Avaliação da contaminação e interferência antropogênica através da análise de fósforo em sedimentos superficiais da bacia hidrográfica do rio Japaratuba

• Ano de defesa: 2021
• Autor(a) principal: Fonseca, Elisânia Kelly Barbosa
• Orientador(a): Passos, Elisangela de Andrade
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Programa de Pós-Graduação: Pós-Graduação em Química
• Palavras-chave em Português: Química; Poluição; Rio Japaratuba (SE); Eutrofização; Análise multivariada; Fracionamento químico; Protocolo SMT; Ambiente aquático
• Palavras-chave em Inglês: Chemical fractionation; Pollution; Eutrophication; SMT protocol; Aquatic environment; Multivariate analysis
• Área do conhecimento CNPq: CIENCIAS EXATAS E DA TERRA::QUIMICA
• Link de acesso: https://ri.ufs.br/jspui/handle/riufs/15661

Aquatic environments have been unbalanced by the deposition and accumulation of some chemical species such as phosphorus (P), which despite being an essential nutrient, can be also a contaminant and generate impacts to the environment. The main problem generated by the excessive deposition of this element is the eutrophication of water bodies. Thus, it is necessary to evaluate the concentration of phosphorus in aquatic environments. Therefore, this study aimed to evaluate the contamination and anthropogenic interference by phosphorus in surface sediments of the Rio Japaratuba River Basin (BHRJ), Sergipe state, northeastern Brazil. Surface sediment samples were collected on twenty points distributed along the basin and its main tributaries: Japaratuba Mirim and Siriri rivers. For the fractionation of phosphorus in the samples, the Standards Measurements and Testing (SMT) extraction protocol was used. The P content in the extracts was determined by molecular absorption spectrometry in the UV-VIS region, based on the molybdenum blue method. The extraction methodology proved to be efficient, with a percentage of agreement for the values found between 99 and 104% in the certified sediment reference material (BCR 684). The total concentration of P in the samples varied between 65 and 987 µg.g-1, the inorganic fraction was between 33 and 900 µg.g-1, in the organic fraction between 19 and 159 µg.g-1 and the apatite fractions between 21 and 850 µg.g-1 and non-apatite between 28 and 248 µg.g-1. The highest concentrations occurred at points P3, P5, and P18. These points are located in regions that receive the largest contribution of effluents from BHRJ, especially those of agricultural origin. Through the phosphorus pollution index, points P3, P5 and P18 were classified as moderately polluted, since the total P content was between 500 and 1300 µg.g-1, on the other hand, the other points were classified as unpolluted. (P < 500 µg.g-1). After applying principal components analysis (PCA) and hierarchical cluster analysis (HCA), it was verified that the BHRJ sampling points were divided into two groups. The first was formed by the points P3, P5, and P18, with higher concentrations of the forms of phosphorus, while the second group agglomerated the other points, where the lowest values of concentration of the element were found. Given the above, the results suggest that points P3, P5, and P18 suffer the greatest environmental interference compared to the other points, mainly due to anthropogenic activities carried out at BHRJ.