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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.
1

Desenvolvimento de uma metodologia para caracteriza??o de amostras de sedimento: Rio Jundia? RN

Lira, D?bora de Carvalho 29 August 2008 (has links)
Made available in DSpace on 2014-12-17T15:41:44Z (GMT). No. of bitstreams: 1 DeboraCLpdf.pdf: 2815268 bytes, checksum: 20ee0425ac91194078b0ceeae8b42810 (MD5) Previous issue date: 2008-08-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The study of sediment in water bodies presents great environmental importance, because of its ability to adsorb the pollutants, they may facilitate the understanding of the history of the current quality of the water system. Depending on how it is done the collection, analysis can show both a recent contamination as old. The detailed characterization of the sediment may reveal details that can understand how each type of pollutant interacts with the material given its composition. In this work it has developed a systematic methodology to characterize samples of sediment, with the aim to understand how a series of metal is distributed in different size fractions of the sediment. This study was conducted in five samples of sediment (P1, P2, P3a, P3B and P3c) collected in Jundia? river, one of the most important tributaries of the river Potengi in the region of Maca?ba, RN. The characterization was made with the samples previously sieved into meshes with different granulometries (+8#, -8+16#, -16+65# - 65+100#,-100+200#,-200+250# and -250#), using the following techniques: Analysis of specific surface area by BET method, determining the levels of organic matter (OM%) and humidity through the gravimetry and Analysis Thermogravimetric (TG), Infrared Spectroscopy in a Fourier transform (FTIR ), Analysis of X ray diffraction (XRD), analysis of heavy metals by optical emission spectrometry with the Argon Plasma (ICP-OES). The analyzed elements were Al, Cd, Cr, Cu, Fe, Mn, Ni, Zn and P. In addition to the techniques of characterization above, was also made the rebuilding of the samples P1, P2 and P3B in relation to the levels of organic matter and concentration of heavy metals. Then, the results of the recomposed samples were compared with those obtained in crude samples, showing great consistency. The gravimetry, used in determining the levels of organic matter, was not considered an appropriate method because the clay minerals present in the sediment samples analyzed fall apart in the same range of temperature (550-600 0C) used in roasting (600 0C). The results also showed the trend of organic matter and heavy metals to focus on the thin fractions, although the largest concentrations of metals are in intermediate fractions / O estudo dos sedimentos em corpos d ?gua apresenta grande import?ncia ambiental, pois, devido sua capacidade de adsor??o de poluentes, estes podem facilitar a compreens?o do hist?rico da qualidade atual do sistema aqu?tico. Dependendo da forma como ? feita a coleta, a an?lise pode mostrar tanto uma contamina??o recente quanto antiga. A caracteriza??o detalhada do sedimento pode revelar detalhes que permitem entender como cada tipo de poluente interage com dado material de sua composi??o. Neste trabalho desenvolveu-se uma metodologia sistem?tica para caracterizar amostras de sedimento, com o intuito de se entender como uma s?rie de metais se distribui nas diferentes fra??es granulom?tricas do sedimento. Este estudo foi desenvolvido com cinco amostras de sedimentos (P1, P2, P3a, P3b e P3c) coletadas no rio Jundia?, um dos mais importantes afluentes do rio Potengi, na regi?o de Maca?ba, RN. A caracteriza??o foi feita com as amostras previamente peneiradas em malhas com diferentes granulomentrias (+8#, -8+16#, -16+65#, -65+100#, -100+200#, -200+250# e - 250#), utilizando-se as seguintes t?cnicas: An?lise da ?rea Superficial Espec?fica pelo m?todo BET; determina??o dos teores de mat?ria org?nica (%MO) e umidade atrav?s da Gravimetria e An?lise Termogravim?trica (TG); Espectroscopia no Infravermelho por Transformada de Fourier (FTIR); An?lise de Difra??o de raios X (DRX); an?lise de metais pesados por Espectrometria de Emiss?o ?ptica com Plasma de Arg?nio (ICP-OES). Os elementos analisados foram Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn e P. Al?m das t?cnicas de caracteriza??o citadas acima, tamb?m foi feito a recomposi??o das amostras P1, P2 e P3b em rela??o aos teores de mat?ria org?nica e concentra??o de metais pesados. Em seguida, os resultados das amostras recompostas foram comparados com aqueles obtidos nas amostras brutas, apresentando grande concord?ncia. A gravimetria, utilizada na determina??o dos teores de mat?ria org?nica, n?o foi considerada um m?todo apropriado, uma vez que os argilominerais presentes nas amostras de sedimento analisadas se decomp?em na mesma faixa de temperatura (550-600 0C) utilizada na calcina??o (600 0C). Os resultados tamb?m mostraram a tend?ncia da mat?ria org?nica e dos metais pesados de se concentrarem nas fra??es mais finas, embora as maiores concentra??es dos metais se encontrem nas fra??es intermedi?rias

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