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 ( NH 4 + ), nitrite ( NO 2 - ), nitrate ( NO 3 - ), 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 1.02 g NH 4 + – N / L d ) with a NH 4 + – N removal of 71%. The transformation of much of the NH 4 + – N to gaseous nitrogen was confirmed, with the concentration of NO 2 - – N and NO 3 - – N increasing during the reaction phase but decreasing in the effluent due to its transformation to gaseous nitrogen.