eclosão dos ovos de diapausa durante os primeiros dias de incubação. Assim, podemos inferir que, no geral, a comunidade zooplanctônica presente em todos os ambientes aquáticos temporários estudados se comporta de maneira semelhante. / CNPq: 141023/2013-9
255

Avaliação de desempenho de lagoas de estabilização no tratamento de dejetos de suínos: aspectos microbiológicos / Performance valuation of stabilization ponds for swine wastewater treatment: microbiological aspects

Alves, Renato Vieira 25 March 2004 (has links)
Made available in DSpace on 2015-03-26T13:46:43Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1035711 bytes, checksum: 8bfda17a9052b539367681b5d54200ed (MD5) Previous issue date: 2004-03-25 / Fundação de Amparo a Pesquisa do Estado de Minas Gerais / The development of the hog production in Brazil evidenced the problem of the treatment and destination of the swine manure, subject that until the 70 s it was not reason concern for. However, besides environmental consequences, the absence or treatment inadequacy can bring damages for the health, human or animal. Two different systems of stabilization ponds for swine wastewater treatment were monitored for, approximately, one year. One of them composed for three anaerobic ponds and one facultative pond (Farm A) and the other for an anaerobic reactor and a series of polishing ponds (Farm B). Pathogenics (Salmonella spp. and porcine parvovirus) and indicators (total coliforms, Escherichia coli, enterococci and Streptococcus spp) microrganisms were researched in the not treated effluent and in the effluent of each unit. Other six farms also had the feces of the herd evaluated, for the same parameters, in three samples of each property. Salmonella spp. was found in 40% of the samples (14/35), and, in the Farm B ponds system, it was identified until the effluent of the second anaerobic pond. 45% (9/20) of the samples were positive for parvovirus. Statistically significant differences were not observed between the coliforms and streptococci concentrations in the samples of not treated effluent, the same was found in the samples of swine feces. In both monitored systems, the removal efficiency was below the expected. For the system of Farm A, the efficiency was close to 99,9% (3log10) with a hidraulic detention time of 52,6 days. For the other system, the efficiency was among 90-99% (1-2 log10) with a hydraulic detention time of 122,5 days. In contrast to the performance of the systems as a whole, the anaerobic ponds revealed good efficiency of bacterial removal. However, in the event of the optional ponds - of polishing - the results indicate that should have better conception of the system so that these indeed accomplish the expected performance in the bacterial removal. Regression studies among the volumetric loading rates of Biochemical Oxygen Demand (BOD), Chemical Oxygen Demands (COD) and volatile solids and the removal efficiency of the four indicative organisms was accomplished, revealing, generally, excellent association among the variables. / O desenvolvimento da suinocultura no país evidenciou o problema do tratamento e da destinação dos dejetos de suínos, questão que até a década de 70 não era motivo de preocupação. Porém, além de conseqüências ambientais, a ausência ou inadequação de tratamento pode trazer prejuízos para a saúde, humana ou animal. Dois diferentes sistemas de lagoas de estabilização para tratamento de dejetos de suínos foram monitorados por, aproximadamente, um ano. Um deles composto por três lagoas anaeróbias e uma facultativa (Granja A) e o outro por um reator anaeróbio e uma série de lagoas de polimento (Granja B). Pesquisaram-se microrganismos patogênicos (Salmonella spp. e parvovírus suíno) e indicadores (coliformes totais, Escherichia coli, enterococos e Streptococcus spp) no dejeto bruto e no efluente da cada unidade de tratamento. Outras seis granjas também tiveram as fezes dos suínos avaliadas para os mesmos parâmetros, em três amostras de cada propriedade. Salmonella spp. foi encontrada em 40% das amostras (14/35), sendo que, no sistema de lagoas da Granja B, foi identificada até o efluente da segunda lagoa anaeróbia. Os resultados para parvovírus foram positivos em 45% das amostras (9/20). Não foram observadas diferenças estatisticamente significativas entre as concentrações de coliformes e estreptococos no dejeto bruto, mesmo resultado encontrado nas amostras de fezes de suínos. Em ambos os sistemas monitorados, a eficiência de remoção dos indicadores esteve abaixo do esperado. Para o sistema da Granja A, a eficiência foi próxima de 99,9% (3log10) com um tempo de detenção hidráulica (TDH) de 52,6 dias. Para o outro sistema, da Granja B, a eficiência foi entre 90-99% (1-2 log10) para TDH de 122,5 dias. Em contraste ao desempenho global dos sistemas, as lagoas anaeróbias, individualmente, revelaram boa eficiência de remoção bacteriana. Já no caso das lagoas facultativas de polimento os resultados indicam que deve haver melhor concepção do sistema para que estas efetivamente cumpram o papel esperado na remoção bacteriana. Estudos de regressão entre as taxas volumétricas de Demanda Bioquímica de Oxigênio (DBO), Demanda Química de Oxigênio (DQO) e Sólidos Voláteis (SV) e a eficiência de remoção dos quatro organismos indicadores foram realizados, revelando, em geral, excelente associação entre as variáveis.
