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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

An?lise de sedimento de fundo: uma amostragem representativa do estu?rio Potengi/RN

Dantas, A?cia Seleide 02 September 2009 (has links)
Made available in DSpace on 2014-12-17T15:41:47Z (GMT). No. of bitstreams: 1 AeciaSD.pdf: 4171408 bytes, checksum: b9c9bc4aed8af7d73b5b0b74a8b69ab1 (MD5) Previous issue date: 2009-09-02 / The aim of this study is to quantify the presence of major and minor elements in the sediments of estuary Potengi. Four georeferenced sampling points were used in the study, at which sediment samples were collected in the channel of the river and on the right and left banks. In addition, dissolved oxygen, salinity and water conductivity were taken in situ at the time of sample collection. The percentage of organic matter, determined by gravimetry, and granulometric analysis of the sediment samples were conducted in the laboratory. To quantify the major and minor elements a prior test to open the sample was conducted with standard NIST 1646? estuarine sediment to choose the best methodology to be adopted. The sediment samples were dissolved in microwaves with nitric acid and chloridric acid, according to methodology proposed by US EPA 3051?. Quantitative analyses of the elements Al, Fe, Cd, Cr, Cu, Mn, Ni, Pb and Zn were conducted by inductively coupled plasma optical emission spectrometry (ICPOES). The results showed that the partial concentrations of the elements analyzed are below average worldwide shale levels, the standard described by Turekian and Wedepohl (1961) / Esse trabalho objetiva avaliar, por meio da quantifica??o, a presen?a dos elementos maiores e menores nos sedimentos do estu?rio Potengi. Para o estudo, foram definidos quatro pontos de amostragem georeferenciados, onde em cada um deles foram coletadas amostras de sedimento na calha do rio e nas margens esquerda e direita. Al?m disso, foram realizadas medidas de pH, oxig?nio dissolvido, salinidade e condutividade da ?gua in situ no momento da coleta. Em laborat?rio foram feitas determina??es da porcentagem de mat?ria org?nica por Gravimetria e an?lise granulom?trica nas amostras de sedimento. Para quantifica??o dos elementos maiores e menores foi realizado um teste pr?vio para abertura da amostra com um padr?o de sedimento estuarino NIST 1646a para escolha da melhor metodologia a ser adotada. As amostras de sedimento foram digeridas em microondas com ?cido n?trico e ?cido lor?drico segundo metodologia proposta pela US EPA 3051A. As an?lises quantitativas dos elementos Al, Fe, Cd, Cr, Cu, Mn, Ni, Pb e Zn foram realizadas por espectrometria de emiss?o ?tica com plasma acoplado indutivamente (ICP-OES). Atrav?s destas observou-se que as concentra??es parciais dos elementos analisados est?o abaixo do folhelho padr?o tomado como m?dia mundial descritas por Turekian e Wedepohl (1961)

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