Caracterização da matéria orgânica dissolvida nas águas das bacias hidrográficas do estado de Sergipe

Detalhes bibliográficos
Ano de defesa: 2011
Autor(a) principal: Costa, Adnivia Santos lattes
Orientador(a): Alves, José do Patrocínio Hora lattes
Banca de defesa: Não Informado pela instituição
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Federal de Sergipe
Programa de Pós-Graduação: Pós-Graduação em Química
Departamento: Não Informado pela instituição
País: BR
Palavras-chave em Português:
MOD
COD
Palavras-chave em Inglês:
DOM
DOC
Área do conhecimento CNPq:
Link de acesso: https://ri.ufs.br/handle/riufs/6159
Resumo: In this work, the water obtained from six watersheds in Sergipe State from Brazil was analyzed using fluorescence spectroscopy, dissolved organic carbon(DOC) and UVVis absorbance, to characterize the dissolved organic matter (DOM). The water sample were collected in the period from may 2009to january 2010. Twenty-three sampling sites distributed in different rivers from watersheds were used for collection. As results, DOC concentrations showed the following variation: from 0.35 to 34.7mg.L-1 in Sergipe river basin; 0.50 to 18.95mg.L-1 in Piauí river basin;0.93 to 56mg.L-1 in São Francisco river basin; 1.1 to 14.85mg.L-1 in Vaza Barris river basin; 1.7 to 11.85mg.L-1 in Japaratuba river Basin and 20.3 to 27.2mg.L-1 in Real River basin. The synchronous fluorescence spectra presented four peaks (I, II, III and IV) with varying intensities, depending on the localization and period sampling. The highest fluorescence intensity occurred in peaks II and III, showing that the origin of DOM is predominantly terrestrial from a lixiviated soil due to superficial runoff in raining period that occurs from may/09 to september/09. From December/09 to January/10, the peaks I and II were predominant due to autochthonous organic matter produced by algal activity and anthropogenic sources, respectively. In Japaratuba, São Francisco, Piauí and Real basins, was observed a linear regression between DOC and absorbance at 254nm, suggesting that the DOM, in these rivers, are predominantly from land source, consisting of humic substances. Though, in Sergipe and Vaza Barris Basins the nonlinearity of the DOC according to the absorbance at 254nm highlights a significative contribution from anthropogenic sources in the DOM of these rivers. The principal component analysis was applied to data from May(rainy season) and December(dry season) of 2009 and separated the samples from the rainy season into three groups while a single cluster was obtained for the dry season. The most important factor to separate the samples was the qualitative characteristics of DOM in the water. The input of organic matter from terrestrial and anthropogenic origin, transported to rivers by rain water was essential for the separation process.