256

Estrutura e din?mica do fitopl?nctone bacteriopl?ncton em cultivos de camar?o no Rio Grande do Norte-Brasil: impacto sobre o ambiente natural

Santos, Margarida de Lourdes Melo Nelson dos 25 February 2008 (has links)
Made available in DSpace on 2014-12-17T14:01:58Z (GMT). No. of bitstreams: 1 MargaridaLMNS.pdf: 1054716 bytes, checksum: bc213979524001331468154edb0d566e (MD5) Previous issue date: 2008-02-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This work aimed to study the structure and dynamic of Phytoplankton and Bacterioplankton in a complete cycle of shrimp cultivation (Litopenaeus vannamei) and determine the environmental factors responsible for the structural changes of these communities. The study was realized in a saltwater shrimp farm (Maca?ba, RN), between September/2005 and February/2006, and in a freshwater shrimp farm (Cear? Mirim, RN), between May/2007 and September 2007. The samplings were collected weekly in saltwater farm and every fifteen days in freshwater farm. Total phosphorus, chlorophyll a and environmental parameters (pH, dissolved oxygen, salinity, temperature, depth and water transparency) were measured. Qualitative and quantitative analysis of the phytoplankton and bacterioplankton were carried out. The Shannon-Wiener ecologic indexes of diversity and the Pielou equitability indexes were calculated to the phytoplankton. Bacterial density was determined by epifluorescence microscopy. The data were statistically analyzed by Pearson correlation and t-Test. Chlorophycea were predominat in salt water and in the captation/drainage point (24 to 99%). Diatoms had higher wealth. The species Choricystis minor had the highest occurrence (100%) and dominance (90-100%), thus showing its adaptation to the high temperatures, salinity and low water transparency conditions. Filamentous Cyanobacteria like Oscillatoria sp., Pseudoanabaena sp. and Phormidium sp. had constant levels. The negative correlation between chlorophycea and water transparency, and the positive correlation between chlorophyll a and salinity, showed that the phytoplankton was well adapted to the low transparency and to the high salinity. The bacterioplankton was negatively correlated with the total phosphorus and salinity. In freshwater, Cyanobacteria were predominant (>80%), presenting some producers of toxins species like Microcystis sp., Aphanizomenon sp., Cylindrospermopsis raciborskii e Anabaena circinalis. Cyanobacterial density and total phosphorus and chlorophyll a concentrations exceeded the maximum value allowed by legislation. The means of total phosphorus varied from 264 to 627 Wg.L-1 and the means of chlorophyll a oscillated between 22 and 182 Wg.L-1. The phytoplankton species were selected by low availability of the light, high pH, temperature and high availability of total phosphorus. The bacterioplankton showed high densities (5,13 x 107 to 8,50 x107 Bac.mL-1). The studied environments (ponds and rivers) presented a high level of trophic state based on the high concentrations of chlorophyll a and total phosphorus and cyanobacteria dominance. The composition of species in the ponds and rivers was similar, as well as high concentrations of total phosphorus and chlorophyll a, highlighting the pollution caused by the discharges of the farms in natural environment / O presente trabalho teve como objetivo estudar a estrutura e din?mica do fitopl?ncton e bacteriopl?ncton em ciclos completos de cultivos de camar?o (Litopenaeus vannamei), determinar os fatores ambientais respons?veis pelas mudan?as estruturais destas comunidades. O estudo foi realizado em duas fazendas de camar?o: uma de ?gua salgada (Maca?ba, RN) entre setembro de 2005 a fevereiro de 2006 e outra de ?gua doce (Cear? Mirim, RN), durante o per?odo de maio de 2007 a setembro de 2007. As coletas tiveram periodicidade semanal no viveiro de ?gua salgada e quinzenal no viveiro de ?gua doce. Foram determinadas clorofila-a e f?sforo total e par?metros ambientais foram medidos (pH, oxig?nio dissolvido, salinidade, temperatura, transpar?ncia e n?vel da ?gua). An?lises qualiquantitativas do fitopl?ncton e bacteriopl?ncton foram realizadas. Os ?ndices ecol?gicos de diversidade de Shannon-Wiener e equitabilidade de Pielou foram calculados para a comunidade fitoplanct?nica. A densidade bacteriana foi realizada por microscopia de fluoresc?ncia. Os dados foram analisados estatisticamente atrav?s da correla??o de Pearson e teste t. No viveiro de ?gua salgada e no ponto de capta??o-drenagem as clorof?ceas foram dominantes (24 % -99%) e as diatom?ceas tiveram maior riqueza. A esp?cie Choricystis minor foi a esp?cie de maior ocorr?ncia (100%) e domin?ncia (90-100%), mostrando-se bem adaptada a condi??es de altas temperaturas e salinidade e baixa transpar?ncia da ?gua. Cianobact?rias filamentosas como Oscillatoria sp., Pseudoanabaena sp. e Phormidium sp. foram constantes. A correla??o negativa, entre o grupo clorof?cea e a transpar?ncia, e positiva, entre clorofila-a e salinidade, demonstrou que o fitopl?ncton esteve bem adaptado ? baixa transpar?ncia e elevada salinidade. O bacteriopl?ncton correlacionou-se negativamente com a salinidade e f?sforo total. No viveiro de ?gua doce, cianobact?rias foram dominantes (>80%), apresentando algumas esp?cies produtoras de toxinas como Microcystis sp., Aphanizomenon sp., Cylindrospermopsis raciborskii e Anabaena circinalis. A densidade de c?lulas de cianobact?rias, os n?veis de f?sforo e clorofila-a excederam o valor m?ximo permitido pela legisla??o. Os valores m?dios do f?sforo total nos ambientes estudados foram de 264 a 627 Wg.L-1e para clorofila-a foi de 22 a 182 Wg.L-1. As esp?cies do fitopl?ncton foram selecionadas pela baixa disponibilidade de luz, alto pH, temperatura e elevada disponibilidade de f?sforo total. O bacteriopl?ncton apresentou elevada densidade (5,13 x107 a 8,50 x107 Bac.mL-1). Os ambientes estudados (viveiros e rios) configuram elevado estado de trofia, com base nas altas concentra??es de clorofila-a e f?sforo total e domin?ncia de cianobact?rias. A composi??o de esp?cies nos viveiros e nos rios (ponto de capta??o/drenagem) foi semelhante, assim como altos valores de concentra??es de f?sforo e clorofila-a, evidenciando o efeito poluidor das descargas dos viveiros no ambiente natural
257

Decaimento bacteriano em lagoas de estabiliza??o no Nordeste brasileiro

Torres, Dayana Melo 17 June 2011 (has links)
Made available in DSpace on 2014-12-17T15:03:27Z (GMT). No. of bitstreams: 1 DayanaMT_DISSERT.pdf: 5461193 bytes, checksum: e14ad35e988326c6b2deb98ea1ef274e (MD5) Previous issue date: 2011-06-17 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Stabilization pond system consisting in more sewage treatment used in Rio Grande do Norte (RN), Brazil, representing about 90% of all systems. Fecal bacteria are removed mainly facultative ponds and in maturation ponds. Many factors influence bacterial decay, such as the levels of pH and DO, temperature, light intensity, HDT and nutrient availability. The bacterial decay rate (Kb) is calculated considering many variables, but the hydraulic regime is a significant influence for microorganisms removal, and the dispersed flow which best characterizes a stabilization pond. However, some authors developed equations for the Kb accordant plug flow and complete mixing. This research study aimed to evaluate the bacterial decay of fecal coliform and Enterococcus sp. in stabilization ponds designed