Application of Simultaneous Partial Nitritation/Anammox With Granular Sludge to the Treatment of Low Ammonia Concentration Wastewater

To evaluate the performance of the simultaneous partial nitritation/Anammox with granular sludge(SPNAGS) process to treat low ammonia concentration wastewater,a lab-scale study was conducted.Results show that when ammonia concentration is 20 ~ 50 mg/L,granular sludge breaks up gradually and the color varies from reddish-brown to grayish yellow,although the ammonia removal rate is always higher than 95% ,the total nitrogen(TN) removal rate is only 20% at the final phase of the experiment.80% ammonia is converted into nitrate.Thus,the out-selection of wastewater nitriteoxidizing bacteria(NOB) control is very important to the SPNAGS process to treat low ammonia concentration wastewater.