Avaliação da qualidade das águas e sedimentos oriundos da mineração de calcário

Abstract

The municipality of Caçapava do Sul is considered a major industrial pole in the area of exploration and mining of limestone, where its exploitation generates numerous environmental impacts, mainly by the movement of soil and disposal of waste. Considering that the sources are water sources used for a wide variety of purposes, including water supply, monitoring the quality of water and sediments is essential to identify possible changes and toxic elements present in it. Through physical-chemical analyzes of the waters and determination of the elements present in the sediments of the sedimentation basins of the cavas and also of two streams that receive contribution from the basins, the objective was to evaluate the possible environmental impacts from the limestone mining activity in the area of considering that the cavas and basins receive contribution of precipitations from areas of disposition of waste and waste. The results showed a great variation, where turbidity ranged from 0.3 to 330 uT, the pH from 6.3 to 9.81, the conductivity from 53 to 883.5 uS / cm, the alkalinity from 16 to 498 mg / L , the hardness varied from 23 to 680 mgCO3 / L, calcium varied from 6.5 to 105 mgCa / L and for magnesium the values ranged from 2.4 to 78.3 mgMg / L, with Point 4 presenting the higher value in all physical-chemical analyzes of water. As for the chemical elements analyzed with X-ray Fluorescence Spectrometer, the results presented a great difference between the solid state and liquid state analyzes. However, the same elements presented greater relevance, both for water and for sediment, being: Magnesium (Mg), Aluminum (Al), Silicon (Si), Potassium (K), Calcium (Ca) and Iron (Fe). Finally, it was concluded that there was no presence of the chemical elements Ar, Se and Cd in all the water samples submitted to the Atomic Absorption analysis. The Cd was found in the analyzes of water and sediment submitted to EDX analysis, however due to the method it was not possible to quantify it for comparison with the legislation. Through the physical-chemical analysis of the streams, it was verified that there was no significant change in the characteristics of the streams due to the contribution of waters from the settling basins of the cavas and the waste and sterile piles.