to treat domestic sewage, full-scale, in RN. All systems have assessed pretreatment, a facultative pond (LF) followed by two maturation (LM1 and LM2). The parameters availed were: temperature, pH, DO, BOD5, COD, fecal coliform, Enterococcus sp., Chlorophyll a, total suspended solids, fixed and volatile. In general, there were not significant differences for pH, DO and temperature in the ponds, except for the new systems, since they have low flow and hydraulic loads. The removal of organic matter in the ponds was low, about 70%, and nearly all are overloaded organic and operational problems. The bacterial removals were low, with average 96% for LF for fecal coliform, and 98% for Enterococcus sp.; LM1 were in itself a removal for fecal coliform about 71%, and 81% for Enterococcus sp.; LM2 have efficiency of 69% for fecal coliform, and 68% for Enterococcus sp. The equation proposed by Von Sperling (1999), according to the dispersed flow regime, generated empirical values of Kb more approximate to calculated values of Kb. On average, the calculated Kb to coliforms in the LF was 0.31 d-1, and for both maturation ponds were 0.35 d-1. For Enterococcus sp. the average was 0.40 d-1 for LF, 0.55 d-1 for LM1, and 0.58 d-1 for LM2. These results also showed that the Kb obtained in full-scale systems are smaller than those found in pilot-scale ponds. Moreover, one can say that the equation proposed by Marais (1974), according to the complete-mix regime, overestimates Kb. Actual results of Kb indicated that fecal coliforms are more resistant to adverse conditions present in stabilization ponds than Enterococcus sp., therefore, an indicator of microbiological safety and efficiency. The factors significant interventions in the rate of bacterial decay were concentrations of COD, the organic loading and HDT. The few Kb relationship between pH, DO and temperature were not significant. Finally, we conclude that it s essential to correct operation and maintenance, for not performing these activities is one of the main factors contributing to low rates of bacterial decay. / Lagoas de estabiliza??o consistem no sistema de tratamento de esgotos mais utilizado no Rio Grande do Norte (RN), Brasil, correspondendo a cerca de 90% de todos os sistemas. As bact?rias fecais s?o removidas principalmente nas lagoas facultativas e de matura??o. Muitos fatores influenciam no decaimento de bact?rias, como: os n?veis de pH e OD, temperatura, intensidade luminosa, TDH e disponibilidade de alimento. A taxa de decaimento bacteriano (Kb) ? calculada a partir de muitas vari?veis, mas o regime hidr?ulico possui significativa influ?ncia na remo??o de microorganismos, sendo o de fluxo disperso o que melhor caracteriza uma lagoa de estabiliza??o. Todavia, alguns autores elaboraram equa??es para o Kb conforme o regime de mistura completa. Essa pesquisa teve como objetivo avaliar o decaimento bacteriano de coliformes termotolerantes e Enterococcus sp. em lagoas de estabiliza??o destinadas ao tratamento de esgotos dom?sticos, em escala real, no RN. Todos os sistemas avaliados possuem tratamento preliminar, uma lagoa facultativa (LF), seguida de duas de matura??o (LM1 e LM2). Os par?metros avaliados foram: temperatura, pH, OD, DBO5, DQO, coliformes termotolerantes, Enterococcus sp., clorofila a, s?lidos em suspens?o totais, fixos e vol?teis. N?o foram identificadas diferen?as significativas entre os valores de pH, OD e temperatura nas lagoas, exceto para os sistemas mais novos, j? que eles possuem baixas vaz?es e cargas hidr?ulicas. A remo??o de mat?ria org?nica nos sistemas de tratamento foi baixa, cerca de 70%, e praticamente todas est?o com sobrecarga org?nica e com problemas operacionais. As remo??es bacterianas