Abstract

The Mindu microbasin, the main tributary of the São Raimundo basin drains part of the urban waters of the city of Manaus-AM to one of the largest rivers in the world, the Rio Negro. The Mindu stream, commonly called in the region by igarapé by virtue of its narrow channel, presents itself under a great threat of degradation of its waters. The great pollution and contamination of the water is characterized by the contribution of domestic and industrial waste, silting of its bed and release of solid waste on the bed of the stream. The following parameters were analyzed: pH, electrical conductivity, dissolved oxygen, turbidity, temperature, and total dissolved solids, with the aid of a multiparameter probe at 11 points, to evaluate the physico-chemical characteristics of the water quality of the Mindu microbasin. of the main channel of the Mindu stream. Sulphide, ammoniacal nitrogen, and total phosphate analyzes were performed in the laboratory. The results showed that the stream has a slightly acidic pH at the point near the springs and it is sensible alkaline in the other stretches, dissolved oxygen content below that stipulated for the legislation, characterization of dissolved and suspended solids that contribute to high concentrations of electrical conductivity, turbidity, and total dissolved solids. The analyzed sections were still influenced by the contribution of domestic and industrial effluents with the characterization of sulfides, phosphorus in the form of phosphates and nitrogen in the form of ammoniacal nitrogen dissolved in the waters.

Keywords: Igarapé; Mindu; degradation; basin.