Role of Aerobic Denitrification in Short-cut Nitrification and Denitrification Process

The SBR was used to treat landfill leachate,and the role of aerobic denitrification in short-cut nitrification and denitrification process was studied.The results show that the nitrosation efficiency in the SBR is preferable,and ammonia nitrogen is completely oxidized to NO-2-N.The aerobic denitrifiers able to reduce NO-3-N and NO-2-N co-exist in the activated sludge,and the amount and total activity of the aerobic denitrifiers reducing NO-3-N and ammonia oxidizers are higher than those of nitrite oxidizers,which is an important reason why the SBR can maintain nitrosation.The organics significantly increase the aerobic denitrification rate.Ammonia is oxidized to NO-2-N.The aerobic denitrification rate keeps constant when the organic concentration reaches a critical value.At the lower DO levels,the aerobic denitrification rate increases,and the released OH-can cause the rise of pH.Therefore,the aerobic denitrification plays an important role in maintaining and promoting the short-cut nitrification and denitrification.