tamb?m foram baixas, com m?dia para as LF de 96% para coliformes termotolerantes, e de 98% para Enterococcus sp.; nas LM1 obteve-se remo??o para coliformes termotolerantes de 71%, e para Enterococcus sp. de 81%; e, nas LM2 a efici?ncia foi de 69% para coliformes termotolerantes e de 68% para Enterococcus sp. A equa??o proposta por Von Sperling (1999), segundo o regime de fluxo disperso, foi a que gerou valores de Kb emp?ricos mais aproximados dos valores de Kb calculados a partir de dados reais. Em m?dia, o Kb calculado com base nos dados reais para coliformes termotolerantes nas LF foi de 0,31 d-1, e em ambas as lagoas de matura??o foram de 0,35 d-1. Para Enterococcus sp. a m?dia nas LF foi de 0,40 d-1, nas LM1 foi igual a 0,55 d-1, e nas LM2 de 0,58 d-1. Esses resultados tamb?m demonstraram que os Kb obtidos em sistemas em escala real s?o menores do que os verificados em lagoas em escala piloto. Al?m disso, pode-se afirmar que a equa??o proposta por Marais (1974), segundo o regime de mistura completa, superestima o Kb. Os resultados dos Kb calculados indicaram que os coliformes termotolerantes s?o mais resistentes ?s condi??es adversas presentes em lagoas de estabiliza??o do que os Enterococcus sp., sendo, portanto, um indicador microbiol?gico mais eficiente e seguro. Os fatores de significativa interven??o na taxa de decaimento bacteriano foram as concentra??es de DQO, a carga org?nica e o TDH. As poucas rela??es existentes entre Kb com pH, OD e temperatura n?o foram estatisticamente significativas. Por fim, conclui-se que ? fundamental a opera??o e manuten??o corretas, pois a n?o realiza??o dessas atividades consiste em um dos principais fatores que contribuem para as baixas taxas de decaimento bacteriano.
258

Remo??o de mat?ria org?nica em sistemas de lagoas de estabiliza??o no Nordeste brasileiro

Silva, Od?nia Alves de Lima 24 October 2011 (has links)
Made available in DSpace on 2014-12-17T15:03:28Z (GMT). No. of bitstreams: 1 OdeniaALS_DISSERT.pdf: 3500566 bytes, checksum: bcbbd86a88f2dade1ad704684123cb31 (MD5) Previous issue date: 2011-10-24 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Stabilization pond is the main technology used for treatment wastewater, in northeast Brazil, due to lower cost of deployment, operation and maintenance compared to other technologies. Most systems of stabilization ponds has been in operation for some time, on average 10 years of operation, receiving high organic loads and do not have good removal efficiencies of the main parameters for which have been designed. Therefore it is necessary to work to quantify the efficiency of current systems. This study evaluated the biodegradability of organic matter in raw sewage, the removal of organic matter in reactors and determination of the kinetic constant removal of organic matter (k), both in reactors and in raw sewage, based on the analysis made in the laboratory and through mathematical methods proposed in the literature, in nine systems stabilization ponds, located in Rio Grande do Norte. In relation the degradation kinetics in stabilization ponds, it was observed that many papers published in the literature were obtained in pilot-scale systems, which often, due to the action of external factors such as wind and temperature, these can t be considered as a reference in the analysis of the kinetic constant K, so the need for more research into systems of scale. This study had three distinct phases and simultaneous, routine monitoring, study of the daily cycle and the determination of kinetic constant of degradation of organic matter (K). The monitoring showed that the removal efficiencies of organic matter on most systems were lower than suggested by the literature, the best