Water quality of stream due to release of effluent from cattle slaughter

The objective of this study was to evaluate the influence of release of effluent from a cattle slaughter house on water quality of Jurubatuba stream, in Anapolis - Goias. The treated effluent before release into the stream, the stream water at 50 m upstream, and 50 and 500 m downstream from the launch place were analysed. Eight samples were taken during the dry season (08/07 to 24/09/2009) and eight in the rainy season (01/10 to 03/12/2009), quantifying pH, turbidity, dissolved oxygen, oxygen saturation, total organic carbon, chlorine, aluminum, ammonia, copper, manganese, total iron, total phosphorus, sulfate, sodium, biological oxygen demand, chemical oxygen demand, total nitrogen, electrical conductivity, nitrate and nitrite. The values of pH, NH3-, Zn++, sulfide, NO3, chloride during the two periods at all analyzed points matched the criteria of water of class 2. Na+, NH3, total organic carbon, total P, CE and NO3 increase at some points after the release of the effluent. Turbidity, Al and Mg in the treated effluent during dry and rainy season were higher than allowed for class 2 water bodies; total Fe in the effluent had medium risk for use in irrigation.