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Influência da mineração na geoquímica das águas superficiais e dos sedimentos no alto curso da bacia do Ribeirão Mata Porcos, Quadrilátero Ferrífero – Minas Gerais.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Mendonça, Fellipe Pinheiro Chagas |
| Copyright Year | 2012 |
| Abstract | The study in subject assessed the influence of different mining activities at the headboard of the drainage basin of Mata Porcos stream. Even though acknowledged as a zone where the mineral enterprises hold a high significance, there is a lack of further studies in the area, looking for the comprehension between the geology, the mines and the water resources. Thus, the monitoring of the quality parameters of the water, as well as the concentration of chemical elements in the water and streambed sediments, were evaluated during four quarterly campaigns, conducted from September 2010 until June 2011. The samples were collected in the major watercourses of the zone: Silva's stream, Benevides brook, Aredes stream and some of the most important tributaries. The physicochemical parameters determined for the waters were: pH, Eh, dissolved oxygen, electrical conductibility, total dissolved solids, turbidity, alkalinity, sulfate and chloride. In the water and sediments, the chemical concentration of major and trace chemical elements were analyzed by ICP-OES. The data were submitted to the uni and multivariate statistical analysis, being the principal components analysis (PCA) the main tool used to discriminate the samples. The waters were, in most of cases, satisfactory regarding the legal parameters established by CONAMA's resolution 357/05. Except for one drainage that receives adduced waters from Minas do Pico complex, which acidic condition (PH = 4,5 average) was detected, increasing the concentration of Fe and Al dissolved as well. In the sediments, high concentrations of Fe (until 409,7 g/kg) and Mn (until 9,7 g/kg) were observed both upstream and downstream of mining, being associated especially to the lithogenic sources. However, the time evaluation of geochemical data and remote sensing suggests that anthropogenic sources contributed to the increase of these elements over the years. Distinct geochemical signatures were evidenced in the sediments, those which reflect the contribution of the different lithostratigraphic unities of Supergrupo Minas, demonstrating the strong control exercised by the local geology. Carbonate rocks and marble outcrops of shaping Fecho do Funil are the main sources of Ca and Mg for the Aredes stream and Silva's stream. These rocks are responsible for the elevation of the pH in the waters and play an important role in conditions control of the acidity inserted to the environment. The tamponade effect demonstrated in this work suggests that acid mine drainages in Quadrilatero Ferrifero may be naturally fixed up by the existence of these lithologies. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://www.repositorio.ufop.br/bitstream/123456789/2886/1/DISSERTA%C3%87%C3%83O_Influ%C3%AAnciaMinera%C3%A7%C3%A3oGeoqu%C3%ADmica.PDF |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
