AVALIAÇÃO DE LODO DA CIDADE DE GOIANÉSIA E REGIÃO UTILIZANDO UVVIS E FTIR

Abstract

Due to the inadequate disposal of domestic and industrial effluents, an increase in the level of contamination of rivers and lakes has been perceived. The contamination of these bodies of water is not only due to toxic elements such as Pb, such contamination can also occur by the uncontrolled increase of organic matter present. Some of this organic matter is absorbed in the formation of sludge. Because of this, an evaluation of this material regarding its organic composition becomes important. Infrared Absorption Spectroscopy is an important tool in this type of evaluation, as well as multivariate statistical tools such as Principal Component Analysis (PCA). The spectra obtained from the analyzed samples showed signs indicating the presence of functional groups that are observed in structures of humic acids, such as, 3750-3400 cm-1 of stretching and deformations of OH and SiO bonds, at 1675-1645 cm-1 C = O, at 1100-1020 cm-1 CO, plus 3640-3610 cm-1 for free OH. The PCA performed revealed that 67.1% of the data variance is explained by PC1. In the scoring chart of PC1xPC2 the formation of clusters was observed. The formation of these groups is related to the concentration of the humic acids in the sludge and the locality of sample collection. In the loadings chart of PC1 it was possible to verify the influence of the OH and C = O groups on the sample separation observed in the score graph. The determination of the elements K and Cu in the samples showed that the concentration of both elements is below the concentrations reported by other authors.