RESUMO
Since February 1999, the Municipal Wastewater Treatment Plant (MWTP) of Balneário Camboriú, Brazil, started a complementary treatment with ClO(2) application on its effluent. It was realized to minimize its impacts caused by increase of the population during summer. This study was realized in order to verify the influence of this compound in the water quality and the environmental evaluations. Samples of surface water were collected in this environment between January 1997 and June 2001 for chemical and microbiological surveys. The results had shown that after application of ClO(2), fecal coliforms were decreased about six times in the beach (2.3 x 10(3) to 3.5 x 10(2) MPN/100 ml) and three times in the river (3.3 x 10(4) to 1.0 x 10(4) MPN/100 ml), during summer time. NH(4) (+) showed an increase of about four times and 1.5 times, respectively, to beach and river. These results are showing the influence of ClO(2) on chemical and microbiological parameters.