efficiencies of around 76% (BOD) and 72% (COD) and the worst of the order of 48% (BOD) and 55% (COD). The calculation of K in raw sewage (Ke) was within the range of variation expected in the literature (0.35 to 0.60 days-1). Already for the results obtained for K in the reactors (Kr), there were well below the values recommended in the literature (0.25 to 0.40 d-1 for complete mix and from 0.13 to 0.17 d-1 for flow dispersed), in line with the overloads that organic systems are subject / Lagoa de estabiliza??o ? a principal tecnologia utilizada para tratamento de esgotos dom?sticos no Nordeste brasileiro, devido ao menor custo de implanta??o, opera??o e manuten??o, quando comparada com outras tecnologias. A maioria dos sistemas de lagoas de estabiliza??o est? em opera??o h? bastante tempo, em m?dia 10 anos de opera??o, recebem altas cargas org?nicas e n?o apresentam boas efici?ncias de remo??o dos principais par?metros a qual foram projetadas. Portanto, faz-se necess?rio um trabalho que quantifique a efici?ncia atual desses sistemas. O presente estudo avaliou a biodegradabilidade da mat?ria org?nica no esgoto bruto, a remo??o da mat?ria org?nica nos reatores e a determina??o da constante cin?tica de remo??o de mat?ria org?nica (k), tanto nos reatores quanto no esgoto bruto, baseadas nas an?lises feitas em laborat?rio e atrav?s dos m?todos matem?ticos propostos pela literatura, em nove sistemas de lagoas de estabiliza??o, no Rio Grande do Norte. Em rela??o ? cin?tica de degrada??o em lagoas de estabiliza??o, observou-se que muitos trabalhos publicados na literatura foram obtidos em sistemas em escala piloto, o que muitas vezes, devido ? a??o de fatores externos, tais como vento e temperatura, esses n?o podem ser considerados como refer?ncia na an?lise da constante cin?tica K, por isso a necessidade de se pesquisar mais em sistemas de escala real. Essa pesquisa teve tr?s fases distintas e simult?neas: monitora??o de rotina, estudo do ciclo di?rio e a determina??o da constante cin?tica de degrada??o da mat?ria org?nica (K). O monitoramento mostrou que as efici?ncias de remo??o de mat?ria org?nica, na maioria dos sistemas, estavam abaixo do sugerido pela literatura, sendo as melhores efici?ncias da ordem de 76% (DBO) e de 72% (DQO) e as piores da ordem de 48% (DBO) e 55% (DQO). O calculo do K no esgoto bruto (Ke) mostrou-se dentro da faixa de varia??o prevista na literatura (0,35 a 0,60 dia-1). J? para os resultados obtidos para K nos reatores (Kr), verificaram-se valores bem abaixo do preconizado pela literatura (0,25 a 0,40 d-1 para mistura completa e 0,13 a 0,17 d-1 para fluxo disperso), em conson?ncia com as sobrecargas org?nicas a que os sistemas est?o sujeitos
259

Caracteriza??o do lodo de lagoa anaer?bia tratando res?duos esgotados de tanques s?pticos e fossas com vistas ao aproveitamento

Assun??o, Marcella de S? Leit?o 28 December 2012 (has links)
Made available in DSpace on 2014-12-17T15:03:32Z (GMT). No. of bitstreams: 1 MarcellaSLA_DISSERT.pdf: 2551228 bytes, checksum: 0102a63798a5e4ea6258e625c054ceb4 (MD5) Previous issue date: 2012-12-28 / The sludge generated in stabilization ponds can be designed for various purposes, among them we mention agricultural use, recovery of degraded areas and civil construction. The choice of these alternatives should be made based on qualitative and quantitative characteristics of the sludge. In this context, this study characterized the digested sludge from an anaerobic lagoon in Cidade do Natal/RN, which deals exclusively with residues of depleted septic tanks and pits. The sludge showed levels of macro and micronutrients that confirm its potential for agriculture, with 139.49 g.kg -1 organic matter, 15.40 g.kg-1 nitrogen and