Agroindustrial systems are among the largest sources of water pollution in Brazil, due to the large amount of waste produced, containing organic substances, nutrients, solids, oils and fats. This study aimed to analyze the effect of release of cattle slaughter treated effluent on the water quality of the Jurubatuba Stream in the municipality of Anápolis, GO. The effluent and stream water samples were obtained at six different days and at four positions in relation to the point of discharge: P1 - the discharge of the treated wastewater, before launching it into the stream; P2 - upstream, 50 m away from the discharge point; P3 - downstream, 50 m away from the discharge point; and P4 - downstream, 120 m away from the discharge point. The concentrations of DO, BOD, COD, ammonia, nitrite and nitrate were analyzed. The BOD values at all samphing points in the Jurubatuba Stream were higher than the described standards of CONAMA Resolution n°. 357/2005 for class 2 water bodies. The effluent launch in Jurubatuba Stream increased values of BOD and COD at point P3, while at point P4 values were similar to those obtained upstream the effluent release (P2). The concentrations of DO, ammonia, nitrite and nitrate did not change significantly in the stream.
BOD; self-purification; receiving water body
