Research about the use of monolith bioreactor for degradation nitrogen compound in domestic wastewater was carried out. The degradation process involved nitrosomonas and nitrobacter bacteria which come from wastewater it self. During the continuous process, the air flowrate has variation 0.2 l/min, 0.4 l/min, 0.6 1/min, 0.8 I/min, and the feed flowrate 2.5 ml/min, 6 ml/min, 8 i/min, 9 mI/min at room temperature, with the wastewater fed containing ammonium 6.8451 mg/I, nitrate 6.7883 mg/llmnt, nitrite 0.3975 mg/l/mnt, and COD 186 mg/l. It was found that removal of nitrogen compounds affected by air flowrate and feed flowrate. The best performance of monolith bioreactor was observed at air flowrate 0.8 l/min and feed flowrate 2.5 ml/min, giving removal of COD 81.18%, ammonium 91.74 % dan nitrat 81.64%.
Keywords : nitrification, denitrification, monolith bioreactor, aerasion