Avaliação da qualidade da água do rio ligeiro por meio de análises físico-químicas e microbiológicas

Abstract

This study aimed to evaluate the quality of the water in Ligeiro River, located in the city of Pato Branco, in the southwest of the state of Parana. To this end, we analyzed the physical-chemical and microbiological parameters, comparing the values obtained with legal standards and classification of the respective river according to the CONAMA Resolution 357/05. Then, the overall assessment of the data was performed using as a general indicator of water quality, the Water Quality Index (AQI) Cetesb. The variables monitored were: BOD, COD, Chlorides, Total Nitrogen, pH, dissolved oxygen, temperature and environment of the sample, turbidity, total solids, fixed solids, volatile solids, thermo tolerant coliforms and total coliforms. Except the parameters DO and thermo tolerant coliforms, the other physical-chemical results obtained in this study are within the guidelines required for this source pursuant to CONAMA Resolution 357/05. Individual analysis of OD values and thermo tolerant coliforms, extrapolated from the maximum limit for these items according to what is required for class 2 rivers, and therefore, within these benchmarks, framed as a class 3 river. In the analysis of water quality using the AQI Cetesb, the waters were presented as classified as good. The results of this study showed that even with the various forms of interference that the river has been receiving over the years in the urban perimeter, water quality examined between December 2010 and April 2011 was revealed to be into the Class 2, suggested to the referred source and according to AQI, the waters were classified as good. However, it is noteworthy that waters are unsuitable for recreation because they have significant amount of pathogenic microorganisms.