Orlandina Martins Dos Santos Messias,Ermelinda Maria De-Lamonica Freire,Edna Lopes Hardoim, Universidade de Brasília, Engenharia civil, orlandina@unb.br
Abstract
As in the great civilizations, in Brazil, the first settlements were established and developed near major waterways creating a great responsibility in maintaining them. The aim of this study was to assist in the implementation of environmental legislation as there is consensus on the need for urgent measures. Almost all Brazilian legislation, including the 1988 Federal Constitution and Federal Law No. 9.433/97, consider rivers and streams conservation. This study was conducted in an urban stretch of the Cuiabá River (Mato Grosso, Brazil) along a gradient of organic pollution. Analyses were performed in times of drought and flood, with the aim of assessing the sanitary quality, biological and physical-chemical water properties. Moreover, algae and cyanobacteria indicators of different degrees of organic pollution were inventoried. The samples were collected along the river channel in February and August 1999. Fecal coliforms, total coliforms and others were quantified. The cyanobacterium Oscillatoria spp. showed higher densities in locations with high organic content, phosphorus, turbidity, suspended solids indicators of discharge from tributaries polluted with domestic sewage.
Keywords: Cyanobacteria, organic pollution, environmental law