Avaliação das concentrações de nitrato nas águas minerais produzidas na Região da Grande Natal

Abstract

The Metropolitan Region of Natal, located in the state of the Rio Grande do Norte, is detainer of great reserves of groundwater from Dunas/Barreiras aquifer. These waters are used by the population for your supplying and industrial consumption; moreover these reserves possess mineral water characteristics, situated mainly in the cities of Parnamirim and Macaíba, in the south region, and in the city of Extremoz, in the part north. However, the fast urban growth of Natal, associate with the lack of sanitation and drainage, has caused the increase of contamination, mainly by the infiltration of septic tanks effluents in soil. The presented work has as main purpose the evaluation of nitrate concentrations in the mineral water sources, taking in consideration the proximity of wells already contaminated by nitrate. For this, data of nitrate concentrations in mineral waters were compared with those from wells of the public or private supplying from the surrounding region. The work comprised the localization of the study area, selection wells to collect samples, laboratory analyses of the ion nitrate, treatment of data, and the global evaluation of underground waters quality. Through the results was possible to demonstrate the levels of nitrate concentration on mineral water wells, including two with concentration higher than 10 mg/L.