metal concentrations below those required by Resolution No. 375/06 of CONAMA, besides the absence of fecal coliform and less than 0.15 viable helminthes eggs/g, on average. The particle size distribution showed that most of the particles have a diameter similar to the sand, allowing the replacement of this input, for example. Analysis of the leachate and of the sludge solubilized classified as non-inert and non-hazardous according to NBR 10.004/04. The volume produced in three years of operation by the pond was 1903.50m?, equivalent to approximately 400 kg of dry sludge. Overall, the concentrations of the parameters were similar to literature, although none of them addresses sludge anaerobic pond treating sewer from septic tanks and pits.The sludgepresents technical feasibility to various types of use, however the cost of dewatering and especially with transport can derail it. It needs to be made a more thorough study of the costs to prove its economic viability / O lodo gerado em lagoas de estabiliza??o pode ser destinado para diversos fins, dentre eles citam-se o uso agr?cola, a recupera??o de ?reas degradas e a constru??o civil. A escolha dessas alternativas deve ser feita baseada nas caracter?sticas qualitativas e quantitativas do lodo. Nesse contexto, esse trabalho caracterizou o lodo digerido de uma lagoa anaer?bia na Cidade do Natal/RN, que trata exclusivamente os res?duos esgotados de tanques s?pticos e fossas. O lodo apresentou teores de macro e micronutrientes que confirmam seu potencial para a pr?tica agr?cola, com 139,49 g.kg-1 de mat?ria org?nica, 15,40 g.kg-1 de nitrog?nio e concentra??es de metais inferiores ?s exigidas pela Resolu??o n? 375/06 do CONAMA, al?m de aus?ncia de coliformes termotolerantes e menos de 0,15 ovos de helmintos vi?veis/g. em m?dia. As granulometria mostrou que a maioria das part?culas tem di?metro semelhante ao da areia, permitindo a substitui??o desse insumo, por exemplo. An?lises do lixiviado e do solubilizado classificaram o lodo como n?o inerte e n?o perigoso, de acordo com a NBR 10.004/04. O volume produzido em tr?s anos de funcionamento pela lagoa foi de 1.903,50m?, equivalente a aproximadamente400 kg de lodo seco.De forma geral, as concentra??es dos par?metros foram semelhantes ? literatura pesquisada, embora nenhuma delas aborde lodo de lagoa anaer?bia tratando res?duos esgotados de tanques s?pticos e fossas. O lodo apresenta viabilidade t?cnica para v?rios tipos de uso, por?m os custos com desaguamento e principalmente com transporte podem inviabiliz?-lo. ? necess?rio que seja feito um estudo mais aprofundado dos custos para atestar sua viabilidade econ?mica
260

Emprego de biofiltro de pedra para remo??o de microalgas e s?lidos suspensos de efluentes de lagoas de estabiliza??o

Queiroz, Mois?s Andrade de Farias 28 February 2014 (has links)
Made available in DSpace on 2014-12-17T15:03:33Z (GMT). No. of bitstreams: 1 MoisesAFQ_DISSERT.pdf: 1322817 bytes, checksum: d69733a37de991cb265f0cf0939bee27 (MD5) Previous issue date: 2014-02-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This research evaluated the microalgae removal produced in a stabilization pond system using biofilters as post-treatment, besides characterizing the effluents of stabilization ponds and filters in relation to concentrations of algal biomass (chlorophyll a and suspended solids), organic matter (BOD and COD), total phosphorus, orthophosphate, pH and dissolved oxygen, and tried to correlate physicochemical parameters with chlorophyll "a". It was held at the Ponta Negra ETE which is constituted by three stabilization ponds, with a primary facultative pond and two of maturation. For the algae removal were used two submerged bio-filters: the filter