Monitoring the removal of nitrogen by applying a nitrification-denitrification process in a Sequencing Batch Reactor (SBR)

In this study the evaluation of nitrogen removal in wastewater from a meat products processing company was performed, using a Sequencing Batch Reactor (SBR) at pilot scale. The phases of the SBR operation were: filling, reaction (aeration and intermittent anoxia), sedimentation and discharge. In each of these phases analyses of ammonium (NH4+), nitrite (NO2-), nitrate (NO3-), pH and dissolved oxygen (DO) were carried out to monitor the process of nitrification-denitrification. The results showed that stage IV had the best performance (2.49 g CODF/L d and 1.02gNH4+-N/Ld) with a NH4+-N removal of 71%. The transformation of much of the NH4+-N to gaseous nitrogen was confirmed, with the concentration of NO2--N and NO3--N increasing during the reaction phase but decreasing in the effluent due to its transformation to gaseous nitrogen.