Caracterização físico-química dos ácidos húmicos extraídos do carvão da jazida de Candiota/RS

Abstract

Humic acids (HA) are extremely important due to its environmental aspects. Determining structural characteristics is essential for understanding these structures. The aim of the present study was to characterize the humic acids extracted from the coal of the Candiota reservoir through chemical and spectroscopic analyses, such as using the Fourier transformed infrared method, absorption of UV-VIS, scanning electron microscopy, thermal analysis, diffraction of X ray and emission atomic spectroscopy with inductively coupled plasma. The results showed that the HA of coal from Candiota present high levels of humification, containing a higher amount of aromatic structures as compared to aliphatic ones. The lack of purification of the samples leads to some interference related to the mineral impurities and the amount of NaCl, some peaks related to organic structures tend to be covered by signals from impurities. Analyses of the characterization show it is possible to use non-purified fractions instead of pure ones. However, for calculating efficiency, more specific analyses are needed.