Evaluación de la eficiencia de un reactor por carga secuencial tratando aguas residuales provenientes de un matadero de reses

The treatment of wastewater from a cattle slaughterhouse was evaluated using a sequential loading reactor (SBR). The study was carried out using wastewater from a cattle slaughterhouse located in the Rosario de Perija, Zulia State, Venezuela. A sequencing batch reactor at laboratory scale was used with a working volume of 2 L, an anaerobic-aerobic-anoxic operating sequence (An/Ae/Ax) for simultaneous removal of organic matter and nutrients, two hydraulic retention times of 10 and 12 hours and a cell retention time of 25 days. The parameters measured at the beginning and end of each evaluated cycles were: chemical oxygen demand total (COD_T), biochemical oxygen demand (BOD_5,20), total Kjeldahl nitrogen (TKN), ammonia nitrogen (N-NH₄⁺), nitrite (N-NO₂^-), nitrates (N-NO₃^-), pH, total alkalinity, total suspended solids (TSS) and volatile (VSS), total phosphorus (TP), color and turbidity. The industrial effluent was characterized by a COD of 11748 mg/L, one BOD_5,20 of 5176 mg/L, and a content of TN and TP of 554.2 and 17.3 mg/L, respectively. It was found that both treatments (T1 y T2) achieved above average values of 89% removal of DQO_T. However, treatment T2 with an HRT of 12 hours generated higher yields in terms of the simultaneous removal of TKN (81%), N-NH₄⁺ (81%), total nitrogen (TN) (69%) than T1. Of all the parameters analyzed, TP and pH were the only parameters at the reactor outlet that comply with the limits set by the Venezuelan standard for discharge of bodies of water.