• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • Tagged with
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 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

DeterminaÃÃo de contaminaÃÃo por coliformes termotolerantes, fÃsforo e metais traÃo (Cu, Pb e Hg) em Ãgua e sedimentos de galerias pluviais / Determination of contamination by thermotolerant coliform, phosphorus and trace metals (Cu, Pb and Hg) in water and sediments of rain galleries

Maria Gardenny Ribeiro Pimenta 12 June 2006 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Volumes considerÃveis de esgoto domÃstico e efluentes industriais, sem tratamento, sÃo lanÃados nos oceanos causando a contaminaÃÃo dos ecossistemas aquÃticos e colocando em risco a saÃde pÃblica e ambiental. O presente estudo teve por objetivo investigar a presenÃa de metais-traÃo, fosfato, coliformes termotolerantes e Escherichia coli em Ãgua e sedimento de galerias pluviais de Fortaleza que, freqÃentemente, encontram-se contaminadas por esgoto domÃstico, buscando representatividade das medidas de balneabilidade nas praias de Fortaleza. As anÃlises de Cu e Pb foram realizadas por espectrofotometria de absorÃÃo atÃmica pelas tÃcnicas de forno de grafite e chama para as medidas em Ãgua e sedimento, respectivamente. Para a detecÃÃo do Hg em Ãgua foi usada a espectrofotometria de fluorescÃncia com tÃcnica de geraÃÃo de vapor frio e em sedimento a espectrofotometria de absorÃÃo atÃmica utilizando a tÃcnica de vapor frio. O fosfato foi medido por espectrofotometria de absorÃÃo molecular na regiÃo do visÃvel. Nas anÃlises microbiolÃgicas empregou-se a tÃcnica dos tubos mÃltiplos. Os resultados obtidos para coliformes termotolerantes variaram na Ãgua de 1,3 x103 a 1,6 x 108 NMP/100mL e no sedimento de 0,3 x 10 a 1,0 x 106 NMP/g. Os valores de E. coli em Ãgua variaram de 0,3 x 10 a 9,2 x 107 NMP/100mL e no sedimento de 0,3 x 10 a 4,6 x 104 NMP/g. As concentraÃÃes de metais-traÃo na Ãgua variaram de 0,36 a 16,34 &#956;g.L-1 para Cu, 0,08 a 3,71 &#956;g.L-1 para Pb e 1,1 a 150,4 ng.L-1 para Hg. Nas anÃlises de sedimento as variaÃÃes foram de 0,23 a 9,64 &#956;g.g-1 para Cu, 1,41 a 21,73 &#956;g.g-1 para Pb e 0,7 a 21,4 ng.g -1 para Hg. Os teores de fosfato na Ãgua variaram de <0,01 a 1,32 mg.L-1 e no sedimento de 1,12 a 13,39 &#956;g.g-1. Os resultados mostraram que a contaminaÃÃo das Ãguas pluviais drenadas para orla de Fortaleza à constante e elevada para coliformes termotolerantes, E. coli e fosfato, com correlaÃÃes estatÃsticas significativas (p=0,05) entre esses parÃmetros. No entanto, os dados obtidos de metais-traÃo se mostraram pouco eficientes para determinaÃÃo da balneabilidade. / Considerable volumes of domestic and industrial effluent sewage, without treatment, are released in the oceans having caused the contamination of aquatic ecosystems and placing at risk the public and ambient health. The aim of this study was to investigate the presence of trace metals, phosphate, thermotolerant coliforms and Escherichia coli in water and sediment of storm sewers of Fortaleza, frequently, contaminated by domestic sewage, thus decreasing the environmental quality and balneability in Fortalezaâs beaches. The analyses of Cu and Pb in the water and sediment were perfomed by atomic absorption espectrophotometry, graphite furnace and flame techniques, respectively. To evaluate the concentration of Hg in water, cold vapor fluorescence espectrophotometry were used and cold vapor atomic absorption espectrophotometry was used for sediment. In the microbiological analyses a multiple tubes assay was used. Phosphate was measured by molecular absorption espectrophotometry. The results for thermotolerant coliforms varied in water from 1.3 x103 to 1.6 x 108 NMP/100mL and in sediment from 0.3 x 10 to 1.0 x 106 NMP/g. The values of E. coli in water varied between 0.3 x 10 to 9.2 x 107 NMP/100mL and in sediment from 0.3 x 10 to 4.6 x 104 NMP/g. Trace metal concentrations in water varied between 0.36 to 16.34 &#956;g.L-1 for Cu, 0.08 to 3.71 &#956;g.L-1 for Pb and 1.1 to 150.4 ng.L-1 for Hg. In sediment they varied between 0.23 to 9.64 &#956;g.g-1 for Cu, 1.41 to 21.73 &#956;g.g-1 for Pb and 0.7 a 21.4 ng.g-1 for Hg. Phosphate concentrations in the water varied between 0,01 to 1.32 mg.L-1 and in sediment from 1.12 to 13.39 &#956;g.g-1. The results had shown a constant and high contamination of drained pluvial waters of Fortalezaâs coast by thermotolerant coliforms, E. coli and phosphate, with correlate statistical signification (p=0.05). However, the results of trace metal had showed poor efficiency as balneability parameters.

Page generated in 0.0646 seconds