Qualidade da água de três locais com potenciais fontes de contaminação no Rio Taquari, RS

Abstract

The Taquari Valley has several food industries and tanneries which release their effluents into the Taquari River, as well as a cemetery in a Permanent Preservation Area in Mugum town. This study performed physicochemical and microbiological analyses of water from before and after three Taquari River sites considered potentially polluting and compared the results of those samples. The chosen sites were a cemetery and a tannery in Mugum and a tannery next to a poultry processing plant located in Roca Sales. We analyzed pH, turbidity,dissolved oxygen (O2), total nitrogen (N) and thermotolerant coliforms. We also isolated Escherichia coli and performed resistance tests to neomycin, rifampicin, clindamycin and penicillin antibiotics. The physicochemical analyses showed that only turbidity, in four out of the six analyzed spots, had values above the established threshold of class I water. These elevated values are probably of inorganic origin. Bacteria isolated from the samples collected after the cemetery and both before and after the Roca Sales industries were sensitive to neomycin, rifampicin and clindamycin, and resistant to penicillin. It can be concluded, therefore, that even the release of the pollutant effluents does not substantially interfere with the water quality of the three analyzed sites.