FPF (Facultative Pond Filter), fed with facultative pond effluent; and the filter MPF (Maturation Pond Filter), fed with second maturation pond effluent. The filling material of both filters was predominantly gravel no. 2, although it contains portions of gravel no. 1 and no. 3. The filters operating conditions were bad, they were nearly 10 years without maintenance, without cleaning or removal of sludge since the time of its construction, and part of the filling material may be obstruct. Despite poor operating conditions were obtained satisfactory results, in level of posttreatment. Removal efficiencies in relation to BOD and COD were 7 and 25% in FPF and 9 and 19% and in MPF, respectively. In relation to TSS efficiencies in MPF and FPF were 37 and 20%, respectively. As for the chlorophyll "a" removal, the FPF efficiency was 44% and the MPF was 40%. There was 50% of consumption of dissolved oxygen, on average, within the filters. Two profiles were performed in the filters, and it was possible to conclude that variations throughout the day were not statistically significant, and that, regardless of the time of collection, they would have the same representation comparing to the time of data collection (7 am) and the daily average, although individual variations throughout the day have been shown to be significant. Another important observation is that the correlations between Chlorophyll a and TSS were bigger and more significant in the effluent of the filters than in the effluent of the ponds / A pesquisa avaliou a remo??o das microalgas produzidas em um sistema de lagoas de estabiliza??o utilizando biofiltros como p?s-tratamento, al?m de caracterizar os efluentes de lagoas de estabiliza??o e dos filtros no tocante ?s concentra??es de biomassa algal (clorofila a e s?lidos suspensos), mat?ria org?nica (DBO e DQO), ortofosfato, f?sforo total, pH e oxig?nio dissolvido, e buscou correlacionar os par?metros f?sico-qu?micos com a clorofila a . Foi realizada na ETE Ponta Negra que ? constitu?da por tr?s lagoas de estabiliza??o, sendo uma lagoa facultativa prim?ria e duas de matura??o. Para a remo??o das algas, foram utilizados dois biofiltros submersos: o filtro FLF -alimentado com efluente da lagoa facultativa; e o filtro FLM - alimentado com efluente da segunda lagoa de matura??o. O material de enchimento de ambos os filtros foi predominantemente brita n? 2, apesar de conter por??es de brita n? 1 e n? 3. As condi??es operacionais dos filtros eram p?ssimas, pois estavam h? quase 10 anos sem manuten??o, sem limpeza ou remo??o do lodo desde a ?poca da constru??o, podendo parte do material de enchimento estar colmatado. Apesar das condi??es operacionais prec?rias foram obtidos resultados satisfat?rios, em n?vel de p?s-tratamento. As efici?ncias de remo??o em rela??o ? DBO e DQO foram de 7 e 25% no FLF e 9 e 19% no FLM, respectivamente. Em rela??o aos SST as efici?ncias no FLF e FLM foram de 37 e 20%, respectivamente. Quanto ? remo??o de clorofila a , a efici?ncia no FLF foi de 44% e no FLM foi de 40%. Houve o consumo de 50% do oxig?nio dissolvido, em m?dia, no interior dos filtros. Foram realizados dois perfis nos filtros, e foi poss?vel concluir que as varia??es ao longo do dia n?o foram estatisticamente significativas, e que, independentemente do hor?rio da coleta, teriam a mesma representatividade ao comparar com o hor?rio da coleta da pesquisa (7 horas da manh?) e a m?dia di?ria, embora as varia??es pontuais ao longo do dia tenham se mostrado expressivas. Outra importante observa??o foi que as correla??es entre Clorofila a e SST foram maiores e mais significativas nos efluentes dos filtros do que nos efluentes das lagoas

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