Removal of nitrogen from ammonium-rich synthetic wastewater in an upflow column type anammox reactor

The aim of this study is to illustrate the efficiency of nitrogen removal from synthetic wastewater using a fixed-bed anaerobic ammonium oxidation (anammox) reactor. A continuous fed flow reactor was inoculated with upflow anammox and fed with synthetic wastewater. The reactor was operated for 75 days without pH control. The maximum ammonium and nitrite removal efficiencies achieved were 95 and 97.5%, respectively. The maximum nitrogen conversion capacity was 3.2 kg NH4+-N/m3/day, 1.89 kg NO2--Nm3/day and 4.6 kg total Nm3/day with maximum loadings of 3.9 kg NH4+-N/m3/day, 2.00 kg NO2---N/m3/day and 5.64 kg total-N/m3/day, respectively. The experimental results suggest that a fixed-bed anammox reactor can be operated under high ammonium and nitrite concentration with no pH control.   Key words: Ammonium, anammox, nitrogen removal, nitrite, reactor, wastewater.