Aeration intensity is an important parameter to control intermittent aeration DO. To clarify the effects of same total aeration intensities and different aeration intensities on the intermittent aeration SBR nitrosation process

activated sludge with good nitration abilities was inoculated in reactors at 25-28 ℃. Effect of aeration intensity under intermittent aeration on the stability of nitrosation system was studied using response surface analysis in an intermittent aeration SBR reactor. Results show that the controlled aeration intensity of 1.2 L/(h·L) could inhibit the activity of NOB

where the nitrite nitrogen accumulation rate could reach 93%

while the ammonia nitrogen removal rate was only 80%. When the aeration intensity was increased to 1.58 L/(h·L)

the nitrosation performance was deteriorated with the increase of the operating cycle. When the aeration intensity was 1.93 L/(h·L)

and the ammonia oxidation rate and nitrite accumulation rate were 90% and 91.6%

higher ammonia oxygen removal and nitrite accumulation were achieved. Batch experiments and response surface analysis showed that aeration intensity and aeration time had significant effects on ammonia nitrogen removal and nitrite accumulation. The shorter the aeration time was

the higher the nitrite accumulation rate would be achieved

and the higher the aeration intensity was

the higher the ammonia nitrogen removal efficiencies would be achieved. However

the activity of AOB was suppressed under low aeration intensity

and the high ammonia nitrogen removal efficiency could not be maintained by prolonging the aeration time. Under high aeration intensity

the activity of AOB could not be enhanced accordingly. The ammonia nitrogen removal rate and the nitrite accumulation rate were only affected by the aeration time. Therefore

under the same total aeration intensities

higher aeration intensity should be adopted with the combination of short aeration time to achieve high ammonia nitrogen removal and nitrite accumulation.