Características da Matéria Orgânica: Estudo Comparativo de Padrões de Espectrometria de Fluorescência e UV-Vis de Rio e Lago em Bacias Urbanizadas

Abstract

Este estudo teve como objetivo analisar as características da matéria orgânica em bacias urbanizadas, por meio de espectros UV-VIS e de fluorescência. Foram estudados dois diferentes ambientes na cidade de Curitiba e Região Metropolitana, o rio Iguaçu, numa extensão de 107 km com 7 pontos de monitoramento, e o lago Barigui, na porção intermediária da Bacia do Alto Iguaçu, com 3 pontos de monitoramento. Os resultados desta pesquisa indicaram que, tanto no rio Iguaçu como no lago Barigui, o carbono orgânico dissolvido têm origem principalmente de efluentes domésticos, refletindo as consequências dos mecanismos de desenvolvimento urbano com lançamento de efluentes domésticos sem tratamento nos respectivos corpos receptores. No lago Barigui, em função de suas características hidrodinâmicas, também foi observada a contribuição de fonte autóctone (produtividade primária) de carbono orgânico dissolvido. Este estudo demonstrou como o uso dos ensaios de espectroscopia e ultravioleta e fluorescência associado ao COD pode colaborar para melhor compreensão da dinâmica da matéria orgânica em ambientes lênticos e lóticos e potencialmente, indicar uma nova aborgadem para a gestão de recursos hídricos e a compreensão das potenciais alterações de qualidade da água.

Quali-quantitative characterization of organic matter in urbanized drainage basins as a basis for the application of Water Resources Management Instruments

“…In this research, the objective is the characterization of aquatic organic matter (OM) in the Upper Iguaçu basin in the Metropolitan Region of Curitiba (MRC), following the conceptual and applied evolution through several studies such as Lopardo, Fernandes and Azevedo (2008), Santos et al (2011), Bem et al (2013) and Knapik, Fernandes and Azevedo (2014).…”

“…However, values close to 20 L g −1 would be associated to the presence of organic pedogenic matter, composed mainly of fulvic acids, whose molecular structure is basically aromatic (ROSTAN; CELLOT, 1995). Low values of A 285 /DOC can also indicate the presence of labile compounds present in domestic effluents (BEM et al, 2013).…”

“…However, many researchers have used optical methods, such as fluorescence spectroscopy and ultraviolet-visible absorption, which were also used in the qualitative characterization of organic matter in water bodies such as lakes and reservoirs (NGUYEN;HUR, 2011;HESTIR et al, 2015), regions with strong presence of urbanization (HUR; KONG, 2008;LOPARDO;AZEVEDO, 2008;SANTOS et al, 2011;BEM et al, 2013;MENG et al, 2013;DONG et al, 2014;KNAPIK;AZEVEDO, 2014;YU et al, 2015) and oceanic regions (DANG et al, 2014;YAMASHITA et al, 2015). Additionally, researchers have performed comparisons between water bodies' characteristics in different aquatic (WEISHAAR et al, 2003) environments.…”

“…Regarding the Excitation-Emission Matrices (EEMs) and the comparison between the results obtained for the points studied, the authors assessed the fractions of OM prevalent, suggesting that the rivers analyzed had contamination by domestic effluent. Bem et al (2013) used spectroscopic techniques (fluorescence and UV-visible) to evaluate and compare the OM in monitoring points of Iguaçu River and the Barigüi Lake. Based on the results of SUVA 254 (average varying from 0.85 to 2.01 L (mg m) −1 ) and A 285 /DOC (average varying from 6.04 to 13.94 L g −1 ) was verified that the OM in the points studied showed predominance of labile fraction.…”

“…In this context, the present study had as objective to: a) characterize organic matter present in the Iguaçu River quali-quantitatively evaluating the pressure exerted by the urbanization of the MRC on its waters, extending the analysis undertaken by works such as those of Bem et al (2013) and Knapik, Fernandes and Azevedo (2014) by the inclusion of 3 monitoring points in the municipalities of Porto Amazonas, São Mateus do Sul and União da Vitória; b) investigate the possible recovery of water quality on the Iguaçu River downstream of the MRC, in areas with lower impact of urbanization; c) use in an integrated manner the DO, BOD, COD, DOC data, and the SUVA 254 and A 285 /DOC indices in order to understand the sources of pollution and changes in the predominance of organic matter along the route studied the river.…”