A pilot study on biological nitrogen removal in a frequent anoxic-aerobic alternation sequencing batch reactor

The present study focused on investigation of biological nitrogen removal efficiency and the superiority of continuous feeding sequencing batch reactor system with a frequent anoxic-aerobic alternation strategy. The result indicated that continuous feeding SBR achieved an excellent efficiency for pollutants removal. The removal efficiency of COD and NH₄⁺-N reached above 90% and 91.4% respectively which was not significantly affected by A/O alternating frequency. Removal efficiency of TN was positively related to A/O alternating frequency, the average TN removal efficiencies reached 71.5%, 82.4% and 87.2% respectively with the alternating frequency changed from 5 to 15 and 30, the 5-5min agitation-aeration mode was the best one for nitrogen removal. Moreover, continuous feeding SBR was proved to be better in domestic wastewater treatment compared with instantaneous feeding SBR, and this superiority was more significant with a 5-5min agitation/ aeration operation strategy.