Risks associated of the waters from hydric systems urban’s : the case of the rio Barigui, south of Brazil

Abstract

The quantification of a chemical species isolated in natural waters does not allow the characterization of it as an environmental stressor. Therefore, it is necessary to associate different lines of research that allows the evaluation of risk on the water system. In this perspective, this study carries out approaches based on distinct research lines, allowing physical and chemical quantification in situ, determination of nutrient concentrations, chlorophyll-a, total alkalinity and metallic species (Cu, Ni, Fe, Cr, Zn and Pb). In addition, the dissolved organic matter was evaluated by means of spectrophotometric techniques and testing of acute toxicity with the organism Artemia sp. and Daphnia magna in water samples from the Barigüi River, southern Brazil. The results point to the existence of degradation processes and the input of organic matter that are affecting the dynamics of the species, influencing their chemical availability and toxicity in the water system.