Efluentes urbanos na água do Rio Marau (Brasil).

The objective of this study was to analyze the impact of urban and industrial waste in the municipality of Marau (Rio Grande do Sul - Brasil) on the water quality of the Marau River. The analyzed parameters were: pH, turbidity, electrical conductivity, surface tension, organic carbon, metals, nitrite, nitrate, chloride, phosphate, sulfate and dissolved phosphorus. The river water samples were collected in September 2014 and 2016 in the points: upstream of the Marau city and the tannery; upstream of the tannery; at the point of mixing the effluent from the leather processing industry and river; downstream of the Marau city. The physicalchemical analysis of river water showed that the effluents of the Marau city represents the major source of local contamination, since present values of Al, Pb and P higher than allowed by law. It was concluded that the industrial activities and the sewage of the Marau city have a negative impact on the river water quality