Hydrogeochemical Diagnosis in Guapirimirim - Macacu Basin (RJ)

With current perspectives on water issues in Brazil and worldwide, research on water quality has often been carried out, mainly to supply the population. This study aims to present a diagnosis about the Guapimirim-Macacu basin, located in the area of inluence of the metropolitan area of the Rio de Janeiro city. The information on the hydrogeochemical quality of the waters help to manage the local water resources. The analytical raw and maximum permissible values obtained were organized in a database and represented in a geoprocessing environment that allowed a more detailed analysis of the basin. Chemical analysis relating to cations (Na, K, Ca, Mg, Fe, Mn, Pb, Cu and Zn) allowed to identify that only Fe and Mn exceeded the limits of current legislation in all sampling points, and that these elements are naturally occurring due to the oxidation of iron minerals. The contents related to anions (Fˉ, Clˉ, Brˉ, NO 3 ˉ, PO 4 3, SO 4 2 e HCO 3 ) allowed to classify the waters of the basin studied mainly as bicarbonated. The Water Quality Index values for the Macacu-Guapimirim basin ranged from 36 to 64 (reasonable to bad) which makes the exploitation of this basin water for human consumption a costly activity.