Diagnóstico do ambiente aquático da foz do rio Ocoy por meio de indicadores microbiológicos e físico-químicos

Abstract

The three sediment sampling sites on the mouth of the river Ocoy - Tributary of Lake Itaipu, located in São Miguel do Iguaçu, in western Paraná, was studied to assess the presenceand content of the drug caffeine, the presence of microorganisms along with analysis ofphysical and chemical parameters. There were two collections, one in October 2010 and another in February 2011. The threesampling points are located along six kilometers upstream the river mouth. Thequantification of the drug caffeine was performed by UV-Vis spectrophotometer and the concentrations reached levels of parts per billion, ranging from 0.78 to 1.73 mg. Kg-1. In relation to the microorganisms in the sediment, total bacteria count indicated a decreasing number of organisms to the mouth of the spring: 3,5.103, 2,4.103 and 1,6.103 CFU g-1respectively. For the count of total and fecal coliforms was obtained values: 460 and 240 g-1 at the point located at the source. In two points downstream of the river, the results for total and fecal coliforms were similar: 4-g-1 and 3.g-1). The phosphorus content ranged from 172 to 304 (mg kg-1), showing that there is contamination from anthropogenic sources, the values are below a critical value of those considered by the law of CONAMA 344. According to the pH values, the sediment can be considered slightly acid values ranging from 4.15 to 5.81, and CO levels ranging from 10.2% to 15.4%. The results indicate that the environmental quality of the river mouth is in Ocoy favorable for maintenance of the ecosystem.